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Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T06:29:12Z

JamesVanderBeek: /* Water Quality */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry, conservation science, and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

== Introduction ==

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

== Drivers of Permafrost Thaw ==

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref name=":5" /><ref name=":6">{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref>. These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty<ref name=":5" /><ref name=":6" />. Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others<ref name=":3" /><ref name=":5" /><ref name=":6" />.

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2<ref name=":7" />. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally<ref name=":7">{{Cite journal|last=Voight|first=Carolina|last2=Marushchak|first2=Maija|last3=Lamprecht|first3=Richard|last4=Jackowicz-Korczynski|first4=Marcin|last5=Lindgren|first5=Amelie|date=2017|title=Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw|url=https://www.researchgate.net/publication/318084896_Increased_nitrous_oxide_emissions_from_Arctic_peatlands_after_permafrost_thaw|journal=Proceedings of the National Academy of Sciences|volume=114|pages=6238-6243}}</ref>.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock<ref name=":8">{{Cite journal|last=Skierszkan|first=Elliott K.|last2=Szeitz|first2=Andras J.|last3=Lindsay|first3=Matthew B.J.|last4=Carey|first4=Sean K.|date=2026|title=Abrupt stream acidification and metal mobilization from permafrost degradation|url=https://www.science.org/doi/10.1126/science.aea2898|journal=Science|volume=392|pages=863-867}}</ref>. As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward an inland base level, such as a lake, or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs<ref name=":8" /><ref>{{Cite journal|last=Smith|first=Isabel M.|last2=Ke|first2=Yutian|last3=Geyman|first3=Emily C.|last4=Reahl|first4=Jocelyn N.|last5=Douglas|first5=Madison M.|date=2024|title=Mercury stocks in discontinuous permafrost and their mobilization by river migration in the Yukon River Basin|url=https://doi.org/10.1088/1748-9326/ad536e|journal=Environmental Research Letters|volume=19|issue=8|pages=1-12}}</ref>. Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals<ref name=":8" />.
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==
Arctic permafrost melt is a complex process involving both positive and negative feedbacks with numerous geological, ecological and socioeconomic consequences, ultimately driven by anthropogenic causes. The implications for this loss go far beyond the Arctic's borders and impact the Earth's global climate system itself, but uncertainty as to the extent and magnitude of the fundamental processes driving them remains. This is an ongoing issue that demands further research and attention, but more importantly, policy and protection that can curb the greenhouse emissions that are driving this climate feedback.

== Group Roles and Usage of AI ==

=== Adrienne ===
Worked on Statement of Connection, Introduction, Overview of Arctic Permafrost and Drivers of Permafrost Thaw sections. Assigned group roles. Provided feedback, source gathering sources and editing throughout.

=== Cruz ===
Worked on Geological Impacts, Ecological and Environmental Impacts, Conclusion and Group Roles sections. Provided feedback, source gathering and editing throughout.

=== James ===
Worked on Human and Global Implications and Conclusion sections. Collated images and formatted references. Provided feedback, source gathering and editing throughout and formatted references.

=== AI Usage ===
AI was used to summarize the content of some research papers used in analysis. Images and text used in this wiki page were written entirely by hand, with no direct involvement from AI.

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T06:25:37Z

JamesVanderBeek: /* Statement of Connection */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry, conservation science, and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

== Introduction ==

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

== Drivers of Permafrost Thaw ==

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref name=":5" /><ref name=":6">{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref>. These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty<ref name=":5" /><ref name=":6" />. Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others<ref name=":3" /><ref name=":5" /><ref name=":6" />.

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2<ref name=":7" />. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally<ref name=":7">{{Cite journal|last=Voight|first=Carolina|last2=Marushchak|first2=Maija|last3=Lamprecht|first3=Richard|last4=Jackowicz-Korczynski|first4=Marcin|last5=Lindgren|first5=Amelie|date=2017|title=Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw|url=https://www.researchgate.net/publication/318084896_Increased_nitrous_oxide_emissions_from_Arctic_peatlands_after_permafrost_thaw|journal=Proceedings of the National Academy of Sciences|volume=114|pages=6238-6243}}</ref>.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock<ref name=":8">{{Cite journal|last=Skierszkan|first=Elliott K.|last2=Szeitz|first2=Andras J.|last3=Lindsay|first3=Matthew B.J.|last4=Carey|first4=Sean K.|date=2026|title=Abrupt stream acidification and metal mobilization from permafrost degradation|url=https://www.science.org/doi/10.1126/science.aea2898|journal=Science|volume=392|pages=863-867}}</ref>. As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs<ref name=":8" /><ref>{{Cite journal|last=Smith|first=Isabel M.|last2=Ke|first2=Yutian|last3=Geyman|first3=Emily C.|last4=Reahl|first4=Jocelyn N.|last5=Douglas|first5=Madison M.|date=2024|title=Mercury stocks in discontinuous permafrost and their mobilization by river migration in the Yukon River Basin|url=https://doi.org/10.1088/1748-9326/ad536e|journal=Environmental Research Letters|volume=19|issue=8|pages=1-12}}</ref>. Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals<ref name=":8" />.
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==
Arctic permafrost melt is a complex process involving both positive and negative feedbacks with numerous geological, ecological and socioeconomic consequences, ultimately driven by anthropogenic causes. The implications for this loss go far beyond the Arctic's borders and impact the Earth's global climate system itself, but uncertainty as to the extent and magnitude of the fundamental processes driving them remains. This is an ongoing issue that demands further research and attention, but more importantly, policy and protection that can curb the greenhouse emissions that are driving this climate feedback.

== Group Roles and Usage of AI ==

=== Adrienne ===
Worked on Statement of Connection, Introduction, Overview of Arctic Permafrost and Drivers of Permafrost Thaw sections. Assigned group roles. Provided feedback, source gathering sources and editing throughout.

=== Cruz ===
Worked on Geological Impacts, Ecological and Environmental Impacts, Conclusion and Group Roles sections. Provided feedback, source gathering and editing throughout.

=== James ===
Worked on Human and Global Implications and Conclusion sections. Collated images and formatted references. Provided feedback, source gathering and editing throughout and formatted references.

=== AI Usage ===
AI was used to summarize the content of some research papers used in analysis. Images and text used in this wiki page were written entirely by hand, with no direct involvement from AI.

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T06:24:14Z

JamesVanderBeek: /* Conclusion / Your Evaluation of the Connections */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

== Introduction ==

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

== Drivers of Permafrost Thaw ==

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref name=":5" /><ref name=":6">{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref>. These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty<ref name=":5" /><ref name=":6" />. Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others<ref name=":3" /><ref name=":5" /><ref name=":6" />.

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2<ref name=":7" />. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally<ref name=":7">{{Cite journal|last=Voight|first=Carolina|last2=Marushchak|first2=Maija|last3=Lamprecht|first3=Richard|last4=Jackowicz-Korczynski|first4=Marcin|last5=Lindgren|first5=Amelie|date=2017|title=Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw|url=https://www.researchgate.net/publication/318084896_Increased_nitrous_oxide_emissions_from_Arctic_peatlands_after_permafrost_thaw|journal=Proceedings of the National Academy of Sciences|volume=114|pages=6238-6243}}</ref>.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock<ref name=":8">{{Cite journal|last=Skierszkan|first=Elliott K.|last2=Szeitz|first2=Andras J.|last3=Lindsay|first3=Matthew B.J.|last4=Carey|first4=Sean K.|date=2026|title=Abrupt stream acidification and metal mobilization from permafrost degradation|url=https://www.science.org/doi/10.1126/science.aea2898|journal=Science|volume=392|pages=863-867}}</ref>. As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs<ref name=":8" /><ref>{{Cite journal|last=Smith|first=Isabel M.|last2=Ke|first2=Yutian|last3=Geyman|first3=Emily C.|last4=Reahl|first4=Jocelyn N.|last5=Douglas|first5=Madison M.|date=2024|title=Mercury stocks in discontinuous permafrost and their mobilization by river migration in the Yukon River Basin|url=https://doi.org/10.1088/1748-9326/ad536e|journal=Environmental Research Letters|volume=19|issue=8|pages=1-12}}</ref>. Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals<ref name=":8" />.
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==
Arctic permafrost melt is a complex process involving both positive and negative feedbacks with numerous geological, ecological and socioeconomic consequences, ultimately driven by anthropogenic causes. The implications for this loss go far beyond the Arctic's borders and impact the Earth's global climate system itself, but uncertainty as to the extent and magnitude of the fundamental processes driving them remains. This is an ongoing issue that demands further research and attention, but more importantly, policy and protection that can curb the greenhouse emissions that are driving this climate feedback.

== Group Roles and Usage of AI ==

=== Adrienne ===
Worked on Statement of Connection, Introduction, Overview of Arctic Permafrost and Drivers of Permafrost Thaw sections. Assigned group roles. Provided feedback, source gathering sources and editing throughout.

=== Cruz ===
Worked on Geological Impacts, Ecological and Environmental Impacts, Conclusion and Group Roles sections. Provided feedback, source gathering and editing throughout.

=== James ===
Worked on Human and Global Implications and Conclusion sections. Collated images and formatted references. Provided feedback, source gathering and editing throughout and formatted references.

=== AI Usage ===
AI was used to summarize the content of some research papers used in analysis. Images and text used in this wiki page were written entirely by hand, with no direct involvement from AI.

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T06:19:27Z

JamesVanderBeek: /* Water Quality */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

== Introduction ==

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

== Drivers of Permafrost Thaw ==

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref name=":5" /><ref name=":6">{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref>. These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty<ref name=":5" /><ref name=":6" />. Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others<ref name=":3" /><ref name=":5" /><ref name=":6" />.

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2<ref name=":7" />. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally<ref name=":7">{{Cite journal|last=Voight|first=Carolina|last2=Marushchak|first2=Maija|last3=Lamprecht|first3=Richard|last4=Jackowicz-Korczynski|first4=Marcin|last5=Lindgren|first5=Amelie|date=2017|title=Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw|url=https://www.researchgate.net/publication/318084896_Increased_nitrous_oxide_emissions_from_Arctic_peatlands_after_permafrost_thaw|journal=Proceedings of the National Academy of Sciences|volume=114|pages=6238-6243}}</ref>.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock<ref name=":8">{{Cite journal|last=Skierszkan|first=Elliott K.|last2=Szeitz|first2=Andras J.|last3=Lindsay|first3=Matthew B.J.|last4=Carey|first4=Sean K.|date=2026|title=Abrupt stream acidification and metal mobilization from permafrost degradation|url=https://www.science.org/doi/10.1126/science.aea2898|journal=Science|volume=392|pages=863-867}}</ref>. As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs<ref name=":8" /><ref>{{Cite journal|last=Smith|first=Isabel M.|last2=Ke|first2=Yutian|last3=Geyman|first3=Emily C.|last4=Reahl|first4=Jocelyn N.|last5=Douglas|first5=Madison M.|date=2024|title=Mercury stocks in discontinuous permafrost and their mobilization by river migration in the Yukon River Basin|url=https://doi.org/10.1088/1748-9326/ad536e|journal=Environmental Research Letters|volume=19|issue=8|pages=1-12}}</ref>. Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals<ref name=":8" />.
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==
Arctic permafrost melt is a complex process involving both positive and negative feedbacks with numerous geological, ecological and socioeconomic consequences, ultimately driven by anthropogenic causes. The implications for this loss go far beyond the Arctic's borders and impact the Earth's global climate system itself, but uncertainty as to the extent and magnitude of the fundamental processes driving them remains. This is an ongoing issue that demands further research and attention, but more importantly, policy and protection that can curb the greenhouse emissions that are driving this climate feedback.

== Group Roles and Usage of AI ==

=== Adrienne ===
Worked on Statement of Connection, Introduction, Overview of Arctic Permafrost and Drivers of Permafrost Thaw sections. Assigned group roles. Provided feedback, source gathering sources and editing throughout.

=== Cruz ===
Worked on Geological Impacts, Ecological and Environmental Impacts, Conclusion and Group Roles sections. Provided feedback, source gathering and editing throughout.

=== James ===
Worked on Human and Global Implications and Conclusion sections. Collated images and formatted references. Provided feedback, source gathering and editing throughout and formatted references.

=== AI Usage ===
AI was used to summarize the content of some research papers used in analysis. Images and text used in this wiki page were written entirely by hand, with no direct involvement from AI.

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T06:19:16Z

JamesVanderBeek: /* Water Quality */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

== Introduction ==

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

== Drivers of Permafrost Thaw ==

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref name=":5" /><ref name=":6">{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref>. These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty<ref name=":5" /><ref name=":6" />. Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others<ref name=":3" /><ref name=":5" /><ref name=":6" />.

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2<ref name=":7" />. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally<ref name=":7">{{Cite journal|last=Voight|first=Carolina|last2=Marushchak|first2=Maija|last3=Lamprecht|first3=Richard|last4=Jackowicz-Korczynski|first4=Marcin|last5=Lindgren|first5=Amelie|date=2017|title=Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw|url=https://www.researchgate.net/publication/318084896_Increased_nitrous_oxide_emissions_from_Arctic_peatlands_after_permafrost_thaw|journal=Proceedings of the National Academy of Sciences|volume=114|pages=6238-6243}}</ref>.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock<ref name=":8">{{Cite journal|last=Skierszkan|first=Elliott K.|last2=Szeitz|first2=Andras J.|last3=Lindsay|first3=Matthew B.J.|last4=Carey|first4=Sean K.|date=2026|title=Abrupt stream acidification and metal mobilization from permafrost degradation|url=https://www.science.org/doi/10.1126/science.aea2898|journal=Science|volume=392|pages=863-867}}</ref>. As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs<ref name=":8" /><ref>{{Cite journal|last=Smith|first=Isabel M.|last2=Ke|first2=Yutian|last3=Geyman|first3=Emily C.|last4=Reahl|first4=Jocelyn N.|last5=Douglas|first5=Madison M.|date=2024|title=Mercury stocks in discontinuous permafrost and their mobilization by river migration in the Yukon River Basin|url=https://doi.org/10.1088/1748-9326/ad536e|journal=Environmental Research Letters|volume=19|issue=8|pages=1-12}}</ref> (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals<ref name=":8" />.
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==
Arctic permafrost melt is a complex process involving both positive and negative feedbacks with numerous geological, ecological and socioeconomic consequences, ultimately driven by anthropogenic causes. The implications for this loss go far beyond the Arctic's borders and impact the Earth's global climate system itself, but uncertainty as to the extent and magnitude of the fundamental processes driving them remains. This is an ongoing issue that demands further research and attention, but more importantly, policy and protection that can curb the greenhouse emissions that are driving this climate feedback.

== Group Roles and Usage of AI ==

=== Adrienne ===
Worked on Statement of Connection, Introduction, Overview of Arctic Permafrost and Drivers of Permafrost Thaw sections. Assigned group roles. Provided feedback, source gathering sources and editing throughout.

=== Cruz ===
Worked on Geological Impacts, Ecological and Environmental Impacts, Conclusion and Group Roles sections. Provided feedback, source gathering and editing throughout.

=== James ===
Worked on Human and Global Implications and Conclusion sections. Collated images and formatted references. Provided feedback, source gathering and editing throughout and formatted references.

=== AI Usage ===
AI was used to summarize the content of some research papers used in analysis. Images and text used in this wiki page were written entirely by hand, with no direct involvement from AI.

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T06:12:34Z

JamesVanderBeek: /* Water Quality */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref name=":5" /><ref name=":6">{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref>. These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty<ref name=":5" /><ref name=":6" />. Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others<ref name=":3" /><ref name=":5" /><ref name=":6" />.

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2<ref name=":7" />. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally<ref name=":7">{{Cite journal|last=Voight|first=Carolina|last2=Marushchak|first2=Maija|last3=Lamprecht|first3=Richard|last4=Jackowicz-Korczynski|first4=Marcin|last5=Lindgren|first5=Amelie|date=2017|title=Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw|url=https://www.researchgate.net/publication/318084896_Increased_nitrous_oxide_emissions_from_Arctic_peatlands_after_permafrost_thaw|journal=Proceedings of the National Academy of Sciences|volume=114|pages=6238-6243}}</ref>.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock<ref name=":8">{{Cite journal|last=Skierszkan|first=Elliott K.|last2=Szeitz|first2=Andras J.|last3=Lindsay|first3=Matthew B.J.|last4=Carey|first4=Sean K.|date=2026|title=Abrupt stream acidification and metal mobilization from permafrost degradation|url=https://www.science.org/doi/10.1126/science.aea2898|journal=Science|volume=392|pages=863-867}}</ref>. As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals<ref name=":8" />.
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T06:08:54Z

JamesVanderBeek: /* Water Quality */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref name=":5" /><ref name=":6">{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref>. These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty<ref name=":5" /><ref name=":6" />. Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others<ref name=":3" /><ref name=":5" /><ref name=":6" />.

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2<ref name=":7" />. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally<ref name=":7">{{Cite journal|last=Voight|first=Carolina|last2=Marushchak|first2=Maija|last3=Lamprecht|first3=Richard|last4=Jackowicz-Korczynski|first4=Marcin|last5=Lindgren|first5=Amelie|date=2017|title=Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw|url=https://www.researchgate.net/publication/318084896_Increased_nitrous_oxide_emissions_from_Arctic_peatlands_after_permafrost_thaw|journal=Proceedings of the National Academy of Sciences|volume=114|pages=6238-6243}}</ref>.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock<ref name=":8">{{Cite journal|last=Smith|first=Isabel M.|last2=Ke|first2=Yutian|last3=Geyman|first3=Emily C.|last4=Reahl|first4=Jocelyn N.|last5=Douglas|first5=Madison M.|date=2024|title=Mercury stocks in discontinuous permafrost and their mobilization by river migration in the Yukon River Basin|url=https://doi.org/10.1088/1748-9326/ad536e|journal=Environmental Research Letters|volume=19|issue=8}}</ref>. As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals<ref name=":8" />.
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T06:08:28Z

JamesVanderBeek: /* Water Quality */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref name=":5" /><ref name=":6">{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref>. These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty<ref name=":5" /><ref name=":6" />. Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others<ref name=":3" /><ref name=":5" /><ref name=":6" />.

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2<ref name=":7" />. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally<ref name=":7">{{Cite journal|last=Voight|first=Carolina|last2=Marushchak|first2=Maija|last3=Lamprecht|first3=Richard|last4=Jackowicz-Korczynski|first4=Marcin|last5=Lindgren|first5=Amelie|date=2017|title=Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw|url=https://www.researchgate.net/publication/318084896_Increased_nitrous_oxide_emissions_from_Arctic_peatlands_after_permafrost_thaw|journal=Proceedings of the National Academy of Sciences|volume=114|pages=6238-6243}}</ref>.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock<ref>{{Cite journal|last=Smith|first=Isabel M.|last2=Ke|first2=Yutian|last3=Geyman|first3=Emily C.|last4=Reahl|first4=Jocelyn N.|last5=Douglas|first5=Madison M.|date=2024|title=Mercury stocks in discontinuous permafrost and their mobilization by river migration in the Yukon River Basin|url=https://doi.org/10.1088/1748-9326/ad536e|journal=Environmental Research Letters|volume=19|issue=8}}</ref> (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T06:04:03Z

JamesVanderBeek: /* Greenhouse Gas Release */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref name=":5" /><ref name=":6">{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref>. These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty<ref name=":5" /><ref name=":6" />. Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others<ref name=":3" /><ref name=":5" /><ref name=":6" />.

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2<ref name=":7" />. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally<ref name=":7">{{Cite journal|last=Voight|first=Carolina|last2=Marushchak|first2=Maija|last3=Lamprecht|first3=Richard|last4=Jackowicz-Korczynski|first4=Marcin|last5=Lindgren|first5=Amelie|date=2017|title=Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw|url=https://www.researchgate.net/publication/318084896_Increased_nitrous_oxide_emissions_from_Arctic_peatlands_after_permafrost_thaw|journal=Proceedings of the National Academy of Sciences|volume=114|pages=6238-6243}}</ref>.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T06:02:24Z

JamesVanderBeek: /* Greenhouse Gas Release */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref name=":5" /><ref name=":6">{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref>. These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty<ref name=":5" /><ref name=":6" />. Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others<ref name=":3" /><ref name=":5" /><ref name=":6" />.

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally<ref>{{Cite journal|last=Voight|first=Carolina|last2=Marushchak|first2=Maija|last3=Lamprecht|first3=Richard|last4=Jackowicz-Korczynski|first4=Marcin|last5=Lindgren|first5=Amelie|date=2017|title=Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw|journal=Proceedings of the National Academy of Sciences|volume=114|pages=6238-6243}}</ref>.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:59:44Z

JamesVanderBeek: /* Alterations to Aquatic Food Webs */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref name=":5" /><ref name=":6">{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref>. These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty<ref name=":5" /><ref name=":6" />. Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others<ref name=":3" /><ref name=":5" /><ref name=":6" />.

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:58:42Z

JamesVanderBeek: /* Alterations to Aquatic Food Webs */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />. It should also be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water<ref>{{Cite journal|last=Kendrick|first=Michael R.|last2=Huryn|first2=Alexander D.|last3=Bowden|first3=William B.|last4=Deegan|first4=Linda A.|last5=Findlay|first5=Robert H.|date=2018|title=Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14448|journal=Global Change Biology|volume=24|issue=12|pages=5378-5750}}</ref> (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:56:19Z

JamesVanderBeek: /* Terrestrial Nutrient and Carbon Storage Reduction */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref>. The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:56:07Z

JamesVanderBeek: /* Terrestrial Nutrient and Carbon Storage Reduction */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can eventually stabilize slopes<ref name=":3" />. Thermokarst lakes (i.e. those formed in lake thermokarst terrain) can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage<ref>{{Cite journal|last=Kazumichi|first=Fujii|last2=Chie|first2=Hayakawa|date=2022|title=Recalcitrance of lichen and moss litters increases soil carbon storage on permafrost|url=https://doi.org/10.1007/s11104-021-05273-5|journal=Plant and Soil|volume=472|pages=595-608}}</ref> (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:54:02Z

JamesVanderBeek: /* Terrestrial Nutrient and Carbon Storage Reduction */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />. Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope<ref name=":3" />. Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes<ref name=":4" />. In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer<ref name=":2" /><ref name=":3" />. This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:53:22Z

JamesVanderBeek: /* Human and Global Implications */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />. Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope<ref name=":3" />. Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within<ref name=":2" /><ref name=":4" />. This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost<ref name=":3" />. It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process<ref name=":3" />. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:52:18Z

JamesVanderBeek: /* Human and Global Implications */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />. Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope<ref name=":3" />. Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in the active layer (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation and uncertainty (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity<ref name=":3" />.

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:49:13Z

JamesVanderBeek: /* Subsidence */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref name=":5">{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes<ref name=":3" /><ref name=":5" />. Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope<ref name=":3" />. Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities<ref name=":2" /><ref name=":3" />. Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds<ref name=":3" />. The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions<ref name=":3" />. These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:48:09Z

JamesVanderBeek: /* Subsidence */

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon Storage in Permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface<ref name=":3" /><ref>{{Cite journal|last=Vonk|first=J.E|last2=Tank|first2=S.E|last3=Bowden|first3=W.B|last4=Laurion|first4=I.|last5=Vincent|first5=W.F|date=08 December, 2015|title=Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems|url=https://doi.org/10.5194/bg-12-7129-2015|journal=Biogeosciences|volume=12|issue=23|pages=7129-7167}}</ref>. These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope<ref name=":3" />. Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:45:01Z

JamesVanderBeek: /* Erosion */

Add Summary Here

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon storage in permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface (Schuur & Mack, 2018; Vonk et al., 2015). These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides<ref name=":3" />. These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope<ref name=":3" />. Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water<ref name=":3" />. This would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes<ref name=":3" />.

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:43:56Z

JamesVanderBeek: /* Subsidence */

Add Summary Here

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon storage in permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow<ref name=":3" />. Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink<ref name=":3" />.

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface (Schuur & Mack, 2018; Vonk et al., 2015). These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them<ref name=":3" />. However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation<ref name=":3" />. Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion<ref name=":3" />.

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides (Schuur & Mack, 2018). These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope (Schuur & Mack, 2018). Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water (Schuur & Mack, 2018). These would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes (Schuur & Mack, 2018).

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:42:52Z

JamesVanderBeek: /* Case Study: [Yukon] */

Add Summary Here

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon storage in permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow (Schuur & Mack, 2018). Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink (Schuur & Mack, 2018).

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface (Schuur & Mack, 2018; Vonk et al., 2015). These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them (Schuur & Mack, 2018). However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation (Schuur & Mack, 2018). Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion (Schuur & Mack, 2018).

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides (Schuur & Mack, 2018). These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope (Schuur & Mack, 2018). Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water (Schuur & Mack, 2018). These would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes (Schuur & Mack, 2018).

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:42:22Z

JamesVanderBeek: /* Subsidence */

Add Summary Here

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon storage in permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence<ref name=":2" /><ref name=":3" />. This can also cause surface water to move elsewhere and further thaw areas downstream<ref name=":3" />. Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist<ref name=":3" />. [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow (Schuur & Mack, 2018). Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink (Schuur & Mack, 2018).

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface (Schuur & Mack, 2018; Vonk et al., 2015). These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them (Schuur & Mack, 2018). However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation (Schuur & Mack, 2018). Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion (Schuur & Mack, 2018).

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides (Schuur & Mack, 2018). These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope (Schuur & Mack, 2018). Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water (Schuur & Mack, 2018). These would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes (Schuur & Mack, 2018).

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:41:07Z

JamesVanderBeek: /* Definition and Formation */

Add Summary Here

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon storage in permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

=== Significance of Permafrost Thaw ===
The impacts of permafrost thaw extend far beyond greenhouse gas emissions. As frozen ground degrades, landscapes can become unstable, resulting in ground subsidence, erosion, and changes in hydrological systems <ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. Infrastructure such as roads, pipelines, buildings, and transportation networks may also be damaged as the ground beneath them shifts and settles<ref name=":3" />. Permafrost thaw additionally influences Arctic ecosystems by altering vegetation communities, nutrient cycling, and habitat availability for wildlife<ref name=":3" />. Because of these wide-ranging consequences, understanding the causes and impacts of permafrost degradation is essential for predicting future environmental change both within the Arctic and globally.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3" />. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures<ref name=":4" />. As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability<ref name=":4" />. However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally<ref name=":4" />. These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems<ref name=":4" />. What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified<ref name=":4" />. For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt<ref name=":4" />.

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence (Schuur & Mack, 2018; Liebmann et al., 2024). This can also cause surface water to move elsewhere and further thaw areas downstream (Schuur & Mack, 2018). Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist (Schuur & Mack, 2018). [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow (Schuur & Mack, 2018). Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink (Schuur & Mack, 2018).

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface (Schuur & Mack, 2018; Vonk et al., 2015). These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them (Schuur & Mack, 2018). However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation (Schuur & Mack, 2018). Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion (Schuur & Mack, 2018).

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides (Schuur & Mack, 2018). These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope (Schuur & Mack, 2018). Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water (Schuur & Mack, 2018). These would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes (Schuur & Mack, 2018).

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:39:25Z

JamesVanderBeek: /* Significance of Permafrost Thaw */

Add Summary Here

== Statement of Connection ==
As three students studying Natural Resources and Conservation, we chose to investigate Arctic permafrost thaw because it relates to many of the concepts explored in EOSC 311, including the carbon cycle, the rock cycle, and the interactions between Earth's systems and climate. Permafrost stores large amounts of organic carbon that can be released as greenhouse gases when thawing occurs, making it an important component of the global carbon cycle. Permafrost thaw also drives erosion, sediment transport, and deposition, linking it to the surface processes and landscape changes associated with the rock cycle.

We were particularly interested in this topic because it highlights how environmental change can have cascading effects across both natural and human systems. Many of the impacts of permafrost thaw, such as changes in soil stability, hydrology and vegetation are also highly relevant to forestry and natural resource management. By examining permafrost thaw through both geological and ecological perspectives, we can better understand the threats affecting these northern environments.

= Introduction =

=== Arctic Warming ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon storage in permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

=== Significance of Permafrost Thaw ===
The impacts of permafrost thaw extend far beyond greenhouse gas emissions. As frozen ground degrades, landscapes can become unstable, resulting in ground subsidence, erosion, and changes in hydrological systems <ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. Infrastructure such as roads, pipelines, buildings, and transportation networks may also be damaged as the ground beneath them shifts and settles<ref name=":3" />. Permafrost thaw additionally influences Arctic ecosystems by altering vegetation communities, nutrient cycling, and habitat availability for wildlife<ref name=":3" />. Because of these wide-ranging consequences, understanding the causes and impacts of permafrost degradation is essential for predicting future environmental change both within the Arctic and globally.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3" />. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== Permafrost Classification ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Vegetation can both protect and destabilize permafrost depending on local conditions, as they affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates<ref name=":4" />. For example, during the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter (Loranty et al., 2018). Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures (Loranty et al., 2018). As such, changes in vegetation communities and snow cover as a result of permafrost melt can also influence permafrost stability (Loranty et al., 2018). However, because vegetation, snow and soil interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes spatially and temporally (Loranty et al., 2018). These interactions are not fully understood, and it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems (Loranty et al., 2018). What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified (Loranty et al., 2018). For instance, permafrost melt-induced changes in vegetation communities can result in increased amounts of longwave radiation generated by plants, heating up the soil and further contributing to permafrost melt (Loranty et al., 2018).

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence (Schuur & Mack, 2018; Liebmann et al., 2024). This can also cause surface water to move elsewhere and further thaw areas downstream (Schuur & Mack, 2018). Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist (Schuur & Mack, 2018). [[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance, the relative elevation change is approximately 10 feet.]]

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow (Schuur & Mack, 2018). Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink (Schuur & Mack, 2018).

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface (Schuur & Mack, 2018; Vonk et al., 2015). These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them (Schuur & Mack, 2018). However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation (Schuur & Mack, 2018). Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion (Schuur & Mack, 2018).

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides (Schuur & Mack, 2018). These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope (Schuur & Mack, 2018). Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water (Schuur & Mack, 2018). These would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes (Schuur & Mack, 2018).

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.
== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T05:00:43Z

JamesVanderBeek: /* Infrastructure Damage */

Add Summary Here

==Statement of connection and why we chose it==

= Introduction =

=== '''Arctic Warming''' ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon storage in permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

=== Significance of Permafrost Thaw ===
The impacts of permafrost thaw extend far beyond greenhouse gas emissions. As frozen ground degrades, landscapes can become unstable, resulting in ground subsidence, erosion, and changes in hydrological systems <ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. Infrastructure such as roads, pipelines, buildings, and transportation networks may also be damaged as the ground beneath them shifts and settles (Schuur & Mack, 2018). Permafrost thaw additionally influences Arctic ecosystems by altering vegetation communities, nutrient cycling, and habitat availability for wildlife (Schuur & Mack, 2018). Because of these wide-ranging consequences, understanding the causes and impacts of permafrost degradation is essential for predicting future environmental change both within the Arctic and globally.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3" />. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== '''Permafrost Classification''' ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost <ref>{{Cite journal|last=Diak|first=Magdalena|last2=Böttcher|first2=Michael Ernst|last3=Ehlert von Ahn|first3=Cátia Milene|last4=Hong|first4=Wei-Li|last5=Kędra|first5=Monika|date=13 November, 2023|title=Permafrost and groundwater interaction: current state and future perspective|url=https://doi.org/10.3389/feart.2023.1254309|journal=Frontiers in Earth Science|volume=11}}</ref>. These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change<ref name=":4">{{Cite journal|last=Loranty|first=Michael M.|last2=Abbott|first2=Benjamin W.|last3=Blok|first3=Daan|last4=Douglas|first4=Thomas A.|last5=Epstein|first5=Howard E.|date=31 August, 2018|title=Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions|url=https://doi.org/10.5194/bg-15-5287-2018|journal=Biogeosciences|volume=15|issue=17|pages=5287-5313}}</ref>. In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation<ref name=":3" /><ref name=":4" />.

=== Vegetation and Snow Cover ===
Changes in vegetation communities and snow cover can also influence permafrost stability. Warming temperatures have allowed shrubs and woody vegetation to expand into many Arctic regions previously dominated by low-growing tundra plants. These changes affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates (Loranty et al., 2018). Vegetation can both protect and destabilize permafrost depending on local conditions. During the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures. Because vegetation, snow cover, and soil temperatures interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes (Loranty et al., 2018).

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence (Schuur & Mack, 2018; Liebmann et al., 2024). This can also cause surface water to move elsewhere and further thaw areas downstream (Schuur & Mack, 2018). Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist (Schuur & Mack, 2018).

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow (Schuur & Mack, 2018). Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink (Schuur & Mack, 2018).

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface (Schuur & Mack, 2018; Vonk et al., 2015). These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them (Schuur & Mack, 2018). However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation (Schuur & Mack, 2018). Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion (Schuur & Mack, 2018).

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides (Schuur & Mack, 2018). These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope (Schuur & Mack, 2018). Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water (Schuur & Mack, 2018). These would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes (Schuur & Mack, 2018).

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Terrestrial Soil Thermal Dynamics ===
Ecosystems in the Arctic influence soil temperatures and therefore permafrost through a variety of factors (Loranty et al., 2018). For example, vegetation cover shields the ground from incoming sunlight, resulting in a reduction of heat energy entering soils, and vegetation can also release heat from the soil as water vapor through transpiration (Loranty et al., 2018). These factors interact in many complex ways with significant local and temporal variability across different scales (Loranty et al., 2018). Due to the complexity of these interactions, it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems (Loranty et al., 2018). What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified (Loranty et al., 2018). For instance, changes in vegetation communities can result in increased amounts of snow becoming trapped in vegetation canopies, leading to a deeper snow cover that insulates the soil and raises its temperature (Loranty et al., 2018).

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
[[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance the relative elevation change is approximately 10 feet.]]

=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.

== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T04:50:21Z

JamesVanderBeek: /* Infrastructure Damage */

Add Summary Here

==Statement of connection and why we chose it==

= Introduction =

=== '''Arctic Warming''' ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon storage in permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

=== Significance of Permafrost Thaw ===
The impacts of permafrost thaw extend far beyond greenhouse gas emissions. As frozen ground degrades, landscapes can become unstable, resulting in ground subsidence, erosion, and changes in hydrological systems <ref name=":3">{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. Infrastructure such as roads, pipelines, buildings, and transportation networks may also be damaged as the ground beneath them shifts and settles (Schuur & Mack, 2018). Permafrost thaw additionally influences Arctic ecosystems by altering vegetation communities, nutrient cycling, and habitat availability for wildlife (Schuur & Mack, 2018). Because of these wide-ranging consequences, understanding the causes and impacts of permafrost degradation is essential for predicting future environmental change both within the Arctic and globally.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years, consisting of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems<ref name=":3" />. In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes. Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change<ref name=":1" /><ref name=":3" />.

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter<ref name=":3" />. The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics. Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions<ref name=":3" />.

=== '''Permafrost Classification''' ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost (Diak et al., 2023). These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change (Loranty et al., 2018). In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation (Loranty et al., 2018; Schuur & Mack, 2018).

=== Vegetation and Snow Cover ===
Changes in vegetation communities and snow cover can also influence permafrost stability. Warming temperatures have allowed shrubs and woody vegetation to expand into many Arctic regions previously dominated by low-growing tundra plants. These changes affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates (Loranty et al., 2018). Vegetation can both protect and destabilize permafrost depending on local conditions. During the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures. Because vegetation, snow cover, and soil temperatures interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes (Loranty et al., 2018).

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence (Schuur & Mack, 2018; Liebmann et al., 2024). This can also cause surface water to move elsewhere and further thaw areas downstream (Schuur & Mack, 2018). Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist (Schuur & Mack, 2018).

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow (Schuur & Mack, 2018). Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink (Schuur & Mack, 2018).

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface (Schuur & Mack, 2018; Vonk et al., 2015). These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them (Schuur & Mack, 2018). However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation (Schuur & Mack, 2018). Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion (Schuur & Mack, 2018).

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides (Schuur & Mack, 2018). These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope (Schuur & Mack, 2018). Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water (Schuur & Mack, 2018). These would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes (Schuur & Mack, 2018).

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Terrestrial Soil Thermal Dynamics ===
Ecosystems in the Arctic influence soil temperatures and therefore permafrost through a variety of factors (Loranty et al., 2018). For example, vegetation cover shields the ground from incoming sunlight, resulting in a reduction of heat energy entering soils, and vegetation can also release heat from the soil as water vapor through transpiration (Loranty et al., 2018). These factors interact in many complex ways with significant local and temporal variability across different scales (Loranty et al., 2018). Due to the complexity of these interactions, it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems (Loranty et al., 2018). What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified (Loranty et al., 2018). For instance, changes in vegetation communities can result in increased amounts of snow becoming trapped in vegetation canopies, leading to a deeper snow cover that insulates the soil and raises its temperature (Loranty et al., 2018).

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
[[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance the relative elevation change is approximately 10 feet.]]

=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings, pipelines, and transportation networks can also be damaged as underlying ground settles<ref name=":3" />.

== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T04:42:55Z

JamesVanderBeek: /* Geological Impacts */

Add Summary Here

==Statement of connection and why we chose it==

= Introduction =

=== '''Arctic Warming''' ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions <ref name=":0">{{Cite journal|last=Langer|first=Moritz|last2=Nitzbon|first2=Jan|last3=Groenke|first3=Brian|last4=Assmann|first4=Lisa-Marie|last5=Schneider von Deimling|first5=Thomas|last6=Stuenzi|first6=Simone Maria|last7=Westermann|first7=Sebastian|date=2024|title=The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model|url=https://doi.org/10.5194/tc-18-363-2024|journal=The Cryosphere|volume=18|issue=1|pages=363-385}}</ref>. Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes<ref name=":0" />. In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness<ref name=":0" />. These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases <ref name=":1">{{Cite journal|last=Miner|first=Kimberley R.|last2=Turetsky|first2=Merritt R.|last3=Malina|first3=Edward|last4=Bartsch|first4=Annett|last5=Tamminen|first5=Johanna|last6=McGuire|first6=David A.|last7=Fix|first7=Andreas|last8=Sweeney|first8=Colm|last9=Elder|first9=Clayton D.|date=11 January, 2022|title=Permafrost carbon emissions in a changing Arctic|url=https://www.nature.com/articles/s43017-021-00230-3|journal=Nature Reviews Earth & Environment|volume=3|issue=1|pages=55-67}}</ref>.

=== Carbon storage in permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere<ref name=":2">{{Cite journal|last=Liebmann|first=Patrick|last2=Bárta|first2=Jiří|last3=Vogel|first3=Cordula|last4=Urich|first4=Tim|last5=Kholodov|first5=Alexander|last6=Varsadiya|first6=Milan|last7=Mewes|first7=Ole|last8=Dultz|first8=Stefan|last9=Waqas|first9=Muhammad|date=09 March, 2024|title=Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska|url=https://link.springer.com/article/10.1007/s10533-024-01132-4|journal=Biogeochemistry|volume=167|pages=199-223}}</ref>. While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane<ref name=":2" />. These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback<ref name=":1" />.

=== Significance of Permafrost Thaw ===
The impacts of permafrost thaw extend far beyond greenhouse gas emissions. As frozen ground degrades, landscapes can become unstable, resulting in ground subsidence, erosion, and changes in hydrological systems <ref>{{Cite journal|last=Schuur|first=Edward A.G.|last2=Mack|first2=Michelle C.|date=2018|title=Ecological Response to Permafrost Thaw and Consequences for Local and Global Ecosystem Services|url=https://www.annualreviews.org/doi/10.1146/annurev-ecolsys-121415-032349|journal=Annual Review of Ecology, Evolution, and Systematics|volume=49|pages=279-301}}</ref>. Infrastructure such as roads, pipelines, buildings, and transportation networks may also be damaged as the ground beneath them shifts and settles (Schuur & Mack, 2018). Permafrost thaw additionally influences Arctic ecosystems by altering vegetation communities, nutrient cycling, and habitat availability for wildlife (Schuur & Mack, 2018). Because of these wide-ranging consequences, understanding the causes and impacts of permafrost degradation is essential for predicting future environmental change both within the Arctic and globally.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years (Schuur & Mack, 2018). It consists of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems (Schuur & Mack, 2018). In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes (Schuur & Mack, 2018). Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change (Schuur & Mack, 2018; Miner et al., 2022).

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter (Schuur & Mack, 2018). The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics (Schuur & Mack, 2018). Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions (Schuur & Mack, 2018).

=== '''Permafrost Classification''' ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost (Diak et al., 2023). These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change (Loranty et al., 2018). In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation (Loranty et al., 2018; Schuur & Mack, 2018).

=== Vegetation and Snow Cover ===
Changes in vegetation communities and snow cover can also influence permafrost stability. Warming temperatures have allowed shrubs and woody vegetation to expand into many Arctic regions previously dominated by low-growing tundra plants. These changes affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates (Loranty et al., 2018). Vegetation can both protect and destabilize permafrost depending on local conditions. During the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures. Because vegetation, snow cover, and soil temperatures interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes (Loranty et al., 2018).

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions<ref name=":0" />. Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels<ref name=":0" />. As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence (Schuur & Mack, 2018; Liebmann et al., 2024). This can also cause surface water to move elsewhere and further thaw areas downstream (Schuur & Mack, 2018). Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist (Schuur & Mack, 2018).

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow (Schuur & Mack, 2018). Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink (Schuur & Mack, 2018).

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface (Schuur & Mack, 2018; Vonk et al., 2015). These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them (Schuur & Mack, 2018). However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation (Schuur & Mack, 2018). Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion (Schuur & Mack, 2018).

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides (Schuur & Mack, 2018). These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope (Schuur & Mack, 2018). Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water (Schuur & Mack, 2018). These would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes (Schuur & Mack, 2018).

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery<ref name=":2" />.

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity<ref name=":2" />.

=== Alterations to Terrestrial Soil Thermal Dynamics ===
Ecosystems in the Arctic influence soil temperatures and therefore permafrost through a variety of factors (Loranty et al., 2018). For example, vegetation cover shields the ground from incoming sunlight, resulting in a reduction of heat energy entering soils, and vegetation can also release heat from the soil as water vapor through transpiration (Loranty et al., 2018). These factors interact in many complex ways with significant local and temporal variability across different scales (Loranty et al., 2018). Due to the complexity of these interactions, it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems (Loranty et al., 2018). What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified (Loranty et al., 2018). For instance, changes in vegetation communities can result in increased amounts of snow becoming trapped in vegetation canopies, leading to a deeper snow cover that insulates the soil and raises its temperature (Loranty et al., 2018).

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).
[[File:Road dip caused by melting permafrost.jpg|thumb|346x346px|An example of thermokarst topography resulting from melting permafrost, causing the road to drop. In this instance the relative elevation change is approximately 10 feet.]]

=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings can also be damaged as underlying ground settles.

== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T03:08:55Z

JamesVanderBeek: Added picture

Add Summary Here

==Statement of connection and why we chose it==

= Introduction =

=== '''Arctic Warming''' ===
[[File:Permafrost Extent in the Northern Hemisphere (SVS30578 - permafrost northern hemisphere unep).png|thumb|426x426px|Permafrost extent and glacier coverage in the Northern Hemisphere]]
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions (Langer et al., 2024). Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes (Langer et al., 2024). In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness (Langer et al., 2024). These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases (Miner et al., 2022).

=== Carbon storage in permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere (Liebmann et al., 2024). While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane (Liebmann et al., 2024). These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback (Miner et al., 2022).

=== Significance of Permafrost Thaw ===
The impacts of permafrost thaw extend far beyond greenhouse gas emissions. As frozen ground degrades, landscapes can become unstable, resulting in ground subsidence, erosion, and changes in hydrological systems (Schuur & Mack, 2018). Infrastructure such as roads, pipelines, buildings, and transportation networks may also be damaged as the ground beneath them shifts and settles (Schuur & Mack, 2018). Permafrost thaw additionally influences Arctic ecosystems by altering vegetation communities, nutrient cycling, and habitat availability for wildlife (Schuur & Mack, 2018). Because of these wide-ranging consequences, understanding the causes and impacts of permafrost degradation is essential for predicting future environmental change both within the Arctic and globally.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years (Schuur & Mack, 2018). It consists of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems (Schuur & Mack, 2018). In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes (Schuur & Mack, 2018). Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change (Schuur & Mack, 2018; Miner et al., 2022).

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter (Schuur & Mack, 2018). The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics (Schuur & Mack, 2018). Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions (Schuur & Mack, 2018).

=== '''Permafrost Classification''' ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost (Diak et al., 2023). These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change (Loranty et al., 2018). In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation (Loranty et al., 2018; Schuur & Mack, 2018).

=== Vegetation and Snow Cover ===
Changes in vegetation communities and snow cover can also influence permafrost stability. Warming temperatures have allowed shrubs and woody vegetation to expand into many Arctic regions previously dominated by low-growing tundra plants. These changes affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates (Loranty et al., 2018). Vegetation can both protect and destabilize permafrost depending on local conditions. During the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures. Because vegetation, snow cover, and soil temperatures interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes (Loranty et al., 2018).

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions (Langer et al., 2024). Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels (Langer et al., 2024). As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
[[File:Canada British Columbia location map Okanagan.svg|thumb|Map Example]]

=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence (Schuur & Mack, 2018; Liebmann et al., 2024). This can also cause surface water to move elsewhere and further thaw areas downstream (Schuur & Mack, 2018). Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist (Schuur & Mack, 2018).

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow (Schuur & Mack, 2018). Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink (Schuur & Mack, 2018).

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface (Schuur & Mack, 2018; Vonk et al., 2015). These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them (Schuur & Mack, 2018). However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation (Schuur & Mack, 2018). Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion (Schuur & Mack, 2018).

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides (Schuur & Mack, 2018). These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope (Schuur & Mack, 2018). Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water (Schuur & Mack, 2018). These would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes (Schuur & Mack, 2018).

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery (Liebmann et al., 2024).

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity (Liebmann et al., 2024).

=== Alterations to Terrestrial Soil Thermal Dynamics ===
Ecosystems in the Arctic influence soil temperatures and therefore permafrost through a variety of factors (Loranty et al., 2018). For example, vegetation cover shields the ground from incoming sunlight, resulting in a reduction of heat energy entering soils, and vegetation can also release heat from the soil as water vapor through transpiration (Loranty et al., 2018). These factors interact in many complex ways with significant local and temporal variability across different scales (Loranty et al., 2018). Due to the complexity of these interactions, it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems (Loranty et al., 2018). What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified (Loranty et al., 2018). For instance, changes in vegetation communities can result in increased amounts of snow becoming trapped in vegetation canopies, leading to a deeper snow cover that insulates the soil and raises its temperature (Loranty et al., 2018).

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).

=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings can also be damaged as underlying ground settles.

== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-18T02:46:24Z

JamesVanderBeek: /* Alterations to Aquatic Food Webs */

Add Summary Here

==Statement of connection and why we chose it==

= Introduction =

=== '''Arctic Warming''' ===
The Arctic has experienced significant warming over the past several centuries, leading to widespread changes in permafrost across northern high-latitude regions (Langer et al., 2024). Permafrost is the largest non-seasonal component of Earth's cryosphere and plays an important role in Arctic ecosystems by influencing water movement, soil conditions, and biogeochemical processes (Langer et al., 2024). In many areas, this frozen ground has remained stable for thousands of years, making its recent thaw a growing environmental concern. Research suggests that Arctic permafrost has warmed considerably since industrialization, with many regions experiencing reductions in permafrost extent and increases in active layer thickness (Langer et al., 2024). These changes are reshaping Arctic landscapes and ecosystems while also raising concerns about the release of carbon stored in frozen soils. Arctic permafrost contains an estimated 1,700 billion metric tons of carbon, and continued warming may result in the release of some of this stored carbon to the atmosphere as greenhouse gases (Miner et al., 2022).

=== Carbon storage in permafrost ===
Permafrost serves as one of the largest terrestrial carbon reservoirs on Earth. Over thousands of years, organic matter accumulated in Arctic soils and was preserved because cold temperatures slowed decomposition processes. As a result, large amounts of carbon became stored within frozen ground rather than being returned to the atmosphere (Liebmann et al., 2024). While permafrost remains frozen, much of this carbon stays relatively stable. However, as permafrost thaws, previously frozen organic matter becomes available for decomposition, resulting in the release of greenhouse gases such as carbon dioxide and methane (Liebmann et al., 2024). These emissions contribute to additional warming and can accelerate further permafrost thaw through a process known as the permafrost carbon feedback (Miner et al., 2022).

=== Significance of Permafrost Thaw ===
The impacts of permafrost thaw extend far beyond greenhouse gas emissions. As frozen ground degrades, landscapes can become unstable, resulting in ground subsidence, erosion, and changes in hydrological systems (Schuur & Mack, 2018). Infrastructure such as roads, pipelines, buildings, and transportation networks may also be damaged as the ground beneath them shifts and settles (Schuur & Mack, 2018). Permafrost thaw additionally influences Arctic ecosystems by altering vegetation communities, nutrient cycling, and habitat availability for wildlife (Schuur & Mack, 2018). Because of these wide-ranging consequences, understanding the causes and impacts of permafrost degradation is essential for predicting future environmental change both within the Arctic and globally.

== Overview of Arctic permafrost ==

=== Definition and Formation ===
Permafrost is ground that remains at or below 0°C for at least two consecutive years (Schuur & Mack, 2018). It consists of frozen rock, soil, ice, and organic material that underlies many Arctic and subarctic ecosystems (Schuur & Mack, 2018). In many regions, permafrost has remained frozen for centuries to millennia, making it an important component of northern landscapes (Schuur & Mack, 2018). Permafrost also stores large amounts of organic carbon that have accumulated over long periods of time, linking it closely to global carbon cycling and climate change (Schuur & Mack, 2018; Miner et al., 2022).

=== Active Layer ===
Above the permafrost lies the active layer, a zone of soil that thaws during the summer and refreezes during the winter (Schuur & Mack, 2018). The active layer is the primary zone of biological activity in permafrost ecosystems and varies in thickness depending on local climatic conditions and vegetation characteristics (Schuur & Mack, 2018). Because it thaws seasonally, the active layer provides the conditions necessary for many ecological processes to occur during the short Arctic growing season. The thickness of the active layer can range from tens of centimeters to several meters depending on environmental conditions (Schuur & Mack, 2018).

=== '''Permafrost Classification''' ===
Permafrost is commonly classified according to the proportion of the landscape underlain by permanently frozen ground. Continuous permafrost occurs where frozen ground is present beneath more than 90% of the landscape and is characteristic of the coldest Arctic regions. In contrast, discontinuous permafrost occurs where frozen ground is less widespread and is interspersed with unfrozen areas. Discontinuous permafrost can be further divided into extensive discontinuous, intermediate discontinuous, sporadic, and isolated patch categories based on the percentage of land underlain by permafrost (Diak et al., 2023). These classifications help researchers describe the distribution of permafrost across northern regions and assess how different landscapes may respond to environmental change. Because discontinuous, sporadic, and isolated permafrost exist in regions where temperatures are already closer to the freezing point, they are generally considered more vulnerable to thaw as Arctic temperatures continue to rise. In contrast, continuous permafrost is often more resilient in the short term due to the colder conditions in which it occurs, although it is also experiencing significant warming and degradation in many Arctic regions.

= Drivers of Permafrost Thaw =

=== Arctic Amplification ===
The primary driver of modern permafrost thaw is rising Arctic temperatures associated with climate change. The Arctic is warming much faster than the global average due to a process known as Arctic amplification. One of the main mechanisms behind this phenomenon is the loss of snow and ice cover. Because snow and ice reflect a large proportion of incoming solar radiation, their decline exposes darker land and water surfaces that absorb more heat. This creates a positive feedback loop that further accelerates regional warming and contributes to the continued degradation of permafrost across the Arctic. As temperatures rise, more heat is transferred into the ground, altering the thermal dynamics of permafrost soils. Changes in vegetation, snow cover, and other ecosystem characteristics can further influence soil temperatures and affect how permafrost responds to climate change (Loranty et al., 2018). In many regions, warming causes the active layer to deepen and exposes previously frozen ground to seasonal thaw, increasing the vulnerability of permafrost landscapes to degradation (Loranty et al., 2018; Schuur & Mack, 2018).

=== Vegetation and Snow Cover ===
Changes in vegetation communities and snow cover can also influence permafrost stability. Warming temperatures have allowed shrubs and woody vegetation to expand into many Arctic regions previously dominated by low-growing tundra plants. These changes affect the transfer of energy between the atmosphere and the ground, influencing soil temperatures and thaw rates (Loranty et al., 2018). Vegetation can both protect and destabilize permafrost depending on local conditions. During the summer, plant cover may shade the ground and reduce soil warming, while taller vegetation can trap greater amounts of snow during the winter. Snow acts as an insulating layer that reduces heat loss from the ground and can contribute to warmer soil temperatures. Because vegetation, snow cover, and soil temperatures interact in complex ways, their influence on permafrost varies considerably across Arctic landscapes (Loranty et al., 2018).

=== Anthropogenic Climate Change ===
Human activities are ultimately largely responsible for the environmental changes driving modern permafrost thaw. The combustion of fossil fuels, industrial development, agriculture, and deforestation have increased atmospheric concentrations of greenhouse gases, strengthening the Earth's greenhouse effect and raising global temperatures. The Arctic is particularly sensitive to these changes due to amplification processes that intensify regional warming. Although permafrost has naturally expanded and contracted throughout Earth's history in response to climate fluctuations, the rapid pace of modern warming has accelerated permafrost degradation across many northern regions (Langer et al., 2024). Climate projections indicate that large areas of Arctic permafrost may disappear during the coming centuries if greenhouse gas emissions continue at current levels (Langer et al., 2024). As a result, the widespread thaw observed today is closely linked to human-caused climate change and its influence on global temperature patterns, while the extent of future permafrost loss will depend largely on future greenhouse gas emissions and the effectiveness of global climate mitigation efforts.

==Geological Impacts==
[[File:Canada British Columbia location map Okanagan.svg|thumb|Map Example]]

=== Subsidence ===
The loss of Arctic permafrost can alter the appearance of landscapes and trigger several geological processes. As it melts, spaces it once took up in the soil and on the surface are left open, causing the soil surface to collapse where it once occupied in a process called subsidence (Schuur & Mack, 2018; Liebmann et al., 2024). This can also cause surface water to move elsewhere and further thaw areas downstream (Schuur & Mack, 2018). Both of these changes occur rapidly, creating what’s known as thermokarst terrain, of which two main categories exist (Schuur & Mack, 2018).

Wetland thermokarst occurs in wetlands that possess permafrost, which feature mosaics of terrain close to the water table and raised plateaus that allow plants that can thrive in drier and wetter conditions to grow (Schuur & Mack, 2018). Thawing as a result of altered water flows making contact with these plateaus or from raised air temperature can cause the plateaus to sink (Schuur & Mack, 2018).

Lake thermokarst occurs on lowlands where the melting of permafrost creates and exposes ponds of water on the surface (Schuur & Mack, 2018; Vonk et al., 2015). These tend to absorb heat due to their low surface reflectivity (albedo), resulting in further permafrost melting along their banks and beds and eventually forming into lakes (Schuur & Mack, 2018; Vonk et al., 2015). Thermokarst lakes can also be subject to erosion, causing further expansion, and potentially connect and drain into other bodies of water should permafrost melt remove barriers between them (Schuur & Mack, 2018). However, it should be noted permafrost could potentially reform in lake thermokarst landscapes following drainage should plants be allowed to regrow, restore soil organic layers and provide sufficient insulation (Schuur & Mack, 2018). Even in such a scenario, ecosystem structure and function would still be altered by the removal of ground ice and erosion (Schuur & Mack, 2018).

=== Erosion ===
Erosion is also a major geological consideration regarding permafrost melt. In uplands, particularly on steeper slopes, the removal of permafrost can initially destabilize the soil, causing erosion and potentially landslides (Schuur & Mack, 2018). These processes can also expose and subject deeper parts of the soil and bedrock to erosion until physical processes can stabilize the slope (Schuur & Mack, 2018). Permafrost melt can expand bodies of water, including lakes that arise from the melt itself, through bank erosion, potentially draining them and connecting them to other bodies of water (Schuur & Mack, 2018). These would also increase the movement of nutrients between bodies of water where former terrestrial environments collapse into wetlands and lakes (Schuur & Mack, 2018).

== Ecological and Environmental Impacts ==

=== Terrestrial Vegetation Regime Change ===
Permafrost melt is associated with a wide variety of local ecological and environmental feedbacks, some not fully understood. Within terrestrial ecosystems that have adapted to the presence of permafrost, several ecological changes have been observed in relation to the loss of permafrost from their soils. Regions subject to differing conditions associated with permafrost melt, such as increased temperatures, exposed soils and more severe fires, may also face shifts in plant communities (Schuur & Mack, 2018; Liebmann et al., 2024). Tundra and evergreen forest plant and animal communities may get out-competed by species better suited to new permafrost-free environments, particularly where newly-exposed soil and more frequent disturbance creates opportunities for other plants to establish new seeds (Schuur & Mack, 2018). The formation of thermokarst lakes would also cause shifts in vegetation communities as terrestrial plants are replaced by those better suited to aquatic conditions (Schuur & Mack, 2018). These changes could potentially result in a thicker vegetation cover, which would reduce thawing in the summer, but also increase the snow cover’s thickness in the winter, slowing potential permafrost recovery (Liebmann et al., 2024).

=== Terrestrial Nutrient and Carbon Storage Reduction ===
Permafrost soil stores nutrients important for ecosystems, such as carbon, within organic matter, and the permafrost itself plays an important role in that its presence slows their decomposition and uptake by plants and microbes (Loranty et al., 2018). In addition, these are also host to plants such as lichens and mosses that produce slowly-decomposing organic matter, contributing to its longevity in storage (Kazumichi & Chie, 2022). The loss of this ice would accelerate decomposition in wet soil and free the nutrients trapped within (Liebmann et al., 2024; Loranty et al., 2018). This release would favor terrestrial plants that have greater nutrient demand and faster growth rates in soils formerly containing permafrost (Schuur & Mack, 2018). It should also be noted that these conditions could also result in increased productivity for new plant communities (i.e. more energy available for plants and animals), and therefore more incorporation of organic matter and carbon in topsoils (Schuur & Mack, 2018; Liebmann et al., 2024). This effect is, however, offset by the decomposition of organic matter within deeper soils where permafrost once resided, which lacks such an input, and would still result in a net decline in storage capacity (Liebmann et al., 2024).

=== Alterations to Terrestrial Soil Thermal Dynamics ===
Ecosystems in the Arctic influence soil temperatures and therefore permafrost through a variety of factors (Loranty et al., 2018). For example, vegetation cover shields the ground from incoming sunlight, resulting in a reduction of heat energy entering soils, and vegetation can also release heat from the soil as water vapor through transpiration (Loranty et al., 2018). These factors interact in many complex ways with significant local and temporal variability across different scales (Loranty et al., 2018). Due to the complexity of these interactions, it is uncertain as to the true extent and timing of the effects permafrost melt would have on these systems (Loranty et al., 2018). What is known is that both positive and negative feedbacks associated with soil temperatures in response to permafrost thaw have been identified (Loranty et al., 2018). For instance, changes in vegetation communities can result in increased amounts of snow becoming trapped in vegetation canopies, leading to a deeper snow cover that insulates the soil and raises its temperature (Loranty et al., 2018).

=== Alterations to Aquatic Food Webs ===
Aquatic ecosystems in regions affected by permafrost melt face alterations to the composition of water as a result of permafrost melt-driven erosion, transport of resulting sediment and increased connectivity between bodies of water (Kendrick et al., 2018; Vonk et al., 2015). These include changes to the concentrations of organic nutrients, sediment and oxygen, alongside the amount of light received, all of which can be subject to variation (Kendrick et al., 2018; Vonk et al., 2015). Due to these changing conditions, shifts in nutrient availability for different organisms would occur, and similar to terrestrial ecosystems, certain organisms will be better adapted to these new conditions than others (Kendrick et al., 2018; Schuur & Mack, 2018; Vonk et al., 2015).

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As a part of permafrost thaw-induced decomposition of carbon- and nitrogen-rich organic material trapped within soils and ice, these gases are released as a byproduct.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).

=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings can also be damaged as underlying ground settles.

== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-17T22:59:56Z

JamesVanderBeek: /* Greenhouse Gas Release */

Add Summary Here

==Statement of connection and why you chose it==

==Main text==
[[File:Canada British Columbia location map Okanagan.svg|thumb|Map Example]]

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As these formerly frozen soils thaw, the partially decayed carbon- and nitrogen-rich organic material trapped within them resumes decomposition, leading to the release of gases as a by-product.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).

=== Infrastructure Damage ===
Infrastructure which has been built upon permafrost is commonly subject to deformation, degradation, or destruction as a result of permafrost thaw. Slumping, shifting, and settling of underlying ground material can break or deform overlying roads, which can disconnect communities or limit their access to key hunting, trapping, and culturally important locations. Buildings can also be damaged as underlying ground settles.

== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-17T21:37:47Z

JamesVanderBeek: /* Human and Global Implications */

Add Summary Here

==Statement of connection and why you chose it==

==Main text==
[[File:Canada British Columbia location map Okanagan.svg|thumb|Map Example]]

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As these formerly frozen soils thaw, the partially decayed carbon- and nitrogen-rich organic material trapped within them resumes decomposition, leading to the release of gases as a by-product.

Carbon Dioxide (CO2) is released in the decomposition of organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).

== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-17T21:09:47Z

JamesVanderBeek: /* Greenhouse Gas Release */

Add Summary Here

==Statement of connection and why you chose it==

==Main text==
[[File:Canada British Columbia location map Okanagan.svg|thumb|Map Example]]

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As these formerly frozen soils thaw, the partially decayed carbon- and nitrogen-rich organic material trapped within them resumes decomposition, leading to the release of gases as a by-product.

Carbon Dioxide (CO2) is released by bacteria feeding on carbon-rich organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas many times more powerful than CO2, albeit with a significantly shorter lifespan in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of global warming on permafrost thaw.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of sulfate-rich silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).

== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:EOSC311/2026/Arctic Permafrost Retreat: The Causes and Consequences

2026-06-17T02:52:28Z

JamesVanderBeek: /* Main text */

Add Summary Here

==Statement of connection and why you chose it==

==Main text==
[[File:Canada British Columbia location map Okanagan.svg|thumb|Map Example]]

== Human and Global Implications ==

=== Greenhouse Gas Release ===
Permafrost thaw is associated with the release of several greenhouse gases. As these formerly frozen soils thaw, the partially decayed carbon- and nitrogen-rich organic material trapped within them resumes decomposition, leading to the release of gases as a by-product.

Carbon Dioxide (CO2) is released by bacteria feeding on carbon-rich organic material. There is ~1,035 petagrams (Pg) (1 Pg = 1 billion metric tons) of carbon stored in permafrost soils globally, representing a potential source of CO2 many times larger than the current ~10 Pg released by anthropogenic activity (Schuur & Mack, 2018).

Methane (CH4) is also released as part of the decomposition process. Methane is a greenhouse gas [ ] times more powerful than CO2, albeit with a significantly shorter half life in the atmosphere.

Nitrous oxide (N2O) is released when mineralization turns organically-bound Nitrogen (N) into mineral N, predominantly in the forms of nitrate (NO3) and ammonium (NH4+). These in turn undergo de-nitrification and nitrification respectively, releasing N2O gas into the atmosphere. N2O is a greenhouse gas over 300 times more powerful than CO2. Arctic permafrost provides a potential stock of roughly 67 million tons of N, 500 times more than is currently utilized in agricultural industries globally.

In all cases, the release of greenhouse gases serves to reinforce the positive feedback loop of the circumpolar arctic related to climate change.

=== Water Quality ===
Water quality may be heavily impacted by permafrost thaw and the water features which form as a result of thermokarst processes. Sulfate-mineral oxidation (SMO) is the acidification of water and mobilization of metals resulting from permafrost thaw in areas where underlying bedrock material consists of silicaclastic rock (Skierszkan et al., 2026). As thawing occurs, oxygen penetrates and reacts with sulfate-rich sediments, raising the pH of the water generated by the thawing and releasing metal oxides. When this contaminated water seeps from the soil into surface streams, it is carried toward a drainage basin or out into the ocean. Mobile metals include mercury, zinc, aluminum, cadmium, iron, and manganese, all of which rapidly accumulate in stream headwaters to acutely toxic levels where SOM and seepage occurs (Skierszkan et al., 2026; Smith et al., 2024). Contaminated water seepage of this nature is indicated by vegetation die-off in the immediate vicinity, clouding or ‘rusting’ of the water, and presence of secondary precipitate minerals (Skierszkan et al., 2026).

== Case Study: [Yukon] ==

==Conclusion / Your Evaluation of the Connections==

==References==
<references />

{{Projectbox_EOSC311}}
[[Category:EOSC311]]

Course:CONS200/2025WT2/The effects of wildfires on outmigration in California

2025-04-12T05:34:26Z

JamesVanderBeek: /* Environmental Impact */

As a result of [https://en.wikipedia.org/wiki/Climate_change climate change], the world has seen a significant increase in the frequency of extreme [https://en.wikipedia.org/wiki/Wildfire wildfires]. [https://en.wikipedia.org/wiki/California California] especially is a region that has been greatly impacted by severe wildfires. The damage caused by these fires damage infrastructure and cause health impacts to the people affected. 49% of residents reported being highly impacted by mandatory evacuations, 42% reported being impacted by poor air quality, and 61% reported being high to moderately impacted by power shutoffs.<ref>{{Cite journal|last=Howe|first=Alexander A|last2=Blomdahl|first2=Erika M|last3=Smith-Eskridge|first3=Ellie|last4=Pinto|first4=Dakoeta R|last5=Brunson|first5=Mark W|last6=Howe|first6=Peter D|last7=Huntly|first7=Nancy J|last8=Klain|first8=Sarah C|date=April 19, 2024|title=Worldviews more than experience predict Californians' support for wildfire risk mitigation policies|url=https://iopscience.iop.org/article/10.1088/1748-9326/ad3cf6|journal=Environmental Research Letters}}</ref> [https://en.wikipedia.org/wiki/Human_migration Out-migration], or the process of people permanently leaving an area in order to live somewhere else, can be affected by: an area’s perception as a ‘safe’ or ‘unsafe’ place, the actual severity and frequency of natural disasters, and the distribution and application of resources for disaster recovery.<ref>{{Cite journal|last=Lambrou|first=Nicole|last2=Kolden|first2=Crystal|last3=Loukaitou-Sideris|first3=Anastasia|date=February 15, 2025|title=Disaster recovery gentrification in post-wildfire landscapes: The case of Paradise, CA|url=https://www.sciencedirect.com/science/article/pii/S2212420925000597?via%3Dihub|journal=International Journal of Disaster Risk Reduction|via=}}</ref> The impacts of wildfires in California, and the perception of the state as a place where wildfires occur, may be impacting outmigration from the area. In recent years, the state has shown a relative increase in out-migration rates compared to the previous decade.<ref>Gabriel, S., Freyd, B., Brand, J., Fultz, N., & Tzen, M. (2005). Recent Trends in California Migration Evidence from the American Community Survey. https://www.universityofcalifornia.edu/sites/default/files/ucla-california-migration-report.pdf </ref> We will discuss if and how the mental and physical impacts of wildfires could be related to this increase.

==History==
[[File:NOAA Satellites Watch as California Burns (NESDIS 2020-10-01).gif|thumb|The [https://en.wikipedia.org/wiki/National_Oceanic_and_Atmospheric_Administration NOAA's] [https://en.wikipedia.org/wiki/Geostationary_Operational_Environmental_Satellite GOES-West satellite] capture of the [https://en.wikipedia.org/wiki/August_Complex_fire August Complex fires] and [https://en.wikipedia.org/wiki/Glass_Fire Glass Fire] in California's West Coast region, 2020.|337x337px]]California’s ecosystems are historically adapted to wildfire as a disturbance agent. Prior to establishment of the United States of America, fire was utilized as a tool to shape and maintain the landscape. The state of California has monitored wildfire activity since the early twentieth century, revealing patterns of increasing wildfire frequency and severity throughout the state. 19 of the 20 largest fires in the state’s history have occurred in the twenty-first century, and 13 of these 19 have occurred within the last decade (2015-2025).<ref>[https://34c031f8-c9fd-4018-8c5a-4159cdff6b0d-cdn-endpoint.azureedge.net/-/media/calfire-website/our-impact/fire-statistics/top-20-largest-ca-wildfires.pdf?rev=097f901c128347149e2614f2fca4f546&hash=27DDE83DFEF9A69E67C73765892A2B75 "Top 20 Largest California Wildfires"] </ref>

The state of California has historically used traditional fire suppression techniques within its semi-arid mixed conifer forests. Suppression allows for the accumulation of biomass as fuel beyond natural fire intervals (between 5-20 years), which in turn contributes to the increased risk of severe wildfire for these ecosystems. Long-term fire suppression encourages the development of atypical forest features, such as continuous closed canopies, establishment of shade-tolerant tree species, and buildup of understory fuels.<ref>{{Cite journal|last=Klimaszewski-Patterson|first=Anna|last2=Dingemans|first2=Theodore|last3=Morgan|first3=Christopher T|last4=Mensing|first4=Scott A|date=January 15, 2024|title=Human influence on late Holocene fire history in a mixed-conifer forest, Sierra National Forest, California|url=https://link.springer.com/article/10.1186/s42408-023-00245-9|journal=Fire Ecology}}</ref>

Recent shifts in climate have increased both the degree and frequency of drought experienced in California's ecosystems beyond historic norms, further contributing to fuel buildup and wildfire risk.

==Causes==
Wildfires have always been a part of forest ecosystems. Forests frequently experience small fires that cause stand regeneration, where plants at the forest floor are destroyed, adding nutrients to the forest floor and causing new growth that increases biodiversity. These can be caused by weather or climate conditions, as well as by humans using prescribed fires for forest management.<ref>{{Cite web|last=Mondal|first=Tamali|last2=Dasgupta|first2=Soumya|last3=Bhatt|first3=Dinesh Chandra|last4=Ramesh|first4=K.|date=March 20, 2024|title=Natural or man-made? Finding the drivers of forest fires within the protected area habitats: a case study from the lower Shivalik Landscape, Western Himalaya|url=https://link.springer.com/article/10.1007/s11069-024-06523-2|url-status=live|website=Springer Nature}}</ref> However, recent years have seen a sharp increase in occurrence of severe fires.<ref>{{Cite web|last=Brown|first=Patrick T|last2=Hanley|first2=Holt|last3=Mahesh|first3=Ankur|last4=Reed|first4=Colorado|last5=Strenfel|first5=Scott J|last6=Davis|first6=Steven J|last7=Kochanski|first7=Adam K|last8=Clements|first8=Craig B|date=2023, September 28|title=Climate warming increases extreme daily wildfire growth risk in California|url=https://www.proquest.com/docview/2871925930?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref> Climate change and human activities are the most highly attributed to this trend.

==== Climate ====
In recent years, the climate has become undeniably warmer. In the twenty-first century, global temperatures have risen between 0.6 to 0.7℃.<ref>{{Cite web|last=Cayan|first=Daniel R|last2=Maurer|first2=Edwin P|last3=Dettinger|first3=Michael D|last4=Tyree|first4=Mary|last5=Hayhoe|first5=Katharine|date=2008, January 26|title=Climate change scenarios for the California region|url=https://link.springer.com/article/10.1007/s10584-007-9377-6|url-status=live|website=Springer Nature}}</ref> In the United States, the time period from 1960 to 2013 was warmer than periods of comparable length from the past 600 years.<ref name=":1">{{Cite web|last=Garfin|first=Gregg|last2=Jardine|first2=Angela|last3=Merideth|first3=Robert|last4=Black|first4=Mary|last5=LeRoy|first5=Sarah|date=2013|title=Assessment of Climate Change in the Southwest United States|url=https://link.springer.com/book/10.5822/978-1-61091-484-0|url-status=live|website=Springer Nature}}</ref> This has been especially significant in the Southwest, which tends to be warmer than the rest of the United States.<ref name=":1" />

Temperature can be an important determinant in wildfire occurrence, affecting humidity and fuel sources. With the higher temperatures of recent years, air is able to hold more water, so as total moisture content remains the same, the relative humidity becomes lower. Precipitation has also decreased as a result of this increase in water storage capacity, leading to drought. The Santa Ana winds, hot and cold winds that flow over Southern California, can also contribute to these warming conditions. These winds are attributed to many extreme temperatures across Southern California. Hot winds, which though less severe than cold winds, can contribute to dry conditions that cause wildfires.<ref>{{Cite web|last=Gershunov|first=Alexander|last2=Guzman|first2=Morales Janin|last3=Hatchett|first3=Benjamin|last4=Guirguis|first4=Kristen|last5=Aguilera|first5=Rosana|last6=Shulgina|first6=Tamara|last7=Abatzoglou|first7=John T|last8=Cayan|first8=Daniel|last9=Pierce|first9=David|authors=Williams, Park; Small Ivory; Clemesha, Rachel; Schwarz, Lara; Benmarhnia, Tarik; Tardy, Alex|date=2021, October|title=Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire|url=https://www.proquest.com/docview/2573150518/abstract?accountid=14656&scrollToView=Author&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref> These conditions cause fuel such as wood debris on the forest floor to lose more moisture. Combined with the preexisting dry conditions, it leads to larger and more frequent wildfires.<ref>{{Cite web|last=Varga|first=Kevin|last2=Jones|first2=Charles|last3=Trugman|first3=Anna|last4=Carvalho|first4=Leila M V|last5=McLoughlin|first5=Neal|last6=Seto|first6=Daisuke|last7=Thompson|first7=Callum|last8=Daum|first8=Kristofer|date=2022|title=Megafires in a Warming World: What Wildfire Risk Factors Led to California’s Largest Recorded Wildfire|url=https://www.proquest.com/docview/2632816567?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>

==== Human Activity ====
While climate plays a part in causing wildfires, the recent increase in wildfires can be highly attributed to human activities. From 1992 to 2012, humans could be connected to 84% of fires across the United States.<ref name=":2">{{Cite web|last=Balch|first=Jennifer K|last2=Bradley|first2=Bethany A|last3=Abatzoglou|first3=John T|last4=Nagy|first4=R Chelsea|last5=Fusco|first5=Emily J|last6=Mahood|first6=Adam L|date=2017, February 27|title=Human-started wildfires expand the fire niche across the United States|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC5358354/|url-status=live|website=PubMed Central}}</ref> Human development introduces sources of ignition to the environment, which combined with dry fuels, creates severe wildfires. Proximity to roads and boundaries between wilderness and human developed areas have both been attributed to higher rates of wildfire occurrence.<ref name=":2" />

Current wildfire management practices aim to suppress all forest fires, regardless of severity. There is evidence that fires are actually an important disturbance event for forests that increases biodiversity and resilience.<ref>{{Cite web|date=2023, December 25|title=Twenty-year study confirms California forests are healthier when burned - or thinned|url=https://go.exlibris.link/q3XqDwBJ|url-status=live|website=Factiva}}</ref> Small fires create vertical and horizontal diversity in forests, allowing for fire resilience as some species are more tolerant of fire than others. This also creates gaps in fuel distribution that deter larger fires from occurring. Without this, forests become homogeneous, and fuel builds up rather than being periodically consumed. This leads to more wildfires at higher severities.<ref name=":3">{{Cite web|last=Koontz|first=Michael J|last2=North|first2=Malcolm P|last3=Werner|first3=Chhaya M|last4=Fick|first4=Stephen E|last5=Latimer|first5=Andrew M|date=2020, January 10|title=Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13447|url-status=live|website=Wiley Online Library}}</ref> This creates a feedback loop where, as fires get more severe, forests are no longer gaining biodiversity through small disturbances. Instead, when all vegetation is destroyed in a large fire, biodiversity is reduced and makes forest ecosystems more vulnerable.<ref name=":3" />

==Impacts==
[[File:Destroyed home and vehicle caused by the Eaton Fire, 2025.jpg|thumb|296x296px|Destroyed home and vehicle caused by the [https://en.wikipedia.org/wiki/Eaton_Fire Eaton Fire], 2025]]

==== '''Economic Impact''' ====
Wildfires have caused a significant amount of economic damage in California. These types of damages include property damage, capital loss, and wage loss. The January 2025 wildfires of Southern California caused significant amounts of financial damage. The fires caused property damages and capital loss that range from 76 billion USD to 131 billion USD.<ref name=":0">{{Cite web|last=Li|first=Zhiyun|last2=Yu|first2=William|date=2025, March 7|title=Economic impact of the Los Angeles wildfires|url=https://www.anderson.ucla.edu/about/centers/ucla-anderson-forecast/economic-impact-los-angeles-wildfires|url-status=live|website=UCLA Anderson School of Management}}</ref> These damages mainly comes from the 16,251 homes, properties, and structures destroyed in the fire.<ref name=":0" /> The amount also includes damage to other belongings such as automobiles.

Additionally, business and employees of affected areas suffered an additional 297 million USD in lost wages.<ref name=":0" /> The fire is also expected to cause a 0.48% loss in county GDP, leading to an approximate 4.6 billion USD in further economic damage.<ref name=":0" /> Wildfires are expected to become more prevalent as climate change worsens. Examples of other devastating fires in California include the Tubbs wildfire of 2018 and the Camp wildfire of 2017.<ref name=":0" /> The Tubbs wildfire caused 8.76 billion USD in insurance claims, and the Camp wildfire caused 8.26 billion USD in insurance claims.<ref name=":0" />

==== '''Social Impact''' ====
Wildfires have had a significant impact on the Californian society. For one, wildfires have lead to higher living costs for the Californian populace. Wildfires have led to higher housing costs, as well as growing insurance premiums.<ref name=":0" /> Low-income communities tend to suffer greater consequences from wildfires. These communities tend to lack the savings and adequate insurance needed to recover from the disaster.<ref name=":5" /> This is one of the reasons why wildfires can exacerbate homelessness.<ref name=":5" />

Furthermore, low-income communities are also more likely to not have sufficient preventative measures. This makes their properties 29% more likely to be destroyed by wildfires than those that have such measures installed. An example of such preventative measures is roof renewals, with a roof renewal, the risk of a property being destroyed by wildfires can be reduced by up to 27%.<ref name=":5">{{Cite journal|last=Reining|first=Sebastian|last2=Wussow|first2=Moritz|last3=Zanocco|first3=Chad|last4=Neumann|first4=Dirk|date=07 January 2025|title=Roof renewal disparities widen the equity gap in residential wildfire protection|url=https://www.nature.com/articles/s41467-024-55705-w|journal=Nature Communications}}</ref> As such, while wildfires negatively affect the entire population, it is much worse for low-income communities. Wildfires have also had major health implications for the Californian populace. Smoke from wildfires carries fine, often toxic, particulate matter, which damages the lungs of the inhaler.<ref name=":4">{{Cite web|date=30 Jan 2025|title=Health Affects Attributed to Wildfire Smoke|url=https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke|url-status=live|website=United States Environmental Protection Agency}}</ref> This can result in a reduction in the ability to expel foreign objects, such as virus and bacteria, from the lungs. Inhaling these particles can also exacerbate existing respiratory diseases, as well as premature mortality.<ref name=":4" />

==== '''Environmental Impact''' ====
Wildfires can have dire effects on the environment. Wildfires have the potential to heavily damage ecosystems. Examples include polluted water sources, loss of vegetation, endangerment of wildlife, and degraded air quality<ref name=":11">{{Cite news|url=https://earth.org/environmental-impact-of-wildfires/|title=The Environmental Impact of Wildfires|last=Morrison|first=Rose|date=August 18, 2022|work=Earth.org}}</ref>. Wildfire effects, especially vegetation loss, have been known to be particularly harmful to herbivores (land grazing mammals and insects)<ref name=":11" />. Essentially, the lack of food and resources leads to decreases in the realized niche of the affected species. In severe cases, this can cause decreases in essential ecosystem functions such as nutrient cycling and pollination<ref name=":11" />.

While the damages done by disturbances do eventually heal, it is important to note that severe disturbances do not always result in an earlier stage of succession. Severe disturbances such as wildfires can exceed the tipping point of ecosystems, leading to a regime shift. A regime shift is when an ecosystem, as a result of a major disturbance, transitions into a different type of ecosystem.

The growing frequency and intensity of wildfires in a major concern. Low-intensity wildfires may not have major environmental effects, but severe wildfires can transition old-growth forests into primary succession<ref name=":12">{{Cite news|url=https://news.uchicago.edu/explainer/what-is-ecological-succession|title=Ecological succession, explained|last=Witynski|first=Max|work=UChicago News}}</ref>. It takes centuries for a primary succession forest to transition into old growth<ref name=":12" />. When severe wildfires become frequent, it not only drastically increases the amount of carbon in the atmosphere but also decreases the habitat range of forest-reliant species. Wildfires in California are projected to grow in both intensity and frequency through 2100<ref>{{Cite journal|last=Hurteau|first=Matthew D|last2=Westerling|first2=Anthony L|last3=Wiedinmyers|first3=Christine|last4=Bryant|first4=Benjamin P|date=January 20, 2014|title=Projected Effects of Climate and Development on California Wildfire Emissions through 2100|url=https://pubs.acs.org/doi/full/10.1021/es4050133|journal=Environmental Science & Technology|volume=Vol 48/Issue 4|via=ACS Publications}}</ref>. This pose a major threat to species and ecosystems.

== Human Mobility ==

==== Out-migration ====
The term out-migration (also written as outmigration or out migration) is used to categorize the number of residents of an area who then leave for another area. Out-migration within the context of wildfires, then, refers only to how wildfires (and their effects) push people away from where they have settled. Out-migration is not to be confused with a decrease to in-migration, which represents the number of people settling an area. Additionally, in-migration is not to be confused with immigration, which refers to settlement within a new country. The sum of in-migration minus out-migration results in the net migration for a region. A positive net migration means more people are settling in a region while a negative number means more people are leaving the region for another. Literature on the effects environmental hazards have on human mobility vary widely and migration driven by the interaction between climatic and non-climatic elements is not entirely transparent.<ref name=":6" /><ref name=":7" /> However, existing studies agree wildfires do influence out-migration, along with in-migration.<ref name=":6" /><ref name=":8" /><ref name=":9" /> The predicted and observed severity of wildfires has continued to grow in recent decades at the same time as the populations of high-risk regions have increased<ref name=":6" /> with an estimate of 1.2 million people [https://en.wikipedia.org/wiki/Climate_migration displaced] by wildfires globally in 2020, and more affected by smoke which may travel hundreds of miles from its origin.<ref name=":9" />

In a representative survey following the 2020 fire season, 1/12 of the 1,108 California respondents reported they intended to move within 5 years, and this decision was at least moderately impacted by wildfires and smoke.<ref name=":9" /> The 2020 California survey reported 73.8% of respondents had prolonged exposure to wildfire smoke, 55.7% had at least one negative experience during the 2020 wildfire season, and 28.4% indicated they know someone who was harmed.<ref name=":9" /> It was also found that prior negative outcomes, such as evacuations and losing property, were associated with intentions to migrate, while for those intending to remain prior wildfire experiences negatively affected their residency satisfaction and therefore might influence future out-migration.<ref name=":9" /> Another study estimates for each additional 10 days reaching 90 degrees above the average number of extreme heat days, net migrants were reduced by 4 per 10,000 starting population.<ref name=":8">{{Cite journal|last=Winkler|first=Richelle L|last2=Rouleau|first2=Mark D|date=2020, September 30|title=Amenities or disamenities? Estimating the impacts of extreme heat and wildfire on domestic US migration|url=https://www.proquest.com/docview/2541128629?sourcetype=Scholarly%20Journals|journal=Population and Environment|volume=42|pages=622-648|via=Proquest}}</ref> [https://en.wikipedia.org/wiki/County_(United_States) Counties] that experienced a fire had a reduction of 32 net migrants per 10,000 starting population compared to those that did not experience or have a neighbour that experienced a fire in the previous year. Counties neighbouring those that experienced a fire saw a net decrease of 18 migrants per 10,000 starting population when compared to those with no fire (self or near) the previous year. It was also found that a fire disaster declared by [https://en.wikipedia.org/wiki/Federal_Emergency_Management_Agency FEMA] had a net migration impact on par with losing 47 jobs.<ref name=":8" />

Generally, sources agree counties with disaster-level fires or extreme heat in the year prior had increased out-migration and lower in-migration.<ref name=":6" /><ref name=":7" /><ref name=":8" /><ref name=":9" /> While human migration patterns are undeniably influenced by wildfires in the short term, particularly in counties that tend to attract migrants for environmental amenities and outdoor recreation,<ref name=":8" /> long-term trends are elusive.<ref name=":6" /> For example, only 6% of those displaced by the [https://en.wikipedia.org/wiki/October_2017_Northern_California_wildfires 2017 Sonoma County fires] left the county within a year<ref name=":9" /> while the deadly [https://en.wikipedia.org/wiki/Camp_Fire_(2018) 2018 Camp Fire] resulted in elevated out-migration for the following two years. It has been argued the extent of wildfire’s influence on population mobility was rare and operated mainly through the destruction of the built environment.<ref name=":6" /> Studies of the contiguous United States’ wildfires between 1999 and 2020, showed only extreme wildfires (those destroying 258+ structures) influenced migration patterns.<ref name=":6" /> It should be noted that from the same dataset, to reach the top 10% of most destructive fires required 14+ structures be destroyed.<ref name=":6" /> The authors of these findings assert most wildfires were less destructive and did not significantly alter in- or out-migration.<ref name=":6" /> Also note wildfire control strategies may continue to change and influence mobility indirectly. Wildfire-driven structure loss is on the rise, with a substantial number of the most extreme events being from recent years, which leads to an expectation of increased direct displacement in lieu of other remediation or adaptation efforts.<ref name=":6" />

==== Persistence ====
Studies have shown in-situ adaptation serves as a default response to wildfires, whether voluntary or implicit, and migration is seen as an act of last resort when other adaptation is no longer possible.<ref name=":9">{{Cite journal|last=Berlin Rubin|first=Nina|last2=Wong-Parodi|first2=Gabrielle|date=2022, August 24|title=As California burns: the psychology of wildfire- and wildfire smoke-related migration intentions|url=https://www.proquest.com/docview/2721075294?accountid=14656&pq-origsite=summon&sourcetype=Scholarly%20Journals#|journal=Population and Environment|volume=44|pages=15-45|via=Proquest}}</ref> Voluntary non-migration has been described by researcher Nick Tinoco as a collective community response to wildfires through the mobilization of resources for community self-reliance as a climate adaptation measure.<ref name=":7" /> People, when faced with increasing environmental risks, have been shown to develop explicit non-migration aspirations.<ref name=":6">{{Cite journal|last=McConnell|first=Kathryn|last2=Fussell|first2=Elizabeth|last3=DeWaard|first3=Jack|last4=Whitaker|first4=Stephan|last5=Curtis|first5=Katherine J|last6=St Denis|first6=Lise|last7=Balch|first7=Jennifer|last8=Price|first8=Kobie|date=2024, August 5|title=Rare and highly destructive wildfires drive human migration in the U.S.|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC11300458/|journal=Nature Communications|volume=15|via=PubMed Central}}</ref> For example, evidence of successful wildfire property defence was shown to inspire community members to plan to resist future evacuation to defend homes.<ref name=":7">{{Cite journal|last=Tinoco|first=Nick|date=2023, April 11|title=Post-disaster (im)mobility aspiration and capability formation: case study of Southern California wildfire|url=https://www.proquest.com/docview/2799289828?sourcetype=Scholarly%20Journals|journal=Population and Environment|volume=45|via=Proquest}}</ref> Tinoco also suggests this is a symptom of the erosion of trust in local institutions. It is also noted how community organizatios were more likely to consider tangible goals such as [https://en.wikipedia.org/wiki/Volunteer_fire_department volunteer fire brigades] over broader climate change strategies.<ref name=":7" /> On the other hand, the immobile group shows disparity in response to wildfires, along with other disasters.<ref name=":7" /> However, many adaptation opportunities are based on community wealth leading to an “immobility” in disadvantaged areas or areas affected by the destruction of wealth via property.<ref name=":7" /> There is a disparity in the response these communities can muster as they do not have the same resources to mobilize, leading to lower feelings of preparedness which has been shown to increase the likelihood of out-migration.<ref name=":7" /><ref name=":9" /> This, along with wildfires being considered a rare experience in aggregate across the continental United States, may explain the limited impact on net migration from non-extreme wildfires.<ref name=":6" />

== Solutions ==
==== Fire Management ====
Current forest management solutions have shown to be ineffective to prevent wildfires. Current practices that aggressively suppress any fire occurrence cause fuel buildup that increases fire severity. Management strategies that allow controlled fires to burn through built up fuel would reduce the severity of wildfires. Indigenous methods traditionally utilized fire to manage forest structures and fuels, however current management practices rarely utilize prescribed fire and continue to heavily favor traditional suppression practices. Fines, detainment, policies, and political attitudes towards fire also prevent the use of prescribed fire as a management strategy<ref>{{Cite web|last=Rodríguez|first=Iokiñe|last2=Inturias|first2=Mirna|last3=Masay|first3=Elmar|last4=Peña|first4=Anacleto|date=September, 2023|title=Decolonizing wildfire risk management: indigenous responses to fire criminalization policies and increasingly flammable forest landscapes in Lomerío, Bolivia|url=https://www.sciencedirect.com/science/article/pii/S1462901123001624|url-status=live|website=ScienceDirect}}</ref>. Should California begin to proactively utilize prescribed fire and other management techniques engineered to return its forests to a more native state, it would likely see a change in the frequency and severity of future fires.

==== Public Policy ====
It is also important to put efforts towards negating the harmful health effects caused by wildfires. Due to the large impact of smoke on human health<ref name=":10">{{Cite web|last=Edgeley|first=Catrin M.|last2=Burnett|first2=Jack T.|date=2025|title=Understanding rural adaptation to smoke from wildfires and forest management: insights for aligning approaches with community contexts|url=https://www.proquest.com/docview/3171408310?accountid=14656&pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>, smoke suppression tactics should be developed and implemented. Designing buildings to keep smoke outside can create areas of clean air to lower health impacts. It would also be important to create public spaces that give people without the means to evacuate a safe area without the risk of smoke inhalation. Knowing that there are structures in place to protect against wildfires would help people feel safer in their community, decreasing the incentive to migrate<ref name=":10" />.

==Conclusion==
Wildfire has a range of complex impacts on human out-migration from the state of California. Socio-economic factors such as negative experiences of friends and loved ones with fire, prior negative experiences such as evacuations or losing property, and level of infrastructure damage are all associated with out-migration following large fires, either as a direct response or as an influencing factor for future out-migration. As climate change continues to influence frequency of drought conditions and other climate and weather patterns in the state, the frequency and intensity of wildfires is expected to continue to rise and burn with less predictability. Continued use of fire suppression techniques and policy will likely also continue negatively affecting California’s forest structures, perpetuating the extreme buildup of understory fuels which leads to the transition of surface fires into massive crown fires, and of individual fires into fire complexes. Lack of predictability in how, when, and where these wildfires will spark may increase the likelihood of human communities being affected in ways that encourage out-migration.

==References==
<references />

{{Projectbox CONS200
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|share=no
}}

[[Category:Conservation]]

Course:CONS200/2025WT2/The effects of wildfires on outmigration in California

2025-04-12T05:10:51Z

JamesVanderBeek: Added image

As a result of [https://en.wikipedia.org/wiki/Climate_change climate change], the world has seen a significant increase in the frequency of extreme [https://en.wikipedia.org/wiki/Wildfire wildfires]. [https://en.wikipedia.org/wiki/California California] especially is a region that has been greatly impacted by severe wildfires. The damage caused by these fires damage infrastructure and cause health impacts to the people affected. 49% of residents reported being highly impacted by mandatory evacuations, 42% reported being impacted by poor air quality, and 61% reported being high to moderately impacted by power shutoffs.<ref>{{Cite journal|last=Howe|first=Alexander A|last2=Blomdahl|first2=Erika M|last3=Smith-Eskridge|first3=Ellie|last4=Pinto|first4=Dakoeta R|last5=Brunson|first5=Mark W|last6=Howe|first6=Peter D|last7=Huntly|first7=Nancy J|last8=Klain|first8=Sarah C|date=April 19, 2024|title=Worldviews more than experience predict Californians' support for wildfire risk mitigation policies|url=https://iopscience.iop.org/article/10.1088/1748-9326/ad3cf6|journal=Environmental Research Letters}}</ref> [https://en.wikipedia.org/wiki/Human_migration Out-migration], or the process of people permanently leaving an area in order to live somewhere else, can be affected by: an area’s perception as a ‘safe’ or ‘unsafe’ place, the actual severity and frequency of natural disasters, and the distribution and application of resources for disaster recovery.<ref>{{Cite journal|last=Lambrou|first=Nicole|last2=Kolden|first2=Crystal|last3=Loukaitou-Sideris|first3=Anastasia|date=February 15, 2025|title=Disaster recovery gentrification in post-wildfire landscapes: The case of Paradise, CA|url=https://www.sciencedirect.com/science/article/pii/S2212420925000597?via%3Dihub|journal=International Journal of Disaster Risk Reduction|via=}}</ref> The impacts of wildfires in California, and the perception of the state as a place where wildfires occur, may be impacting outmigration from the area. In recent years, the state has shown a relative increase in out-migration rates compared to the previous decade.<ref>Gabriel, S., Freyd, B., Brand, J., Fultz, N., & Tzen, M. (2005). Recent Trends in California Migration Evidence from the American Community Survey. https://www.universityofcalifornia.edu/sites/default/files/ucla-california-migration-report.pdf </ref> We will discuss if and how the mental and physical impacts of wildfires could be related to this increase.

==History==
[[File:NOAA Satellites Watch as California Burns (NESDIS 2020-10-01).gif|thumb|The [https://en.wikipedia.org/wiki/National_Oceanic_and_Atmospheric_Administration NOAA's] [https://en.wikipedia.org/wiki/Geostationary_Operational_Environmental_Satellite GOES-West satellite] capture of the August Complex fires and Glass fire in California's West Coast region, 2020.|337x337px]]California’s ecosystems are historically adapted to wildfire as a disturbance agent. Prior to establishment of the United States of America, fire was utilized as a tool to shape and maintain the landscape. The state of California has monitored wildfire activity since the early twentieth century, revealing patterns of increasing wildfire frequency and severity throughout the state. 19 of the 20 largest fires in the state’s history have occurred in the twenty-first century, and 13 of these 19 have occurred within the last decade (2015-2025).<ref>[https://34c031f8-c9fd-4018-8c5a-4159cdff6b0d-cdn-endpoint.azureedge.net/-/media/calfire-website/our-impact/fire-statistics/top-20-largest-ca-wildfires.pdf?rev=097f901c128347149e2614f2fca4f546&hash=27DDE83DFEF9A69E67C73765892A2B75 "Top 20 Largest California Wildfires"] </ref>

The state of California has historically used traditional fire suppression techniques within its semi-arid mixed conifer forests. Suppression allows for the accumulation of biomass as fuel beyond natural fire intervals (between 5-20 years), which in turn contributes to the increased risk of severe wildfire for these ecosystems. Long-term fire suppression encourages the development of atypical forest features, such as continuous closed canopies, establishment of shade-tolerant tree species, and buildup of understory fuels.<ref>{{Cite journal|last=Klimaszewski-Patterson|first=Anna|last2=Dingemans|first2=Theodore|last3=Morgan|first3=Christopher T|last4=Mensing|first4=Scott A|date=January 15, 2024|title=Human influence on late Holocene fire history in a mixed-conifer forest, Sierra National Forest, California|url=https://link.springer.com/article/10.1186/s42408-023-00245-9|journal=Fire Ecology}}</ref>

Recent shifts in climate have increased both the degree and frequency of drought experienced in California's ecosystems beyond historic norms, further contributing to fuel buildup and wildfire risk.

==Causes==
Wildfires have always been a part of forest ecosystems. Forests frequently experience small fires that cause stand regeneration, where plants at the forest floor are destroyed, adding nutrients to the forest floor and causing new growth that increases biodiversity. These can be caused by weather or climate conditions, as well as by humans using prescribed fires for forest management.<ref>{{Cite web|last=Mondal|first=Tamali|last2=Dasgupta|first2=Soumya|last3=Bhatt|first3=Dinesh Chandra|last4=Ramesh|first4=K.|date=March 20, 2024|title=Natural or man-made? Finding the drivers of forest fires within the protected area habitats: a case study from the lower Shivalik Landscape, Western Himalaya|url=https://link.springer.com/article/10.1007/s11069-024-06523-2|url-status=live|website=Springer Nature}}</ref> However, recent years have seen a sharp increase in occurrence of severe fires.<ref>{{Cite web|last=Brown|first=Patrick T|last2=Hanley|first2=Holt|last3=Mahesh|first3=Ankur|last4=Reed|first4=Colorado|last5=Strenfel|first5=Scott J|last6=Davis|first6=Steven J|last7=Kochanski|first7=Adam K|last8=Clements|first8=Craig B|date=2023, September 28|title=Climate warming increases extreme daily wildfire growth risk in California|url=https://www.proquest.com/docview/2871925930?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref> Climate change and human activities are the most highly attributed to this trend.

==== Climate ====
In recent years, the climate has become undeniably warmer. In the twenty-first century, global temperatures have risen between 0.6 to 0.7℃.<ref>{{Cite web|last=Cayan|first=Daniel R|last2=Maurer|first2=Edwin P|last3=Dettinger|first3=Michael D|last4=Tyree|first4=Mary|last5=Hayhoe|first5=Katharine|date=2008, January 26|title=Climate change scenarios for the California region|url=https://link.springer.com/article/10.1007/s10584-007-9377-6|url-status=live|website=Springer Nature}}</ref> In the United States, the time period from 1960 to 2013 was warmer than periods of comparable length from the past 600 years.<ref name=":1">{{Cite web|last=Garfin|first=Gregg|last2=Jardine|first2=Angela|last3=Merideth|first3=Robert|last4=Black|first4=Mary|last5=LeRoy|first5=Sarah|date=2013|title=Assessment of Climate Change in the Southwest United States|url=https://link.springer.com/book/10.5822/978-1-61091-484-0|url-status=live|website=Springer Nature}}</ref> This has been especially significant in the Southwest, which tends to be warmer than the rest of the United States.<ref name=":1" />

Temperature can be an important determinant in wildfire occurrence, affecting humidity and fuel sources. With the higher temperatures of recent years, air is able to hold more water, so as total moisture content remains the same, the relative humidity becomes lower. Precipitation has also decreased as a result of this increase in water storage capacity, leading to drought. The Santa Ana winds, hot and cold winds that flow over Southern California, can also contribute to these warming conditions. These winds are attributed to many extreme temperatures across Southern California. Hot winds, which though less severe than cold winds, can contribute to dry conditions that cause wildfires.<ref>{{Cite web|last=Gershunov|first=Alexander|last2=Guzman|first2=Morales Janin|last3=Hatchett|first3=Benjamin|last4=Guirguis|first4=Kristen|last5=Aguilera|first5=Rosana|last6=Shulgina|first6=Tamara|last7=Abatzoglou|first7=John T|last8=Cayan|first8=Daniel|last9=Pierce|first9=David|authors=Williams, Park; Small Ivory; Clemesha, Rachel; Schwarz, Lara; Benmarhnia, Tarik; Tardy, Alex|date=2021, October|title=Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire|url=https://www.proquest.com/docview/2573150518/abstract?accountid=14656&scrollToView=Author&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref> These conditions cause fuel such as wood debris on the forest floor to lose more moisture. Combined with the preexisting dry conditions, it leads to larger and more frequent wildfires.<ref>{{Cite web|last=Varga|first=Kevin|last2=Jones|first2=Charles|last3=Trugman|first3=Anna|last4=Carvalho|first4=Leila M V|last5=McLoughlin|first5=Neal|last6=Seto|first6=Daisuke|last7=Thompson|first7=Callum|last8=Daum|first8=Kristofer|date=2022|title=Megafires in a Warming World: What Wildfire Risk Factors Led to California’s Largest Recorded Wildfire|url=https://www.proquest.com/docview/2632816567?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>

==== Human Activity ====
While climate plays a part in causing wildfires, the recent increase in wildfires can be highly attributed to human activities. From 1992 to 2012, humans could be connected to 84% of fires across the United States.<ref name=":2">{{Cite web|last=Balch|first=Jennifer K|last2=Bradley|first2=Bethany A|last3=Abatzoglou|first3=John T|last4=Nagy|first4=R Chelsea|last5=Fusco|first5=Emily J|last6=Mahood|first6=Adam L|date=2017, February 27|title=Human-started wildfires expand the fire niche across the United States|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC5358354/|url-status=live|website=PubMed Central}}</ref> Human development introduces sources of ignition to the environment, which combined with dry fuels, creates severe wildfires. Proximity to roads and boundaries between wilderness and human developed areas have both been attributed to higher rates of wildfire occurrence.<ref name=":2" />

Current wildfire management practices aim to suppress all forest fires, regardless of severity. There is evidence that fires are actually an important disturbance event for forests that increases biodiversity and resilience.<ref>{{Cite web|date=2023, December 25|title=Twenty-year study confirms California forests are healthier when burned - or thinned|url=https://go.exlibris.link/q3XqDwBJ|url-status=live|website=Factiva}}</ref> Small fires create vertical and horizontal diversity in forests, allowing for fire resilience as some species are more tolerant of fire than others. This also creates gaps in fuel distribution that deter larger fires from occurring. Without this, forests become homogeneous, and fuel builds up rather than being periodically consumed. This leads to more wildfires at higher severities.<ref name=":3">{{Cite web|last=Koontz|first=Michael J|last2=North|first2=Malcolm P|last3=Werner|first3=Chhaya M|last4=Fick|first4=Stephen E|last5=Latimer|first5=Andrew M|date=2020, January 10|title=Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13447|url-status=live|website=Wiley Online Library}}</ref> This creates a feedback loop where, as fires get more severe, forests are no longer gaining biodiversity through small disturbances. Instead, when all vegetation is destroyed in a large fire, biodiversity is reduced and makes forest ecosystems more vulnerable.<ref name=":3" />

==Impacts==
[[File:Destroyed home and vehicle caused by the Eaton Fire, 2025.jpg|thumb|296x296px|Destroyed home and vehicle caused by the Eaton Fire, 2025]]

==== '''Economic Impact''' ====
Wildfires have caused a significant amount of economic damage in California. These types of damages include property damage, capital loss, and wage loss. The January 2025 wildfires of Southern California caused significant amounts of financial damage. The fires caused property damages and capital loss that range from 76 billion USD to 131 billion USD.<ref name=":0">{{Cite web|last=Li|first=Zhiyun|last2=Yu|first2=William|date=2025, March 7|title=Economic impact of the Los Angeles wildfires|url=https://www.anderson.ucla.edu/about/centers/ucla-anderson-forecast/economic-impact-los-angeles-wildfires|url-status=live|website=UCLA Anderson School of Management}}</ref> These damages mainly comes from the 16,251 homes, properties, and structures destroyed in the fire.<ref name=":0" /> The amount also includes damage to other belongings such as automobiles.

Additionally, business and employees of affected areas suffered an additional 297 million USD in lost wages.<ref name=":0" /> The fire is also expected to cause a 0.48% loss in county GDP, leading to an approximate 4.6 billion USD in further economic damage.<ref name=":0" /> Wildfires are expected to become more prevalent as climate change worsens. Examples of other devastating fires in California include the Tubbs wildfire of 2018 and the Camp wildfire of 2017.<ref name=":0" /> The Tubbs wildfire caused 8.76 billion USD in insurance claims, and the Camp wildfire caused 8.26 billion USD in insurance claims.<ref name=":0" />

==== '''Social Impact''' ====
Wildfires have had a significant impact on the Californian society. For one, wildfires have lead to higher living costs for the Californian populace. Wildfires have led to higher housing costs, as well as growing insurance premiums.<ref name=":0" /> Low-income communities tend to suffer greater consequences from wildfires. These communities tend to lack the savings and adequate insurance needed to recover from the disaster.<ref name=":5" /> This is one of the reasons why wildfires can exacerbate homelessness.<ref name=":5" />

Furthermore, low-income communities are also more likely to not have sufficient preventative measures. This makes their properties 29% more likely to be destroyed by wildfires than those that have such measures installed. An example of such preventative measures is roof renewals, with a roof renewal, the risk of a property being destroyed by wildfires can be reduced by up to 27%.<ref name=":5">{{Cite journal|last=Reining|first=Sebastian|last2=Wussow|first2=Moritz|last3=Zanocco|first3=Chad|last4=Neumann|first4=Dirk|date=07 January 2025|title=Roof renewal disparities widen the equity gap in residential wildfire protection|url=https://www.nature.com/articles/s41467-024-55705-w|journal=Nature Communications}}</ref> As such, while wildfires negatively affect the entire population, it is much worse for low-income communities. Wildfires have also had major health implications for the Californian populace. Smoke from wildfires carries fine, often toxic, particulate matter, which damages the lungs of the inhaler.<ref name=":4">{{Cite web|date=30 Jan 2025|title=Health Affects Attributed to Wildfire Smoke|url=https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke|url-status=live|website=United States Environmental Protection Agency}}</ref> This can result in a reduction in the ability to expel foreign objects, such as virus and bacteria, from the lungs. Inhaling these particles can also exacerbate existing respiratory diseases, as well as premature mortality.<ref name=":4" />

== Human Mobility ==

==== Out-migration ====
The term out-migration (also written as outmigration or out migration) is used to categorize the number of residents of an area who then leave for another area. Out-migration within the context of wildfires, then, refers only to how wildfires (and their effects) push people away from where they have settled. Out-migration is not to be confused with a decrease to in-migration, which represents the number of people settling an area. Additionally, in-migration is not to be confused with immigration, which refers to settlement within a new country. The sum of in-migration minus out-migration results in the net migration for a region. A positive net migration means more people are settling in a region while a negative number means more people are leaving the region for another. Literature on the effects environmental hazards have on human mobility vary widely and migration driven by the interaction between climatic and non-climatic elements is not entirely transparent.<ref name=":6" /><ref name=":7" /> However, existing studies agree wildfires do influence out-migration, along with in-migration.<ref name=":6" /><ref name=":8" /><ref name=":9" /> The predicted and observed severity of wildfires has continued to grow in recent decades at the same time as the populations of high-risk regions have increased<ref name=":6" /> with an estimate of 1.2 million people [https://en.wikipedia.org/wiki/Climate_migration displaced] by wildfires globally in 2020, and more affected by smoke which may travel hundreds of miles from its origin.<ref name=":9" />

In a representative survey following the 2020 fire season, 1/12 of the 1,108 California respondents reported they intended to move within 5 years, and this decision was at least moderately impacted by wildfires and smoke.<ref name=":9" /> The 2020 California survey reported 73.8% of respondents had prolonged exposure to wildfire smoke, 55.7% had at least one negative experience during the 2020 wildfire season, and 28.4% indicated they know someone who was harmed.<ref name=":9" /> It was also found that prior negative outcomes, such as evacuations and losing property, were associated with intentions to migrate, while for those intending to remain prior wildfire experiences negatively affected their residency satisfaction and therefore might influence future out-migration.<ref name=":9" /> Another study estimates for each additional 10 days reaching 90 degrees above the average number of extreme heat days, net migrants were reduced by 4 per 10,000 starting population.<ref name=":8">{{Cite journal|last=Winkler|first=Richelle L|last2=Rouleau|first2=Mark D|date=2020, September 30|title=Amenities or disamenities? Estimating the impacts of extreme heat and wildfire on domestic US migration|url=https://www.proquest.com/docview/2541128629?sourcetype=Scholarly%20Journals|journal=Population and Environment|volume=42|pages=622-648|via=Proquest}}</ref> [https://en.wikipedia.org/wiki/County_(United_States) Counties] that experienced a fire had a reduction of 32 net migrants per 10,000 starting population compared to those that did not experience or have a neighbour that experienced a fire in the previous year. Counties neighbouring those that experienced a fire saw a net decrease of 18 migrants per 10,000 starting population when compared to those with no fire (self or near) the previous year. It was also found that a fire disaster declared by [https://en.wikipedia.org/wiki/Federal_Emergency_Management_Agency FEMA] had a net migration impact on par with losing 47 jobs.<ref name=":8" />

Generally, sources agree counties with disaster-level fires or extreme heat in the year prior had increased out-migration and lower in-migration.<ref name=":6" /><ref name=":7" /><ref name=":8" /><ref name=":9" /> While human migration patterns are undeniably influenced by wildfires in the short term, particularly in counties that tend to attract migrants for environmental amenities and outdoor recreation,<ref name=":8" /> long-term trends are elusive.<ref name=":6" /> For example, only 6% of those displaced by the [https://en.wikipedia.org/wiki/October_2017_Northern_California_wildfires 2017 Sonoma County fires] left the county within a year<ref name=":9" /> while the deadly [https://en.wikipedia.org/wiki/Camp_Fire_(2018) 2018 Camp Fire] resulted in elevated out-migration for the following two years. It has been argued the extent of wildfire’s influence on population mobility was rare and operated mainly through the destruction of the built environment.<ref name=":6" /> Studies of the contiguous United States’ wildfires between 1999 and 2020, showed only extreme wildfires (those destroying 258+ structures) influenced migration patterns.<ref name=":6" /> It should be noted that from the same dataset, to reach the top 10% of most destructive fires required 14+ structures be destroyed.<ref name=":6" /> The authors of these findings assert most wildfires were less destructive and did not significantly alter in- or out-migration.<ref name=":6" /> Also note wildfire control strategies may continue to change and influence mobility indirectly. Wildfire-driven structure loss is on the rise, with a substantial number of the most extreme events being from recent years, which leads to an expectation of increased direct displacement in lieu of other remediation or adaptation efforts.<ref name=":6" />

==== Persistence ====
Studies have shown in-situ adaptation serves as a default response to wildfires, whether voluntary or implicit, and migration is seen as an act of last resort when other adaptation is no longer possible.<ref name=":9">{{Cite journal|last=Berlin Rubin|first=Nina|last2=Wong-Parodi|first2=Gabrielle|date=2022, August 24|title=As California burns: the psychology of wildfire- and wildfire smoke-related migration intentions|url=https://www.proquest.com/docview/2721075294?accountid=14656&pq-origsite=summon&sourcetype=Scholarly%20Journals#|journal=Population and Environment|volume=44|pages=15-45|via=Proquest}}</ref> Voluntary non-migration has been described by researcher Nick Tinoco as a collective community response to wildfires through the mobilization of resources for community self-reliance as a climate adaptation measure.<ref name=":7" /> People, when faced with increasing environmental risks, have been shown to develop explicit non-migration aspirations.<ref name=":6">{{Cite journal|last=McConnell|first=Kathryn|last2=Fussell|first2=Elizabeth|last3=DeWaard|first3=Jack|last4=Whitaker|first4=Stephan|last5=Curtis|first5=Katherine J|last6=St Denis|first6=Lise|last7=Balch|first7=Jennifer|last8=Price|first8=Kobie|date=2024, August 5|title=Rare and highly destructive wildfires drive human migration in the U.S.|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC11300458/|journal=Nature Communications|volume=15|via=PubMed Central}}</ref> For example, evidence of successful wildfire property defence was shown to inspire community members to plan to resist future evacuation to defend homes.<ref name=":7">{{Cite journal|last=Tinoco|first=Nick|date=2023, April 11|title=Post-disaster (im)mobility aspiration and capability formation: case study of Southern California wildfire|url=https://www.proquest.com/docview/2799289828?sourcetype=Scholarly%20Journals|journal=Population and Environment|volume=45|via=Proquest}}</ref> Tinoco also suggests this is a symptom of the erosion of trust in local institutions. It is also noted how community organizatios were more likely to consider tangible goals such as [https://en.wikipedia.org/wiki/Volunteer_fire_department volunteer fire brigades] over broader climate change strategies.<ref name=":7" /> On the other hand, the immobile group shows disparity in response to wildfires, along with other disasters.<ref name=":7" /> However, many adaptation opportunities are based on community wealth leading to an “immobility” in disadvantaged areas or areas affected by the destruction of wealth via property.<ref name=":7" /> There is a disparity in the response these communities can muster as they do not have the same resources to mobilize, leading to lower feelings of preparedness which has been shown to increase the likelihood of out-migration.<ref name=":7" /><ref name=":9" /> This, along with wildfires being considered a rare experience in aggregate across the continental United States, may explain the limited impact on net migration from non-extreme wildfires.<ref name=":6" />

== Solutions ==
==== Fire Management ====
Current forest management solutions have shown to be ineffective to prevent wildfires. Current practices that aggressively suppress any fire occurrence cause fuel buildup that increases fire severity. Management strategies that allow controlled fires to burn through built up fuel would reduce the severity of wildfires. Indigenous methods traditionally utilized fire to manage forest structures and fuels, however current management practices rarely utilize prescribed fire and continue to heavily favor traditional suppression practices. Fines, detainment, policies, and political attitudes towards fire also prevent the use of prescribed fire as a management strategy<ref>{{Cite web|last=Rodríguez|first=Iokiñe|last2=Inturias|first2=Mirna|last3=Masay|first3=Elmar|last4=Peña|first4=Anacleto|date=September, 2023|title=Decolonizing wildfire risk management: indigenous responses to fire criminalization policies and increasingly flammable forest landscapes in Lomerío, Bolivia|url=https://www.sciencedirect.com/science/article/pii/S1462901123001624|url-status=live|website=ScienceDirect}}</ref>. Should California begin to proactively utilize prescribed fire and other management techniques engineered to return its forests to a more native state, it would likely see a change in the frequency and severity of future fires.

==== Public Policy ====
It is also important to put efforts towards negating the harmful health effects caused by wildfires. Due to the large impact of smoke on human health<ref name=":10">{{Cite web|last=Edgeley|first=Catrin M.|last2=Burnett|first2=Jack T.|date=2025|title=Understanding rural adaptation to smoke from wildfires and forest management: insights for aligning approaches with community contexts|url=https://www.proquest.com/docview/3171408310?accountid=14656&pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>, smoke suppression tactics should be developed and implemented. Designing buildings to keep smoke outside can create areas of clean air to lower health impacts. It would also be important to create public spaces that give people without the means to evacuate a safe area without the risk of smoke inhalation. Knowing that there are structures in place to protect against wildfires would help people feel safer in their community, decreasing the incentive to migrate<ref name=":10" />.

==Conclusion==
Wildfire has a range of complex impacts on human out-migration from the state of California. Socio-economic factors such as negative experiences of friends and loved ones with fire, prior negative experiences such as evacuations or losing property, and level of infrastructure damage are all associated with out-migration following large fires, either as a direct response or as an influencing factor for future out-migration. As climate change continues to influence frequency of drought conditions and other climate and weather patterns in the state, the frequency and intensity of wildfires is expected to continue to rise and burn with less predictability. Continued use of fire suppression techniques and policy will likely also continue negatively affecting California’s forest structures, perpetuating the extreme buildup of understory fuels which leads to the transition of surface fires into massive crown fires, and of individual fires into fire complexes. Lack of predictability in how, when, and where these wildfires will spark may increase the likelihood of human communities being affected in ways that encourage out-migration.

==References==
<references />

{{Projectbox CONS200
|names=
|share=no
}}

[[Category:Conservation]]

Course:CONS200/2025WT2/The effects of wildfires on outmigration in California

2025-04-12T05:05:27Z

JamesVanderBeek: /* Solutions */

As a result of [https://en.wikipedia.org/wiki/Climate_change climate change], the world has seen a significant increase in the frequency of extreme [https://en.wikipedia.org/wiki/Wildfire wildfires]. [https://en.wikipedia.org/wiki/California California] especially is a region that has been greatly impacted by severe wildfires. The damage caused by these fires damage infrastructure and cause health impacts to the people affected. 49% of residents reported being highly impacted by mandatory evacuations, 42% reported being impacted by poor air quality, and 61% reported being high to moderately impacted by power shutoffs.<ref>{{Cite journal|last=Howe|first=Alexander A|last2=Blomdahl|first2=Erika M|last3=Smith-Eskridge|first3=Ellie|last4=Pinto|first4=Dakoeta R|last5=Brunson|first5=Mark W|last6=Howe|first6=Peter D|last7=Huntly|first7=Nancy J|last8=Klain|first8=Sarah C|date=April 19, 2024|title=Worldviews more than experience predict Californians' support for wildfire risk mitigation policies|url=https://iopscience.iop.org/article/10.1088/1748-9326/ad3cf6|journal=Environmental Research Letters}}</ref> [https://en.wikipedia.org/wiki/Human_migration Out-migration], or the process of people permanently leaving an area in order to live somewhere else, can be affected by: an area’s perception as a ‘safe’ or ‘unsafe’ place, the actual severity and frequency of natural disasters, and the distribution and application of resources for disaster recovery.<ref>{{Cite journal|last=Lambrou|first=Nicole|last2=Kolden|first2=Crystal|last3=Loukaitou-Sideris|first3=Anastasia|date=February 15, 2025|title=Disaster recovery gentrification in post-wildfire landscapes: The case of Paradise, CA|url=https://www.sciencedirect.com/science/article/pii/S2212420925000597?via%3Dihub|journal=International Journal of Disaster Risk Reduction|via=}}</ref> The impacts of wildfires in California, and the perception of the state as a place where wildfires occur, may be impacting outmigration from the area. In recent years, the state has shown a relative increase in out-migration rates compared to the previous decade.<ref>Gabriel, S., Freyd, B., Brand, J., Fultz, N., & Tzen, M. (2005). Recent Trends in California Migration Evidence from the American Community Survey. https://www.universityofcalifornia.edu/sites/default/files/ucla-california-migration-report.pdf </ref> We will discuss if and how the mental and physical impacts of wildfires could be related to this increase.

==History==
[[File:NOAA Satellites Watch as California Burns (NESDIS 2020-10-01).gif|thumb|The [https://en.wikipedia.org/wiki/National_Oceanic_and_Atmospheric_Administration NOAA's] [https://en.wikipedia.org/wiki/Geostationary_Operational_Environmental_Satellite GOES-West satellite] capture of the August Complex fires and Glass fire in California's West Coast region, 2020.]]California’s ecosystems are historically adapted to wildfire as a disturbance agent. Prior to establishment of the United States of America, fire was utilized as a tool to shape and maintain the landscape. The state of California has monitored wildfire activity since the early twentieth century, revealing patterns of increasing wildfire frequency and severity throughout the state. 19 of the 20 largest fires in the state’s history have occurred in the twenty-first century, and 13 of these 19 have occurred within the last decade (2015-2025).<ref>[https://34c031f8-c9fd-4018-8c5a-4159cdff6b0d-cdn-endpoint.azureedge.net/-/media/calfire-website/our-impact/fire-statistics/top-20-largest-ca-wildfires.pdf?rev=097f901c128347149e2614f2fca4f546&hash=27DDE83DFEF9A69E67C73765892A2B75 "Top 20 Largest California Wildfires"] </ref>

The state of California has historically used traditional fire suppression techniques within its semi-arid mixed conifer forests. Suppression allows for the accumulation of biomass as fuel beyond natural fire intervals (between 5-20 years), which in turn contributes to the increased risk of severe wildfire for these ecosystems. Long-term fire suppression encourages the development of atypical forest features, such as continuous closed canopies, establishment of shade-tolerant tree species, and buildup of understory fuels.<ref>{{Cite journal|last=Klimaszewski-Patterson|first=Anna|last2=Dingemans|first2=Theodore|last3=Morgan|first3=Christopher T|last4=Mensing|first4=Scott A|date=January 15, 2024|title=Human influence on late Holocene fire history in a mixed-conifer forest, Sierra National Forest, California|url=https://link.springer.com/article/10.1186/s42408-023-00245-9|journal=Fire Ecology}}</ref>

Recent shifts in climate have increased both the degree and frequency of drought experienced in California's ecosystems beyond historic norms, further contributing to fuel buildup and wildfire risk.

==Causes==
Wildfires have always been a part of forest ecosystems. Forests frequently experience small fires that cause stand regeneration, where plants at the forest floor are destroyed, adding nutrients to the forest floor and causing new growth that increases biodiversity. These can be caused by weather or climate conditions, as well as by humans using prescribed fires for forest management.<ref>{{Cite web|last=Mondal|first=Tamali|last2=Dasgupta|first2=Soumya|last3=Bhatt|first3=Dinesh Chandra|last4=Ramesh|first4=K.|date=March 20, 2024|title=Natural or man-made? Finding the drivers of forest fires within the protected area habitats: a case study from the lower Shivalik Landscape, Western Himalaya|url=https://link.springer.com/article/10.1007/s11069-024-06523-2|url-status=live|website=Springer Nature}}</ref> However, recent years have seen a sharp increase in occurrence of severe fires.<ref>{{Cite web|last=Brown|first=Patrick T|last2=Hanley|first2=Holt|last3=Mahesh|first3=Ankur|last4=Reed|first4=Colorado|last5=Strenfel|first5=Scott J|last6=Davis|first6=Steven J|last7=Kochanski|first7=Adam K|last8=Clements|first8=Craig B|date=2023, September 28|title=Climate warming increases extreme daily wildfire growth risk in California|url=https://www.proquest.com/docview/2871925930?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref> Climate change and human activities are the most highly attributed to this trend.

==== Climate ====
In recent years, the climate has become undeniably warmer. In the twenty-first century, global temperatures have risen between 0.6 to 0.7℃.<ref>{{Cite web|last=Cayan|first=Daniel R|last2=Maurer|first2=Edwin P|last3=Dettinger|first3=Michael D|last4=Tyree|first4=Mary|last5=Hayhoe|first5=Katharine|date=2008, January 26|title=Climate change scenarios for the California region|url=https://link.springer.com/article/10.1007/s10584-007-9377-6|url-status=live|website=Springer Nature}}</ref> In the United States, the time period from 1960 to 2013 was warmer than periods of comparable length from the past 600 years.<ref name=":1">{{Cite web|last=Garfin|first=Gregg|last2=Jardine|first2=Angela|last3=Merideth|first3=Robert|last4=Black|first4=Mary|last5=LeRoy|first5=Sarah|date=2013|title=Assessment of Climate Change in the Southwest United States|url=https://link.springer.com/book/10.5822/978-1-61091-484-0|url-status=live|website=Springer Nature}}</ref> This has been especially significant in the Southwest, which tends to be warmer than the rest of the United States.<ref name=":1" />

Temperature can be an important determinant in wildfire occurrence, affecting humidity and fuel sources. With the higher temperatures of recent years, air is able to hold more water, so as total moisture content remains the same, the relative humidity becomes lower. Precipitation has also decreased as a result of this increase in water storage capacity, leading to drought. The Santa Ana winds, hot and cold winds that flow over Southern California, can also contribute to these warming conditions. These winds are attributed to many extreme temperatures across Southern California. Hot winds, which though less severe than cold winds, can contribute to dry conditions that cause wildfires.<ref>{{Cite web|last=Gershunov|first=Alexander|last2=Guzman|first2=Morales Janin|last3=Hatchett|first3=Benjamin|last4=Guirguis|first4=Kristen|last5=Aguilera|first5=Rosana|last6=Shulgina|first6=Tamara|last7=Abatzoglou|first7=John T|last8=Cayan|first8=Daniel|last9=Pierce|first9=David|authors=Williams, Park; Small Ivory; Clemesha, Rachel; Schwarz, Lara; Benmarhnia, Tarik; Tardy, Alex|date=2021, October|title=Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire|url=https://www.proquest.com/docview/2573150518/abstract?accountid=14656&scrollToView=Author&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref> These conditions cause fuel such as wood debris on the forest floor to lose more moisture. Combined with the preexisting dry conditions, it leads to larger and more frequent wildfires.<ref>{{Cite web|last=Varga|first=Kevin|last2=Jones|first2=Charles|last3=Trugman|first3=Anna|last4=Carvalho|first4=Leila M V|last5=McLoughlin|first5=Neal|last6=Seto|first6=Daisuke|last7=Thompson|first7=Callum|last8=Daum|first8=Kristofer|date=2022|title=Megafires in a Warming World: What Wildfire Risk Factors Led to California’s Largest Recorded Wildfire|url=https://www.proquest.com/docview/2632816567?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>

==== Human Activity ====
While climate plays a part in causing wildfires, the recent increase in wildfires can be highly attributed to human activities. From 1992 to 2012, humans could be connected to 84% of fires across the United States.<ref name=":2">{{Cite web|last=Balch|first=Jennifer K|last2=Bradley|first2=Bethany A|last3=Abatzoglou|first3=John T|last4=Nagy|first4=R Chelsea|last5=Fusco|first5=Emily J|last6=Mahood|first6=Adam L|date=2017, February 27|title=Human-started wildfires expand the fire niche across the United States|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC5358354/|url-status=live|website=PubMed Central}}</ref> Human development introduces sources of ignition to the environment, which combined with dry fuels, creates severe wildfires. Proximity to roads and boundaries between wilderness and human developed areas have both been attributed to higher rates of wildfire occurrence.<ref name=":2" />

Current wildfire management practices aim to suppress all forest fires, regardless of severity. There is evidence that fires are actually an important disturbance event for forests that increases biodiversity and resilience.<ref>{{Cite web|date=2023, December 25|title=Twenty-year study confirms California forests are healthier when burned - or thinned|url=https://go.exlibris.link/q3XqDwBJ|url-status=live|website=Factiva}}</ref> Small fires create vertical and horizontal diversity in forests, allowing for fire resilience as some species are more tolerant of fire than others. This also creates gaps in fuel distribution that deter larger fires from occurring. Without this, forests become homogeneous, and fuel builds up rather than being periodically consumed. This leads to more wildfires at higher severities.<ref name=":3">{{Cite web|last=Koontz|first=Michael J|last2=North|first2=Malcolm P|last3=Werner|first3=Chhaya M|last4=Fick|first4=Stephen E|last5=Latimer|first5=Andrew M|date=2020, January 10|title=Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13447|url-status=live|website=Wiley Online Library}}</ref> This creates a feedback loop where, as fires get more severe, forests are no longer gaining biodiversity through small disturbances. Instead, when all vegetation is destroyed in a large fire, biodiversity is reduced and makes forest ecosystems more vulnerable.<ref name=":3" />

==Impacts==

==== '''Economic Impact''' ====
Wildfires have caused a significant amount of economic damage in California. These types of damages include property damage, capital loss, and wage loss. The January 2025 wildfires of Southern California caused significant amounts of financial damage. The fires caused property damages and capital loss that range from 76 billion USD to 131 billion USD.<ref name=":0">{{Cite web|last=Li|first=Zhiyun|last2=Yu|first2=William|date=2025, March 7|title=Economic impact of the Los Angeles wildfires|url=https://www.anderson.ucla.edu/about/centers/ucla-anderson-forecast/economic-impact-los-angeles-wildfires|url-status=live|website=UCLA Anderson School of Management}}</ref> These damages mainly comes from the 16,251 homes, properties, and structures destroyed in the fire.<ref name=":0" /> The amount also includes damage to other belongings such as automobiles.

Additionally, business and employees of affected areas suffered an additional 297 million USD in lost wages.<ref name=":0" /> The fire is also expected to cause a 0.48% loss in county GDP, leading to an approximate 4.6 billion USD in further economic damage.<ref name=":0" /> Wildfires are expected to become more prevalent as climate change worsens. Examples of other devastating fires in California include the Tubbs wildfire of 2018 and the Camp wildfire of 2017.<ref name=":0" /> The Tubbs wildfire caused 8.76 billion USD in insurance claims, and the Camp wildfire caused 8.26 billion USD in insurance claims.<ref name=":0" />

==== '''Social Impact''' ====
Wildfires have had a significant impact on the Californian society. For one, wildfires have lead to higher living costs for the Californian populace. Wildfires have led to higher housing costs, as well as growing insurance premiums.<ref name=":0" /> Low-income communities tend to suffer greater consequences from wildfires. These communities tend to lack the savings and adequate insurance needed to recover from the disaster.<ref name=":5" /> This is one of the reasons why wildfires can exacerbate homelessness.<ref name=":5" />

Furthermore, low-income communities are also more likely to not have sufficient preventative measures. This makes their properties 29% more likely to be destroyed by wildfires than those that have such measures installed. An example of such preventative measures is roof renewals, with a roof renewal, the risk of a property being destroyed by wildfires can be reduced by up to 27%.<ref name=":5">{{Cite journal|last=Reining|first=Sebastian|last2=Wussow|first2=Moritz|last3=Zanocco|first3=Chad|last4=Neumann|first4=Dirk|date=07 January 2025|title=Roof renewal disparities widen the equity gap in residential wildfire protection|url=https://www.nature.com/articles/s41467-024-55705-w|journal=Nature Communications}}</ref> As such, while wildfires negatively affect the entire population, it is much worse for low-income communities. Wildfires have also had major health implications for the Californian populace. Smoke from wildfires carries fine, often toxic, particulate matter, which damages the lungs of the inhaler.<ref name=":4">{{Cite web|date=30 Jan 2025|title=Health Affects Attributed to Wildfire Smoke|url=https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke|url-status=live|website=United States Environmental Protection Agency}}</ref> This can result in a reduction in the ability to expel foreign objects, such as virus and bacteria, from the lungs. Inhaling these particles can also exacerbate existing respiratory diseases, as well as premature mortality.<ref name=":4" />

== Human Mobility ==

==== Out-migration ====
The term out-migration (also written as outmigration or out migration) is used to categorize the number of residents of an area who then leave for another area. Out-migration within the context of wildfires, then, refers only to how wildfires (and their effects) push people away from where they have settled. Out-migration is not to be confused with a decrease to in-migration, which represents the number of people settling an area. Additionally, in-migration is not to be confused with immigration, which refers to settlement within a new country. The sum of in-migration minus out-migration results in the net migration for a region. A positive net migration means more people are settling in a region while a negative number means more people are leaving the region for another. Literature on the effects environmental hazards have on human mobility vary widely and migration driven by the interaction between climatic and non-climatic elements is not entirely transparent.<ref name=":6" /><ref name=":7" /> However, existing studies agree wildfires do influence out-migration, along with in-migration.<ref name=":6" /><ref name=":8" /><ref name=":9" /> The predicted and observed severity of wildfires has continued to grow in recent decades at the same time as the populations of high-risk regions have increased<ref name=":6" /> with an estimate of 1.2 million people [https://en.wikipedia.org/wiki/Climate_migration displaced] by wildfires globally in 2020, and more affected by smoke which may travel hundreds of miles from its origin.<ref name=":9" />

In a representative survey following the 2020 fire season, 1/12 of the 1,108 California respondents reported they intended to move within 5 years, and this decision was at least moderately impacted by wildfires and smoke.<ref name=":9" /> The 2020 California survey reported 73.8% of respondents had prolonged exposure to wildfire smoke, 55.7% had at least one negative experience during the 2020 wildfire season, and 28.4% indicated they know someone who was harmed.<ref name=":9" /> It was also found that prior negative outcomes, such as evacuations and losing property, were associated with intentions to migrate, while for those intending to remain prior wildfire experiences negatively affected their residency satisfaction and therefore might influence future out-migration.<ref name=":9" /> Another study estimates for each additional 10 days reaching 90 degrees above the average number of extreme heat days, net migrants were reduced by 4 per 10,000 starting population.<ref name=":8">{{Cite journal|last=Winkler|first=Richelle L|last2=Rouleau|first2=Mark D|date=2020, September 30|title=Amenities or disamenities? Estimating the impacts of extreme heat and wildfire on domestic US migration|url=https://www.proquest.com/docview/2541128629?sourcetype=Scholarly%20Journals|journal=Population and Environment|volume=42|pages=622-648|via=Proquest}}</ref> [https://en.wikipedia.org/wiki/County_(United_States) Counties] that experienced a fire had a reduction of 32 net migrants per 10,000 starting population compared to those that did not experience or have a neighbour that experienced a fire in the previous year. Counties neighbouring those that experienced a fire saw a net decrease of 18 migrants per 10,000 starting population when compared to those with no fire (self or near) the previous year. It was also found that a fire disaster declared by [https://en.wikipedia.org/wiki/Federal_Emergency_Management_Agency FEMA] had a net migration impact on par with losing 47 jobs.<ref name=":8" />

Generally, sources agree counties with disaster-level fires or extreme heat in the year prior had increased out-migration and lower in-migration.<ref name=":6" /><ref name=":7" /><ref name=":8" /><ref name=":9" /> While human migration patterns are undeniably influenced by wildfires in the short term, particularly in counties that tend to attract migrants for environmental amenities and outdoor recreation,<ref name=":8" /> long-term trends are elusive.<ref name=":6" /> For example, only 6% of those displaced by the [https://en.wikipedia.org/wiki/October_2017_Northern_California_wildfires 2017 Sonoma County fires] left the county within a year<ref name=":9" /> while the deadly [https://en.wikipedia.org/wiki/Camp_Fire_(2018) 2018 Camp Fire] resulted in elevated out-migration for the following two years. It has been argued the extent of wildfire’s influence on population mobility was rare and operated mainly through the destruction of the built environment.<ref name=":6" /> Studies of the contiguous United States’ wildfires between 1999 and 2020, showed only extreme wildfires (those destroying 258+ structures) influenced migration patterns.<ref name=":6" /> It should be noted that from the same dataset, to reach the top 10% of most destructive fires required 14+ structures be destroyed.<ref name=":6" /> The authors of these findings assert most wildfires were less destructive and did not significantly alter in- or out-migration.<ref name=":6" /> Also note wildfire control strategies may continue to change and influence mobility indirectly. Wildfire-driven structure loss is on the rise, with a substantial number of the most extreme events being from recent years, which leads to an expectation of increased direct displacement in lieu of other remediation or adaptation efforts.<ref name=":6" />

==== Persistence ====
Studies have shown in-situ adaptation serves as a default response to wildfires, whether voluntary or implicit, and migration is seen as an act of last resort when other adaptation is no longer possible.<ref name=":9">{{Cite journal|last=Berlin Rubin|first=Nina|last2=Wong-Parodi|first2=Gabrielle|date=2022, August 24|title=As California burns: the psychology of wildfire- and wildfire smoke-related migration intentions|url=https://www.proquest.com/docview/2721075294?accountid=14656&pq-origsite=summon&sourcetype=Scholarly%20Journals#|journal=Population and Environment|volume=44|pages=15-45|via=Proquest}}</ref> Voluntary non-migration has been described by researcher Nick Tinoco as a collective community response to wildfires through the mobilization of resources for community self-reliance as a climate adaptation measure.<ref name=":7" /> People, when faced with increasing environmental risks, have been shown to develop explicit non-migration aspirations.<ref name=":6">{{Cite journal|last=McConnell|first=Kathryn|last2=Fussell|first2=Elizabeth|last3=DeWaard|first3=Jack|last4=Whitaker|first4=Stephan|last5=Curtis|first5=Katherine J|last6=St Denis|first6=Lise|last7=Balch|first7=Jennifer|last8=Price|first8=Kobie|date=2024, August 5|title=Rare and highly destructive wildfires drive human migration in the U.S.|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC11300458/|journal=Nature Communications|volume=15|via=PubMed Central}}</ref> For example, evidence of successful wildfire property defence was shown to inspire community members to plan to resist future evacuation to defend homes.<ref name=":7">{{Cite journal|last=Tinoco|first=Nick|date=2023, April 11|title=Post-disaster (im)mobility aspiration and capability formation: case study of Southern California wildfire|url=https://www.proquest.com/docview/2799289828?sourcetype=Scholarly%20Journals|journal=Population and Environment|volume=45|via=Proquest}}</ref> Tinoco also suggests this is a symptom of the erosion of trust in local institutions. It is also noted how community organizatios were more likely to consider tangible goals such as [https://en.wikipedia.org/wiki/Volunteer_fire_department volunteer fire brigades] over broader climate change strategies.<ref name=":7" /> On the other hand, the immobile group shows disparity in response to wildfires, along with other disasters.<ref name=":7" /> However, many adaptation opportunities are based on community wealth leading to an “immobility” in disadvantaged areas or areas affected by the destruction of wealth via property.<ref name=":7" /> There is a disparity in the response these communities can muster as they do not have the same resources to mobilize, leading to lower feelings of preparedness which has been shown to increase the likelihood of out-migration.<ref name=":7" /><ref name=":9" /> This, along with wildfires being considered a rare experience in aggregate across the continental United States, may explain the limited impact on net migration from non-extreme wildfires.<ref name=":6" />

== Solutions ==
==== Fire Management ====
Current forest management solutions have shown to be ineffective to prevent wildfires. Current practices that aggressively suppress any fire occurrence cause fuel buildup that increases fire severity. Management strategies that allow controlled fires to burn through built up fuel would reduce the severity of wildfires. Indigenous methods traditionally utilized fire to manage forest structures and fuels, however current management practices rarely utilize prescribed fire and continue to heavily favor traditional suppression practices. Fines, detainment, policies, and political attitudes towards fire also prevent the use of prescribed fire as a management strategy<ref>{{Cite web|last=Rodríguez|first=Iokiñe|last2=Inturias|first2=Mirna|last3=Masay|first3=Elmar|last4=Peña|first4=Anacleto|date=September, 2023|title=Decolonizing wildfire risk management: indigenous responses to fire criminalization policies and increasingly flammable forest landscapes in Lomerío, Bolivia|url=https://www.sciencedirect.com/science/article/pii/S1462901123001624|url-status=live|website=ScienceDirect}}</ref>. Should California begin to proactively utilize prescribed fire and other management techniques engineered to return its forests to a more native state, it would likely see a change in the frequency and severity of future fires.

==== Public Policy ====
It is also important to put efforts towards negating the harmful health effects caused by wildfires. Due to the large impact of smoke on human health<ref name=":10">{{Cite web|last=Edgeley|first=Catrin M.|last2=Burnett|first2=Jack T.|date=2025|title=Understanding rural adaptation to smoke from wildfires and forest management: insights for aligning approaches with community contexts|url=https://www.proquest.com/docview/3171408310?accountid=14656&pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>, smoke suppression tactics should be developed and implemented. Designing buildings to keep smoke outside can create areas of clean air to lower health impacts. It would also be important to create public spaces that give people without the means to evacuate a safe area without the risk of smoke inhalation. Knowing that there are structures in place to protect against wildfires would help people feel safer in their community, decreasing the incentive to migrate<ref name=":10" />.

==Conclusion==
Wildfire has a range of complex impacts on human out-migration from the state of California. Socio-economic factors such as negative experiences of friends and loved ones with fire, prior negative experiences such as evacuations or losing property, and level of infrastructure damage are all associated with out-migration following large fires, either as a direct response or as an influencing factor for future out-migration. As climate change continues to influence frequency of drought conditions and other climate and weather patterns in the state, the frequency and intensity of wildfires is expected to continue to rise and burn with less predictability. Continued use of fire suppression techniques and policy will likely also continue negatively affecting California’s forest structures, perpetuating the extreme buildup of understory fuels which leads to the transition of surface fires into massive crown fires, and of individual fires into fire complexes. Lack of predictability in how, when, and where these wildfires will spark may increase the likelihood of human communities being affected in ways that encourage out-migration.

==References==
<references />

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[[Category:Conservation]]

Course:CONS200/2025WT2/The effects of wildfires on outmigration in California

2025-04-12T05:04:32Z

JamesVanderBeek: /* Solutions */

As a result of [https://en.wikipedia.org/wiki/Climate_change climate change], the world has seen a significant increase in the frequency of extreme [https://en.wikipedia.org/wiki/Wildfire wildfires]. [https://en.wikipedia.org/wiki/California California] especially is a region that has been greatly impacted by severe wildfires. The damage caused by these fires damage infrastructure and cause health impacts to the people affected. 49% of residents reported being highly impacted by mandatory evacuations, 42% reported being impacted by poor air quality, and 61% reported being high to moderately impacted by power shutoffs.<ref>{{Cite journal|last=Howe|first=Alexander A|last2=Blomdahl|first2=Erika M|last3=Smith-Eskridge|first3=Ellie|last4=Pinto|first4=Dakoeta R|last5=Brunson|first5=Mark W|last6=Howe|first6=Peter D|last7=Huntly|first7=Nancy J|last8=Klain|first8=Sarah C|date=April 19, 2024|title=Worldviews more than experience predict Californians' support for wildfire risk mitigation policies|url=https://iopscience.iop.org/article/10.1088/1748-9326/ad3cf6|journal=Environmental Research Letters}}</ref> [https://en.wikipedia.org/wiki/Human_migration Out-migration], or the process of people permanently leaving an area in order to live somewhere else, can be affected by: an area’s perception as a ‘safe’ or ‘unsafe’ place, the actual severity and frequency of natural disasters, and the distribution and application of resources for disaster recovery.<ref>{{Cite journal|last=Lambrou|first=Nicole|last2=Kolden|first2=Crystal|last3=Loukaitou-Sideris|first3=Anastasia|date=February 15, 2025|title=Disaster recovery gentrification in post-wildfire landscapes: The case of Paradise, CA|url=https://www.sciencedirect.com/science/article/pii/S2212420925000597?via%3Dihub|journal=International Journal of Disaster Risk Reduction|via=}}</ref> The impacts of wildfires in California, and the perception of the state as a place where wildfires occur, may be impacting outmigration from the area. In recent years, the state has shown a relative increase in out-migration rates compared to the previous decade.<ref>Gabriel, S., Freyd, B., Brand, J., Fultz, N., & Tzen, M. (2005). Recent Trends in California Migration Evidence from the American Community Survey. https://www.universityofcalifornia.edu/sites/default/files/ucla-california-migration-report.pdf </ref> We will discuss if and how the mental and physical impacts of wildfires could be related to this increase.

==History==
[[File:NOAA Satellites Watch as California Burns (NESDIS 2020-10-01).gif|thumb|The [https://en.wikipedia.org/wiki/National_Oceanic_and_Atmospheric_Administration NOAA's] [https://en.wikipedia.org/wiki/Geostationary_Operational_Environmental_Satellite GOES-West satellite] capture of the August Complex fires and Glass fire in California's West Coast region, 2020.]]California’s ecosystems are historically adapted to wildfire as a disturbance agent. Prior to establishment of the United States of America, fire was utilized as a tool to shape and maintain the landscape. The state of California has monitored wildfire activity since the early twentieth century, revealing patterns of increasing wildfire frequency and severity throughout the state. 19 of the 20 largest fires in the state’s history have occurred in the twenty-first century, and 13 of these 19 have occurred within the last decade (2015-2025).<ref>[https://34c031f8-c9fd-4018-8c5a-4159cdff6b0d-cdn-endpoint.azureedge.net/-/media/calfire-website/our-impact/fire-statistics/top-20-largest-ca-wildfires.pdf?rev=097f901c128347149e2614f2fca4f546&hash=27DDE83DFEF9A69E67C73765892A2B75 "Top 20 Largest California Wildfires"] </ref>

The state of California has historically used traditional fire suppression techniques within its semi-arid mixed conifer forests. Suppression allows for the accumulation of biomass as fuel beyond natural fire intervals (between 5-20 years), which in turn contributes to the increased risk of severe wildfire for these ecosystems. Long-term fire suppression encourages the development of atypical forest features, such as continuous closed canopies, establishment of shade-tolerant tree species, and buildup of understory fuels.<ref>{{Cite journal|last=Klimaszewski-Patterson|first=Anna|last2=Dingemans|first2=Theodore|last3=Morgan|first3=Christopher T|last4=Mensing|first4=Scott A|date=January 15, 2024|title=Human influence on late Holocene fire history in a mixed-conifer forest, Sierra National Forest, California|url=https://link.springer.com/article/10.1186/s42408-023-00245-9|journal=Fire Ecology}}</ref>

Recent shifts in climate have increased both the degree and frequency of drought experienced in California's ecosystems beyond historic norms, further contributing to fuel buildup and wildfire risk.

==Causes==
Wildfires have always been a part of forest ecosystems. Forests frequently experience small fires that cause stand regeneration, where plants at the forest floor are destroyed, adding nutrients to the forest floor and causing new growth that increases biodiversity. These can be caused by weather or climate conditions, as well as by humans using prescribed fires for forest management.<ref>{{Cite web|last=Mondal|first=Tamali|last2=Dasgupta|first2=Soumya|last3=Bhatt|first3=Dinesh Chandra|last4=Ramesh|first4=K.|date=March 20, 2024|title=Natural or man-made? Finding the drivers of forest fires within the protected area habitats: a case study from the lower Shivalik Landscape, Western Himalaya|url=https://link.springer.com/article/10.1007/s11069-024-06523-2|url-status=live|website=Springer Nature}}</ref> However, recent years have seen a sharp increase in occurrence of severe fires.<ref>{{Cite web|last=Brown|first=Patrick T|last2=Hanley|first2=Holt|last3=Mahesh|first3=Ankur|last4=Reed|first4=Colorado|last5=Strenfel|first5=Scott J|last6=Davis|first6=Steven J|last7=Kochanski|first7=Adam K|last8=Clements|first8=Craig B|date=2023, September 28|title=Climate warming increases extreme daily wildfire growth risk in California|url=https://www.proquest.com/docview/2871925930?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref> Climate change and human activities are the most highly attributed to this trend.

==== Climate ====
In recent years, the climate has become undeniably warmer. In the twenty-first century, global temperatures have risen between 0.6 to 0.7℃.<ref>{{Cite web|last=Cayan|first=Daniel R|last2=Maurer|first2=Edwin P|last3=Dettinger|first3=Michael D|last4=Tyree|first4=Mary|last5=Hayhoe|first5=Katharine|date=2008, January 26|title=Climate change scenarios for the California region|url=https://link.springer.com/article/10.1007/s10584-007-9377-6|url-status=live|website=Springer Nature}}</ref> In the United States, the time period from 1960 to 2013 was warmer than periods of comparable length from the past 600 years.<ref name=":1">{{Cite web|last=Garfin|first=Gregg|last2=Jardine|first2=Angela|last3=Merideth|first3=Robert|last4=Black|first4=Mary|last5=LeRoy|first5=Sarah|date=2013|title=Assessment of Climate Change in the Southwest United States|url=https://link.springer.com/book/10.5822/978-1-61091-484-0|url-status=live|website=Springer Nature}}</ref> This has been especially significant in the Southwest, which tends to be warmer than the rest of the United States.<ref name=":1" />

Temperature can be an important determinant in wildfire occurrence, affecting humidity and fuel sources. With the higher temperatures of recent years, air is able to hold more water, so as total moisture content remains the same, the relative humidity becomes lower. Precipitation has also decreased as a result of this increase in water storage capacity, leading to drought. The Santa Ana winds, hot and cold winds that flow over Southern California, can also contribute to these warming conditions. These winds are attributed to many extreme temperatures across Southern California. Hot winds, which though less severe than cold winds, can contribute to dry conditions that cause wildfires.<ref>{{Cite web|last=Gershunov|first=Alexander|last2=Guzman|first2=Morales Janin|last3=Hatchett|first3=Benjamin|last4=Guirguis|first4=Kristen|last5=Aguilera|first5=Rosana|last6=Shulgina|first6=Tamara|last7=Abatzoglou|first7=John T|last8=Cayan|first8=Daniel|last9=Pierce|first9=David|authors=Williams, Park; Small Ivory; Clemesha, Rachel; Schwarz, Lara; Benmarhnia, Tarik; Tardy, Alex|date=2021, October|title=Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire|url=https://www.proquest.com/docview/2573150518/abstract?accountid=14656&scrollToView=Author&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref> These conditions cause fuel such as wood debris on the forest floor to lose more moisture. Combined with the preexisting dry conditions, it leads to larger and more frequent wildfires.<ref>{{Cite web|last=Varga|first=Kevin|last2=Jones|first2=Charles|last3=Trugman|first3=Anna|last4=Carvalho|first4=Leila M V|last5=McLoughlin|first5=Neal|last6=Seto|first6=Daisuke|last7=Thompson|first7=Callum|last8=Daum|first8=Kristofer|date=2022|title=Megafires in a Warming World: What Wildfire Risk Factors Led to California’s Largest Recorded Wildfire|url=https://www.proquest.com/docview/2632816567?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>

==== Human Activity ====
While climate plays a part in causing wildfires, the recent increase in wildfires can be highly attributed to human activities. From 1992 to 2012, humans could be connected to 84% of fires across the United States.<ref name=":2">{{Cite web|last=Balch|first=Jennifer K|last2=Bradley|first2=Bethany A|last3=Abatzoglou|first3=John T|last4=Nagy|first4=R Chelsea|last5=Fusco|first5=Emily J|last6=Mahood|first6=Adam L|date=2017, February 27|title=Human-started wildfires expand the fire niche across the United States|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC5358354/|url-status=live|website=PubMed Central}}</ref> Human development introduces sources of ignition to the environment, which combined with dry fuels, creates severe wildfires. Proximity to roads and boundaries between wilderness and human developed areas have both been attributed to higher rates of wildfire occurrence.<ref name=":2" />

Current wildfire management practices aim to suppress all forest fires, regardless of severity. There is evidence that fires are actually an important disturbance event for forests that increases biodiversity and resilience.<ref>{{Cite web|date=2023, December 25|title=Twenty-year study confirms California forests are healthier when burned - or thinned|url=https://go.exlibris.link/q3XqDwBJ|url-status=live|website=Factiva}}</ref> Small fires create vertical and horizontal diversity in forests, allowing for fire resilience as some species are more tolerant of fire than others. This also creates gaps in fuel distribution that deter larger fires from occurring. Without this, forests become homogeneous, and fuel builds up rather than being periodically consumed. This leads to more wildfires at higher severities.<ref name=":3">{{Cite web|last=Koontz|first=Michael J|last2=North|first2=Malcolm P|last3=Werner|first3=Chhaya M|last4=Fick|first4=Stephen E|last5=Latimer|first5=Andrew M|date=2020, January 10|title=Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13447|url-status=live|website=Wiley Online Library}}</ref> This creates a feedback loop where, as fires get more severe, forests are no longer gaining biodiversity through small disturbances. Instead, when all vegetation is destroyed in a large fire, biodiversity is reduced and makes forest ecosystems more vulnerable.<ref name=":3" />

==Impacts==

==== '''Economic Impact''' ====
Wildfires have caused a significant amount of economic damage in California. These types of damages include property damage, capital loss, and wage loss. The January 2025 wildfires of Southern California caused significant amounts of financial damage. The fires caused property damages and capital loss that range from 76 billion USD to 131 billion USD.<ref name=":0">{{Cite web|last=Li|first=Zhiyun|last2=Yu|first2=William|date=2025, March 7|title=Economic impact of the Los Angeles wildfires|url=https://www.anderson.ucla.edu/about/centers/ucla-anderson-forecast/economic-impact-los-angeles-wildfires|url-status=live|website=UCLA Anderson School of Management}}</ref> These damages mainly comes from the 16,251 homes, properties, and structures destroyed in the fire.<ref name=":0" /> The amount also includes damage to other belongings such as automobiles.

Additionally, business and employees of affected areas suffered an additional 297 million USD in lost wages.<ref name=":0" /> The fire is also expected to cause a 0.48% loss in county GDP, leading to an approximate 4.6 billion USD in further economic damage.<ref name=":0" /> Wildfires are expected to become more prevalent as climate change worsens. Examples of other devastating fires in California include the Tubbs wildfire of 2018 and the Camp wildfire of 2017.<ref name=":0" /> The Tubbs wildfire caused 8.76 billion USD in insurance claims, and the Camp wildfire caused 8.26 billion USD in insurance claims.<ref name=":0" />

==== '''Social Impact''' ====
Wildfires have had a significant impact on the Californian society. For one, wildfires have lead to higher living costs for the Californian populace. Wildfires have led to higher housing costs, as well as growing insurance premiums.<ref name=":0" /> Low-income communities tend to suffer greater consequences from wildfires. These communities tend to lack the savings and adequate insurance needed to recover from the disaster.<ref name=":5" /> This is one of the reasons why wildfires can exacerbate homelessness.<ref name=":5" />

Furthermore, low-income communities are also more likely to not have sufficient preventative measures. This makes their properties 29% more likely to be destroyed by wildfires than those that have such measures installed. An example of such preventative measures is roof renewals, with a roof renewal, the risk of a property being destroyed by wildfires can be reduced by up to 27%.<ref name=":5">{{Cite journal|last=Reining|first=Sebastian|last2=Wussow|first2=Moritz|last3=Zanocco|first3=Chad|last4=Neumann|first4=Dirk|date=07 January 2025|title=Roof renewal disparities widen the equity gap in residential wildfire protection|url=https://www.nature.com/articles/s41467-024-55705-w|journal=Nature Communications}}</ref> As such, while wildfires negatively affect the entire population, it is much worse for low-income communities. Wildfires have also had major health implications for the Californian populace. Smoke from wildfires carries fine, often toxic, particulate matter, which damages the lungs of the inhaler.<ref name=":4">{{Cite web|date=30 Jan 2025|title=Health Affects Attributed to Wildfire Smoke|url=https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke|url-status=live|website=United States Environmental Protection Agency}}</ref> This can result in a reduction in the ability to expel foreign objects, such as virus and bacteria, from the lungs. Inhaling these particles can also exacerbate existing respiratory diseases, as well as premature mortality.<ref name=":4" />

== Human Mobility ==

==== Out-migration ====
The term out-migration (also written as outmigration or out migration) is used to categorize the number of residents of an area who then leave for another area. Out-migration within the context of wildfires, then, refers only to how wildfires (and their effects) push people away from where they have settled. Out-migration is not to be confused with a decrease to in-migration, which represents the number of people settling an area. Additionally, in-migration is not to be confused with immigration, which refers to settlement within a new country. The sum of in-migration minus out-migration results in the net migration for a region. A positive net migration means more people are settling in a region while a negative number means more people are leaving the region for another. Literature on the effects environmental hazards have on human mobility vary widely and migration driven by the interaction between climatic and non-climatic elements is not entirely transparent.<ref name=":6" /><ref name=":7" /> However, existing studies agree wildfires do influence out-migration, along with in-migration.<ref name=":6" /><ref name=":8" /><ref name=":9" /> The predicted and observed severity of wildfires has continued to grow in recent decades at the same time as the populations of high-risk regions have increased<ref name=":6" /> with an estimate of 1.2 million people [https://en.wikipedia.org/wiki/Climate_migration displaced] by wildfires globally in 2020, and more affected by smoke which may travel hundreds of miles from its origin.<ref name=":9" />

In a representative survey following the 2020 fire season, 1/12 of the 1,108 California respondents reported they intended to move within 5 years, and this decision was at least moderately impacted by wildfires and smoke.<ref name=":9" /> The 2020 California survey reported 73.8% of respondents had prolonged exposure to wildfire smoke, 55.7% had at least one negative experience during the 2020 wildfire season, and 28.4% indicated they know someone who was harmed.<ref name=":9" /> It was also found that prior negative outcomes, such as evacuations and losing property, were associated with intentions to migrate, while for those intending to remain prior wildfire experiences negatively affected their residency satisfaction and therefore might influence future out-migration.<ref name=":9" /> Another study estimates for each additional 10 days reaching 90 degrees above the average number of extreme heat days, net migrants were reduced by 4 per 10,000 starting population.<ref name=":8">{{Cite journal|last=Winkler|first=Richelle L|last2=Rouleau|first2=Mark D|date=2020, September 30|title=Amenities or disamenities? Estimating the impacts of extreme heat and wildfire on domestic US migration|url=https://www.proquest.com/docview/2541128629?sourcetype=Scholarly%20Journals|journal=Population and Environment|volume=42|pages=622-648|via=Proquest}}</ref> [https://en.wikipedia.org/wiki/County_(United_States) Counties] that experienced a fire had a reduction of 32 net migrants per 10,000 starting population compared to those that did not experience or have a neighbour that experienced a fire in the previous year. Counties neighbouring those that experienced a fire saw a net decrease of 18 migrants per 10,000 starting population when compared to those with no fire (self or near) the previous year. It was also found that a fire disaster declared by [https://en.wikipedia.org/wiki/Federal_Emergency_Management_Agency FEMA] had a net migration impact on par with losing 47 jobs.<ref name=":8" />

Generally, sources agree counties with disaster-level fires or extreme heat in the year prior had increased out-migration and lower in-migration.<ref name=":6" /><ref name=":7" /><ref name=":8" /><ref name=":9" /> While human migration patterns are undeniably influenced by wildfires in the short term, particularly in counties that tend to attract migrants for environmental amenities and outdoor recreation,<ref name=":8" /> long-term trends are elusive.<ref name=":6" /> For example, only 6% of those displaced by the [https://en.wikipedia.org/wiki/October_2017_Northern_California_wildfires 2017 Sonoma County fires] left the county within a year<ref name=":9" /> while the deadly [https://en.wikipedia.org/wiki/Camp_Fire_(2018) 2018 Camp Fire] resulted in elevated out-migration for the following two years. It has been argued the extent of wildfire’s influence on population mobility was rare and operated mainly through the destruction of the built environment.<ref name=":6" /> Studies of the contiguous United States’ wildfires between 1999 and 2020, showed only extreme wildfires (those destroying 258+ structures) influenced migration patterns.<ref name=":6" /> It should be noted that from the same dataset, to reach the top 10% of most destructive fires required 14+ structures be destroyed.<ref name=":6" /> The authors of these findings assert most wildfires were less destructive and did not significantly alter in- or out-migration.<ref name=":6" /> Also note wildfire control strategies may continue to change and influence mobility indirectly. Wildfire-driven structure loss is on the rise, with a substantial number of the most extreme events being from recent years, which leads to an expectation of increased direct displacement in lieu of other remediation or adaptation efforts.<ref name=":6" />

==== Persistence ====
Studies have shown in-situ adaptation serves as a default response to wildfires, whether voluntary or implicit, and migration is seen as an act of last resort when other adaptation is no longer possible.<ref name=":9">{{Cite journal|last=Berlin Rubin|first=Nina|last2=Wong-Parodi|first2=Gabrielle|date=2022, August 24|title=As California burns: the psychology of wildfire- and wildfire smoke-related migration intentions|url=https://www.proquest.com/docview/2721075294?accountid=14656&pq-origsite=summon&sourcetype=Scholarly%20Journals#|journal=Population and Environment|volume=44|pages=15-45|via=Proquest}}</ref> Voluntary non-migration has been described by researcher Nick Tinoco as a collective community response to wildfires through the mobilization of resources for community self-reliance as a climate adaptation measure.<ref name=":7" /> People, when faced with increasing environmental risks, have been shown to develop explicit non-migration aspirations.<ref name=":6">{{Cite journal|last=McConnell|first=Kathryn|last2=Fussell|first2=Elizabeth|last3=DeWaard|first3=Jack|last4=Whitaker|first4=Stephan|last5=Curtis|first5=Katherine J|last6=St Denis|first6=Lise|last7=Balch|first7=Jennifer|last8=Price|first8=Kobie|date=2024, August 5|title=Rare and highly destructive wildfires drive human migration in the U.S.|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC11300458/|journal=Nature Communications|volume=15|via=PubMed Central}}</ref> For example, evidence of successful wildfire property defence was shown to inspire community members to plan to resist future evacuation to defend homes.<ref name=":7">{{Cite journal|last=Tinoco|first=Nick|date=2023, April 11|title=Post-disaster (im)mobility aspiration and capability formation: case study of Southern California wildfire|url=https://www.proquest.com/docview/2799289828?sourcetype=Scholarly%20Journals|journal=Population and Environment|volume=45|via=Proquest}}</ref> Tinoco also suggests this is a symptom of the erosion of trust in local institutions. It is also noted how community organizatios were more likely to consider tangible goals such as [https://en.wikipedia.org/wiki/Volunteer_fire_department volunteer fire brigades] over broader climate change strategies.<ref name=":7" /> On the other hand, the immobile group shows disparity in response to wildfires, along with other disasters.<ref name=":7" /> However, many adaptation opportunities are based on community wealth leading to an “immobility” in disadvantaged areas or areas affected by the destruction of wealth via property.<ref name=":7" /> There is a disparity in the response these communities can muster as they do not have the same resources to mobilize, leading to lower feelings of preparedness which has been shown to increase the likelihood of out-migration.<ref name=":7" /><ref name=":9" /> This, along with wildfires being considered a rare experience in aggregate across the continental United States, may explain the limited impact on net migration from non-extreme wildfires.<ref name=":6" />

== Solutions ==
==== Fire Management ====
Current forest management solutions have shown to be ineffective to prevent wildfires. Current practices that aggressively suppress any fire occurrence cause fuel buildup that increases fire severity. Management strategies that allow controlled fires to burn through built up fuel would reduce the severity of wildfires. Indigenous methods traditionally utilized fire to manage forest structures and fuels, however current management practices rarely utilize prescribed fire and continue to heavily favor traditional suppression practices. Fines, detainment, and other policies also prevent the use of prescribed fire as a management strategy<ref>{{Cite web|last=Rodríguez|first=Iokiñe|last2=Inturias|first2=Mirna|last3=Masay|first3=Elmar|last4=Peña|first4=Anacleto|date=September, 2023|title=Decolonizing wildfire risk management: indigenous responses to fire criminalization policies and increasingly flammable forest landscapes in Lomerío, Bolivia|url=https://www.sciencedirect.com/science/article/pii/S1462901123001624|url-status=live|website=ScienceDirect}}</ref>. Should California begin to proactively utilize prescribed fire and other management techniques engineered to return its forests to a more native state, it would likely see a change in the frequency and severity of future fires.

==== Public Policy ====
It is also important to put efforts towards negating the harmful health effects caused by wildfires. Due to the large impact of smoke on human health<ref name=":10">{{Cite web|last=Edgeley|first=Catrin M.|last2=Burnett|first2=Jack T.|date=2025|title=Understanding rural adaptation to smoke from wildfires and forest management: insights for aligning approaches with community contexts|url=https://www.proquest.com/docview/3171408310?accountid=14656&pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>, smoke suppression tactics should be developed and implemented. Designing buildings to keep smoke outside can create areas of clean air to lower health impacts. It would also be important to create public spaces that give people without the means to evacuate a safe area without the risk of smoke inhalation. Knowing that there are structures in place to protect against wildfires would help people feel safer in their community, decreasing the incentive to migrate<ref name=":10" />.

==Conclusion==
Wildfire has a range of complex impacts on human out-migration from the state of California. Socio-economic factors such as negative experiences of friends and loved ones with fire, prior negative experiences such as evacuations or losing property, and level of infrastructure damage are all associated with out-migration following large fires, either as a direct response or as an influencing factor for future out-migration. As climate change continues to influence frequency of drought conditions and other climate and weather patterns in the state, the frequency and intensity of wildfires is expected to continue to rise and burn with less predictability. Continued use of fire suppression techniques and policy will likely also continue negatively affecting California’s forest structures, perpetuating the extreme buildup of understory fuels which leads to the transition of surface fires into massive crown fires, and of individual fires into fire complexes. Lack of predictability in how, when, and where these wildfires will spark may increase the likelihood of human communities being affected in ways that encourage out-migration.

==References==
<references />

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[[Category:Conservation]]

Course:CONS200/2025WT2/The effects of wildfires on outmigration in California

2025-04-11T20:03:39Z

JamesVanderBeek: Conclusion paragraph added

As a result of climate change, the world has seen a significant increase in the frequency of extreme wildfires. California especially is a region that has been greatly impacted by severe wildfires. The damage caused by these fires damage infrastructure and cause health impacts to the people affected. 49% of residents reported being highly impacted by mandatory evacuations, 42% reported being impacted by poor air quality, and 61% reported being high to moderately impacted by power shutoffs<ref>{{Cite journal|last=Howe|first=Alexander A|last2=Blomdahl|first2=Erika M|last3=Smith-Eskridge|first3=Ellie|last4=Pinto|first4=Dakoeta R|last5=Brunson|first5=Mark W|last6=Howe|first6=Peter D|last7=Huntly|first7=Nancy J|last8=Klain|first8=Sarah C|date=April 19, 2024|title=Worldviews more than experience predict Californians' support for wildfire risk mitigation policies|url=https://iopscience.iop.org/article/10.1088/1748-9326/ad3cf6|journal=Environmental Research Letters}}</ref>. Outmigration, or the process of people permanently leaving an area in order to live somewhere else, can be affected by: an area’s perception as a ‘safe’ or ‘unsafe’ place, the actual severity and frequency of natural disasters, and the distribution and application of resources for disaster recovery<ref>{{Cite journal|last=Lambrou|first=Nicole|last2=Kolden|first2=Crystal|last3=Loukaitou-Sideris|first3=Anastasia|date=February 15, 2025|title=Disaster recovery gentrification in post-wildfire landscapes: The case of Paradise, CA|url=https://www.sciencedirect.com/science/article/pii/S2212420925000597?via%3Dihub|journal=International Journal of Disaster Risk Reduction|via=}}</ref>. The impacts of wildfires in California, and the perception of the state as a place where wildfires occur, may be impacting outmigration from the area. In recent years, the state has shown a relative increase in out-migration rates compared to the previous decade<ref>Gabriel, S., Freyd, B., Brand, J., Fultz, N., & Tzen, M. (2005). Recent Trends in California Migration Evidence from the American Community Survey. https://www.universityofcalifornia.edu/sites/default/files/ucla-california-migration-report.pdf </ref>. We will discuss if and how the mental and physical impacts of wildfires could be related to this increase.

==History==
[[File:NOAA Satellites Watch as California Burns (NESDIS 2020-10-01).gif|thumb|The NOAA's GOES-West satellite capture of the August Complex fires and Glass fire in California's West Coast region, 2020.]]California’s ecosystems are historically adapted to wildfire as a disturbance agent. Prior to establishment of the United States of America, fire was utilized as a tool to shape and maintain the landscape. The state of California has monitored wildfire activity since the early twentieth century, revealing patterns of increasing wildfire frequency and severity throughout the state. 19 of the 20 largest fires in the state’s history have occurred in the twenty-first century, and 13 of these 19 have occurred within the last decade (2015-2025)<ref>[https://34c031f8-c9fd-4018-8c5a-4159cdff6b0d-cdn-endpoint.azureedge.net/-/media/calfire-website/our-impact/fire-statistics/top-20-largest-ca-wildfires.pdf?rev=097f901c128347149e2614f2fca4f546&hash=27DDE83DFEF9A69E67C73765892A2B75 "Top 20 Largest California Wildfires"] </ref>.

The state of California has historically used traditional fire suppression techniques within its semi-arid mixed conifer forests. Suppression allows for the accumulation of biomass as fuel beyond natural fire intervals (between 5-20 years), which in turn contributes to the increased risk of severe wildfire for these ecosystems. Long-term fire suppression encourages the development of atypical forest features, such as continuous closed canopies, establishment of shade-tolerant tree species, and buildup of understory fuels<ref>{{Cite journal|last=Klimaszewski-Patterson|first=Anna|last2=Dingemans|first2=Theodore|last3=Morgan|first3=Christopher T|last4=Mensing|first4=Scott A|date=January 15, 2024|title=Human influence on late Holocene fire history in a mixed-conifer forest, Sierra National Forest, California|url=https://link.springer.com/article/10.1186/s42408-023-00245-9|journal=Fire Ecology}}</ref>.

Recent shifts in climate have increased both the degree and frequency of drought experienced in California's ecosystems beyond historic norms, further contributing to fuel buildup and wildfire risk.

==Causes==
Wildfires have always been a part of forest ecosystems. Forests frequently experience small fires that cause stand regeneration, maintaining biodiversity. These are usually caused by natural events such as lightning strikes or drought. However, recent years have seen a sharp increase in occurrence of severe fires<ref>{{Cite web|last=Brown|first=Patrick T|last2=Hanley|first2=Holt|last3=Mahesh|first3=Ankur|last4=Reed|first4=Colorado|last5=Strenfel|first5=Scott J|last6=Davis|first6=Steven J|last7=Kochanski|first7=Adam K|last8=Clements|first8=Craig B|date=2023, September 28|title=Climate warming increases extreme daily wildfire growth risk in California|url=https://www.proquest.com/docview/2871925930?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. Climate change and human activities are the most highly attributed to this trend.

==== Climate ====
In recent years, the climate has become undeniably warmer. In the twenty-first century, global temperatures have risen between 0.6 to 0.7℃ <ref>{{Cite web|last=Cayan|first=Daniel R|last2=Maurer|first2=Edwin P|last3=Dettinger|first3=Michael D|last4=Tyree|first4=Mary|last5=Hayhoe|first5=Katharine|date=2008, January 26|title=Climate change scenarios for the California region|url=https://link.springer.com/article/10.1007/s10584-007-9377-6|url-status=live|website=Springer Nature}}</ref>. In the United States, the time period from 1960 to 2013 was warmer than periods of comparable length from the past 600 years<ref name=":1">{{Cite web|last=Garfin|first=Gregg|last2=Jardine|first2=Angela|last3=Merideth|first3=Robert|last4=Black|first4=Mary|last5=LeRoy|first5=Sarah|date=2013|title=Assessment of Climate Change in the Southwest United States|url=https://link.springer.com/book/10.5822/978-1-61091-484-0|url-status=live|website=Springer Nature}}</ref>. This has been especially significant in the Southwest, which tends to be warmer than the rest of the U.S<ref name=":1" />.

Temperature can be an important determinant in wildfire occurrence, affecting humidity and fuel sources. With the higher temperatures of recent years, air is able to hold more water, so as total moisture content remains the same, the relative humidity becomes lower. Precipitation has also decreased as a result of this increase in water storage capacity, leading to drought. The Santa Ana winds, hot and cold winds that flow over Southern California, can also contribute to these warming conditions. These winds are attributed to many extreme temperatures across Southern California. Hot winds, which though less severe than cold winds, can contribute to dry conditions that cause wildfires<ref>{{Cite web|last=Gershunov|first=Alexander|last2=Guzman|first2=Morales Janin|last3=Hatchett|first3=Benjamin|last4=Guirguis|first4=Kristen|last5=Aguilera|first5=Rosana|last6=Shulgina|first6=Tamara|last7=Abatzoglou|first7=John T|last8=Cayan|first8=Daniel|last9=Pierce|first9=David|authors=Williams, Park; Small Ivory; Clemesha, Rachel; Schwarz, Lara; Benmarhnia, Tarik; Tardy, Alex|date=2021, October|title=Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire|url=https://www.proquest.com/docview/2573150518/abstract?accountid=14656&scrollToView=Author&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. These conditions cause fuel such as wood debris on the forest floor to lose more moisture. Combined with the preexisting dry conditions, it leads to larger and more frequent wildfires<ref>{{Cite web|last=Varga|first=Kevin|last2=Jones|first2=Charles|last3=Trugman|first3=Anna|last4=Carvalho|first4=Leila M V|last5=McLoughlin|first5=Neal|last6=Seto|first6=Daisuke|last7=Thompson|first7=Callum|last8=Daum|first8=Kristofer|date=2022|title=Megafires in a Warming World: What Wildfire Risk Factors Led to California’s Largest Recorded Wildfire|url=https://www.proquest.com/docview/2632816567?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>.

==== Human Activity ====
While climate plays a part in causing wildfires, the recent increase in wildfires can be highly attributed to human activities. From 1992 to 2012, humans could be connected to 84% of fires across the United States<ref name=":2">{{Cite web|last=Balch|first=Jennifer K|last2=Bradley|first2=Bethany A|last3=Abatzoglou|first3=John T|last4=Nagy|first4=R Chelsea|last5=Fusco|first5=Emily J|last6=Mahood|first6=Adam L|date=2017, February 27|title=Human-started wildfires expand the fire niche across the United States|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC5358354/|url-status=live|website=PubMed Central}}</ref>. Human development introduces sources of ignition to the environment, which combined with dry fuels, creates severe wildfires. Proximity to roads and boundaries between wilderness and human developed areas have both been attributed to higher rates of wildfire occurrence<ref name=":2" />.

Current wildfire management practices aim to suppress all forest fires, regardless of severity. There is evidence that fires are actually an important disturbance event for forests that increases biodiversity and resilience<ref>{{Cite web|date=2023, December 25|title=Twenty-year study confirms California forests are healthier when burned - or thinned|url=https://go.exlibris.link/q3XqDwBJ|url-status=live|website=Factiva}}</ref>. Small fires create vertical and horizontal diversity in forests, allowing for fire resilience as some species are more tolerant of fire than others. This also creates gaps in fuel distribution that deter larger fires from occurring. Without this, forests become homogeneous, and fuel builds up rather than being periodically consumed. This leads to more wildfires at higher severities<ref name=":3">{{Cite web|last=Koontz|first=Michael J|last2=North|first2=Malcolm P|last3=Werner|first3=Chhaya M|last4=Fick|first4=Stephen E|last5=Latimer|first5=Andrew M|date=2020, January 10|title=Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13447|url-status=live|website=Wiley Online Library}}</ref>. This creates a feedback loop where, as fires get more severe, forests are no longer gaining biodiversity through small disturbances. Instead, when all vegetation is destroyed in a large fire, biodiversity is reduced and makes forest ecosystems more vulnerable<ref name=":3" />.

==Impacts==

'''Economic Impact'''

Wildfires have caused a significant amount of economic damage in California. These types of damages include property damage, capital loss, and wage loss. The January 2025 wildfires of Southern California caused significant amounts of financial damage. The fires caused property damages and capital loss that range from 76 billion USD to 131 billion USD<ref name=":0">{{Cite web|last=Li|first=Zhiyun|last2=Yu|first2=William|date=2025, March 7|title=Economic impact of the Los Angeles wildfires|url=https://www.anderson.ucla.edu/about/centers/ucla-anderson-forecast/economic-impact-los-angeles-wildfires|url-status=live|website=UCLA Anderson School of Management}}</ref>. These damages mainly comes from the 16,251 homes, properties, and structures destroyed in the fire<ref name=":0" />. The amount also includes damage in other belongings such as automobiles. Additionally, business and employees of affected areas suffered an additional 297 million USD in lost wages<ref name=":0" />. The fire is also expected to cause a 0.48% loss in county GDP leading to an approximate 4.6 billion USD in further economic damage<ref name=":0" />. Wildfires are expected to become more prevalent as climate change worsens. Examples of other devastating fires in California include the Tubbs wildfire of 2018, and the Camp wildfire of 2017<ref name=":0" />. The Tubbs wildfire caused 8.76 billion USD in insurance claims, and the Camp wildfire caused 8.26 billion USD in insurance claims<ref name=":0" />.

'''Social Impact'''

Wildfires have had a significant impact on the Californian society. For one, wildfires have lead to higher living costs for the Californian populace. Wildfires have led to higher housing costs, as well as growing insurance premiums<ref name=":0" />. Low-income communities tend to suffer greater consequences from wildfires. These communities tend to lack the savings and adequate insurance needed to recover from the disaster<ref name=":5" />. This is one of the reasons why wildfires can exacerbate homelessness<ref name=":5" />. Furthermore, low-income communities are also more likely to not have sufficient preventative measures. This makes their properties 29% more likely to be destroyed by wildfires than those that have such measures installed. An example of such preventative measures is roof renewals, with a roof renewal, the risk of a property being destroyed by wildfires can be reduced by up to 27%<ref name=":5">{{Cite journal|last=Reining|first=Sebastian|last2=Wussow|first2=Moritz|last3=Zanocco|first3=Chad|last4=Neumann|first4=Dirk|date=07 January 2025|title=Roof renewal disparities widen the equity gap in residential wildfire protection|url=https://www.nature.com/articles/s41467-024-55705-w|journal=Nature Communications}}</ref>. As such, while wildfires negatively affect the entire population, it is much worse for low-income communities. Wildfires have also had major health implications on the Californian populace. Smoke from wildfires carry fine, often toxic, particulate matter, which damages the lungs of the inhaler<ref name=":4">{{Cite web|date=30 Jan 2025|title=Health Affects Attributed to Wildfire Smoke|url=https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke|url-status=live|website=United States Environmental Protection Agency}}</ref>. This can result in reductions in the ability to expel foreign objects, such as virus and bacteria, from the lungs. Inhaling these particles can also exacerbate existing respiratory diseases, as well as premature mortality<ref name=":4" />.

== Outward Migration ==

==Conclusion==
Wildfire has a range of complex impacts on human out-migration from the state of California. Socio-economic factors such as negative experiences of friends and loved ones with fire, prior negative experiences such as evacuations or losing property, and level of infrastructure damage are all associated with out-migration following large fires, either as a direct response or as an influencing factor for future out-migration. As climate change continues to influence frequency of drought conditions and other climate and weather patterns in the state, the frequency and intensity of wildfires is expected to continue to rise and burn with less predictability. Continued use of fire suppression techniques and policy will likely also continue negatively affecting California’s forest structures, perpetuating the extreme buildup of understory fuels which leads to the transition of surface fires into massive crown fires, and of individual fires into fire complexes. Lack of predictability in how, when, and where these wildfires will spark may increase the likelihood of human communities being affected in ways that encourage out-migration.

==References==
<references />

{{Projectbox CONS200
|names=
|share=no
}}

[[Category:Conservation]]

Course:CONS200/2025WT2/The effects of wildfires on outmigration in California

2025-04-10T02:20:51Z

JamesVanderBeek:

As a result of climate change, the world has seen a significant increase in the frequency of extreme wildfires. California especially is a region that has been greatly impacted by severe wildfires. The damage caused by these fires damage infrastructure and cause health impacts to the people affected. 49% of residents reported being highly impacted by mandatory evacuations, 42% reported being impacted by poor air quality, and 61% reported being high to moderately impacted by power shutoffs<ref>{{Cite journal|last=Howe|first=Alexander A|last2=Blomdahl|first2=Erika M|last3=Smith-Eskridge|first3=Ellie|last4=Pinto|first4=Dakoeta R|last5=Brunson|first5=Mark W|last6=Howe|first6=Peter D|last7=Huntly|first7=Nancy J|last8=Klain|first8=Sarah C|date=April 19, 2024|title=Worldviews more than experience predict Californians' support for wildfire risk mitigation policies|url=https://iopscience.iop.org/article/10.1088/1748-9326/ad3cf6|journal=Environmental Research Letters}}</ref>. Outmigration, or the process of people permanently leaving an area in order to live somewhere else, can be affected by: an area’s perception as a ‘safe’ or ‘unsafe’ place, the actual severity and frequency of natural disasters, and the distribution and application of resources for disaster recovery<ref>{{Cite journal|last=Lambrou|first=Nicole|last2=Kolden|first2=Crystal|last3=Loukaitou-Sideris|first3=Anastasia|date=February 15, 2025|title=Disaster recovery gentrification in post-wildfire landscapes: The case of Paradise, CA|url=https://www.sciencedirect.com/science/article/pii/S2212420925000597?via%3Dihub|journal=International Journal of Disaster Risk Reduction|via=}}</ref>. The impacts of wildfires in California, and the perception of the state as a place where wildfires occur, may be impacting outmigration from the area. In recent years, the state has shown a relative increase in out-migration rates compared to the previous decade<ref>Gabriel, S., Freyd, B., Brand, J., Fultz, N., & Tzen, M. (2005). Recent Trends in California Migration Evidence from the American Community Survey. https://www.universityofcalifornia.edu/sites/default/files/ucla-california-migration-report.pdf </ref>. We will discuss if and how the mental and physical impacts of wildfires could be related to this increase.

==History==
[[File:NOAA Satellites Watch as California Burns (NESDIS 2020-10-01).gif|thumb|The NOAA's GOES-West satellite capture of the August Complex fires and Glass fire in California's West Coast region, 2020.]]California’s ecosystems are historically adapted to wildfire as a disturbance agent. Prior to establishment of the United States of America, fire was utilized as a tool to shape and maintain the landscape. The state of California has monitored wildfire activity since the early twentieth century, revealing patterns of increasing wildfire frequency and severity throughout the state. 19 of the 20 largest fires in the state’s history have occurred in the twenty-first century, and 13 of these 19 have occurred within the last decade (2015-2025)<ref>[https://34c031f8-c9fd-4018-8c5a-4159cdff6b0d-cdn-endpoint.azureedge.net/-/media/calfire-website/our-impact/fire-statistics/top-20-largest-ca-wildfires.pdf?rev=097f901c128347149e2614f2fca4f546&hash=27DDE83DFEF9A69E67C73765892A2B75 "Top 20 Largest California Wildfires"] </ref>.

The state of California has historically used traditional fire suppression techniques within its semi-arid mixed conifer forests. Suppression allows for the accumulation of biomass as fuel beyond natural fire intervals (between 5-20 years), which in turn contributes to the increased risk of severe wildfire for these ecosystems. Long-term fire suppression encourages the development of atypical forest features, such as continuous closed canopies, establishment of shade-tolerant tree species, and buildup of understory fuels<ref>{{Cite journal|last=Klimaszewski-Patterson|first=Anna|last2=Dingemans|first2=Theodore|last3=Morgan|first3=Christopher T|last4=Mensing|first4=Scott A|date=January 15, 2024|title=Human influence on late Holocene fire history in a mixed-conifer forest, Sierra National Forest, California|url=https://link.springer.com/article/10.1186/s42408-023-00245-9|journal=Fire Ecology}}</ref>.

Recent shifts in climate have increased both the degree and frequency of drought experienced in California's ecosystems beyond historic norms, further contributing to fuel buildup and wildfire risk.

==Causes==
Wildfires have always been a part of forest ecosystems, but recent years have seen a sharp increase in occurrence of severe fires<ref>{{Cite web|last=Brown|first=Patrick T|last2=Hanley|first2=Holt|last3=Mahesh|first3=Ankur|last4=Reed|first4=Colorado|last5=Strenfel|first5=Scott J|last6=Davis|first6=Steven J|last7=Kochanski|first7=Adam K|last8=Clements|first8=Craig B|date=2023, September 28|title=Climate warming increases extreme daily wildfire growth risk in California|url=https://www.proquest.com/docview/2871925930?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. Climate and human activities are the most highly attributed to this trend.

==== Climate ====
In recent years, the climate has become undeniably warmer. In the twenty-first century, global temperatures have risen between 0.6 to 0.7℃ <ref>{{Cite web|last=Cayan|first=Daniel R|last2=Maurer|first2=Edwin P|last3=Dettinger|first3=Michael D|last4=Tyree|first4=Mary|last5=Hayhoe|first5=Katharine|date=2008, January 26|title=Climate change scenarios for the California region|url=https://link.springer.com/article/10.1007/s10584-007-9377-6|url-status=live|website=Springer Nature}}</ref>. In the United States, the time period from 1960 to 2013 was warmer than periods of comparable length from the past 600 years<ref name=":1">{{Cite web|last=Garfin|first=Gregg|last2=Jardine|first2=Angela|last3=Merideth|first3=Robert|last4=Black|first4=Mary|last5=LeRoy|first5=Sarah|date=2013|title=Assessment of Climate Change in the Southwest United States|url=https://link.springer.com/book/10.5822/978-1-61091-484-0|url-status=live|website=Springer Nature}}</ref>. This has been especially significant in the Southwest, which tends to be warmer than the rest of the U.S<ref name=":1" />.

Temperature can be an important determinant in wildfire occurrence, affecting humidity and fuel sources. With the higher temperatures of recent years, air is able to hold more water, so as total moisture content remains the same, the relative humidity becomes lower. Precipitation has also decreased as a result of this increase in water storage capacity, leading to drought. The Santa Ana winds, hot and cold winds that flow over Southern California, can also contribute to these warming conditions. These winds are attributed to many extreme temperatures across Southern California. Hot winds, which though less severe than cold winds, can contribute to dry conditions that cause wildfires<ref>{{Cite web|last=Gershunov|first=Alexander|last2=Guzman|first2=Morales Janin|last3=Hatchett|first3=Benjamin|last4=Guirguis|first4=Kristen|last5=Aguilera|first5=Rosana|last6=Shulgina|first6=Tamara|last7=Abatzoglou|first7=John T|last8=Cayan|first8=Daniel|last9=Pierce|first9=David|authors=Williams, Park; Small Ivory; Clemesha, Rachel; Schwarz, Lara; Benmarhnia, Tarik; Tardy, Alex|date=2021, October|title=Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire|url=https://www.proquest.com/docview/2573150518/abstract?accountid=14656&scrollToView=Author&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. These conditions cause fuel such as wood debris on the forest floor to lose more moisture. Combined with the preexisting dry conditions, it leads to larger and more frequent wildfires<ref>{{Cite web|last=Varga|first=Kevin|last2=Jones|first2=Charles|last3=Trugman|first3=Anna|last4=Carvalho|first4=Leila M V|last5=McLoughlin|first5=Neal|last6=Seto|first6=Daisuke|last7=Thompson|first7=Callum|last8=Daum|first8=Kristofer|date=2022|title=Megafires in a Warming World: What Wildfire Risk Factors Led to California’s Largest Recorded Wildfire|url=https://www.proquest.com/docview/2632816567?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>.

==== Human Impacts ====
While climate plays a part in causing wildfires, the recent increase in wildfires can be highly attributed to human activities. From 1992 to 2012, humans could be connected to 84% of fires across the United States<ref name=":2">{{Cite web|last=Balch|first=Jennifer K|last2=Bradley|first2=Bethany A|last3=Abatzoglou|first3=John T|last4=Nagy|first4=R Chelsea|last5=Fusco|first5=Emily J|last6=Mahood|first6=Adam L|date=2017, February 27|title=Human-started wildfires expand the fire niche across the United States|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC5358354/|url-status=live|website=PubMed Central}}</ref>. Human development introduces sources of ignition to the environment, which combined with dry fuels, creates severe wildfires. Proximity to roads and boundaries between wilderness and human developed areas have both been attributed to higher rates of wildfire occurrence<ref name=":2" />.

Current wildfire management practices aim to suppress all forest fires, regardless of severity. There is evidence that fires are actually an important disturbance event for forests that increases biodiversity and resilience<ref>{{Cite web|date=2023, December 25|title=Twenty-year study confirms California forests are healthier when burned - or thinned|url=https://go.exlibris.link/q3XqDwBJ|url-status=live|website=Factiva}}</ref>. Small fires create vertical and horizontal diversity in forests, allowing for fire resilience as some species are more tolerant of fire than others. This also creates gaps in fuel distribution that deter larger fires from occurring. Without this, forests become homogeneous, and fuel builds up rather than being periodically consumed. This leads to more wildfires at higher severities<ref name=":3">{{Cite web|last=Koontz|first=Michael J|last2=North|first2=Malcolm P|last3=Werner|first3=Chhaya M|last4=Fick|first4=Stephen E|last5=Latimer|first5=Andrew M|date=2020, January 10|title=Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13447|url-status=live|website=Wiley Online Library}}</ref>. This creates a feedback loop where, as fires get more severe, forests are no longer gaining biodiversity through small disturbances. Instead, when all vegetation is destroyed in a large fire, biodiversity is reduced and makes forest ecosystems more vulnerable<ref name=":3" />.

==Impacts==

'''Economic Impact'''

Wildfires have caused a significant amount of economic damage in California. These types of damages include property damage, capital loss, and wage loss. The January 2025 wildfires of Southern California caused significant amounts of financial damage. The fires caused property damages and capital loss that range from 76 billion USD to 131 billion USD<ref name=":0">{{Cite web|last=Li|first=Zhiyun|last2=Yu|first2=William|date=2025, March 7|title=Economic impact of the Los Angeles wildfires|url=https://www.anderson.ucla.edu/about/centers/ucla-anderson-forecast/economic-impact-los-angeles-wildfires|url-status=live|website=UCLA Anderson School of Management}}</ref>. These damages mainly comes from the 16,251 homes, properties, and structures destroyed in the fire<ref name=":0" />. The amount also includes damage in other belongings such as automobiles. Additionally, business and employees of affected areas suffered an additional 297 million USD in lost wages<ref name=":0" />. The fire is also expected to cause a 0.48% loss in county GDP leading to an approximate 4.6 billion USD in further economic damage<ref name=":0" />. Wildfires are expected to become more prevalent as climate change worsens. Examples of other devastating fires in California include the Tubbs wildfire of 2018, and the Camp wildfire of 2017<ref name=":0" />. The Tubbs wildfire caused 8.76 billion USD in insurance claims, and the Camp wildfire caused 8.26 billion USD in insurance claims<ref name=":0" />.

'''Social Impact'''

Wildfires have had a significant impact on the Californian society. For one, wildfires have lead to higher living costs for the Californian populace. Wildfires have led to higher housing costs, as well as growing insurance premiums<ref name=":0" />. Low-income communities tend to suffer greater consequences from wildfires. These communities tend to lack the savings and adequate insurance needed to recover from the disaster<ref name=":5" />. This is one of the reasons why wildfires can exacerbate homelessness<ref name=":5" />. Furthermore, low-income communities are also more likely to not have sufficient preventative measures. This makes their properties 29% more likely to be destroyed by wildfires than those that have such measures installed. An example of such preventative measures is roof renewals, with a roof renewal, the risk of a property being destroyed by wildfires can be reduced by up to 27%<ref name=":5">{{Cite journal|last=Reining|first=Sebastian|last2=Wussow|first2=Moritz|last3=Zanocco|first3=Chad|last4=Neumann|first4=Dirk|date=07 January 2025|title=Roof renewal disparities widen the equity gap in residential wildfire protection|url=https://www.nature.com/articles/s41467-024-55705-w|journal=Nature Communications}}</ref>. As such, while wildfires negatively affect the entire population, it is much worse for low-income communities. Wildfires have also had major health implications on the Californian populace. Smoke from wildfires carry fine, often toxic, particulate matter, which damages the lungs of the inhaler<ref name=":4">{{Cite web|date=30 Jan 2025|title=Health Affects Attributed to Wildfire Smoke|url=https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke|url-status=live|website=United States Environmental Protection Agency}}</ref>. This can result in reductions in the ability to expel foreign objects, such as virus and bacteria, from the lungs. Inhaling these particles can also exacerbate existing respiratory diseases, as well as premature mortality<ref name=":4" />.

== Outward Migration ==

==Conclusion==
You should conclude your Wiki paper by summarizing the topic, or some aspect of the topic.

==References==
<references />

{{Projectbox CONS200
|names=
|share=no
}}

[[Category:Conservation]]

Course:CONS200/2025WT2/The effects of wildfires on outmigration in California

2025-04-10T02:17:11Z

JamesVanderBeek:

As a result of climate change, the world has seen a significant increase in the frequency of extreme wildfires. California especially is a region that has been greatly impacted by severe wildfires. The damage caused by these fires damage infrastructure and cause health impacts to the people affected. 49% of residents reported being highly impacted by mandatory evacuations, 42% reported being impacted by poor air quality, and 61% reported being high to moderately impacted by power shutoffs<ref>{{Cite journal|last=Howe|first=Alexander A|last2=Blomdahl|first2=Erika M|last3=Smith-Eskridge|first3=Ellie|last4=Pinto|first4=Dakoeta R|last5=Brunson|first5=Mark W|last6=Howe|first6=Peter D|last7=Huntly|first7=Nancy J|last8=Klain|first8=Sarah C|date=April 19, 2024|title=Worldviews more than experience predict Californians' support for wildfire risk mitigation policies|url=https://iopscience.iop.org/article/10.1088/1748-9326/ad3cf6|journal=Environmental Research Letters}}</ref>. Outmigration, or the process of people permanently leaving an area in order to live somewhere else, can be affected by: an area’s perception as a ‘safe’ or ‘unsafe’ place, the actual severity and frequency of natural disasters, and the distribution and application of resources for disaster recovery<ref>{{Cite journal|last=Lambrou|first=Nicole|last2=Kolden|first2=Crystal|last3=Loukaitou-Sideris|first3=Anastasia|date=February 15, 2025|title=Disaster recovery gentrification in post-wildfire landscapes: The case of Paradise, CA|url=https://www.sciencedirect.com/science/article/pii/S2212420925000597?via%3Dihub|journal=International Journal of Disaster Risk Reduction|via=}}</ref>. The impacts of wildfires in California, and the perception of the state as a place where wildfires occur, may be impacting outmigration from the area. In recent years, the state has shown a relative increase in out-migration rates compared to the previous decade (Gabriel et al.). We will discuss if and how the mental and physical impacts of wildfires could be related to this increase.

==History==
[[File:NOAA Satellites Watch as California Burns (NESDIS 2020-10-01).gif|thumb|The NOAA's GOES-West satellite capture of the August Complex fires and Glass fire in California's West Coast region, 2020.]]California’s ecosystems are historically adapted to wildfire as a disturbance agent. Prior to establishment of the United States of America, fire was utilized as a tool to shape and maintain the landscape. The state of California has monitored wildfire activity since the early twentieth century, revealing patterns of increasing wildfire frequency and severity throughout the state. 19 of the 20 largest fires in the state’s history have occurred in the twenty-first century, and 13 of these 19 have occurred within the last decade (2015-2025)<ref>[https://34c031f8-c9fd-4018-8c5a-4159cdff6b0d-cdn-endpoint.azureedge.net/-/media/calfire-website/our-impact/fire-statistics/top-20-largest-ca-wildfires.pdf?rev=097f901c128347149e2614f2fca4f546&hash=27DDE83DFEF9A69E67C73765892A2B75 "Top 20 Largest California Wildfires"] </ref>.

The state of California has historically used traditional fire suppression techniques within its semi-arid mixed conifer forests. Suppression allows for the accumulation of biomass as fuel beyond natural fire intervals (between 5-20 years), which in turn contributes to the increased risk of severe wildfire for these ecosystems. Long-term fire suppression encourages the development of atypical forest features, such as continuous closed canopies, establishment of shade-tolerant tree species, and buildup of understory fuels<ref>{{Cite journal|last=Klimaszewski-Patterson|first=Anna|last2=Dingemans|first2=Theodore|last3=Morgan|first3=Christopher T|last4=Mensing|first4=Scott A|date=January 15, 2024|title=Human influence on late Holocene fire history in a mixed-conifer forest, Sierra National Forest, California|url=https://link.springer.com/article/10.1186/s42408-023-00245-9|journal=Fire Ecology}}</ref>.

Recent shifts in climate have increased both the degree and frequency of drought experienced in California's ecosystems beyond historic norms, further contributing to fuel buildup and wildfire risk.

==Causes==
Wildfires have always been a part of forest ecosystems, but recent years have seen a sharp increase in occurrence of severe fires<ref>{{Cite web|last=Brown|first=Patrick T|last2=Hanley|first2=Holt|last3=Mahesh|first3=Ankur|last4=Reed|first4=Colorado|last5=Strenfel|first5=Scott J|last6=Davis|first6=Steven J|last7=Kochanski|first7=Adam K|last8=Clements|first8=Craig B|date=2023, September 28|title=Climate warming increases extreme daily wildfire growth risk in California|url=https://www.proquest.com/docview/2871925930?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. Climate and human activities are the most highly attributed to this trend.

==== Climate ====
In recent years, the climate has become undeniably warmer. In the twenty-first century, global temperatures have risen between 0.6 to 0.7℃ <ref>{{Cite web|last=Cayan|first=Daniel R|last2=Maurer|first2=Edwin P|last3=Dettinger|first3=Michael D|last4=Tyree|first4=Mary|last5=Hayhoe|first5=Katharine|date=2008, January 26|title=Climate change scenarios for the California region|url=https://link.springer.com/article/10.1007/s10584-007-9377-6|url-status=live|website=Springer Nature}}</ref>. In the United States, the time period from 1960 to 2013 was warmer than periods of comparable length from the past 600 years<ref name=":1">{{Cite web|last=Garfin|first=Gregg|last2=Jardine|first2=Angela|last3=Merideth|first3=Robert|last4=Black|first4=Mary|last5=LeRoy|first5=Sarah|date=2013|title=Assessment of Climate Change in the Southwest United States|url=https://link.springer.com/book/10.5822/978-1-61091-484-0|url-status=live|website=Springer Nature}}</ref>. This has been especially significant in the Southwest, which tends to be warmer than the rest of the U.S<ref name=":1" />.

Temperature can be an important determinant in wildfire occurrence, affecting humidity and fuel sources. With the higher temperatures of recent years, air is able to hold more water, so as total moisture content remains the same, the relative humidity becomes lower. Precipitation has also decreased as a result of this increase in water storage capacity, leading to drought. The Santa Ana winds, hot and cold winds that flow over Southern California, can also contribute to these warming conditions. These winds are attributed to many extreme temperatures across Southern California. Hot winds, which though less severe than cold winds, can contribute to dry conditions that cause wildfires<ref>{{Cite web|last=Gershunov|first=Alexander|last2=Guzman|first2=Morales Janin|last3=Hatchett|first3=Benjamin|last4=Guirguis|first4=Kristen|last5=Aguilera|first5=Rosana|last6=Shulgina|first6=Tamara|last7=Abatzoglou|first7=John T|last8=Cayan|first8=Daniel|last9=Pierce|first9=David|authors=Williams, Park; Small Ivory; Clemesha, Rachel; Schwarz, Lara; Benmarhnia, Tarik; Tardy, Alex|date=2021, October|title=Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire|url=https://www.proquest.com/docview/2573150518/abstract?accountid=14656&scrollToView=Author&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. These conditions cause fuel such as wood debris on the forest floor to lose more moisture. Combined with the preexisting dry conditions, it leads to larger and more frequent wildfires<ref>{{Cite web|last=Varga|first=Kevin|last2=Jones|first2=Charles|last3=Trugman|first3=Anna|last4=Carvalho|first4=Leila M V|last5=McLoughlin|first5=Neal|last6=Seto|first6=Daisuke|last7=Thompson|first7=Callum|last8=Daum|first8=Kristofer|date=2022|title=Megafires in a Warming World: What Wildfire Risk Factors Led to California’s Largest Recorded Wildfire|url=https://www.proquest.com/docview/2632816567?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>.

==== Human Impacts ====
While climate plays a part in causing wildfires, the recent increase in wildfires can be highly attributed to human activities. From 1992 to 2012, humans could be connected to 84% of fires across the United States<ref name=":2">{{Cite web|last=Balch|first=Jennifer K|last2=Bradley|first2=Bethany A|last3=Abatzoglou|first3=John T|last4=Nagy|first4=R Chelsea|last5=Fusco|first5=Emily J|last6=Mahood|first6=Adam L|date=2017, February 27|title=Human-started wildfires expand the fire niche across the United States|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC5358354/|url-status=live|website=PubMed Central}}</ref>. Human development introduces sources of ignition to the environment, which combined with dry fuels, creates severe wildfires. Proximity to roads and boundaries between wilderness and human developed areas have both been attributed to higher rates of wildfire occurrence<ref name=":2" />.

Current wildfire management practices aim to suppress all forest fires, regardless of severity. There is evidence that fires are actually an important disturbance event for forests that increases biodiversity and resilience<ref>{{Cite web|date=2023, December 25|title=Twenty-year study confirms California forests are healthier when burned - or thinned|url=https://go.exlibris.link/q3XqDwBJ|url-status=live|website=Factiva}}</ref>. Small fires create vertical and horizontal diversity in forests, allowing for fire resilience as some species are more tolerant of fire than others. This also creates gaps in fuel distribution that deter larger fires from occurring. Without this, forests become homogeneous, and fuel builds up rather than being periodically consumed. This leads to more wildfires at higher severities<ref name=":3">{{Cite web|last=Koontz|first=Michael J|last2=North|first2=Malcolm P|last3=Werner|first3=Chhaya M|last4=Fick|first4=Stephen E|last5=Latimer|first5=Andrew M|date=2020, January 10|title=Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13447|url-status=live|website=Wiley Online Library}}</ref>. This creates a feedback loop where, as fires get more severe, forests are no longer gaining biodiversity through small disturbances. Instead, when all vegetation is destroyed in a large fire, biodiversity is reduced and makes forest ecosystems more vulnerable<ref name=":3" />.

==Impacts==

'''Economic Impact'''

Wildfires have caused a significant amount of economic damage in California. These types of damages include property damage, capital loss, and wage loss. The January 2025 wildfires of Southern California caused significant amounts of financial damage. The fires caused property damages and capital loss that range from 76 billion USD to 131 billion USD<ref name=":0">{{Cite web|last=Li|first=Zhiyun|last2=Yu|first2=William|date=2025, March 7|title=Economic impact of the Los Angeles wildfires|url=https://www.anderson.ucla.edu/about/centers/ucla-anderson-forecast/economic-impact-los-angeles-wildfires|url-status=live|website=UCLA Anderson School of Management}}</ref>. These damages mainly comes from the 16,251 homes, properties, and structures destroyed in the fire<ref name=":0" />. The amount also includes damage in other belongings such as automobiles. Additionally, business and employees of affected areas suffered an additional 297 million USD in lost wages<ref name=":0" />. The fire is also expected to cause a 0.48% loss in county GDP leading to an approximate 4.6 billion USD in further economic damage<ref name=":0" />. Wildfires are expected to become more prevalent as climate change worsens. Examples of other devastating fires in California include the Tubbs wildfire of 2018, and the Camp wildfire of 2017<ref name=":0" />. The Tubbs wildfire caused 8.76 billion USD in insurance claims, and the Camp wildfire caused 8.26 billion USD in insurance claims<ref name=":0" />.

'''Social Impact'''

Wildfires have had a significant impact on the Californian society. For one, wildfires have lead to higher living costs for the Californian populace. Wildfires have led to higher housing costs, as well as growing insurance premiums<ref name=":0" />. Low-income communities tend to suffer greater consequences from wildfires. These communities tend to lack the savings and adequate insurance needed to recover from the disaster<ref name=":5" />. This is one of the reasons why wildfires can exacerbate homelessness<ref name=":5" />. Furthermore, low-income communities are also more likely to not have sufficient preventative measures. This makes their properties 29% more likely to be destroyed by wildfires than those that have such measures installed. An example of such preventative measures is roof renewals, with a roof renewal, the risk of a property being destroyed by wildfires can be reduced by up to 27%<ref name=":5">{{Cite journal|last=Reining|first=Sebastian|last2=Wussow|first2=Moritz|last3=Zanocco|first3=Chad|last4=Neumann|first4=Dirk|date=07 January 2025|title=Roof renewal disparities widen the equity gap in residential wildfire protection|url=https://www.nature.com/articles/s41467-024-55705-w|journal=Nature Communications}}</ref>. As such, while wildfires negatively affect the entire population, it is much worse for low-income communities. Wildfires have also had major health implications on the Californian populace. Smoke from wildfires carry fine, often toxic, particulate matter, which damages the lungs of the inhaler<ref name=":4">{{Cite web|date=30 Jan 2025|title=Health Affects Attributed to Wildfire Smoke|url=https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke|url-status=live|website=United States Environmental Protection Agency}}</ref>. This can result in reductions in the ability to expel foreign objects, such as virus and bacteria, from the lungs. Inhaling these particles can also exacerbate existing respiratory diseases, as well as premature mortality<ref name=":4" />.

== Outward Migration ==

==Conclusion==
You should conclude your Wiki paper by summarizing the topic, or some aspect of the topic.

==References==
<references />

{{Projectbox CONS200
|names=
|share=no
}}

[[Category:Conservation]]

Course:CONS200/2025WT2/The effects of wildfires on outmigration in California

2025-04-10T02:14:39Z

JamesVanderBeek:

As a result of climate change, the world has seen a significant increase in the frequency of extreme wildfires. California especially is a region that has been greatly impacted by severe wildfires. The damage caused by these fires damage infrastructure and cause health impacts to the people affected. 49% of residents reported being highly impacted by mandatory evacuations, 42% reported being impacted by poor air quality, and 61% reported being high to moderately impacted by power shutoffs<ref>{{Cite journal|last=Howe|first=Alexander A|last2=Blomdahl|first2=Erika M|last3=Smith-Eskridge|first3=Ellie|last4=Pinto|first4=Dakoeta R|last5=Brunson|first5=Mark W|last6=Howe|first6=Peter D|last7=Huntly|first7=Nancy J|last8=Klain|first8=Sarah C|date=April 19, 2024|title=Worldviews more than experience predict Californians' support for wildfire risk mitigation policies|url=https://iopscience.iop.org/article/10.1088/1748-9326/ad3cf6|journal=Environmental Research Letters}}</ref>. Outmigration, or the process of people permanently leaving an area in order to live somewhere else, can be affected by: an area’s perception as a ‘safe’ or ‘unsafe’ place, the actual severity and frequency of natural disasters, and the distribution and application of resources for disaster recovery<ref>{{Cite journal|last=Lambrou|first=Nicole|last2=Kolden|first2=Crystal|last3=Loukaitou-Sideris|first3=Anastasia|date=February 15, 2025|title=Disaster recovery gentrification in post-wildfire landscapes: The case of Paradise, CA|url=https://www.sciencedirect.com/science/article/pii/S2212420925000597?via%3Dihub|journal=International Journal of Disaster Risk Reduction|via=}}</ref>. The impacts of wildfires in California, and the perception of the state as a place where wildfires occur, may be impacting outmigration from the area. In recent years, the state has shown a relative increase in out-migration rates compared to the previous decade (Gabriel et al.). We will discuss if and how the mental and physical impacts of wildfires could be related to this increase.

==History==
[[File:NOAA Satellites Watch as California Burns (NESDIS 2020-10-01).gif|thumb|The NOAA's GOES-West satellite capture of the August Complex fires and Glass fire in California's West Coast region, 2020.]]
California’s ecosystems are historically adapted to wildfire as a disturbance agent. Prior to establishment of the United States of America, fire was utilized as a tool to shape and maintain the landscape. The state of California has monitored wildfire activity since the early twentieth century, revealing patterns of increasing wildfire frequency and severity throughout the state. 19 of the 20 largest fires in the state’s history have occurred in the twenty-first century, and 13 of these 19 have occurred within the last decade (2015-2025)<ref>[https://34c031f8-c9fd-4018-8c5a-4159cdff6b0d-cdn-endpoint.azureedge.net/-/media/calfire-website/our-impact/fire-statistics/top-20-largest-ca-wildfires.pdf?rev=097f901c128347149e2614f2fca4f546&hash=27DDE83DFEF9A69E67C73765892A2B75 "Top 20 Largest California Wildfires"] </ref>.

The state of California has historically used traditional fire suppression techniques within its semi-arid mixed conifer forests. Suppression allows for the accumulation of biomass as fuel beyond natural fire intervals (between 5-20 years), which in turn contributes to the increased risk of severe wildfire for these ecosystems. Long-term fire suppression encourages the development of atypical forest features, such as continuous closed canopies, establishment of shade-tolerant tree species, and buildup of understory fuels<ref>{{Cite journal|last=Klimaszewski-Patterson|first=Anna|last2=Dingemans|first2=Theodore|last3=Morgan|first3=Christopher T|last4=Mensing|first4=Scott A|date=January 15, 2024|title=Human influence on late Holocene fire history in a mixed-conifer forest, Sierra National Forest, California|url=https://link.springer.com/article/10.1186/s42408-023-00245-9|journal=Fire Ecology}}</ref>.

Recent shifts in climate have increased both the degree and frequency of drought experienced in California's ecosystems beyond historic norms, further contributing to fuel buildup and wildfire risk.

==Causes==
Wildfires have always been a part of forest ecosystems, but recent years have seen a sharp increase in occurrence of severe fires<ref>{{Cite web|last=Brown|first=Patrick T|last2=Hanley|first2=Holt|last3=Mahesh|first3=Ankur|last4=Reed|first4=Colorado|last5=Strenfel|first5=Scott J|last6=Davis|first6=Steven J|last7=Kochanski|first7=Adam K|last8=Clements|first8=Craig B|date=2023, September 28|title=Climate warming increases extreme daily wildfire growth risk in California|url=https://www.proquest.com/docview/2871925930?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. Climate and human activities are the most highly attributed to this trend.

==== Climate ====
In recent years, the climate has become undeniably warmer. In the twenty-first century, global temperatures have risen between 0.6 to 0.7℃ <ref>{{Cite web|last=Cayan|first=Daniel R|last2=Maurer|first2=Edwin P|last3=Dettinger|first3=Michael D|last4=Tyree|first4=Mary|last5=Hayhoe|first5=Katharine|date=2008, January 26|title=Climate change scenarios for the California region|url=https://link.springer.com/article/10.1007/s10584-007-9377-6|url-status=live|website=Springer Nature}}</ref>. In the United States, the time period from 1960 to 2013 was warmer than periods of comparable length from the past 600 years<ref name=":1">{{Cite web|last=Garfin|first=Gregg|last2=Jardine|first2=Angela|last3=Merideth|first3=Robert|last4=Black|first4=Mary|last5=LeRoy|first5=Sarah|date=2013|title=Assessment of Climate Change in the Southwest United States|url=https://link.springer.com/book/10.5822/978-1-61091-484-0|url-status=live|website=Springer Nature}}</ref>. This has been especially significant in the Southwest, which tends to be warmer than the rest of the U.S<ref name=":1" />.

Temperature can be an important determinant in wildfire occurrence, affecting humidity and fuel sources. With the higher temperatures of recent years, air is able to hold more water, so as total moisture content remains the same, the relative humidity becomes lower. Precipitation has also decreased as a result of this increase in water storage capacity, leading to drought. The Santa Ana winds, hot and cold winds that flow over Southern California, can also contribute to these warming conditions. These winds are attributed to many extreme temperatures across Southern California. Hot winds, which though less severe than cold winds, can contribute to dry conditions that cause wildfires<ref>{{Cite web|last=Gershunov|first=Alexander|last2=Guzman|first2=Morales Janin|last3=Hatchett|first3=Benjamin|last4=Guirguis|first4=Kristen|last5=Aguilera|first5=Rosana|last6=Shulgina|first6=Tamara|last7=Abatzoglou|first7=John T|last8=Cayan|first8=Daniel|last9=Pierce|first9=David|authors=Williams, Park; Small Ivory; Clemesha, Rachel; Schwarz, Lara; Benmarhnia, Tarik; Tardy, Alex|date=2021, October|title=Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire|url=https://www.proquest.com/docview/2573150518/abstract?accountid=14656&scrollToView=Author&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. These conditions cause fuel such as wood debris on the forest floor to lose more moisture. Combined with the preexisting dry conditions, it leads to larger and more frequent wildfires<ref>{{Cite web|last=Varga|first=Kevin|last2=Jones|first2=Charles|last3=Trugman|first3=Anna|last4=Carvalho|first4=Leila M V|last5=McLoughlin|first5=Neal|last6=Seto|first6=Daisuke|last7=Thompson|first7=Callum|last8=Daum|first8=Kristofer|date=2022|title=Megafires in a Warming World: What Wildfire Risk Factors Led to California’s Largest Recorded Wildfire|url=https://www.proquest.com/docview/2632816567?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>.

==== Human Impacts ====
While climate plays a part in causing wildfires, the recent increase in wildfires can be highly attributed to human activities. From 1992 to 2012, humans could be connected to 84% of fires across the United States<ref name=":2">{{Cite web|last=Balch|first=Jennifer K|last2=Bradley|first2=Bethany A|last3=Abatzoglou|first3=John T|last4=Nagy|first4=R Chelsea|last5=Fusco|first5=Emily J|last6=Mahood|first6=Adam L|date=2017, February 27|title=Human-started wildfires expand the fire niche across the United States|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC5358354/|url-status=live|website=PubMed Central}}</ref>. Human development introduces sources of ignition to the environment, which combined with dry fuels, creates severe wildfires. Proximity to roads and boundaries between wilderness and human developed areas have both been attributed to higher rates of wildfire occurrence<ref name=":2" />.

Current wildfire management practices aim to suppress all forest fires, regardless of severity. There is evidence that fires are actually an important disturbance event for forests that increases biodiversity and resilience<ref>{{Cite web|date=2023, December 25|title=Twenty-year study confirms California forests are healthier when burned - or thinned|url=https://go.exlibris.link/q3XqDwBJ|url-status=live|website=Factiva}}</ref>. Small fires create vertical and horizontal diversity in forests, allowing for fire resilience as some species are more tolerant of fire than others. This also creates gaps in fuel distribution that deter larger fires from occurring. Without this, forests become homogeneous, and fuel builds up rather than being periodically consumed. This leads to more wildfires at higher severities<ref name=":3">{{Cite web|last=Koontz|first=Michael J|last2=North|first2=Malcolm P|last3=Werner|first3=Chhaya M|last4=Fick|first4=Stephen E|last5=Latimer|first5=Andrew M|date=2020, January 10|title=Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13447|url-status=live|website=Wiley Online Library}}</ref>. This creates a feedback loop where, as fires get more severe, forests are no longer gaining biodiversity through small disturbances. Instead, when all vegetation is destroyed in a large fire, biodiversity is reduced and makes forest ecosystems more vulnerable<ref name=":3" />.

==Impacts==

'''Economic Impact'''

Wildfires have caused a significant amount of economic damage in California. These types of damages include property damage, capital loss, and wage loss. The January 2025 wildfires of Southern California caused significant amounts of financial damage. The fires caused property damages and capital loss that range from 76 billion USD to 131 billion USD<ref name=":0">{{Cite web|last=Li|first=Zhiyun|last2=Yu|first2=William|date=2025, March 7|title=Economic impact of the Los Angeles wildfires|url=https://www.anderson.ucla.edu/about/centers/ucla-anderson-forecast/economic-impact-los-angeles-wildfires|url-status=live|website=UCLA Anderson School of Management}}</ref>. These damages mainly comes from the 16,251 homes, properties, and structures destroyed in the fire<ref name=":0" />. The amount also includes damage in other belongings such as automobiles. Additionally, business and employees of affected areas suffered an additional 297 million USD in lost wages<ref name=":0" />. The fire is also expected to cause a 0.48% loss in county GDP leading to an approximate 4.6 billion USD in further economic damage<ref name=":0" />. Wildfires are expected to become more prevalent as climate change worsens. Examples of other devastating fires in California include the Tubbs wildfire of 2018, and the Camp wildfire of 2017<ref name=":0" />. The Tubbs wildfire caused 8.76 billion USD in insurance claims, and the Camp wildfire caused 8.26 billion USD in insurance claims<ref name=":0" />.

'''Social Impact'''

Wildfires have had a significant impact on the Californian society. For one, wildfires have lead to higher living costs for the Californian populace. Wildfires have led to higher housing costs, as well as growing insurance premiums<ref name=":0" />. Low-income communities tend to suffer greater consequences from wildfires. These communities tend to lack the savings and adequate insurance needed to recover from the disaster<ref name=":5" />. This is one of the reasons why wildfires can exacerbate homelessness<ref name=":5" />. Furthermore, low-income communities are also more likely to not have sufficient preventative measures. This makes their properties 29% more likely to be destroyed by wildfires than those that have such measures installed. An example of such preventative measures is roof renewals, with a roof renewal, the risk of a property being destroyed by wildfires can be reduced by up to 27%<ref name=":5">{{Cite journal|last=Reining|first=Sebastian|last2=Wussow|first2=Moritz|last3=Zanocco|first3=Chad|last4=Neumann|first4=Dirk|date=07 January 2025|title=Roof renewal disparities widen the equity gap in residential wildfire protection|url=https://www.nature.com/articles/s41467-024-55705-w|journal=Nature Communications}}</ref>. As such, while wildfires negatively affect the entire population, it is much worse for low-income communities. Wildfires have also had major health implications on the Californian populace. Smoke from wildfires carry fine, often toxic, particulate matter, which damages the lungs of the inhaler<ref name=":4">{{Cite web|date=30 Jan 2025|title=Health Affects Attributed to Wildfire Smoke|url=https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke|url-status=live|website=United States Environmental Protection Agency}}</ref>. This can result in reductions in the ability to expel foreign objects, such as virus and bacteria, from the lungs. Inhaling these particles can also exacerbate existing respiratory diseases, as well as premature mortality<ref name=":4" />.

== Outward Migration ==

==Conclusion==
You should conclude your Wiki paper by summarizing the topic, or some aspect of the topic.

==References==
<references />

{{Projectbox CONS200
|names=
|share=no
}}

[[Category:Conservation]]

Course:CONS200/2025WT2/The effects of wildfires on outmigration in California

2025-04-10T01:44:51Z

JamesVanderBeek:

As a result of climate change, the world has seen a significant increase in the frequency of extreme wildfires. California especially is a region that has been greatly impacted by severe wildfires. The damage caused by these fires damage infrastructure and cause health impacts to the people affected. 49% of residents reported being highly impacted by mandatory evacuations, 42% reported being impacted by poor air quality, and 61% reported being high to moderately impacted by power shutoffs<ref>{{Cite journal|last=Howe|first=Alexander A|last2=Blomdahl|first2=Erika M|last3=Smith-Eskridge|first3=Ellie|last4=Pinto|first4=Dakoeta R|last5=Brunson|first5=Mark W|last6=Howe|first6=Peter D|last7=Huntly|first7=Nancy J|last8=Klain|first8=Sarah C|date=April 19, 2024|title=Worldviews more than experience predict Californians' support for wildfire risk mitigation policies|url=https://iopscience.iop.org/article/10.1088/1748-9326/ad3cf6|journal=Environmental Research Letters}}</ref>. Outmigration, or the process of people permanently leaving an area in order to live somewhere else, can be affected by: an area’s perception as a ‘safe’ or ‘unsafe’ place, the actual severity and frequency of natural disasters, and the distribution and application of resources for disaster recovery<ref>{{Cite journal|last=Lambrou|first=Nicole|last2=Kolden|first2=Crystal|last3=Loukaitou-Sideris|first3=Anastasia|date=February 15, 2025|title=Disaster recovery gentrification in post-wildfire landscapes: The case of Paradise, CA|url=https://www.sciencedirect.com/science/article/pii/S2212420925000597?via%3Dihub|journal=International Journal of Disaster Risk Reduction|via=}}</ref>. The impacts of wildfires in California, and the perception of the state as a place where wildfires occur, may be impacting outmigration from the area. In recent years, the state has shown a relative increase in out-migration rates compared to the previous decade (Gabriel et al.). We will discuss if and how the mental and physical impacts of wildfires could be related to this increase.

==History==
[[File:Crepuscular Rays in GGP.jpg|thumbnail|right|Images from [https://commons.wikimedia.org/wiki/Main_Page Wikimedia Commons] can be embedded easily.]] California’s ecosystems are historically adapted to wildfire as a disturbance agent. Prior to establishment of the United States of America, fire was utilized as a tool to shape and maintain the landscape. The state of California has monitored wildfire activity since the early twentieth century, revealing patterns of increasing wildfire frequency and severity throughout the state. 19 of the 20 largest fires in the state’s history have occurred in the twenty-first century, and 13 of these 19 have occurred within the last decade (2015-2025)<ref>[https://34c031f8-c9fd-4018-8c5a-4159cdff6b0d-cdn-endpoint.azureedge.net/-/media/calfire-website/our-impact/fire-statistics/top-20-largest-ca-wildfires.pdf?rev=097f901c128347149e2614f2fca4f546&hash=27DDE83DFEF9A69E67C73765892A2B75 "Top 20 Largest California Wildfires"] </ref>.

The state of California has historically used traditional fire suppression techniques within its semi-arid mixed conifer forests. Suppression allows for the accumulation of biomass as fuel beyond natural fire intervals (between 5-20 years), which in turn contributes to the increased risk of severe wildfire for these ecosystems. Long-term fire suppression encourages the development of atypical forest features, such as continuous closed canopies, establishment of shade-tolerant tree species, and buildup of understory fuels<ref>{{Cite journal|last=Klimaszewski-Patterson|first=Anna|last2=Dingemans|first2=Theodore|last3=Morgan|first3=Christopher T|last4=Mensing|first4=Scott A|date=January 15, 2024|title=Human influence on late Holocene fire history in a mixed-conifer forest, Sierra National Forest, California|url=https://link.springer.com/article/10.1186/s42408-023-00245-9|journal=Fire Ecology}}</ref>.

Recent shifts in climate have increased both the degree and frequency of drought experienced in California's ecosystems beyond historic norms, further contributing to fuel buildup and wildfire risk.

==Causes==
Wildfires have always been a part of forest ecosystems, but recent years have seen a sharp increase in occurrence of severe fires<ref>{{Cite web|last=Brown|first=Patrick T|last2=Hanley|first2=Holt|last3=Mahesh|first3=Ankur|last4=Reed|first4=Colorado|last5=Strenfel|first5=Scott J|last6=Davis|first6=Steven J|last7=Kochanski|first7=Adam K|last8=Clements|first8=Craig B|date=2023, September 28|title=Climate warming increases extreme daily wildfire growth risk in California|url=https://www.proquest.com/docview/2871925930?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. Climate and human activities are the most highly attributed to this trend.

==== Climate ====
In recent years, the climate has become undeniably warmer. In the twenty-first century, global temperatures have risen between 0.6 to 0.7℃ <ref>{{Cite web|last=Cayan|first=Daniel R|last2=Maurer|first2=Edwin P|last3=Dettinger|first3=Michael D|last4=Tyree|first4=Mary|last5=Hayhoe|first5=Katharine|date=2008, January 26|title=Climate change scenarios for the California region|url=https://link.springer.com/article/10.1007/s10584-007-9377-6|url-status=live|website=Springer Nature}}</ref>. In the United States, the time period from 1960 to 2013 was warmer than periods of comparable length from the past 600 years<ref name=":1">{{Cite web|last=Garfin|first=Gregg|last2=Jardine|first2=Angela|last3=Merideth|first3=Robert|last4=Black|first4=Mary|last5=LeRoy|first5=Sarah|date=2013|title=Assessment of Climate Change in the Southwest United States|url=https://link.springer.com/book/10.5822/978-1-61091-484-0|url-status=live|website=Springer Nature}}</ref>. This has been especially significant in the Southwest, which tends to be warmer than the rest of the U.S<ref name=":1" />.

Temperature can be an important determinant in wildfire occurrence, affecting humidity and fuel sources. With the higher temperatures of recent years, air is able to hold more water, so as total moisture content remains the same, the relative humidity becomes lower. Precipitation has also decreased as a result of this increase in water storage capacity, leading to drought. The Santa Ana winds, hot and cold winds that flow over Southern California, can also contribute to these warming conditions. These winds are attributed to many extreme temperatures across Southern California. Hot winds, which though less severe than cold winds, can contribute to dry conditions that cause wildfires<ref>{{Cite web|last=Gershunov|first=Alexander|last2=Guzman|first2=Morales Janin|last3=Hatchett|first3=Benjamin|last4=Guirguis|first4=Kristen|last5=Aguilera|first5=Rosana|last6=Shulgina|first6=Tamara|last7=Abatzoglou|first7=John T|last8=Cayan|first8=Daniel|last9=Pierce|first9=David|authors=Williams, Park; Small Ivory; Clemesha, Rachel; Schwarz, Lara; Benmarhnia, Tarik; Tardy, Alex|date=2021, October|title=Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire|url=https://www.proquest.com/docview/2573150518/abstract?accountid=14656&scrollToView=Author&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. These conditions cause fuel such as wood debris on the forest floor to lose more moisture. Combined with the preexisting dry conditions, it leads to larger and more frequent wildfires<ref>{{Cite web|last=Varga|first=Kevin|last2=Jones|first2=Charles|last3=Trugman|first3=Anna|last4=Carvalho|first4=Leila M V|last5=McLoughlin|first5=Neal|last6=Seto|first6=Daisuke|last7=Thompson|first7=Callum|last8=Daum|first8=Kristofer|date=2022|title=Megafires in a Warming World: What Wildfire Risk Factors Led to California’s Largest Recorded Wildfire|url=https://www.proquest.com/docview/2632816567?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>.

==== Human Impacts ====
While climate plays a part in causing wildfires, the recent increase in wildfires can be highly attributed to human activities. From 1992 to 2012, humans could be connected to 84% of fires across the United States<ref name=":2">{{Cite web|last=Balch|first=Jennifer K|last2=Bradley|first2=Bethany A|last3=Abatzoglou|first3=John T|last4=Nagy|first4=R Chelsea|last5=Fusco|first5=Emily J|last6=Mahood|first6=Adam L|date=2017, February 27|title=Human-started wildfires expand the fire niche across the United States|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC5358354/|url-status=live|website=PubMed Central}}</ref>. Human development introduces sources of ignition to the environment, which combined with dry fuels, creates severe wildfires. Proximity to roads and boundaries between wilderness and human developed areas have both been attributed to higher rates of wildfire occurrence<ref name=":2" />.

Current wildfire management practices aim to suppress all forest fires, regardless of severity. There is evidence that fires are actually an important disturbance event for forests that increases biodiversity and resilience<ref>{{Cite web|date=2023, December 25|title=Twenty-year study confirms California forests are healthier when burned - or thinned|url=https://go.exlibris.link/q3XqDwBJ|url-status=live|website=Factiva}}</ref>. Small fires create vertical and horizontal diversity in forests, allowing for fire resilience as some species are more tolerant of fire than others. This also creates gaps in fuel distribution that deter larger fires from occurring. Without this, forests become homogeneous, and fuel builds up rather than being periodically consumed. This leads to more wildfires at higher severities<ref name=":3">{{Cite web|last=Koontz|first=Michael J|last2=North|first2=Malcolm P|last3=Werner|first3=Chhaya M|last4=Fick|first4=Stephen E|last5=Latimer|first5=Andrew M|date=2020, January 10|title=Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13447|url-status=live|website=Wiley Online Library}}</ref>. This creates a feedback loop where, as fires get more severe, forests are no longer gaining biodiversity through small disturbances. Instead, when all vegetation is destroyed in a large fire, biodiversity is reduced and makes forest ecosystems more vulnerable<ref name=":3" />.

==Impacts==

'''Economic Impact'''

Wildfires have caused a significant amount of economic damage in California. These types of damages include property damage, capital loss, and wage loss. The January 2025 wildfires of Southern California caused significant amounts of financial damage. The fires caused property damages and capital loss that range from 76 billion USD to 131 billion USD<ref name=":0">{{Cite web|last=Li|first=Zhiyun|last2=Yu|first2=William|date=2025, March 7|title=Economic impact of the Los Angeles wildfires|url=https://www.anderson.ucla.edu/about/centers/ucla-anderson-forecast/economic-impact-los-angeles-wildfires|url-status=live|website=UCLA Anderson School of Management}}</ref>. These damages mainly comes from the 16,251 homes, properties, and structures destroyed in the fire<ref name=":0" />. The amount also includes damage in other belongings such as automobiles. Additionally, business and employees of affected areas suffered an additional 297 million USD in lost wages<ref name=":0" />. The fire is also expected to cause a 0.48% loss in county GDP leading to an approximate 4.6 billion USD in further economic damage<ref name=":0" />. Wildfires are expected to become more prevalent as climate change worsens. Examples of other devastating fires in California include the Tubbs wildfire of 2018, and the Camp wildfire of 2017<ref name=":0" />. The Tubbs wildfire caused 8.76 billion USD in insurance claims, and the Camp wildfire caused 8.26 billion USD in insurance claims<ref name=":0" />.

'''Social Impact'''

Wildfires have had a significant impact on the Californian society. For one, wildfires have lead to higher living costs for the Californian populace. Wildfires have led to higher housing costs, as well as growing insurance premiums<ref name=":0" />. Low-income communities tend to suffer greater consequences from wildfires. These communities tend to lack the savings and adequate insurance needed to recover from the disaster<ref name=":5" />. This is one of the reasons why wildfires can exacerbate homelessness<ref name=":5" />. Furthermore, low-income communities are also more likely to not have sufficient preventative measures. This makes their properties 29% more likely to be destroyed by wildfires than those that have such measures installed. An example of such preventative measures is roof renewals, with a roof renewal, the risk of a property being destroyed by wildfires can be reduced by up to 27%<ref name=":5">{{Cite journal|last=Reining|first=Sebastian|last2=Wussow|first2=Moritz|last3=Zanocco|first3=Chad|last4=Neumann|first4=Dirk|date=07 January 2025|title=Roof renewal disparities widen the equity gap in residential wildfire protection|url=https://www.nature.com/articles/s41467-024-55705-w|journal=Nature Communications}}</ref>. As such, while wildfires negatively affect the entire population, it is much worse for low-income communities. Wildfires have also had major health implications on the Californian populace. Smoke from wildfires carry fine, often toxic, particulate matter, which damages the lungs of the inhaler<ref name=":4">{{Cite web|date=30 Jan 2025|title=Health Affects Attributed to Wildfire Smoke|url=https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke|url-status=live|website=United States Environmental Protection Agency}}</ref>. This can result in reductions in the ability to expel foreign objects, such as virus and bacteria, from the lungs. Inhaling these particles can also exacerbate existing respiratory diseases, as well as premature mortality<ref name=":4" />.

== Outward Migration ==

==Conclusion==
You should conclude your Wiki paper by summarizing the topic, or some aspect of the topic.

==References==
<references />

{{Projectbox CONS200
|names=
|share=no
}}

[[Category:Conservation]]

Course:CONS200/2025WT2/The effects of wildfires on outmigration in California

2025-03-11T04:39:15Z

JamesVanderBeek: /* Heading #1 */ and content

As a result of climate change, the world has seen a significant increase in the frequency of extreme wildfires. California especially is a region that has been greatly impacted by severe wildfires. The damage caused by these fires damage infrastructure and cause health impacts to the people affected. 49% of residents reported being highly impacted by mandatory evacuations, 42% reported being impacted by poor air quality, and 61% reported being high to moderately impacted by power shutoffs (Howe et al., 2024). Outmigration, or the process of people permanently leaving an area in order to live somewhere else, can be affected by: an area’s perception as a ‘safe’ or ‘unsafe’ place, the actual severity and frequency of natural disasters, and the distribution and application of resources for disaster recovery (Lambrou et al., 2025). The impacts of wildfires in California, and the perception of the state as a place where wildfires occur, may be impacting outmigration from the area. In recent years, the state has shown a relative increase in out-migration rates compared to the previous decade (Gabriel et al.). We will discuss if and how the mental and physical impacts of wildfires could be related to this increase.

==History of wildfire activity==
[[File:Crepuscular Rays in GGP.jpg|thumbnail|right|Images from [https://commons.wikimedia.org/wiki/Main_Page Wikimedia Commons] can be embedded easily.]] California’s ecosystems are historically adapted to wildfire as a disturbance agent. Prior to establishment of the United States of America, Indigenous populations utilized fire to shape the landscape and aid in certain endeavors such as hunting. The state of California has monitored wildfire activity since the early 1900’s, revealing patterns of increasing wildfire frequency and severity throughout the state. 18 of the 20 largest fires in the state’s history have occurred in the 21st century, and 12 of these 18 have occurred within the last decade (2015-2025).

The state of California has historically used traditional fire suppression techniques within its semi-arid mixed conifer forests. Suppression allows for the accumulation of biomass as fuel beyond natural fire intervals (between 5-20 years), which in turn contributes to the increased risk of severe wildfire for these ecosystems. Shifts in climate contribute to the aridity of both legacy and current fuel build-up in these ecosystems, which in turn contributes to severe wildfire risk.

==Causes==
Wildfires have always been a part of forest ecosystems, but in recent years we have seen a sharp increase in occurrence of severe fires<ref>{{Cite web|last=Brown|first=Patrick T|last2=Hanley|first2=Holt|last3=Mahesh|first3=Ankur|last4=Reed|first4=Colorado|last5=Strenfel|first5=Scott J|last6=Davis|first6=Steven J|last7=Kochanski|first7=Adam K|last8=Clements|first8=Craig B|date=2023, September 28|title=Climate warming increases extreme daily wildfire growth risk in California|url=https://www.proquest.com/docview/2871925930?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. Climate and human activities are the most highly attributed to this trend.

==== Climate ====
In recent years, the climate has become undeniably warmer. In the twenty-first century, global temperatures have risen between 0.6 to 0.7℃ <ref>{{Cite web|last=Cayan|first=Daniel R|last2=Maurer|first2=Edwin P|last3=Dettinger|first3=Michael D|last4=Tyree|first4=Mary|last5=Hayhoe|first5=Katharine|date=2008, January 26|title=Climate change scenarios for the California region|url=https://link.springer.com/article/10.1007/s10584-007-9377-6|url-status=live|website=Springer Nature}}</ref>. In the United States, the time period from 1960 to 2013 was warmer than periods of comparable length from the past 600 years<ref name=":1">{{Cite web|last=Garfin|first=Gregg|last2=Jardine|first2=Angela|last3=Merideth|first3=Robert|last4=Black|first4=Mary|last5=LeRoy|first5=Sarah|date=2013|title=Assessment of Climate Change in the Southwest United States|url=https://link.springer.com/book/10.5822/978-1-61091-484-0|url-status=live|website=Springer Nature}}</ref>. This has been especially significant in the Southwest, which tends to be warmer than the rest of the U.S<ref name=":1" />.

Temperature can be an important determinant in wildfire occurrence, affecting humidity and fuel sources. With the higher temperatures of recent years, air is able to hold more water, so as total moisture content remains the same, the relative humidity becomes lower. Precipitation has also decreased as a result of this increase in water storage capacity, leading to drought. The Santa Ana winds, hot and cold winds that flow over Southern California, can also contribute to these warming conditions. These winds are attributed to many extreme temperatures across Southern California. Hot winds, which though less severe than cold winds, can contribute to dry conditions that cause wildfires<ref>{{Cite web|last=Gershunov|first=Alexander|last2=Guzman|first2=Morales Janin|last3=Hatchett|first3=Benjamin|last4=Guirguis|first4=Kristen|last5=Aguilera|first5=Rosana|last6=Shulgina|first6=Tamara|last7=Abatzoglou|first7=John T|last8=Cayan|first8=Daniel|last9=Pierce|first9=David|authors=Williams, Park; Small Ivory; Clemesha, Rachel; Schwarz, Lara; Benmarhnia, Tarik; Tardy, Alex|date=2021, October|title=Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire|url=https://www.proquest.com/docview/2573150518/abstract?accountid=14656&scrollToView=Author&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. These conditions cause fuel such as wood debris on the forest floor to lose more moisture. Combined with the preexisting dry conditions, it leads to larger and more frequent wildfires<ref>{{Cite web|last=Varga|first=Kevin|last2=Jones|first2=Charles|last3=Trugman|first3=Anna|last4=Carvalho|first4=Leila M V|last5=McLoughlin|first5=Neal|last6=Seto|first6=Daisuke|last7=Thompson|first7=Callum|last8=Daum|first8=Kristofer|date=2022|title=Megafires in a Warming World: What Wildfire Risk Factors Led to California’s Largest Recorded Wildfire|url=https://www.proquest.com/docview/2632816567?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>.

==== Human Impacts ====
While climate plays a part in causing wildfires, the recent increase in wildfires can be highly attributed to human activities. From 1992 to 2012, humans could be connected to 84% of fires across the United States<ref name=":2">{{Cite web|last=Balch|first=Jennifer K|last2=Bradley|first2=Bethany A|last3=Abatzoglou|first3=John T|last4=Nagy|first4=R Chelsea|last5=Fusco|first5=Emily J|last6=Mahood|first6=Adam L|date=2017, February 27|title=Human-started wildfires expand the fire niche across the United States|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC5358354/|url-status=live|website=PubMed Central}}</ref>. Human development introduces sources of ignition to the environment, which combined with dry fuels, creates severe wildfires. Proximity to roads and boundaries between wilderness and human developed areas have both been attributed to higher rates of wildfire occurrence<ref name=":2" />.

Current wildfire management practices aim to suppress all forest fires, regardless of severity. There is evidence that fires are actually an important disturbance event for forests that increases biodiversity and resilience<ref>{{Cite web|date=2023, December 25|title=Twenty-year study confirms California forests are healthier when burned - or thinned|url=https://go.exlibris.link/q3XqDwBJ|url-status=live|website=Factiva}}</ref>. Small fires create vertical and horizontal diversity in forests, allowing for fire resilience as some species are more tolerant of fire than others. This also creates gaps in fuel distribution that deter larger fires from occurring. Without this, forests become homogeneous, and fuel builds up rather than being periodically consumed. This leads to more wildfires at higher severities<ref name=":3">{{Cite web|last=Koontz|first=Michael J|last2=North|first2=Malcolm P|last3=Werner|first3=Chhaya M|last4=Fick|first4=Stephen E|last5=Latimer|first5=Andrew M|date=2020, January 10|title=Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13447|url-status=live|website=Wiley Online Library}}</ref>. This creates a feedback loop where, as fires get more severe, forests are no longer gaining biodiversity through small disturbances. Instead, when all vegetation is destroyed in a large fire, biodiversity is reduced and makes forest ecosystems more vulnerable<ref name=":3" />.

==Impacts==

'''Economic Impact'''

Wildfires have caused a significant amount of economic damage in California. These types of damages include property damage, capital loss, and wage loss. The January 2025 wildfires of Southern California caused significant amounts of financial damage. The fires caused property damages and capital loss that range from 76 billion USD to 131 billion USD<ref name=":0">{{Cite web|last=Li|first=Zhiyun|last2=Yu|first2=William|date=2025, March 7|title=Economic impact of the Los Angeles wildfires|url=https://www.anderson.ucla.edu/about/centers/ucla-anderson-forecast/economic-impact-los-angeles-wildfires|url-status=live|website=UCLA Anderson School of Management}}</ref>. These damages mainly comes from the 16,251 homes, properties, and structures destroyed in the fire<ref name=":0" />. The amount also includes damage in other belongings such as automobiles. Additionally, business and employees of affected areas suffered an additional 297 million USD in lost wages<ref name=":0" />. The fire is also expected to cause a 0.48% loss in county GDP leading to an approximate 4.6 billion USD in further economic damage<ref name=":0" />. Wildfires are expected to become more prevalent as climate change worsens. Examples of other devastating fires in California include the Tubbs wildfire of 2018, and the Camp wildfire of 2017<ref name=":0" />. The Tubbs wildfire caused 8.76 billion USD in insurance claims, and the Camp wildfire caused 8.26 billion USD in insurance claims<ref name=":0" />.

'''Social Impact'''

Wildfires have had a significant impact on the Californian society. For one, wildfires have lead to higher living costs for the Californian populace. Wildfires have led to higher housing costs, as well as growing insurance premiums<ref name=":0" />. Low-income communities tend to suffer greater consequences from wildfires. These communities tend to lack the savings and adequate insurance needed to recover from the disaster<ref name=":5" />. This is one of the reasons why wildfires can exacerbate homelessness<ref name=":5" />. Furthermore, low-income communities are also more likely to not have sufficient preventative measures. This makes their properties 29% more likely to be destroyed by wildfires than those that have such measures installed. An example of such preventative measures is roof renewals, with a roof renewal, the risk of a property being destroyed by wildfires can be reduced by up to 27%<ref name=":5">{{Cite journal|last=Reining|first=Sebastian|last2=Wussow|first2=Moritz|last3=Zanocco|first3=Chad|last4=Neumann|first4=Dirk|date=07 January 2025|title=Roof renewal disparities widen the equity gap in residential wildfire protection|url=https://www.nature.com/articles/s41467-024-55705-w|journal=Nature Communications}}</ref>. As such, while wildfires negatively affect the entire population, it is much worse for low-income communities. Wildfires have also had major health implications on the Californian populace. Smoke from wildfires carry fine, often toxic, particulate matter, which damages the lungs of the inhaler<ref name=":4">{{Cite web|date=30 Jan 2025|title=Health Affects Attributed to Wildfire Smoke|url=https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke|url-status=live|website=United States Environmental Protection Agency}}</ref>. This can result in reductions in the ability to expel foreign objects, such as virus and bacteria, from the lungs. Inhaling these particles can also exacerbate existing respiratory diseases, as well as premature mortality<ref name=":4" />.

== Outward Migration ==

==Conclusion==
You should conclude your Wiki paper by summarizing the topic, or some aspect of the topic.

==References==
Please use the Wikipedia reference style. Provide a citation for every sentence, statement, thought, or bit of data not your own, giving the author, year, AND page.
For dictionary references for English-language terms, I strongly recommend you use the Oxford English Dictionary. You can reference foreign-language sources but please also provide translations into English in the reference list.

'''Note:''' Before writing your wiki article on the UBC Wiki, it may be helpful to review the tips in [https://en.wikipedia.org/wiki/Wikipedia:Writing_better_articles Wikipedia: Writing better articles].<ref>En.wikipedia.org. (2018). Writing better articles. [online] Available at: https://en.wikipedia.org/wiki/Wikipedia:Writing_better_articles [Accessed 18 Jan. 2018].</ref>

<references />

{{Projectbox CONS200
|names=
|share=no
}}

[[Category:Conservation]]

Course:CONS200/2025WT2/The effects of wildfires on outmigration in California

2025-03-11T04:35:18Z

JamesVanderBeek:

As a result of climate change, the world has seen a significant increase in the frequency of extreme wildfires. California especially is a region that has been greatly impacted by severe wildfires. The damage caused by these fires damage infrastructure and cause health impacts to the people affected. 49% of residents reported being highly impacted by mandatory evacuations, 42% reported being impacted by poor air quality, and 61% reported being high to moderately impacted by power shutoffs (Howe et al., 2024). Outmigration, or the process of people permanently leaving an area in order to live somewhere else, can be affected by: an area’s perception as a ‘safe’ or ‘unsafe’ place, the actual severity and frequency of natural disasters, and the distribution and application of resources for disaster recovery (Lambrou et al., 2025). The impacts of wildfires in California, and the perception of the state as a place where wildfires occur, may be impacting outmigration from the area. In recent years, the state has shown a relative increase in out-migration rates compared to the previous decade (Gabriel et al.). We will discuss if and how the mental and physical impacts of wildfires could be related to this increase.

==Heading #1==
[[File:Crepuscular Rays in GGP.jpg|thumbnail|right|Images from [https://commons.wikimedia.org/wiki/Main_Page Wikimedia Commons] can be embedded easily.]] Include the scope/scale of the problem, intensity/frequency/severity of negative impacts, variables influencing those impacts and any other relevant information needed for understanding the issue.

==Causes==
Wildfires have always been a part of forest ecosystems, but in recent years we have seen a sharp increase in occurrence of severe fires<ref>{{Cite web|last=Brown|first=Patrick T|last2=Hanley|first2=Holt|last3=Mahesh|first3=Ankur|last4=Reed|first4=Colorado|last5=Strenfel|first5=Scott J|last6=Davis|first6=Steven J|last7=Kochanski|first7=Adam K|last8=Clements|first8=Craig B|date=2023, September 28|title=Climate warming increases extreme daily wildfire growth risk in California|url=https://www.proquest.com/docview/2871925930?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. Climate and human activities are the most highly attributed to this trend.

==== Climate ====
In recent years, the climate has become undeniably warmer. In the twenty-first century, global temperatures have risen between 0.6 to 0.7℃ <ref>{{Cite web|last=Cayan|first=Daniel R|last2=Maurer|first2=Edwin P|last3=Dettinger|first3=Michael D|last4=Tyree|first4=Mary|last5=Hayhoe|first5=Katharine|date=2008, January 26|title=Climate change scenarios for the California region|url=https://link.springer.com/article/10.1007/s10584-007-9377-6|url-status=live|website=Springer Nature}}</ref>. In the United States, the time period from 1960 to 2013 was warmer than periods of comparable length from the past 600 years<ref name=":1">{{Cite web|last=Garfin|first=Gregg|last2=Jardine|first2=Angela|last3=Merideth|first3=Robert|last4=Black|first4=Mary|last5=LeRoy|first5=Sarah|date=2013|title=Assessment of Climate Change in the Southwest United States|url=https://link.springer.com/book/10.5822/978-1-61091-484-0|url-status=live|website=Springer Nature}}</ref>. This has been especially significant in the Southwest, which tends to be warmer than the rest of the U.S<ref name=":1" />.

Temperature can be an important determinant in wildfire occurrence, affecting humidity and fuel sources. With the higher temperatures of recent years, air is able to hold more water, so as total moisture content remains the same, the relative humidity becomes lower. Precipitation has also decreased as a result of this increase in water storage capacity, leading to drought. The Santa Ana winds, hot and cold winds that flow over Southern California, can also contribute to these warming conditions. These winds are attributed to many extreme temperatures across Southern California. Hot winds, which though less severe than cold winds, can contribute to dry conditions that cause wildfires<ref>{{Cite web|last=Gershunov|first=Alexander|last2=Guzman|first2=Morales Janin|last3=Hatchett|first3=Benjamin|last4=Guirguis|first4=Kristen|last5=Aguilera|first5=Rosana|last6=Shulgina|first6=Tamara|last7=Abatzoglou|first7=John T|last8=Cayan|first8=Daniel|last9=Pierce|first9=David|authors=Williams, Park; Small Ivory; Clemesha, Rachel; Schwarz, Lara; Benmarhnia, Tarik; Tardy, Alex|date=2021, October|title=Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire|url=https://www.proquest.com/docview/2573150518/abstract?accountid=14656&scrollToView=Author&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>. These conditions cause fuel such as wood debris on the forest floor to lose more moisture. Combined with the preexisting dry conditions, it leads to larger and more frequent wildfires<ref>{{Cite web|last=Varga|first=Kevin|last2=Jones|first2=Charles|last3=Trugman|first3=Anna|last4=Carvalho|first4=Leila M V|last5=McLoughlin|first5=Neal|last6=Seto|first6=Daisuke|last7=Thompson|first7=Callum|last8=Daum|first8=Kristofer|date=2022|title=Megafires in a Warming World: What Wildfire Risk Factors Led to California’s Largest Recorded Wildfire|url=https://www.proquest.com/docview/2632816567?pq-origsite=summon&sourcetype=Scholarly%20Journals|url-status=live|website=ProQuest}}</ref>.

==== Human Impacts ====
While climate plays a part in causing wildfires, the recent increase in wildfires can be highly attributed to human activities. From 1992 to 2012, humans could be connected to 84% of fires across the United States<ref name=":2">{{Cite web|last=Balch|first=Jennifer K|last2=Bradley|first2=Bethany A|last3=Abatzoglou|first3=John T|last4=Nagy|first4=R Chelsea|last5=Fusco|first5=Emily J|last6=Mahood|first6=Adam L|date=2017, February 27|title=Human-started wildfires expand the fire niche across the United States|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC5358354/|url-status=live|website=PubMed Central}}</ref>. Human development introduces sources of ignition to the environment, which combined with dry fuels, creates severe wildfires. Proximity to roads and boundaries between wilderness and human developed areas have both been attributed to higher rates of wildfire occurrence<ref name=":2" />.

Current wildfire management practices aim to suppress all forest fires, regardless of severity. There is evidence that fires are actually an important disturbance event for forests that increases biodiversity and resilience<ref>{{Cite web|date=2023, December 25|title=Twenty-year study confirms California forests are healthier when burned - or thinned|url=https://go.exlibris.link/q3XqDwBJ|url-status=live|website=Factiva}}</ref>. Small fires create vertical and horizontal diversity in forests, allowing for fire resilience as some species are more tolerant of fire than others. This also creates gaps in fuel distribution that deter larger fires from occurring. Without this, forests become homogeneous, and fuel builds up rather than being periodically consumed. This leads to more wildfires at higher severities<ref name=":3">{{Cite web|last=Koontz|first=Michael J|last2=North|first2=Malcolm P|last3=Werner|first3=Chhaya M|last4=Fick|first4=Stephen E|last5=Latimer|first5=Andrew M|date=2020, January 10|title=Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13447|url-status=live|website=Wiley Online Library}}</ref>. This creates a feedback loop where, as fires get more severe, forests are no longer gaining biodiversity through small disturbances. Instead, when all vegetation is destroyed in a large fire, biodiversity is reduced and makes forest ecosystems more vulnerable<ref name=":3" />.

==Impacts==

'''Economic Impact'''

Wildfires have caused a significant amount of economic damage in California. These types of damages include property damage, capital loss, and wage loss. The January 2025 wildfires of Southern California caused significant amounts of financial damage. The fires caused property damages and capital loss that range from 76 billion USD to 131 billion USD<ref name=":0">{{Cite web|last=Li|first=Zhiyun|last2=Yu|first2=William|date=2025, March 7|title=Economic impact of the Los Angeles wildfires|url=https://www.anderson.ucla.edu/about/centers/ucla-anderson-forecast/economic-impact-los-angeles-wildfires|url-status=live|website=UCLA Anderson School of Management}}</ref>. These damages mainly comes from the 16,251 homes, properties, and structures destroyed in the fire<ref name=":0" />. The amount also includes damage in other belongings such as automobiles. Additionally, business and employees of affected areas suffered an additional 297 million USD in lost wages<ref name=":0" />. The fire is also expected to cause a 0.48% loss in county GDP leading to an approximate 4.6 billion USD in further economic damage<ref name=":0" />. Wildfires are expected to become more prevalent as climate change worsens. Examples of other devastating fires in California include the Tubbs wildfire of 2018, and the Camp wildfire of 2017<ref name=":0" />. The Tubbs wildfire caused 8.76 billion USD in insurance claims, and the Camp wildfire caused 8.26 billion USD in insurance claims<ref name=":0" />.

'''Social Impact'''

Wildfires have had a significant impact on the Californian society. For one, wildfires have lead to higher living costs for the Californian populace. Wildfires have led to higher housing costs, as well as growing insurance premiums<ref name=":0" />. Low-income communities tend to suffer greater consequences from wildfires. These communities tend to lack the savings and adequate insurance needed to recover from the disaster<ref name=":5" />. This is one of the reasons why wildfires can exacerbate homelessness<ref name=":5" />. Furthermore, low-income communities are also more likely to not have sufficient preventative measures. This makes their properties 29% more likely to be destroyed by wildfires than those that have such measures installed. An example of such preventative measures is roof renewals, with a roof renewal, the risk of a property being destroyed by wildfires can be reduced by up to 27%<ref name=":5">{{Cite journal|last=Reining|first=Sebastian|last2=Wussow|first2=Moritz|last3=Zanocco|first3=Chad|last4=Neumann|first4=Dirk|date=07 January 2025|title=Roof renewal disparities widen the equity gap in residential wildfire protection|url=https://www.nature.com/articles/s41467-024-55705-w|journal=Nature Communications}}</ref>. As such, while wildfires negatively affect the entire population, it is much worse for low-income communities. Wildfires have also had major health implications on the Californian populace. Smoke from wildfires carry fine, often toxic, particulate matter, which damages the lungs of the inhaler<ref name=":4">{{Cite web|date=30 Jan 2025|title=Health Affects Attributed to Wildfire Smoke|url=https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke|url-status=live|website=United States Environmental Protection Agency}}</ref>. This can result in reductions in the ability to expel foreign objects, such as virus and bacteria, from the lungs. Inhaling these particles can also exacerbate existing respiratory diseases, as well as premature mortality<ref name=":4" />.

== Outward Migration ==

==Conclusion==
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==References==
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'''Note:''' Before writing your wiki article on the UBC Wiki, it may be helpful to review the tips in [https://en.wikipedia.org/wiki/Wikipedia:Writing_better_articles Wikipedia: Writing better articles].<ref>En.wikipedia.org. (2018). Writing better articles. [online] Available at: https://en.wikipedia.org/wiki/Wikipedia:Writing_better_articles [Accessed 18 Jan. 2018].</ref>

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[[Category:Conservation]]