Environmental impact of fashion

The fashion industry, particularly manufacture and use of apparel and footwear, is a significant driver of greenhouse gas emissions and plastic pollution. The rapid growth of fast fashion has led to around 80 billion items of clothing being consumed annually, with about 85% of clothes consumed in United States being sent to landfill.

Less than one percent of clothing is recycled to make new clothes. The industry was estimated to produce 10% of all greenhouse gas emissions in 2020, which was larger than the emissions produced by international flights and maritime shipping combined. According to a 2017 report from the Ellen MacArthur Foundation, if the fashion sector persists on its same trajectory, its share of global carbon emissions could increase to 26% by 2050. The production and distribution of the crops, fibers, and garments used in fashion all contribute to differing forms of environmental pollution, including water, air, and soil degradation. The textile industry is the second greatest polluter of local freshwater in the world, and is culpable for roughly one-fifth of all industrial water pollution. Some of the main factors that contribute to this industrial caused pollution are the vast overproduction of fashion items, the use of synthetic fibers, the agriculture pollution of fashion crops, and the proliferation of microfibers across global water sources.

Efforts have been made by some retailers and consumers to promote sustainable fashion practices, such as reducing waste, improving energy and water efficiency, and using primarily eco-friendly materials. Counter movements, such as slow fashion, have also developed as a response to the growth of fast fashion.

Fast fashion
Fast fashion is defined as "an approach to the design, creation, and marketing of clothing fashions that emphasizes making fashion trends quickly and cheaply available to consumers." While traditional fashion processes usually take about 6 months to design, manufacture, and market products, fast fashion completes these processes in several weeks, allowing the quickly changing demands of consumers to be met.

The amount of new garments bought by Americans has tripled since the 1960s. Globalization has encouraged the rapid growth of the fast fashion industry. Global retail sales of apparel in 2019 reached 1.9 trillion U.S dollars, a new high – this number is expected to double to three trillion U.S. dollars by the year 2030. The world consumes more than 80 billion items of clothing annually.

Fast fashion is also referred to as “disposable fashion”, as trend cycles change so quickly that many consumers will only wear their items once or twice before disposing of them. Clothing is also often made with poor quality materials, dismissed by the inexpensive price point. This leads the clothing to tear, pop seams, or wear through faster than a sustainable fashion item.

Production and disposal of waste
One concern with fast fashion is the clothes waste it produces. According to the Environmental Protection Agency, 15.1 million tons of textile clothing waste was produced in 2013 alone. In the United States, 64.5% of textile waste is discarded in landfills, 19.3% is incinerated with energy recovery, only 16.2% is recycled. When textile clothing ends up in landfills, chemicals on the clothes such as the dye can leech into the ground and cause environmental damage. When unsold clothing is burned, it releases CO₂ into the atmosphere. According to a report from the World Bank Group, the fashion industry is responsible for 10% of yearly global carbon emissions.  In 2019, France announced that it was making an effort to prevent companies from this practice of burning unsold fashion items. Fashion is produced at such high and fast rates, that more than 40% of fashion goods are sold at a markdown.

The packaging of clothing also contributes to the waste produced by the fashion industry. As online shopping, both for clothing and for other items, has become common, the amount of waste produced has totaled about 75 million tons in the United States alone. Many packaging materials are also non-recyclable.

As the popularity of fast fashion has increased, this has led to the rise of ultra-fast fashion. Ultra-fast fashion is similar to fast fashion, however the speed of production and trend cycles are sped up. The clothing is made of even worse quality than typical fast fashion items, and it is encouraged to be worn only a couple of times before disposing of it. Many of the companies with a high social media presence, such as Shein, Fashion Nova, and PrettyLittleThing, promote ultra-fast fashion.

Slow fashion
Slow fashion is a movement that seeks to oppose fast fashion, focusing on the production and sale of sustainable clothing created with eco-friendly materials. The movement encourages purchasing clothing from local sources as opposed to large brands, as these locally-made pieces are often of a higher quality and will last longer than factory-made clothing, and will reduce pollution caused by the disposal of clothes. The slow fashion movement also challenges the ethical issues of fast fashion, such as the underpaying and overworking of factory workers, who often come from low-income countries.

Materials
The majority of fashion's environmental impact comes from its raw materials.

Synthetic materials
Synthetic materials in clothing require an estimated 342 million barrels of oil per year. Polyester was one of the most popular fibers used in fashion in 2017, found in about 60% of garments in retail stores and equalling about 21.3 million tons of polyester fiber. There was a 157% increase of polyester clothing consumption from 2000 to 2015. Washing polyester clothing leads to shedding of microplastics which enter water systems, including oceans.

Cotton
Cotton is the most common crop in the world aside from food. Cotton production uses 2.5% of the world's farmland. Half of all textiles produced are made of the fiber. Cotton is a water-intensive crop, requiring 3644 cubic meters of water to grow one ton of fiber, or 347 gallons per pound. Growing cotton requires 25% of insecticides and 10-16% of pesticides of what is used globally every year. Half of the top pesticides used in growing cotton in the US are deemed likely to be carcinogenic by the United States Environmental Protection Agency. Cotton production degrades the quality of the soil, leading to exhausted fields and expansion into new areas. Expansion into new areas leads to the destruction of local habitats and the associated pollution affects biodiversity.

Animal fibers and textiles
Animal-based fibers such as wool and leather were responsible for 14.5% of global greenhouse gas emissions in 2005. Cattle have digestive systems that use a process known as foregut fermentation, which creates the greenhouse gas methane as a byproduct. In addition to the CH4 released from the ruminants, CO2 and N2O are released into the atmosphere as byproducts of raising the animals. In total, 44% of emissions caused by livestock are from enteric fermentation, 41% comes from the feed needed to raise the livestock, 10% comes from manure, and 5% comes from energy consumption. Energy use here is measured in megajoules needed to produce one kilogram of the given textile. Water use here is measured in liters of water needed to produce one kilogram of the given textile.

Water
Improperly disposing of clothing can harm the environment, especially through wastewater. Chemicals from decomposing clothing can leach into the air and into the ground, affecting both groundwater and surface water. Aside from plastic pollution, textiles also contributes significantly to marine pollution. Unlike plastic, textile pollution's impact on marine life occurs in its various supply chain processes. Pollutants like pesticides and clothing manufacturing chemicals cling to particles that accumulate in the waters ecosystem and consequently enter into human food chains.

Microfiber pollution
Plastic and synthetic textile are both created from a chemical structure called polymer. The Merriam-Webster dictionary defines polymer as “a chemical compound or mixture of compounds formed by polymerization and consisting essentially of repeating structural units.” For plastic, the common polymer found is PET, polyethylene (PE), or polypropylene (PP), whereas for textile, the polymer found the most abundant in the collection of waste is polyester and nylon textiles.

Textiles shed microfibers at every stage of their life cycle, from production, to use, to end of life disposal. These fibers end up in the soil, air, lakes, and oceans. Microfiber pollution has existed as long as the textile industry has, but only recently has it come under public scrutiny. The Ocean Wise Conservation Association produced a study discussing the textile waste. For polyester, it stated that on average, humans shed around 20 to 800 mg micro polyester waste for every kg textile washed. A smaller amount for nylon is found; for every kg of fabrics washed, around 11 to 63 mg of nylon microfiber waste are shed into bodies of water. Washing synthetic textiles releases microplastics and microfibers into the oceans. This type of waste is most commonly found from washing machine cycles, where fibers of clothes fall loose during the tumbling process. An individual domestic load of laundry can shed up to 700,000 microfibers.

The Association also released a study stating that on average, households in the United States and Canada produce around 135 grams of microfibers, which is equivalent to 22 kilotons of microfibers released to the wastewater annually. These wastewater will go through various waste water treatment plants, however, around 878 tons of those 22 kilotons were left untreated and hence, thrown into the ocean.

Textiles are the main source of microfibers in the environment. Thirty five percent of the microplastics that are found in marine ecosystems, such as shorelines, are from synthetic microfibers and nanofibers. Such microfibers affect marine life in that fish or other species in the marine ecosystems consume them, which end up in the intestine and harm the animals. Microfibers have been found in the digestive tracts of widely consumed fish and shellfish. These fish are then consumed by humans, which leads to the absorption of micro pollutants in the fish in a process called biomagnification. Predators of the affected marine species are also harmed, as they ingest the microfibers previously ingested by their prey. The yearly shellfish consumption of microplastics was found to be 11,000 pieces, and microfibers were found in eighty three percent of fish caught in one lake in Brazil. In one study, the food consumption rates decreased in crabs who were eating food with plastic microfibers, which further lead to the available energy for growth to also decrease.

Techniques to address the environmental impacts of the fashion industry include a marine algal bioabsorbent, which could be used for dye removal through rich algal surface chemistry through heteroatom containing functional groups. Many techniques or potential solutions are difficult in their implementation, for instance the accuracy of marine sediment techniques to detect microplastics is not sufficiently tested among different soil samples or sources.

Eutrophication
Clothing often contains non-organic, excessively farmed cotton which is grown with chemicals that are known to cause eutrophication. Eutrophication is a process in which fresh water sources such as lakes and rivers become overly enriched with nutrients. This causes a dense growth of plant life that is harmful to the ecosystem, such as algae blooms. Algal blooms deplete levels of oxygen in water as they decompose, resulting in changes to the ecosystem, either through the die-off of aquatic creatures or populations moving as water becomes uninhabitable. Algal blooms can also make bodies of water unsuitable for both human consumption and recreation. Two of the main ingredients in pesticides are nitrates and phosphates, and when pesticides leak into stream systems surrounding the cropland via runoff, the nitrates and phosphates contribute to water eutrophication.

Water use
The fashion industry consumes a large amount of water to produce fabrics and manufacture garments every year. The global fashion industry uses 93 billion cubic meters of water per year, or 20 trillion gallons. This is four percent of all freshwater withdrawal globally. This amount is set to double by 2030 if it follows the current trend. According to the United Nations Environment Programme, the fashion industry is responsible for 20 percent of global wastewater. Manufacturing a single pair of Levi jeans, will on average, consume about 3,781 liters of water. On average, producing one kilogram of textiles requires 200 liters of water.

Sustainability efforts
The consumer use phase in the life cycle of clothing and other textiles is a significant area of impact, yet is often overlooked. While there is minimal research into energy efficient washers and dryers as a method of reducing impact on the consumer side, wearing garments for 9 months longer could cut overall waste by 22% and water use by 33%. On the producer side, choosing to make garments in popular colors and designs that consumers are more likely to buy is both a financially and environmentally responsible choice. Designing clothing that is more likely to be purchased can reduce waste on the production side. In 2018 the fashion retailer H&M ended up with $4.3 billion of unsold merchandise. Other retailers, such as Patagonia, have made efforts to create more sustainable clothing by using eco-friendly materials, such as organically-farmed cotton and polyester made from recycled plastic bottles.

In order to extend the life cycle of garments and slow rates of production and overconsumption, business models such as 'clothing libraries' have been considered. These businesses collect pieces both from local shops and companies, and allow customers, who pay for a monthly subscription, to borrow clothes for a certain period of time. Business startups such as these have been tested in the Netherlands and Sweden, but there are concerns that clothing libraries will have little to no effect on reducing the effects of fast fashion.