When people think about who’s responsible for global warming, they’re likely to point fingers at oil and gas companies, logistics companies and air travel. They’re probably not as quick to think about the trendy, cheap tops and jeans they might be wearing.

But fast fashion — the apparel sector that includes brands like H&M, Zara and the now-$100 billion Chinese retailer Shein — is one of the world’s largest carbon emitters. 

Overall, the fashion industry is responsible for 10% of annual global carbon emissions, more than all international flights and maritime shipping combined, according to the World Bank. Of the $551.4 billion global apparel industry, approximately 18% is fast fashion, according to market research firm Business Research Company.

Because inventory turns over so quickly in fast fashion as consumers move on to new trends, it’s particularly worrisome for climate advocates.

Yet if the success of Shein is any indication, those concerns haven’t dampened investors’ enthusiasm for the sector. On the same day in early April when the United Nations released its latest report on climate change, warning that countries were not doing enough to combat global warming, a Wall Street Journal article disclosed that the Chinese retailer has raised between $1 billion and $2 billion. 

So why is our desire for inexpensive, cool clothes fueling a global disaster? And what, if anything, can clothing brands or consumers do to limit the impact? The answers to both questions are starting to become clear.

Retailers, for instance, are already moving to implement more sustainable methods in their supply chains – with varying degrees of speed and success, said Carol Spieckerman, president of Spieckerman Retail consulting firm.

These retailers know that a new generation of shoppers, led by Gen Z, care about sustainability, climate change, and the environment, she said.

"Sustainability is critical to the long term viability of their brands," Spieckerman said. 

Partly out of concern for the environment, and partly out of cost-consciousness, Gen Z has been powering a rise in resale clothing companies, such as apps like Poshmark and Depop. Clothes swapping ventures have also been gaining popularity.

As for Shein, Spieckerman notes that Asia, especially China, are less committed to cutting greenhouse gasses compared to the West if it means damaging their still growing economies. So consumer demand for sustainable products may not be as strong, she said.

So yes, fast fashion is big today. However, "it may not remain that way for long," Spieckerman said.

Chez Target, the root of fast fashion

People normally think of H&M and Zara as the pioneers of fast fashion, in which retailers quickly make and sell inexpensive on-trend clothing to consumers. 

But in many ways, fast fashion's roots go back to Target, at least with the fashion part. Thanks to its limited time partnerships with trendy designers like Isaac Mizrahi, Missoni, and Jason Wu, the company convinced consumers that they could buy fashion–forward apparel and accessories at low prices.

H&M and Zara took Target's model and put it on steroids. They quickly developed, manufactured, and sold inexpensive clothing that could appeal to fashion-conscious consumers on a regular basis. 

While traditional retailers like department stores would need a year to roll out a seasonal collection, fast fashion stores could do so by quarter or even week. It was also no accident that fast fashion's emergence coincided with the rise of social media and the instant gratification culture that the internet encourages.

Why wait for Target's semi-regular design partnerships to hit stores, maybe once or twice a year when you can replace your wardrobe every other week? 

$500 billion in cast-off clothing

By one estimate, fast fashion sales will reach nearly $100 billion this year and grow at an annual rate of 8 percent until 2026. Eight percent is pretty good but the figure represents a significant slow compared to past three years when sales were increasing 20% each year, according to McKinsey consulting firm.

But those booming sales have consequences. A model that encourages consumers to quickly and frequently buy new clothing means the environment will suffer. 

To keep up with demand, manufacturers will run their plants longer hours to to make clothing, producing more greenhouse gasses. And consumers who replace their wardrobes will throw clothing into the trash. The piles of unwanted clothing that end up in landfills will be burned, pouring more carbon into the atmosphere.

In 2000, 50 billion new garments were made; nearly 20 years later, that figure has doubled, according to the Ellen MacArthur Foundation. And every year some $500 billion in value is lost due to clothing that is barely worn, not donated, recycled, or ends up in a landfill, the foundation said.

The World Bank estimates that less than 1% of used clothing is recycled into new garments. If the industry continues at its current pace, its greenhouse gas emissions will surge more than 50% by 2030.

Using wastewater and trash to make jeans?

Spieckerman is a little more optimistic than those numbers suggest. The global pandemic, which forced people to stay home, started to convince people that they don't no longer buy lots of clothing. Why buy a new suit when the company can only see your head in that Zoom call?

And manufacturers and retailers in general are focusing more on sustainability efforts. For example, Levi's Strauss has been using wastewater to make jeans and partnered with the World Bank to provide low cost loans to suppliers who meet sustainability targets.

Even H&M has been exploring ways to make clothing out of grapes and plastic waste. The company is also testing Looop, the world’s first in-store recycling system that turns old clothes into new ones, at one of its stores in Stockholm.

However, those efforts will take time. Meanwhile, greenhouse emissions continue to rise and investors are plowing money into fast fashion startups like Shein.

You can see why. As of June 2021, Shein has overtaken its European rivals to become the top fast fashion brand in the United States, according to data firm Ernest Research. The company controls 28% of the market compared to 20% for H&M and 11% for Zara.

The total US market grew 15% between January and mid-June of the year, while Shein grew nearly 160% in the same period, "suggesting that the brand’s mobile-first strategy resonated with the post-Covid consumer," Ernest Research said.

Perhaps the long term picture favors a more sustainable approach to clothing. But for now, fast fashion retailers are making lots of money and nothing, even alarming climate change reports, is likely to change that any time soon.