A fifth of clothes produced each year are incinerated before they are even worn - with even more ending up in landfill.
Around £140million-worth of clothes is sent to landfill every week.
And the cost of producing these clothes is huge - not just financially, but environmentally.
"The Intergovernmental Panel on Climate Change has found 1.5 trillion litres of water are used to produce our clothing yearly, which is a staggering fact," sustainability blogger Bianca Foley told ITV News.
The co-host of the Sustainably Influenced podcast has long been guiding people through what she describes as a "minefield" of sustainability.
So as part of ITV News' Climate Changes series, we caught up with Bianca about how smart fashion choices can help in the fight against climate change...
Bianca Foley on sustainable fashion
"There are so many different impacts on the planet from the fashion industry," said Bianca.
"One of the biggest stats that I've seen is that 300,000 tonnes of clothing goes into landfill each year and 20% of everything that's produced in a year is incinerated as well.
"The IPCC has found 1.5 trillion litres of water are used to produce our clothing yearly which is a staggering fact."
So what can individuals do to help?
Buying second hand clothes, renting clothes and researching brands is key - even for people on a budget.
Bianca said people can also help by "just buying what you need, and not just shopping for the sake of it".
"The amount of clothing being produced is a big, big factor. Reducing the rate of production - because we end up incinerating some of it anyway - would lower our impact on the planet and the environment.
"If you are on a tighter budget, it means you will have a wardrobe that you love without impacting the environment," she added.
Picking the right fabrics could make more of a difference than you might think, too.
Bianca said: "There are loads of alternatives and they're really going to help bring alternative fabrics and sustainable production further into the mainstream."
These include econyl - which is made of recycled nylon and fishing nets - a cotton-like fabric called ecotex, as well as hemp.
"Hemp is described as a 'super fabric' because it's super durable, it costs less to produce, it doesn't use as much water to produce," Bianca said.