Every item you resell keeps one more garment out of a landfill and saves roughly 3 kg of CO2 and 700+ gallons of water compared to buying new. On Depop, lead with sustainability in your listings. On Poshmark, put it in your closet bio. Some buyers look for it, so make it easy to find.
In 2018, 11.3 million tons of textiles went to US landfills, according to the EPA. That is 22.6 billion pounds of clothing, shoes, and fabric, about two thirds of the textile waste generated that year. Every item you resell is one less thing in that pile. A single Poshmark sale keeps a garment in circulation, saves roughly 3 kg of CO2, and avoids over 700 gallons of water that would have gone into manufacturing a replacement.
Most resellers don't think about this. You got into it for the money, and that's fine. Sustainability is also a selling point. Many Depop buyers look for shops that lead with it, and a line about secondhand values in a Poshmark closet bio gives buyers one more reason to pick you. You are already doing the work, so you may as well get credit for it.
The Fashion Waste Problem, by the Numbers
The US Environmental Protection Agency estimated that 11.3 million tons of textile waste went to landfills in 2018 alone. That is roughly 22.6 billion pounds. Of all the textiles generated that year, 66% were landfilled, 19% were burned for energy recovery, and just 15% were recycled. Those are the most recent official EPA figures, and clothing production has grown since then.
Fashion also accounts for a meaningful share of global greenhouse gas emissions, though estimates vary widely from study to study. The Apparel Impact Institute reported in 2025 that the sector hit 944 million tonnes of CO2 emissions in 2023, a 7.5% year-over-year increase driven largely by overproduction and growing reliance on virgin polyester.
Then there is water. Producing a single cotton t-shirt takes approximately 700 gallons, and a pair of jeans takes far more. Textile dyeing and finishing are also a major source of industrial water pollution.
Meanwhile, people wear each garment fewer times before throwing it out than they did a generation ago, and they buy more clothing to make up the difference.
Each time you source a garment from a thrift store, list it, and send it to someone who will wear it, you take one item out of that cycle.
What Happens When You Extend a Garment's Life
Keeping clothing in use longer is one of the most effective ways to shrink fashion's environmental footprint. Each additional wear can displace a new purchase, and reselling an existing garment costs the environment a fraction of what manufacturing a new one does.
A 2023 life-cycle assessment commissioned by EuRIC (the European Recycling Industries' Confederation) found that reusing a garment has roughly 70 times lower environmental impact than producing a new one, even after accounting for transportation and logistics. Each medium-to-high quality piece of clothing reused saves approximately 3 kg of CO2, and the water required for resale is just 0.01% of what new production demands.
WRAP (the UK-based sustainability nonprofit) found that extending the active life of clothing by just nine months reduces its carbon, water, and waste footprint by 20-30%. By the same logic, doubling how many times a garment gets worn cuts its per-wear footprint sharply.
Apply that to your own volume. At 50 items a month, you may be keeping around 150 kg of CO2 out of the atmosphere and saving tens of thousands of gallons of water each month. At 200 items a month, the totals get large for one person working from home.
The Secondhand Market Is Now Mainstream
According to ThredUp's 2025 Resale Report (conducted with GlobalData), the US secondhand apparel market grew 14% in 2024, its strongest annual growth since 2021 and five times faster than the broader retail clothing market. Online resale specifically grew 23%, accelerating for the second consecutive year. The US secondhand market is projected to reach $74 billion by 2029, and the global market is expected to hit $367 billion by the same year.
Online resale is expected to nearly double over the next five years, growing at a compound annual rate of 13% to reach $40 billion by 2029. Retailers take these projections seriously: Patagonia, Levi's, and Lululemon have all launched their own resale programs.
Price and values both drive the shift. Inflation and tariff worries have pushed price-conscious shoppers toward secondhand. ThredUp reported that 59% of consumers would shift to secondhand apparel if government tariffs increased clothing prices, rising to 69% among Millennials. Saving money is part of it, and many buyers also see secondhand as a more deliberate way to shop.
Gen Z Made Secondhand Normal
If you sell on Depop, you have seen this already. Gen Z treats secondhand as an ordinary way to shop, and many younger buyers check resale apps before they buy new.
Price is only part of it. Younger shoppers tend to say they care about climate impact and have changed how they buy because of it. For many of them, buying secondhand is a preference rather than a compromise.
There is a limit, though. Buyers who care about sustainability still won't pay much of a premium for it. That works in your favor, because secondhand is already cheaper than retail, so you can offer the sustainability angle and a fair price while keeping your margins.
For a growing group of buyers, pre-owned is a deliberate choice that says something about their values and taste. Your listings compete with fast fashion on more than price, and sellers who write for that buyer tend to do better.
How to Use Sustainability as a Selling Point (Without Being Cringey)
If sustainability matters to your buyers, the next step is working it into your listings and shop without sounding like a corporate greenwashing campaign. Be specific and stick to what is true about the item.
On Depop: Lead With It
Depop's audience searches for sustainable fashion. Use relevant hashtags and description language: "pre-loved," "secondhand," "circular fashion," "thrifted find." Depop buyers browse by aesthetic and values, so building sustainability into your shop identity fits the platform. Mention the garment's story when you know it. "Rescued from a vintage shop in Brooklyn" tells a buyer something that "women's blue dress size M" never will. For a deeper look at how the platforms compare for different selling styles, check out our Depop vs Poshmark comparison.
On Poshmark: Be Subtle but Present
Poshmark buyers are motivated by deals and brands, but sustainability resonates as a secondary message. Include a line in your closet description about giving clothing a second life. When bundling, you can note that buying multiple pre-owned items is gentler on the planet than buying new. Posh Parties sometimes have sustainability themes, which are a direct way to reach eco-conscious shoppers. If you are scaling your Poshmark business, the message can help your closet stand out from others with similar inventory.
On eBay: Keep It Factual
eBay buyers tend to be more pragmatic. They care about value, condition, and accuracy. On eBay, sustainability works better as a plain description than as a marketing angle: "pre-owned," "gently used," "extending the life of quality goods." eBay's own pre-loved and certified refurbished categories signal that the platform is leaning into this positioning. Use those categories and filters when applicable.
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Across All Platforms: Show, Don't Preach
- Mention that buying secondhand saves water and reduces carbon emissions, in one sentence rather than a lecture
- Use recycled mailers and skip excess plastic, and mention it in your shipping policy
- If you source from thrift stores, estate sales, or closet cleanouts, say so. Buyers like knowing where things came from
- Consider adding a small note in your packages: "Thanks for choosing secondhand. This purchase kept one more item out of a landfill."
- If you want to build a brand around sustainability, count what you have sold. "This closet has rehomed 500+ items" works well as a bio line
You Are Already Part of the Circular Economy
"Circular economy" sounds like corporate report language, but the idea is simple. Instead of make, use, and throw away, products pass through several owners until they are worn out. In fashion, resellers do much of that work: sorting, curating, and redistributing clothing in a way the fashion industry itself has not managed at scale.
Look at what the job involves. You source items that would otherwise sit in a donation bin or a landfill. You inspect, clean, photograph, and describe them, which adds information a buyer needs. You match them with buyers who want them, and you handle shipping and customer service. That is a full circular supply chain, run from a spare room.
Brands have noticed and started their own resale programs. Those programs are expensive to run and usually cover a single brand. Independent resellers cover many brands, move more volume, and run with lower overhead.
Want to estimate your personal environmental impact? A rough formula: for every garment you resell, count approximately 3 kg of CO2 saved and 700+ gallons of water conserved (for cotton items). If you sell 100 items a month, that is 300 kg of CO2 and 70,000 gallons of water.
Where the Environmental Case Gets Weaker
The story has complications. Researchers have pointed out that if buyers spend the money they save on secondhand clothes on more new clothing, the net benefit shrinks. In that case resale can add to fashion consumption instead of replacing it, and the critique is fair.
Shipping has a footprint too. Every package generates emissions, poly mailers and tape become waste, and sourcing trips mean driving. Shipping a garment still costs far less than manufacturing a new one, so the benefit holds, but calling reselling perfectly green oversimplifies it.
You can reduce the footprint: use recycled and recyclable packaging, combine sourcing trips, and offer bundle discounts so more items travel in one box. When you talk to buyers about it, say reselling is much better than buying new, not that it has zero impact. The accurate claim is the more believable one.
Profit and Impact Point the Same Way
In reselling, making money and reducing waste line up. Each sale keeps a garment in use longer, takes a little demand away from new production, and keeps something out of a landfill. You don't need to present yourself as an activist. It is enough to say what you already do, since a growing number of buyers look for it.
ThredUp puts secondhand growth at five times the pace of traditional retail, younger buyers increasingly choose pre-owned, and brands are building resale programs that independent sellers have run for years. Keep listing and shipping; each package is a small, real reduction.
Frequently Asked Questions
Does shipping cancel out the environmental benefit of reselling?
No. A domestic parcel produces far less CO2 than manufacturing a new garment, so reselling an item stays clearly positive after shipping is counted. Encouraging buyers to bundle items in one order reduces per-item shipping emissions further.
How many items do I need to sell per year to offset a meaningful amount of carbon?
At roughly 3 kg of CO2 saved per item, selling 100 items a month keeps approximately 3,600 kg (3.6 metric tonnes) of CO2 out of the atmosphere per year. That is a real share of a typical American's annual carbon footprint.
How much water does reselling actually save?
A cotton t-shirt takes about 700 gallons of water to produce, and a pair of jeans takes considerably more. When a buyer gets those items from you instead of buying new, that water is never used. A reseller moving 50 items a month could save tens of thousands of gallons monthly, depending on the mix of garments.
What share of textile waste actually ends up in US landfills?
According to EPA data, 66% of all textile waste generated in the US was landfilled in 2018 (the most recent year with official figures), totaling 11.3 million tons. Only 15% was recycled. Because clothing production has grown since then, the absolute tonnage going to landfill is likely higher today than those figures reflect.
Will Gen Z pay a premium for sustainable resale items, or do I need to price lower?
Younger buyers will pay a small premium for sustainable options, but not much. Secondhand is already priced well below retail, so you can keep reasonable margins and still undercut new, which gives buyers both the sustainability angle and the deal they expect.
How big will the secondhand apparel market be by 2029?
ThredUp and GlobalData project the US secondhand apparel market will reach $74 billion by 2029, with online resale specifically expected to nearly double to $40 billion. Globally, the secondhand market is forecast to hit $367 billion by the same year. Online resale grew 23% in 2024.