While most consumer goods suffer from similar issues, what makes the fashion industry particularly problematic is the frenetic pace of change it not only undergoes, but encourages. With each passing season (or microseason), consumers are pushed into buying the latest items to stay on trend.

It’s hard to visualise all of the inputs that go into producing garments, but let’s take denim as an example. The UN estimates that a single pair of jeans requires a kilogram of cotton. And because cotton tends to be grown in dry environments, producing this kilo requires about 7,500–10,000 litres of water. That’s about 10 years’ worth of drinking water for one person.

There are ways to make denim less resource-intensive, but in general, jeans composed of material that is as close to the natural state of cotton as possible use less water and hazardous treatments to produce. This means less bleaching, less sandblasting, and less pre-washing.

Unfortunately it also means that some of the most popular types of jeans are the hardest on the planet. For instance, fabric dyes pollute water bodies, with devastating effects on aquatic life and drinking water. And the stretchy elastane material woven through many trendy styles of tight jeans is made using synthetic materials derived from plastic, which reduces recyclability and increases the environmental impact further.

Jeans manufacturer Levi Strauss estimates that a pair of its iconic 501 jeans will produce the equivalent of 33.4kg of carbon dioxide equivalent across its entire lifespan – about the same as driving 69 miles in the average US car. Just over a third of those emissions come from the fibre and fabric production, while another 8% is from cutting, sewing and finishing the jeans. Packaging, transport and retail accounts for 16% of the emissions while the remaining 40% is from consumer use – mainly from washing the jeans – and disposal in landfill.

Another study of jeans made in India that contained 2% elastane showed that producing the fibres and denim fabric released 7kg more carbon than those in Levi’s analysis. It suggests that choosing raw denim products will have less impact on the climate.

But it is also possible to look for further ways of reducing the impact of your jeans by looking at the label. Certification programmes like the Better Cotton Initiative and Global Organic Textile Standard can help consumers work out how green their denim is (although these programmes aren’t perfect – many suffer from a lack of funding and the complex supply chains for cotton can make it hard to account where it all comes from).

Some manufacturers are also working on ways to reduce the environmental impact from the production of their jeans, while others have been developing ways of recycling denim or even jeans that will decompose within a few months when composted.

It’s not cotton, but the synthetic polymer polyester that is the most common fabric used in clothing. Globally, “65% of the clothing that we wear is polymer-based”, says Lynn Wilson, an expert on the circular economy, who for her PhD research at the University of Glasgow is focusing on consumer behaviour related to clothing disposal.

Around 70 million barrels of oil a year are used to make polyester fibres in our clothes. From waterproof jackets to delicate scarves, it’s extremely hard to get away from the stuff. Part of this stems from the convenience – polyester is easy to clean and durable. It is also lightweight and inexpensive.

But a shirt made from polyester has double the carbon footprint compared to one made from cotton. A polyester shirt produces the equivalent of 5.5kg of carbon dioxide compared to 2.1kg from a cotton shirt.

Switching to recycled polyester fabric can help to reduce the carbon emissions – recycled polyester releases half to a quarter of the emissions of virgin polyester. But it isn’t a long-term solution, as polyester takes hundreds of years to decompose and can lead to microfibres escaping into the environment.

But natural materials aren’t necessarily sustainable either, if they require huge amounts of water, dye and transport. Organic cotton may be better for the farmworkers who would otherwise be exposed to enormous levels of pesticides, but the pressure on water remains.

However, a great deal of innovation is going into crafting lower-impact fabrics.

Biocouture, or fashion made from more environmentally sustainable materials, is increasingly big business. Some companies are looking to use waste from wood, fruit and other natural materials to create their textiles. Others are trying alternative ways of dyeing their fabrics or searching for materials that biodegrade more easily once thrown away.

But the carbon footprint of our clothing can also be reduced in other ways, too. The way we shop has a big impact.

Some research has suggested that online shopping can have a lower carbon footprint than travelling to traditional shops to buy products, particularly if consumers live far away. But the rise of online shopping has also driven changes in consumer behaviour, contributing to a fast fashion culture where consumers buy more than they need, have it delivered to their door and then return a large proportion of their purchases after trying them on.

Returning items can effectively double the emissions from transporting your goods, and if you factor in failed collections and deliveries, that number can grow further.

It can also be cheaper for internet retailers and fashion brands to dump or burn returned goods, rather than attempting to find another home for them. This not only means the greenhouse gas emissions produced in manufacturing the clothing are wasted, but further emissions are released as it rots or burns. The US Environmental Protection Agency estimates that in 2017 10.2m tonnes of textiles ended up in landfills while another 2.9m tonnes were incinerated. In the UK an estimated 350,000 tonnes of clothes end up in landfill every year. 

A simple way to reduce the footprint from online shopping then is to only order what we really want and intend to keep. According to the World Bank, 40% of clothing purchased in some countries is never used.

Piskova has tried to move away from the fast fashion culture herself by learning to appreciate what she already has rather than what she could have. But detaching herself from a fashion-obsessed mindset hasn’t been easy. To help, Piskova resists going to places where she feels pressure to consume, such as shopping malls. She also periodically swaps clothes with her friends, which not only allows them to refresh their own wardrobes but also helps them feel closer to each other. And she has also learned to embrace small blemishes on her clothes, rather than seeing these as an excuse to buy more.

“People are so careful with their clothes, like to not have any scratches on them or have any holes or whatever,” says Piskova. “But then when you think about it, that’s part of the clothes. You remember that one time when you went to a festival, where you ripped your shirt or something like that, and it’s a nice memory.”

The number of times you wear an item of clothing can make a big difference too in its overall carbon footprint. Research by scientists at the Chalmers Institute of Technology in Gothenburg, Sweden, found that an average cotton t-shirt might release just over 2kg of carbon dioxide equivalent into the atmosphere while a polyester dress would release the equivalent of nearly 17kg of carbon dioxide.

They estimated, however, that the average t-shirt in Sweden is worn around 22 times in a year, while the average dress is worn just 10 times. This would mean the amount of carbon released per wear is many times higher for the dress.

According to the Ellen MacArthur Foundation, the average number of times a piece of clothing is worn decreased by 36% between 2000 and 2015. In the same period, clothing production doubled. These gains came at the expense of the quality and longevity of the garments.

A number of public surveys also suggest that many of us have clothes in our wardrobes that we hardly ever wear. According to one survey, nearly half of the clothes in the average UK person’s wardrobe are never worn, primarily because they no longer fit or have gone out of style. Another found that a fifth of the items owned by US consumers are unworn.

It is clear that investing in higher-quality clothing, wearing them more often and holding onto them for longer, is the not-so-secret weapon for combatting the carbon footprint from your garments. In the UK, continuing to actively wear a garment for just nine months longer could diminish its environmental impacts by 20–30%.

Naturally, some clothing companies have sniffed out an opportunity here. Clothing rental services, for instance, are especially appealing in a social-media era where some people are reluctant to be seen online wearing the same outfit more than once. For those who want to look good in their online photos but have even less of an impact on the environment, there is the ephemeral trend for digital fashion, or clothing designed to only appear online by being superimposed onto your images.

Buying less also means caring for clothes more. Websites like Love Your Clothes, set up by UK recycling charity WRAP, offer tips on repairing and extending the life of clothes, which can reduce the carbon footprint of the clothes.

But tackling the underlying reasons for why we over-purchase, yet underuse, clothes could also help. In a consumerist society, people are trained to find fast fashion pleasurable and addictive.

“A lot of the things that we purchase fulfil some kind of function in ourselves – particularly fashion items,” says Mike Kyrios, a clinical psychologist who researches mental disorders at Australia’s Flinders University. People who have lower self-esteem or worry about their status are especially likely to use overspending as a route to feel like they “belong”, he explains. As are people who are sensitive to rewards – indeed the reward centres in the brain are those most activated by impulse shopping.

Online shopping also means that the impulse to buy is harder to control, as internet stores are open 24/7 – including, as Kyrios says, the times “when your decision-making capabilities are at their minimum”.

Though estimates vary, one is that about 5% of the population exhibits compulsive buying behaviour. “The problem is it’s well hidden,” says Kyrios. “People don’t show up for treatment, people don’t acknowledge it’s a problem.”

One solution might be to simply ration the time you spend looking at clothes online, but perhaps a better approach is to find less wasteful ways of achieving the sense of reward that over-spenders are seeking. Mainstream consumers can scratch their itch for new clothes by buying from vintage and secondhand clothing shops.

“Secondhand clothing is giving clothes a second life and it's slowing down that fast-fashion cycle,” says Fee Gilfeather, a sustainable fashion expert at charity Oxfam. “So I would say secondhand (clothing) is actually one of the solutions to the overconsumption challenge.”

Cutting down on washing can also help to further reduce the carbon footprint of your wardrobe, while also helping to lower water use and the number of microfibres shed in the washing machine.

“You don’t need to wash clothes as often as you might think,” says Gilfeather. She hangs some of her dresses out to air, for example, rather than washing them after each wear. “Reducing the amount of washing that you need to do is the best way of making sure that the plastics don’t get into the water system.”