The fact that the fashion industry, and particularly fast fashion, is bad for the planet is no big news. It has been well-publicised that clothing accounts for 10% of global carbon emissions - more than international aviation and shipping combined.  How to stop the fast juggernaut is the thorny issue.

One of the answers often proposed is secondhand. Take someone's cast-offs and you are extending their life, giving those items of clothing further wears. There's no doubting that second-hand clothing is better for the planet than new fashion. 

Last week, Oxfam launched its Second Hand September awareness campaign, with statistics that showed that if everyone in the UK switched to buying second-hand clothing it would prevent the equivalent emissions of flying around the world 17,000 times –a gigantic 12.5 billion kilogrammes of carbon dioxide emissions

Promoting the campaign, Oxfam's Operations  Manager for Scotland, Tom Richardson, urged Scots to "consumer more consciously" and show that "they want a more sustainable fashion industry."

“Right now,” he said, “the fashion industry is a major emitter of the greenhouse gases globally which are threatening the future of our planet.”

Second-hand, of course, is not just about charity shops. The market now has a multiplicity of spaces and platforms: from traditional outlets like Oxfam and vintage stores to online person-to-person sellers, Depop, Vinted and Ebay.

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It was my teenage sons that first brought Depop into my household. I recall when they first started talking about how friends were finding bargain clothes over an app. As an advocate of second-hand buying as a climate-conscious act, I encouraged them, then found myself selling items on Vinted myself - and occasionally buying them. Who, once they start scrolling, can resist?

The story of our times is that preloved is growing and that there are tiny indicators that fast fashion may be slowing. The clothes resale market in the UK grew by 149% between 2016 and 2022, according to Global Data, and it is forecast to rise by over two-thirds more from 2022 to 2026.

Such is the vogue for second-hand that Edinburgh''s St James Quarter is currently hosting a pop-up Charity Super.Mkt, a curated one-stop secondhand clothes store which brings together multiple charity shops under one roof.

Numerous reports have shown that Generation-Z are driving the surge in online person-to-person buying. US online platform ThredUp predicted that the market in second-hand would surge at three times the rate of the overall clothes market by 2027, and be driven by Gen-Z. Depop states that 90% of its active users are under the age of 26.

It also seems many of these younger shoppers, primed with an appetite for a preloved bargain, are now hitting the real-world marketplace of charity and vintage shops.

The young climate movement is indeed teeming with people who extol the virtues of secondhand. Earlier this year, when I interviewed Mikaela Loach, the 25-year-old activist who took the government to court over oil and gas, she was wearing a second-hand jumpsuit in her trademark pink. The colour, she said, simplified her life so that when raking through the second-hand shops in which she buys her clothes she need only head to the pink section.The Herald: Mikaela Loach, climate activist and author of It's Not That Radical

Are the stores noticing this uptick?. At one of Oxfam’s most innovative shops, the DIY Oxfam on Byres Road, the manager, Olivia Nowicki, noted: ”We’re getting more students than ever now. I think people are becoming more aware of charity shops and what good stuff you can get in them. Because of the likes of Depot and Vinted, they are more aware that you can get something for a much lower price.”

Many are buying preloved because its cheap – a fact that matters all the more in a cost-of-living crisis.

Ms Nowicki recalled: “The shops before the pandemic were generally quieter but post-pandemic and with the cost of living crisis that's changed.  People are more aware of what can I do to help the climate and what can I do to save money – and one of those things is shopping second-hand.”

The Herald: Second-hand clothes rail at Oxfam

Experts with an eye on the second-hand market also appear to be noticing a shift. Sustainable fashion influencer Ruth MacGilp believes second-hand shopping has now “reached a point where it’s seen as cool, especially amongst younger consumers”.

“We also," she said, "see a huge amount of second-hand start-ups and we see a lot of major brands investing in resale as well. I’ve seen that more so than any other year that I’ve worked in this space. So I do think we are reaching a tipping point. I guess the question is whether that will actually displace new production.”

“However, it's really positive that people are more accepting of buying used, because ultimately we do have enough clothes in existence to clothes us for many decades, for generations. So the more people are comfortable with that, the better."

"But obviously big brands are going to be capitalising on that. They are worried that secondhand is going to divert spending away from them – so that’s why they’re investing in resale as well. And that’s why I’m a little bit sceptical about the shift”

The number of times the average piece of clothing is worn has been estimated to be 120 times globally, though that figure has been decreasing in recent years. In the UK it is far lower, though how low is difficult to tell.

One UK study, now almost a decade old, found that most fashion purchases by women were only worn seven times. The second-hand market extends out the number of wears - but only if the garment is good enough quality to survive more than those other wears - and one of the problems is that increasingly charity shops are seeing a flood of low-quality cheap clothes that are not built to last.

READ MORE: Mikaela Loach: 'Oil workers are not the enemy of a greener future'

In the midst of all this is the question of whether the second-hand market is really helping us to get off the fast fashion highway? Or is it enabling people to dump their guilt and make money at the same time, creating a parallel market that sustains the fast colossus?

Certainly the story isn’t a straightforward one and some critics have described apps like Depop as acting as another link in the fast fashion chain, and even pointed out that the resale market is “greenwashing” fast fashion.

Ms MacGilp, who has a day job working for the climate campaign community Action Speaks Louder, does not believe its the silver bullet solution when it comes to fashion and climate. "I don’t think anything can be sold as that – but it helped me to wean myself off fast fashion and I know that other people have had similar experiences.”

The Herald: Ruth MacGilp , sustainable fashion influencer, wearing second-hand clothes

Ruth MacGilp, sustainable fashion influencer, image: Ellie Morag

What's also striking is that secondhand is home to a world of creativity – of upcycling, crafting and fixing. Ms MacGilp recalled that second-hand had allowed her to learn a little bit more about my style. She learned to mend and upcycle, to dye things, take them in.

The Byres Road DIY Oxfam store is about some of these more creative aspects of second-hand shopping. It’s about more than giving clothes another wear – it's about expanding their use in a circular economy. Opened in 2008, its aim was to encourage not just the buying of second-hand but its upcycling, and it sells not only clothes, but also linen, buttons, preloved sewing machines and donated goods with the tag ‘handmade’ - some of which are even made from items bought there.

Manager Ms Nowicki said: “People that are studying fashion or textiles at art school and university are buying stuff so that you can upcycle them which is really cool.”

But is second-hand shopping really anything new? Becc Sanderson who runs B's Vintage Market at venues in Edinburgh and Glasgow, however, believes that secondhand/vintage has never been out of fashion.  "I've been running vintage markets for over 10 years now and I love watching the next generation come through the doors, some of whom came as kids with their parents orginally. Zoomers are easily a third of B's Vintage Market csutomers, and that's growing with each event."

A lot of this, she believes, is due to the financial stresses on students. "But I'm also aware that for many of them buying secondhand is the only ethical choice, which is hugely impressive."

None of this, of course, is going to make all that much difference, if we don’t stop consuming so much new and environmentally damaging fashion. Last year Vogue published an article titled, “The trouble with secondhand: It’s becoming like fast fashion." The problem, it observed is that “even when buying used, customers crave constant newness and still overconsume.”

With the Circular Economy bill due to go through parliament, a key challenge is how we can turn the fast-track of clothing from shop to dump into something truly more sustainable.

Circularity is clearly part of the answer - as is secondhand, which allows our clothes to join a merry-go-round of fashion in which we can find novelty without new environmental impact, save for the (not-insignifcant) impact of transport, which is particularly relevant with online sellers like Depop and Vinted.

But, as the Vogue article implied, we also need to consume less - and that is the biggest challenge in terms of making fast fashion slow down.