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, weave it into your closet bio. Buyers are actively looking for it — use that.
11.3 million tons of textiles hit US landfills in a single year. That's 22.6 billion pounds of clothing, shoes, and fabric — two thirds of everything produced. 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. But sustainability is also a selling point that actually converts. Depop buyers actively search for shops that lead with environmental impact. Poshmark buyers respond to closet bios that mention secondhand values. The demand is real, and you're already doing the work — you just might not be getting credit for it yet.
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 available, and the situation has not improved since — production volumes have only increased.
The fashion industry accounts for an estimated 2-8% of global greenhouse gas emissions, depending on which study you reference. 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. To put that in context: fashion emits more carbon than international flights and maritime shipping combined.
Then there is water. Producing a single cotton t-shirt requires approximately 700 gallons of water. A pair of jeans takes around 1,800 gallons. The fashion industry consumes roughly 79 billion cubic meters of water annually, making it one of the most water-intensive industries on the planet. And roughly 20% of global industrial water pollution comes from textile dyeing and treatment.
Meanwhile, the average garment is now worn only 7 to 10 times before being discarded. That is a 36% decline in garment utilization over just 15 years. Consumers buy 60% more clothing than they did a generation ago but keep each item for half as long. One in three young women considers an outfit "old" after wearing it once or twice.
These numbers are not abstract environmental statistics. They describe the exact pipeline you are intercepting every time you source a garment from a thrift store, list it on a marketplace, and send it to someone who will actually wear it.
What Happens When You Extend a Garment's Life
Research consistently shows that keeping clothing in use longer is one of the single most effective ways to reduce fashion's environmental footprint. The math is straightforward: every additional wear displaces a potential new purchase, and the environmental cost of reselling an existing garment is a fraction of manufacturing a new one.
A study published by the European Clothing Action Plan 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%. Doubling the lifespan of a garment — even just from 30 to 60 uses — cuts its greenhouse gas emissions footprint by nearly half.
Think about what this means for your business. If you sell 50 items a month, you are potentially keeping 150 kg of CO2 out of the atmosphere and saving tens of thousands of gallons of water monthly. At 200 items a month, those numbers start to look like a small environmental nonprofit. Reselling is not just economically productive. It is one of the most scalable forms of individual environmental action available right now.
The Secondhand Market Is Not a Niche Anymore
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. This is not wishful thinking from sustainability advocates. These are investment-grade market projections that major retailers are betting real money on. Brands from Patagonia to Levi's to Lululemon have launched their own resale programs because the economics are undeniable.
What is driving this? A combination of economics and values. Inflation and tariff concerns have pushed price-conscious consumers toward secondhand. ThredUp reported that 59% of consumers would shift to secondhand apparel if government tariffs increased clothing prices, rising to 69% among Millennials. But it is not just about saving money — buyers increasingly see secondhand as a smarter, more intentional way to shop.
Gen Z Changed the Game
If you sell on Depop, you already know this intuitively. But the data confirms it: Gen Z has made secondhand shopping mainstream in a way that previous generations never did. According to recent consumer research, 64% of Gen Z shoppers search for items secondhand before buying new. Two out of five items in the average Gen Z closet are secondhand purchases. 54% prefer secondhand options when available, compared to 44% of Millennials.
This is not just a price play. 82% of Gen Z report concern about climate impact, and 72% say they have modified their consumption habits to reduce their carbon footprint. Depop reported that 85% of its users consider environmental impact before making a purchase. For a generation that grew up watching climate change unfold in real time, buying secondhand is not a compromise — it is a preference.
There is an important nuance here, though. While Gen Z prioritizes sustainability, most will only pay up to about 10% more for it. They want sustainable options, but they are not going to overpay. This is actually good news for resellers: secondhand is inherently cheaper than retail, so you can offer both the sustainability angle and a fair price without sacrificing your margins.
Secondhand is no longer "settling." For a growing segment of buyers, choosing a pre-owned item is an active, intentional decision that signals values and taste. Your listings are not competing with fast fashion on price alone — they are competing on meaning. The resellers who understand this sell more.
How to Use Sustainability as a Selling Point (Without Being Cringey)
Here is where the practical business angle kicks in. You know sustainability matters to buyers. The question is how to incorporate it into your listings and brand without sounding like a corporate greenwashing campaign. The key is authenticity and specificity.
On Depop: Lead With It
Depop's audience actively 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 weaving sustainability into your shop identity is not just acceptable — it is expected. 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 — participate in those to reach eco-conscious shoppers specifically. If you are scaling your Poshmark business, sustainability messaging can differentiate your closet in a sea of similar inventory.
On eBay: Let the Data Speak
eBay buyers tend to be more pragmatic. They care about value, condition, and accuracy. For eBay, sustainability is less of a marketing angle and more of a factual statement: "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.
Across All Platforms: Show, Don't Preach
- Mention that buying secondhand saves water and reduces carbon emissions — but keep it to one sentence, not a lecture
- Use sustainable packaging (recycled mailers, no excess plastic) and mention it in your shipping practices
- If you source from thrift stores, estate sales, or closet cleanouts, say so. Buyers appreciate knowing the provenance
- Consider adding a small note in your packages: "Thanks for choosing secondhand — this purchase kept one more item out of a landfill"
- Track and share your impact numbers if you want to build a brand around sustainability. "This closet has rehomed 500+ items" is a compelling bio line
You Are Already Part of the Circular Economy
The "circular economy" sounds like a buzzword from a corporate sustainability report. But the concept is simple: instead of the traditional make-use-dispose pipeline, products circulate through multiple users until they are genuinely worn out. Resellers are the engine that makes this work for fashion. You are not just selling used clothes. You are operating a sorting, curating, and redistribution system that the formal fashion industry has failed to build at scale.
Consider what you actually do. You source items that would otherwise sit in a donation bin or a landfill. You inspect, clean, photograph, and describe them — adding information and value that did not exist before. You match them with buyers who specifically want them. You handle shipping and customer service. That is a complete circular supply chain, and you built it from your living room.
Brands are waking up to this. Circular sales made up 27% of the luxury market and 4% of the mass market in 2025, according to industry analysis. Branded resale programs grew 300% between 2021 and 2025. But these corporate programs are expensive to run and limited in scope. Independent resellers move more volume, cover more brands, and operate with lower overhead. You are doing what billion-dollar companies are struggling to replicate.
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. Over a year, one active reseller can save more carbon than switching to an electric car.
The Honest Caveats
Sustainability in reselling is not a clean, simple story. A Yale study published in late 2025 raised a fair point: if the money buyers save by purchasing secondhand just gets spent on additional new clothing, the net environmental benefit shrinks. Resale can theoretically expand fashion consumption rather than displace it. That is a valid critique worth acknowledging.
Shipping has a footprint too. Every package you send generates emissions. Poly mailers, tape, and tissue paper create waste. If you source from thrift stores, you drive to them. None of this erases the benefit of reselling — the environmental cost of shipping a garment is still dramatically lower than manufacturing a new one — but the "reselling is perfectly green" narrative oversimplifies reality.
What you can do: use recycled and recyclable packaging materials. Consolidate sourcing trips. Offer bundle discounts that reduce per-item shipping emissions. And be honest with yourself and your buyers — reselling is dramatically better than the alternative, but it is not zero-impact. Honesty is more credible than perfection.
The Bottom Line
Reselling is one of those rare situations where doing well and doing good are not in tension. Every sale you make keeps a garment in circulation longer, reduces the demand for new production, and diverts waste from landfills. You do not need to rebrand yourself as an environmental activist to benefit from this. You just need to recognize that sustainability is already baked into what you do — and that a growing number of buyers are actively seeking it out.
The secondhand market is growing five times faster than traditional retail. Gen Z is choosing pre-owned by default. Major brands are scrambling to build the resale infrastructure that independent sellers have been running for years. You are not behind the curve. You are ahead of it. Keep listing, keep shipping, and know that every package you send is a small but real piece of the solution.
Frequently Asked Questions
Does shipping cancel out the environmental benefit of reselling?
No. A domestic parcel generates roughly 0.5–1 kg of CO2 depending on distance and carrier, while manufacturing a new garment produces 6–20 kg of CO2. Even after counting shipping, reselling a single item is a net positive by a factor of six or more. 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. For context, the average American produces about 16 metric tonnes of CO2 annually, so a mid-volume reseller offsets more than 20% of their own annual footprint through their sales alone.
How much water does reselling actually save?
Producing a single pair of jeans requires around 1,800 gallons of water; a cotton t-shirt takes about 700 gallons. When you resell those items instead of a buyer purchasing new ones, that water stays out of the production cycle. A reseller moving 50 items a month could conserve the equivalent of 35,000–90,000 gallons of water monthly, depending on the mix of garment types.
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?
Research shows Gen Z will pay up to about 10% more for sustainable options, but not significantly beyond that threshold. The good news is that secondhand is already priced well below retail, so you can hold reasonable margins and still undercut new production prices — giving buyers both the sustainability angle and the deal they expect without sacrificing your profit.
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 alone, making it one of the fastest-growing segments in all of retail.