The fashion industry might not be the first that comes to mind as a superuser of fossil fuels. But modern textiles rely heavily on petrochemical products that come from many of the same oil and gas companies driving greenhouse gas emissions. Today, in fact, fashion accounts for up to 10% of global carbon dioxide output—more than international flights and shipping combined, according to the United Nations Environment Programme.

It also accounts for a fifth of the 300 million tons of plastic produced globally each year. Polyester, a ubiquitous form of plastic that’s derived from oil, has overtaken cotton as the backbone of textile production. Garments made from polyester and other synthetic fibers are a prime source of microplastic pollution, which is especially harmful to marine life.

More clothing is being produced than ever, as retailers and their customers churn through styles at a frenetic pace. Estimates from consulting firm McKinsey and the World Economic Forum suggest the number of garments produced each year has at least doubled since 2000.

Only a fraction of what’s manufactured gets recycled. Eighty-seven percent of the total fiber input used for clothing is ultimately incinerated or sent to a landfill. Fashion brands have come under criticism for practices such as destroying unsold products and sending piles of clothes to landfills across the Global South, on top of often exploitative and dangerous conditions for workers.

Sustainability has become a major focus of fashion brands in the past decade. Inditex’s Zara committed that 50% of items it sells in 2022 will be made with recycled materials and “ecologically grown cotton.” Parade, the online-first intimate and loungewear brand, launched an initiative to collect and recycle underwear. Other brands–like Boohoo, H&M and Kering (the group that includes the luxury houses Gucci, Saint Laurent and Alexander McQueen)–have released sustainability reports that detail goals to use more recycled or organic materials.

At the same time, production of fossil fuel-based clothing has continued and is projected to grow in the next two decades. Oil and gas companies continue to bet on petrochemical products like polyester to drive their future growth as demand from transportation declines.

The International Energy Agency (IEA) estimates that plastics will be the largest driver of net growth in the demand for oil in the next two decades. Textiles are the second-largest product group made from petrochemical plastics behind packaging, making up 15% of all petrochemical products.

When it comes to the environmental impacts of the industry, fast fashion is often blamed. But high-end brands originate trends and generate demand for new styles, which are then mass produced by fast fashion companies for a fraction of the cost. And they’re often made in similar factories with similar conditions–and even similar materials.

“Fast fashion companies⁠—and consumers⁠—get scapegoated for the problems of the global fashion industry,” said Minh-Ha T. Pham, associate professor of media studies at the Pratt Institute in New York City. Pham’s research focuses on labor, race, gender and power in the global fashion industry in works like her upcoming book, “Why We Can’t Have Nice Things.”

Explosive Growth in Synthetic Fibers

Most clothing around the world is made with polyester, the synthetic fiber derived predominantly from petroleum. It has overtaken cotton as the main textile fiber of the 21st century, ending hundreds of years of cotton’s dominance. The global market for polyester yarn is expected to grow from $106 billion in 2022 to $174.7 billion by 2032. Yearly polyester fiber production is projected to exceed 92 million tons in the next 10 years–an increase of 47%.

Not all polyester is produced from petroleum; it can also be made from natural polymers, like bioplastics, but those alternatives only make up a small fraction of polyester in the fashion industry.

There’s a reason the industry loves polyester. It’s hardy and versatile, used to create everything from athletic clothes to faux fur jackets to silky dresses. It’s been marketed as more sustainable than some natural fibers because the production process doesn’t require as much water or land as growing natural fibers like cotton.

Bloomberg News collected data on more than 15,000 pieces of apparel added to Chinese e-retailer Shein’s online store between Nov. 1 and Nov. 15, 2021, to determine what materials were used to make them. Similar data for 10,000 women’s clothing styles from Asos, Missguided, Boohoo and PrettyLittleThing were also collected and made available to Bloomberg by U.K.-based The Royal Society of Arts. While the data represents women’s styles only, polyester is common in both men’s and women’s clothing.

Almost every piece of clothing we buy is made with some polyester, the data shows. Although the dataset is made up of mostly fast fashion retailers, it’s not just fast fashion that loves polyester. Lululemon joggers? Polyester, nylon and elastane. Gucci skirt? Polyester.

Shein puts out an average of about 1,000 women’s new clothing styles a day based on our sample, 85% of which were made with polyester. Around 95% of styles we sampled from Shein were made with at least some plastics-based material, either from polyester, nylon, acrylic or elastane. A majority of these garments were made with blends of different fibers, like polyester and cotton or polyester and nylon.

Such blends help achieve different textures in clothes but make the process of recycling textile waste even harder. Even without blended fibers, sorting clothing by material to recycle is labor intensive and requires a skilled workforce, though new methods are currently being developed. Then, the actual process of transforming blended fibers into reusable yarn requires separating materials with chemical solvents. Data is almost nonexistent, but a report from the Ellen MacArthur Foundation suggests that less than 1% of clothing collected globally for recycling is actually used to create new garments.

Tasha Lewis, associate professor in the Department of Human Centered Design at Cornell University, said that “brands create blends [of fibers] to achieve a certain type of garment, but are not thinking about end of life of that garment” and what is required to reuse or recycle those fibers.

The Environmental Impact

The environmental effects of polyester’s dominance over the clothing industry are varied. For one, polyester requires a large amount of energy to produce. In 2015, polyester production for clothing emitted 282 billion tons of carbon dioxide, triple that of cotton.

Additionally, synthetic textiles like polyester shed tiny pieces of plastic with every wash and wear. These plastic particles, called microplastics, pollute the oceans, freshwater and land and pose a danger to the animals that consume them, inhibiting their growth and reproduction. Scientists in Australia estimate that between 9.25 to 15.86 million tons of microplastics can be found on the ocean floor.

The U.S. Geological Survey found that 71% of microplastics found in samples of river water came from fibers. Scientists estimate that, globally, 35% of the microplastics found in oceans can be traced to textiles, making them the largest source of microplastic pollution in the world’s oceans. A study in England found that marine mussels exposed to microplastics had broken DNA and deformed gills and digestive tubes.

According to data from the U.S. Environmental Protection Agency, the amount of clothing and footwear waste generated by Americans each year ballooned from around 1.4 million tons in 1960 to over 13 million tons in 2018. Around 70% of that clothing ended up in landfills, while only 13% was recycled into either new clothing or for other use. Those data may be an underestimate, as donated clothes often end up in landfills either in the U.S. or in countries like Ghana and Chile.

The pace of apparel production often exceeds demand, begging the question of what happens to the clothing that never gets sold. H&M came under fire in 2018 for disclosing in its annual report that it had accumulated $4.3 billion of unsold inventory. In the years since, its stockpile has remained roughly at the same level. In 2017, a Swedish power plant abandoned coal as a source of fuel, instead burning mountains of discarded clothing from H&M.

In an email to Bloomberg, H&M declined a request for an interview.

Gabriella Santaniello, founder of retail research firm A-Line Partners, says that overproduction results from the pressure that companies face to grow their sales. “There’s a business case for them to constantly funnel more product out, because they see it as a missed opportunity for sales. But it’s a slippery slope,” she said. “If you don’t get the fashion right one month, it triggers the domino effect. That’s how these retailers end up with such a glut of inventory.”

A spokesperson for Inditex, the parent company of Zara, said that Inditex’s inventory surpluses are not significant. Cumulative inventory across its eight brands decreased by 16% in 2019 and again by 9% in 2020. The spokesperson said that whatever goes unsold at the end of each season gets sold through authorized third parties, donated or recycled.

“The single biggest concern in the fashion industry is that there is too much clothing,” said Sheng Lu, assistant professor of apparel studies at the University of Delaware. “Fashion brands try to address the problem of sustainability by encouraging consumers to shop for more sustainable fabrics, but the reality is that just leads to more and more consumption.”

Stemming the Tide of Textiles

The buying public’s interest in sustainability has never been higher. A recent survey by Swiss global investment group Credit Suisse of 10,000 Gen Z and millennial consumers across the world found that ​​at least 65%  are worried about the environment and almost 80% intend to buy only sustainable products, or at least as many as possible. Over 40% of respondents said they believe the fashion industry to be unsustainable.

With so much clothing saturating the market in recent years, the secondhand market has swelled in parallel. In the first quarter of 2018, Poshmark, an online marketplace where users can buy and sell used clothing and accessories, reported $177 million in sales. The same period in 2020 saw $309 million in sales, a 75% increase. But there’s only so much life left in the clothing that consumers just don’t want to buy–and there is a lot of that.

Colleen Morrone, the chief executive officer of Goodwill of Delaware, said that as of 2015, its 16 stores and four outlets racked up 7 million pounds of unsold clothing a year. More recent data is not available, but donations have increased over the past decade, she said. The shelf life of a donated article of clothing is four to six weeks. If items go unsold after that, the store ships them to Goodwill outlets, which sell clothing at 99 cents per pound. Whatever is left gets sent to textile recyclers or overseas.

“It’s a cliche to say that we can’t shop our way out of a climate catastrophe but it’s absolutely true,” said Pham, the professor at Pratt. “The popular emphasis on individuals knowing where their clothes are made and who made their clothes–as ways of buying ‘better’–obscures the reality that the problems with the global fashion industry aren’t individual bad brands that just need to be called out. The problems are structural and systemic,” she said.

Despite the dizzying number of styles it puts out, Shein says that its business model actually minimizes waste because it produces a small number of items in each style and waits to see how well styles perform online before mass-producing them. Whereas brands that follow the traditional model try to “predict what consumers want and make those products six months ahead of the selling season,” according to Lu. Fashion forecasts like this can easily result in piles of unsold clothing.

“I think there are some misunderstandings about fast fashion compared to conventional fashion retailers,” said the University of Delaware’s Lu. “Fast fashion companies like Shein can actually reduce unwanted clothing, if it’s made efficiently.”

Still, the volume of new products offered by a business model like Shein’s poses its own issues. “The problem is that even if you create exactly what consumers want, you’re also creating a culture that encourages them to throw clothing away too quickly,” he said.

Lu’s research found that in the span of 2021, Zara offered 50,000 new SKUs – stock keeping units, or unique styles – on its website. H&M had 25,000. Shein? 1.5 million.

About 0.2% (26 out of around 12,000) of the Shein styles made from plastics in Bloomberg’s data set included some reference to recycled materials. 5.8% of Asos styles, 4.4% of Missguided’s,  1.9% of Boohoo’s and 0.8% of PrettyLittleThing’swere made with recycled plastics, most commonly from plastic bottles. Nike claims to divert an average of 1 billion plastic bottles annually from landfills and waterways through its use of recycled polyester.

While this makes use of another single-use plastic, textiles aren’t being recycled back into the system, said Lewis. Clothing made from recycled materials end up in landfills rather than made back into clothing. Brands are “taking feedstock from another industry…which is not really closing the loop.”

There are companies working to develop scalable technologies that do make use of textile waste. Ambercycle, a six-year old start-up based in Los Angeles, is developing and scaling technology to “take old garments, put them through a series of processes that separate the fibers out at a molecular level, and recover them to make new yarn,” says co-founder and chief executive officer Shay Sethi. Sethi says turning textile waste into something of value will incentivize reuse and could divert millions of tons of clothes away from landfills.

Ambercycle recently completed a $21 million round of funding to continue to scale its work, which includes a recent collaboration with H&M. Another company, Circ, is collaborating with brands such as Patagonia to recycle textile waste and produce recycled clothing from discarded clothing.

Though sustainability measures are growing in popularity, so far they’re no match for the speed and sheer weight of apparel piling up on the planet. Santaniello, who worked in the fashion industry for 15 years, says retailers and consumers both need to change their habits and expectations for a true reckoning to occur.

“When I worked in fashion, the other sales reps and I would sit there and talk about how we wanted to set fire to the whole industry and start over again,” she says. It may be a chicken-or-egg problem, but “if stores just started offering less inventory, maybe consumers could get used to there being less out there. I think that would make us all a little bit happier.”

Methodology:

To calculate the number of clothes thrown away each second, the annual waste figure—around 11.28 million tons, or 22.56 billion pounds—was divided by the number of seconds per year—around 31.56 million. In that calculation, each piece of clothing was estimated to weigh around 5.33 ounces—one third of a pound—to account for differences in types of clothing and footwear.

In order to estimate the waste per person in terms of pants, one pair of pants is assumed to weigh 16 ounces. The estimated number of pounds of clothing and footwear waste used to generate waste in terms of pants is based on the Environmental Protection Agency’s clothing waste figure.

Data on materials used by Shein was collected between November 1 and 15, 2021. Only women’s new clothing styles were sampled. Data from Asos, Missguided, PrettyLittleThing and Boohoo was collected between May 11 and 29, 2021 by The Royal Society for Arts and shared with Bloomberg News.

Styles collected with no materials data were removed. Sampled datasets represent an average collection of women’s styles from each brand but may not represent other accessories, footwear or men’s clothing or other items and are a rough approximation of offerings by each brand.

Global production of polyester and other fibers through 2030 was projected with a regression analysis by Tecnon Orbichem.

Editors: Amanda Kolson Hurley and Yue Qiu

With additional work by: Todd Woody and Paul Murray