Lululemon executives are aware of the impact apparel manufacturing has on the Earth's climate. On Friday, Lululemon launched a resale program that will allow customers to return their worn clothes and offer them for sale at a discounted price. Lululemon aims to keep clothes in circulation for longer and reduce carbon emissions by reducing production and consumption.

Lululemon isn’t the only major retailer to explore the consignment or resale market to help be more environmentally-friendly.

Arc'teryx and Levi's are just a few of the many mainstream brands working to prolong the lives of their garments. They use more sustainable materials, recycle and reuse fabrics, and resell used apparel.

Eileen Fisher, a womenswear brand, is a pioneer in sustainable fashion. The company has recycled, reused, or resold 1.8 million of its clothing since 2009.

Lilah Horwitz (head of Eileen Fisher’s take-back program) stated that "The point is being completely responsible for our products all through their lifecycle."

2,400 gallons water per pair

Experts say that climate change is accelerating and it is crucial to rethink how apparel is produced in order to reduce carbon emissions. According to a 2019 World Bank report, the garment sector is the most polluting in the world. It accounts for 10% of global greenhouse gas emission -- more than all international flight and maritime shipping combined.

Another measure is that the sector produced more greenhouse gas than 2 billion metric tonnes in 2018, which is about 4% of global total, research by McKinsey & Company reveals.

Another issue is water consumption. According to the Ellen MacArthur Foundation, the fashion industry consumes 93 billion cubic metres of water each year. A single pair of jeans can require nearly 2,400 gallons water.

The traditional manufacturing process often exhausts the planet's natural resources, uses enormous amounts of energy and water, and uses chemicals that are dangerous to the environment. The damage doesn't end there. They end up in landfills after consumers have used and discarded products.

"Our closets have become too full"

Manufacturers produce more clothing than consumers can afford to buy. According to ThredUp (the largest online consignment and thrift store), 9 billion pieces of clothing are left unworn every year in the United States.

This is not surprising, given the fact that many companies' business models depend on increasing production and sales each year.

Peggy Blum, author Circular Fashion: A Supply chain for Sustainability in the Textiles and Apparel Industry, stated that "We are buying too many clothes, our closets have too full." It's not about the brands doing it -- no one can be 100% sustainable and have no impact. We don't believe that producing and not consuming is the best way to make no impact.

Experts say that although many companies are making efforts to reduce carbon emissions per product, it's not enough to achieve their goal of increasing sales.

Lynda Grose is a pioneer in sustainable fashion design and professor at California College of the Arts. "The greatest obstacle to reducing carbon emissions, or climate science-based goals, is the increase sales every year," she said. "That is because the industry has focused for 30 years on selling more products.

"Because so much of the jobs and fortunes of many people are tied to fashion, I don’t see it slowing. It doesn't make less product," stated Elizabeth Cline, author and director of advocacy at Remake, a non-profit group.

Patagonia, an outdoor clothing and gear manufacturer -- known for recycling used clothing from customers and for its long-standing commitment to sustainable materials -- acknowledged in the 2019 Benefit Corporation Report its insufficient efforts.

The company stated that they are striving to become a carbon-neutral business through their supply chain. However, despite making significant progresses such as increased adoption of recycled material, the company's footprint is growing due to its sales growth.

Patagonia's "Worn Wear", a program that allows customers to return clothing they no longer wear, was launched three years ago. According to the company, "the best way for clothes to be recycled and reduce their carbon footprint is to keep them in good condition longer."

Expect a double-digit increase in the secondhand market

This philosophy is gaining momentum. Many other brands have also entered the resale market, including Stella McCartney, a luxury fashion designer, and Adidas, a sportswear brand. Customers can now return their used clothes. These used goods can then be purchased at a discounted price by new customers, either directly through the retailer or through resale sites such as ThreadUp and TheRealReal. This luxury online and brick-and mortar consignment shop offers both high-end online and offline shopping.

According to ThredUp, the value of the secondhand market (including traditional clothing donation) is expected to double over the next five-years to $77 billion. Brands whose business model is based on selling more clothes each year will be able to generate new revenue streams by keeping garments in circulation for longer periods of time.

ThredUp CEO James Reinhart, co-founder of ThredUp, stated that "Branded Resale" is an accelerating trend. It remains to be seen how companies invest and how the math works out to allow them to eventually produce less.

According to ThredUp's annualreport, more than half of a billion apparel items have been replaced by secondhand retailers. This means that customers bought used items instead of buying new.

"The obvious conclusion is that the world produced half of a billion products we didn't use in 2020. Reinhart stated that this is yet another example of how overproduction can be a problem.

Experts believe that a successful clothing resale company could help reduce carbon emissions and also increase the number of customers.

Reinhart stated that as young people acquire more purchasing power over the next five year, it is crucial that brands understand this. "People in their teens or 20s are resale experts. This is part of their experience. This is something brands should be able to do now, I believe.

Cline believes that the resale marketplace holds great promise for both brands and the environment.

"Resale is a success story. It was impossible to imagine that secondhand clothing would be so popular. She said that many brands are using recycled clothing more often. "Reuse is a great idea and good for the industry. While they'll continue to make new products, at least we are reusing existing items and not depending so heavily on virgin resources.