The fashion industry, particularly the manufacturing and use of apparel and footwear, is a significant driver of greenhouse gas emissions, pollution, water use, and textile waste. During the 19th century, industrialization meant a move towards the manufacture of textiles on a large-scale, which only accelerated the environmental degradation.

The rapid growth of the fashion industry has led to around 100 billion items of clothing being consumed annually, with about 85% of clothes consumed in United States being sent to landfill. Recent research suggests that despite constituting a small fraction of total apparel volume, methane emissions from animal-based fibres (such as wool and leather) comprise a disproportionately large share of the fashion industry's greenhouse gas footprint. Indeed, one study estimates that, although wool and leather account for just 3–5% of global fashion production, they could be responsible for 70–80% of its methane emissions over 20 years.

Less than one percent of clothing is recycled to make new clothes. In the late 2010s it emitted 2% of world total greenhouse gases, and contributed to climate change through energy-intensive production. 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 industrially 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 the industry.

Elizabeth L. Cline's 2012 book Overdressed: The Shockingly High Cost of Cheap Fashion was one of the first investigations into the human and environmental toll of fashion. The practice has also come under criticism for contributing to poor working conditions in developing countries.

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. Fast fashion has been enabled by global supply chains, low-cost manufacturing and just-in-time inventory systems that enable retailers to produce and distribute clothing at a scale never before seen.

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, a figure that is still increasing owing to the acceleration of fashion cycles and consumer demand for inexpensive yet fashionable garments.

Impact on waste and overconsumption

The cheaper prices of fast fashion typically lead to impulse purchases, resulting in a higher return rate; many of such returns are then discarded by the companies.

In 2022, fast fashion packaging was accountable for 40% of plastic waste. A recent survey found that nearly 10% of the microplastics found in the ocean occur from textile waste and discarded fashion clothing which may raise concerns going forward.

Fast fashion has led to increased dumping in Ghana, where about 40% of the second hand clothing delivered there from other countries cannot be sold or reused, and is collected by waste management services, burned or dumped in landfill.

In 2018, approximately 85% of the clothing Americans consumed, nearly 3.8 billion pounds annually, was sent to landfills as solid waste, amounting to nearly 80 pounds per American per year.

In 2018, H&M's design team began implementing 3D design, 3D sampling and digital prototyping to help cut waste. Artificial intelligence can be used to produce small garment runs for specific stores.

In contrast to modern overconsumption, fast fashion traces its roots to World War II austerity, where high design was merged with utilitarian materials. The business model of fast fashion is based on consumers' desire for new clothing to wear. In order to fulfill consumers' demand, fast fashion brands provide affordable prices and a wide range of clothing that reflects the latest trends. This ends up persuading consumers to buy more items which leads to the issue of overconsumption. Dana Thomas, author of Fashionopolis, stated that Americans spent 340 billion dollars on clothing in 2012, the year before the Rana Plaza collapse.

Planned obsolescence, which is dominant in fashion marketing where trends change often, plays a key role in overconsumption.

Fast fashion retailers sell clothing that is expected to be disposed of after being worn only a few times.

Low-quality goods make overconsumption more severe since those products have a shorter life span and need to be replaced much more often.

Impact on health The fashion industry incorporates dangerous goods into fabrics, used to preserve and increase the durability of clothes. These include dyes containing heavy metals, lead, phthalates, and per- and poly-fluoroalkyl substances (PFAS), antimicrobial agents that promote bacterial resistance, and synthetic fibers that release microplastics and contain endocrine disruptors, carcinogens, and can cause skin irritation.

Materials and textiles 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. It is estimated that 35% of all microplastics in the ocean come from laundering synthetic textiles.

Cotton

Cotton is the most common non-food crop in the world. 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 437 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 FiberMJ of energy/kg of textileliters of water/kg of textilenylon250 ---acrylic175 ---polyester12550,690-71,409polypropylene115 ---viscose1003,000wool63500cotton5510,000-20,000 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.

Greenhouse gas emissions In the late 2010s fashion emitted 2–4% of world total greenhouse gases, and it contributes to climate change through energy-intensive production. As of 2025 the United Nations Economic Commission for Europe still has a 2018 press release on their website which says 2% to 8%, despite this being criticised by BBC "More or Less" for being unsourced (they say there was a study which said 8% but it is old). According to the BBC "More or less" investigation in 2022 the best study at that time was the 2021 WRI report which gave 2%. The proportion of textile fibres used in clothing must be a factor in the calculation as some are used in other products, such as filters and seat belts.

Production of polyester emits significant amounts of greenhouse gas, followed by cotton, leather, wool, man-made cellulosic fibres and nylon. Most polyester is made in China: whereas the European Union Emissions Trading System may encourage reducing emissions prices on the Chinese national carbon trading scheme are far lower. It has been suggested that exporters to the EU should decarbonize in case clothing is included in the EU Carbon Border Adjustment Mechanism in future. Several strategies were suggested for manufacturers, including more use of textile based feedstock for polyester production, capturing of carbon dioxide from ethylene production, and a certification for low-carbon polyester. Reducing the share of electricity from coal-fired power stations and coal in process heating in clothes manufacturing countries such as China, India, and Pakistan would also help.

Water use and pollution

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 contribute 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 water 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. This 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.