Course:CONS200/2021/Is wool sustainable?

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Sheep that produce wool.

Wool is a versatile fabric resource that can be obtained from animals such as goats, bison, rabbits, and especially sheep. It is widely used in the clothing industry for its ability to resist flame, retain heat and repel water to some extent [1]. The history of trading wool and wool products can be traced back to medieval times, and the wool market still carries a heavy weight in the world economy. This wiki page aims to introduce the environmental benefits and costs of sheep wools. It also aims to briefly analyze sheep wool's production and consumption to discuss whether wool is a sustainable resource or not. A case study focusing on the Life Cycle Assessment of wool farms in Australia will be introduced at the end of this wiki page.

Production and Consumption

Production:

The amount of fleece a sheep can produce is variable on a multitude of factors, including diet, living conditions, and breed of sheep being farmed. Certain breeds like the Suffolk (medium-wool) sheep produce a fleece of approximately 4 - 8 lbs while a breed like the Lincoln (long-wool sheep) produces a fleece of approximately 12 - 16 lbs. Producers of wool in the United states often sell their wool to warehouses or directly to wool mills, while smaller producers of wool likely sell their wool “raw” and through wool pools or to customers [2].

The wool industry produces nearly 1,160 kilograms of clean wool per year, requiring over 1 billion sheep to achieve this. Each sheep is estimated to produce around 10 meters of fabric [3]. Wool makes up roughly 1% of global fiber production, but supplies many people with jobs and also drives certain economies around the globe. While China is the largest producer of wool, Australia dominates the global wool market [4].

Pie chart for world wool production in 2015.

Australia produces roughly 478,492 metric tons of wool per year, followed by China which makes 235,927 metric tons [5]. These two countries produce a combined amount of 714,419 metric tons of wool and control a whopping 43% of the wool market with Australia having the most market control out of any other country sitting at 25% of global production. In comparison, the USA produces 8% of the world’s wool and is a net importer of wool as a result [5]. Australia is the largest exporter of wool, while China is the largest importer [6].

There are roughly 1.16 billion sheep worldwide that produce enough wool yearly to create one sweater per person living on earth today. Only 1% of the fiber used to create clothing is made from wool. Most wool is used in home furnishing, examples would be furniture and carpeting [6].

Only around 1% of the global sheep population and 1% of the global wool production can be considered organically managed. Organically managed sheep are raised without insecticides, modified feedstock, and must be farmed using a regime that bans mulesing (a practice of shaving the rear end of a sheep in order to prevent unwanted parasites from subsisting off the sheep) [4].

In comparison to wool production, polyester is the most produced fiber in the world, sitting at 51.5% of the global fiber production.  Synthetic fibers, like Polyester, are the most common fibers being produced around the globe, and have dominated the market since the 1990’s. Around 66.2 million metric tons of synthetic fiber were produced in 2018, with 62% of the global fiber market being synthetic fibers [4].

Cellulosic fibers are man-made fibers created from wood, thus requiring large amounts of trees to produce these fibers on a mass global scale. Man-made cellulosic fibers make up 6.2% of the global fiber market, with viscose comprising the majority of the cellulosic fibers being produced. Viscose made up 79% of all man-made cellulosic fibers in 2018 [4].

Consumption:

Wool consumption is dependent on the quality and category of wool being sold and produced.

Fine wool is more expensive and sought after for garments and clothing, while longwool sheep are mainly used for carpets and furniture. The global consumption of wool is variable on the products being produced, and this reflects on the type of wool being sold.  Fine wool (fibers less than 20 microns) account for 37% of the global wool production. Long wool (38 microns) accounts for 41% of the global production. Medium wool (medium-long fibers) accounts for roughly 22% of the global production [5].

China is the largest consumer of wool, averaging around 165,538.30 USD THO from 2002 - 2020 and reaching its highest point in January of 2018 at about 373,547.00 USD THO [7].

Net mass of wool imported into the UK from 2010 to 2020

The USA is a net importer of wool, and many other countries also rely on the global wool market to purchase wool. This is mainly due to the lack of local wool production, forcing people to import wool from overseas in order to keep their business running. For example, the UK imported roughly 21.1 million kilograms of wool in 2020 alone [8].

In 2019 the average price paid for a pound of wool was $1.89 USD [2].

Referencing import graphs from countries around the globe, the global wool trade has slowed down due to Covid-19 restrictions on trade, and the economic impact of Covid-19 has also made purchasing materials such as wool more difficult and unimportant. In 2018 the UK imported 44.9 Million kilograms of wool but during the pandemic (2020) the annual import of wool was cut in half [8].

The global wool market was estimated at roughly $4.72 billion US dollars in 2018 [5].

Polyester is most consumed in China, with 22.9kg of polyester consumed per capita. Countries in Europe also consume large quantities of polyester, places like Italy sold 419.74 kilotons of polyester fiber, with Germany selling around 389.12 kilo tons [9].

Environmental Benefits of Wool

Wool insulation being used for a rural chicken coop

No direct environmental benefits could be found for sheep wool. However, it does have an indirect benefit by serving as a renewable, recyclable, and natural alternative to various synthetic materials used in construction. This reduces the carbon footprints of projects requiring these materials such as insulations and buildings. Greasy wool can even decrease the carbon footprint even more as it would otherwise be discarded [10]. According to the United Nation Environmental Program, the construction industry carries the highest environmental impact [10]. This impact can be reduced with sheep wool being used as an alternative material.

Sheep wool has excellent thermal and acoustic insulation qualities and provides an eco-friendly and renewable alternative to synthetic absorbers such as polyurethane foam and fiberglass [11] [10]. It is particularly useful as a thermal insulator for rural industrial buildings such as flour mills and wineries as these products often require strict environmental control [10]. It is also used as an alternative to fiberglass in making soft mats on the concrete floors of factories. These soft mats are used to reduce machine vibrations, which can affect workers and/or reduce the quality of products such as red wine [10]. Sheep wool is reported to have even better vibration absorption qualities than synthetic material such as rock wool [10]. Despite having a lower performance, sheep wool fiber can be used as an eco-friendlier alternative to polypropylene fiber, used to reinforce building components [10]. This alternative allows for eco-friendly buildings to be created [10].

Sheep wool also has another indirect environmental benefit by contributing to environmental cleanup processes. For example, greasy raw wool repels water and attracts oil [12] [13]. Thus, greasy raw wool serves as an excellent sorbent, which is a substance that absorbs oil and separates it from water used to clean up marine oil spills [13]. Greasy raw wool is a natural, low cost, and highly abundant material, which allows for faster responses to oil spills and by extension, less damage to the marine environment [13]. It can also be reused multiple times and works on different oil densities, which makes it more efficient [13].  And since greasy raw wool is a natural material, it once again benefits the environment by reducing the use of synthetic synthetic sorbents such as polyurethane [13] [14].

Environmental Costs of Wool

The overall environmental costs of wool are fairly low, provided that no concerning substances are used. If so, wool can be decomposed and therefore have no harmful environmental effects [15]. Greasy wool, however, is of concern because of its high bacterial load, resulting in expensive disposal costs [10]. The correct method of disposal for greasy wool is to throw it into landfill, but it is oftentimes burned or buried instead, therefore causing serious environmental costs on the soil and air [10].

Animal-derived materials are among the worst for the environment [15]. Though, as of 2020, wool accounts for only three percent of the fibers used in clothing [2], and if produced without concerning substances, can be safely biodegraded and even recycled [15].  However, toxic chemicals are often used in wool, which can pollute rivers and streams and create health problems for communities [15].

In comparison with synthetic materials, wool needs much more agricultural land and water. Though, the trade-off is that synthetic materials are not biodegradable and rely on petrochemical industries [15]. In other words, the process of making synthetic materials is dependent on fossil fuel extraction, which therefore leads to problems that come with the petrochemical industry, such as oil spills [15]. Man-made cellulose fibers are a more sustainable alternative to other synthetics, derived directly from plants or extracted through chemical means. These cellulose fibers can be composted of if not made with harmful products [15]. Thus, a much less environmentally costly alternative from lack of need for land use and reliance on petrochemical industries.

Case Study

Before the nineteenth century, the world wool market was mainly controlled by the UK. However, the alteration in the English woollen industry's size and structure, along with the increase in demand for Australian wool from buyers around Europe in the mid-century, relocated the market to Australia [16]. Since then, Australia has played a dominant role in the world wool market and has become the largest exporter of wool today.

Wool Production in Australia

The three sheep production zones of Australia

Around 70% of wool-producing farms in Australia are mixed farms that grow crops and raise livestock [17]. Therefore, the farms that produce wool also produce grains and breeding animals such as lambs as co-products of wool [18]. Wool in Australia is mainly produced in three agroclimatic zones, which are as follows:

The high rainfall zone

This zone is on the eastern coast of Australia. It has a relatively cool temperate environment with an average annual rainfall >600 mm. The precipitation is concentrated mainly in summer. Farms in this zone consists mostly mixed grazing enterprises that raise smaller-bodied Merino sheep and produce wool and lamb.

The wheat-sheep zone

This zone is also called the western wheat-sheep zone. It has a temperate environment similar to the high rainfall zone, but has precipitation concentrated in winter with a low winter annual average rainfall (300-600 mm). Farms in this zone not only raise sheep but also grow wheat and other grains on arable lands. The crops growing on the farm can be used to support feed deficiencies in summer. Wool is produced from large-bodied Merino sheep, and meat is produced as a co-product of wool.

The pastoral zone

The southern pastoral zone contains mainly arid desert land with annual average rainfall <300 mm. Large-bodied Merino sheep are raised on the small areas of semi-arid native grasslands and savannas in this zone, and they are typically set-stocked in large paddocks. Lambs are also produced in this zone [18].

Life Cycle Assessment Stages

Life Cycle Assessment on Australian Wool Production

A Life Cycle Assessment (LCA) is a method in which assess the environmental impact of a product by analyzing its interaction with the environment. It covers the entire lifetime of a product from raw material to disposal, including resource input, processing, manufacturing, distribution, use and the end of product’s life [17]. By doing LCA, a brief idea about the environmental cost of wool production can be determined.

The environmental cost of wool regarding its lifetime includes supplementary feed for sheep, greenhouse gas (GHG) emissions, fresh water consumed, fossil energy demand and the land used to raise sheep [17][18]. According to the LCA study done by S.G. Wiedemann and his colleagues in 2016, the environmental impact of wool varies from region to region. Climate, production intensity, farm types and level of inputs can all influence the environmental cost of wool. For example, a higher wool production will lead to lower GHG emission. The arable land occupation and energy required for sheep production is higher in mixed grazing and cropping regions, since supplementary feed grown there is used for sheep production [18]. The amount of water consumption in regions with low annual rainfall and high temperature will be higher than regions with relatively higher annual average rainfall, which means that farms in the pastoral zone require the highest amount of water, and water resources used in the high-rainfall zone will be the lowest.

Although there are lots of factors that need to be considered and analyzed in LCA, the total environmental impact of wool production in Australia is relatively lower than expected. For example, the water used for human, industry and environment is comparatively low to produce wool according to the study. Additionally, in Australia there is an economic incentive for cropping on larger areas of land [18]. Farms that produce wool also produce a number of co-products such as meat and grain as a part of the production cycle [18]. This indicates that farms that produce wool also contract part of the animal husbandry of Australia and bring large profit to the farm.

Conclusion

In conclusion, wool is sustainable when managed properly. While wool has environmental costs including the disposal of greasy wool, this can be mitigated. Greasy wool can be repurposed as a building and insulation material in the construction industry, allowing for eco-friendly building (cite). Although the amount of agricultural land and resources used to maintain sheep farms cannot be mitigated, its influence can be reduced by changing factors such as production intensity under proper management. Additionally, wool production is heavily reliant on global demand, with countries like the UK and USA being net importers of wool while Australia and China are net exporters [5]. This dynamic ensures that wool production never exceeds the global demand so that resources are not wasted and unneeded environmental costs are not accumulated. Wool is therefore an overall sustainable fabric with versatile uses.

References

  1. Hoguet, D (April 10, 2014). "Sustainability and performance in textiles: Can you have it all?". The Guardian.
  2. 2.0 2.1 2.2 Schoenian, Susan (March 21, 2020). "Real men wear wool". Sheep 101.
  3. "Global Wool Production and Sustainable Standards". Common Objective. Retrieved March 18, 2021.
  4. 4.0 4.1 4.2 4.3 Truscott, Liesl (2019). "Preferred Fiber & Materials Market Report 2019" (PDF). Textile Exchange. Retrieved March 18, 2021.
  5. 5.0 5.1 5.2 5.3 5.4 Pines, Lawrance. "Is Wool Worth the Weight? Get All the Commodity Facts [+ Price Drivers]". Commodity. Retrieved March 18, 2021.
  6. 6.0 6.1 "Global Wool Production and Sustainable Standards". Common Objective. Retrieved March 18, 2021.
  7. "China Imports". Trading economy. Retrieved March 18, 2021.
  8. 8.0 8.1 Shahbandeh, S (March, 2021). "Net mass of wool imported into the United Kingdom (UK) from 2010 to 2020". Statisa. Retrieved March 18, 2021. Check date values in: |date= (help)
  9. "Polyester Properties, Production, Price, Market and Uses". Plastic Insight. 2016. Retrieved March 18, 2021.
  10. 10.0 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 10.9 Parlato, M; Porto, S (2020). "Organized framework of main possible applications of sheep wool fibers in building compentness". Sustainability. 12: 761.
  11. Del Rey, Romina; Uris, Antonio; Alba, Jesus; Candelas, Pilar (2017). "Characterization of Sheep Wool as a Sustainable Material for Acoustic Applications". Materials. 10: 1277 – via MDPI.
  12. "A golden fleece?". The Economist. n.d.
  13. 13.0 13.1 13.2 13.3 13.4 Periolatto, Monica; Gozzelino, Giuseppe (2015). "Greasy Raw Wool for Clean-up Process of Marine Oil Spill: from Laboratory Test to Scaled Prototype". Chemical Engineering Transactions. 43: 2269–2274 – via ResearchGate.
  14. "Sorbents". United States Environmental Protection Agency. 2016.
  15. 15.0 15.1 15.2 15.3 15.4 15.5 15.6 Young, S (2019). "The Real Cost of Your Clothes: These are the fabrics with the best and worst environmental impact". The Independent.
  16. Ville, Simon; Merrett, David (2016). "Too big to fail: Explaining the timing and nature of intervention in the Australian wool market". Australian Journal of Politics and History. 62: 337–352.
  17. 17.0 17.1 17.2 Henry, Beverley (May 2011). "Understanding the environmental impacts of wool: A review of Life Cycle Assessment studies" (PDF). Australian Wool Innovation & International Wool Textile Organisation.
  18. 18.0 18.1 18.2 18.3 18.4 18.5 Wiedemann, S; Yan, M; Henry, B; Murphy, C (2016). "Resource use and greenhouse gas emissions from three wool production regions in Australia". Journal of Cleaner Production. 122: 121–132.
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This conservation resource was created by Course:CONS200. It is shared under a CC-BY 4.0 International License.