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When it comes to sustainability, what you wear makes a difference. In decades past, clothing was meant to last for more than a few seasons, but today’s era of fast fashion means we now buy more clothes per capita and keep each item for half as long as we did in the 1990s — and fashion wasn’t exactly “slow” then. This generates a tremendous amount of global waste, as the clothing industry accounts for 5 to 10 percent of global emissions and about 20 percent of wastewater production.
So, what’s the solution? Besides buying used clothing when possible, and less of it overall, you can invest in sustainable fibers that leave a lighter mark on the planet. Wool is a fiber that’s been used for millennia, and there’s a strong argument from an environmental perspective to keep it in your wardrobe. Let’s look at the facts behind wool and explore why it makes sense as a zero-waste basic.
Wool is the natural fiber produced by sheep. It grows in wavy locks, known as “staples,” all over their bodies. These fibers are primarily composed of protein, with small amounts of fat, calcium, and sodium, and they’re made of scales that cause the fibers to cling more tightly together when exposed to heat and water.
As wool grows longer, its crimped pattern becomes more obvious, especially in finer fibers. The crimp within these staples adds elasticity, and the wool becomes coated in lanolin, a natural grease that’s removed during processing, but that can be used in skin and hair care products. The curly fibers trap air and create an insulating layer that gives wool its cozy qualities. While different breeds grow wool at different rates, most sheep raised for wool production are shorn at least once a year, and each animal can produce 2 to 30 pounds of wool annually.
Photo by Adobe Stock/Steve Lovegrove
All wool for the garment industry is harvested by shearing, but it doesn’t all have the same characteristics. Today, the majority of wool is divided into three categories — fine, medium, and coarse — based on the diameter of the fibers, which are measured in microns. Fine fiber is most prized for delicate products and high-fashion apparel; Merino sheep are the most common fine-wool breed. Medium wool is most common in mid-range clothing and may come from a blend of fine and other wools, or from sheep breeds that produce thicker wool fibers. Coarse wool, in contrast, often comes from dual-purpose breeds that are also raised for meat, or from breeds that produce long, lustrous wool. Their strong wool is used for durable textiles, such as carpets and outerwear.
Are Wool Garments Environmentally Friendly?
Four main factors affect whether we can classify a fiber as good for the planet: the environmental impact of sourcing the raw material; the textile production process; how the product is used by the consumer; and its end-of-life impact. Let’s look at each of these factors for wool.
Wool as a Raw Resource
Farming sheep can have profoundly positive effects on the environment. Many breeds of sheep thrive in arid rangelands that lack the consistent rainfall necessary for producing food crops, and mindful grazing practices can improve land over time by restoring soil nutrient levels, sequestering atmospheric carbon, and improving the soil’s ability to store and retain water. Contrast this with cotton, a water-intensive textile crop that’s typically planted in spaces that might otherwise go toward food production.
Photo by Adobe Stock/Steve Lovegrove
Wool also acts as a form of carbon storage by sequestering the carbon in the grasses and herbs the sheep consume, as more than half its weight comes from organic carbon. This indicates that good pasture management practices can help combat the effects of climate change. Synthetic fibers, in contrast, are made from fossil fuels, which means they release carbon that was stored millions of years ago.
Once wool is shorn from sheep, it’s “graded,” or sorted into lots with similar staple length and fiber diameter, and then scoured to remove lanolin, dirt, and other impurities. From there, the wool is blended, dyed, and carded to align the fibers before being spun into yarn and woven or knit into the final product. The exact nature of these steps varies significantly by country, manufacturing scale, and official environmental regulations where it’s produced.
Wool in Use
Most wool garments are designed to be durable, which means they often last longer than other fibers. The International Wool Textile Organisation reports that the average life span of a wool garment is 10 years, while cotton and synthetic clothes typically last less than three. That’s partly because of the variance of tensile strength between the fibers. Laboratory tests have shown that wool fibers can resist tearing after being bent more than 20,000 times, while cotton breaks after 3,200 bends and silk snaps after 2,000 bends.
Wearing wool also improves your personal environment. Thanks to its natural insulation properties, wool will keep you warm in winter while remaining breathable enough for comfort in higher temperatures, which will reduce your need to crank up the heat in your home. And because wool is naturally absorbent, it can pull up to 30 percent of its weight in moisture from your skin without feeling damp or heavy. This means that wool blankets have better breathability than cotton and are less likely to make you clammy overnight. Wool products also tend to stay clean longer, and consequently, need to be washed less frequently and at lower temperatures, which reduces the resources required to maintain them.
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There’s evidence that wool products improve the quality of indoor environments as well. That’s because wool fibers naturally absorb indoor air pollutants, such as formaldehyde, sulfur dioxide, and nitrogen dioxide. Because wool won’t re-emit these contaminants after it collects them, some estimates show that wool carpets may work to purify the air for up to 30 years.
Where Wool Goes
Though wool makes up just 1.3 percent of all textiles, it accounts for 5 percent of recycled fabrics, which makes it one of the world’s most reused fibers. Wool also contains a high percentage of nitrogen, which allows it to act as a “slow-release” fertilizer, and it biodegrades quickly. When wool is exposed to moisture for prolonged periods — as in a compost heap or bin — it’ll break down quickly with the help of bacteria and fungi. A soil burial test from AgResearch revealed that wool fabrics lost 95 percent of their weight after 15 weeks in the ground.
In contrast, synthetic fibers, such as polyester, don’t decompose in a human time frame, and they’re contributing to microplastic pollution that leads to a host of environmental problems, including water pollution and toxicity throughout the food chain.
Wool is a sustainable material when sourced in ways that consider the health of planet, but the painful truth is that much of today’s wool production falls short of this ideal and puts more strain on the environment than necessary. One significant problem is overgrazing. Sheep need lots of pasture to feed on, and when they’re confined to small spaces, they’ll deplete the grass and be at greater health risks from crowding. To combat the spread of parasites alone, the United States applies more than 14,000 pounds of pesticides to sheep each year. Many of these contain compounds that are suspected endocrine disrupters, and they’re highly toxic to fish and amphibians when they contaminate regional water systems.
Even sustainably raised sheep take a toll on the environment because of their sheer numbers. New Zealand is home to 45 million sheep, and livestock in the region account for more than half of the country’s greenhouse gas emissions through the methane they produce. Because methane is highly efficient at trapping heat, its effect is more than 25 times greater than an equal weight of carbon dioxide.
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How wool is processed also makes a difference in its environmental impact. Transforming raw wool into fabric requires plenty of heat, water, and chemicals, and much of the global wool supply is processed in countries with lower environmental standards to keep costs and processing time down. The fibers may be subjected to bleaches, which may leave behind dioxins and harsh scouring agents, such as formaldehyde, as well as chemical dyes that may harm both human health and the environment.
There’s also concern from an animal cruelty perspective. Merino sheep in particular often undergo tail docking and a controversial process called “mulesing,” in which the wrinkles of wool-bearing skin around the breech of a sheep is removed. These procedures are done to reduce the risk of potentially fatal infections from blowflies (“flystrike”), which are attracted to urine and feces caught by the wool; however, anaesthetics aren’t required to perform mulesing. New Zealand has banned this procedure, while Australian wool organizations promote mulesing accreditation programs and the use of analgesics as research continues for other solutions to solve the problem of flystrike.
How to Buy Ethical Wool
With these concerns in mind, how can you ensure the wool you wear isn’t hurting the planet? The best step you can take is to buy less and keep wearing the clothing you have. If you need new sweaters, seek out used options to keep existing wool garments in use for as long as possible, or seek out clothing made from recycled fibers. When buying new, be sure to look through the numerous certifications that provide information about a brand’s environmental sustainability and treatment of animals and laborers, including the Responsible Wool Standard, ZQ Merino Standard, Good On You ratings, and the Soil Association Organic Standards.
It’s also smart to avoid products that boast they’re made of “smart wools” with high-performance capabilities, especially if you’re chemically sensitive. These fibers often undergo treatment with a rigorous combination of chemicals during manufacturing to change their natural structure and make them resistant to felting, which some people might find irritating.
Photo by Adobe Stock/Alexander Raths
If you’re looking for a way to make a significant difference with your wool purchases, seek out locally spun, organic yarn so you can support your community. Buying organic will ensure you’re financially supporting sound environmental practices that promote healthy soil, water systems, and sheep. Likewise, organic wool doesn’t get doused in chemicals during the production process, so you won’t be exposing your skin to those compounds as you wear it. This is good for allergy sufferers, as many who react to wool are actually sensitive to the dyes and scouring agents used to treat it.
Overall, wool garments tend to last longer than cotton or silk garments, and they have a lower environmental impact than synthetics. When your wool clothing is too worn to mend anymore, you can compost it, and you can support sustainable agriculture by buying replacement garments from reputable producers.
Lydia Noyes is a freelance author who primarily writes about health, wellness, and gardening. She and her husband recently moved to Michigan to start a small farm after three years on a mountain homestead in central Appalachia.