How this former Adidas executive is tackling the biggest problem in footwear with biodegradable sneakers

• Eric Liedtke cofounded Unless Collective and released a biodegradable sneaker late last year.
• Liedtke, a former Adidas executive, said the sneaker solves one of the hardest problems in footwear.

• An analyst called the sneaker a "game changer" given the industry's addiction to plastic.

Athletic footwear is inherently tough on the environment. Most sneakers are made with pollutants, including plastics and toxic glues.

Eric Liedtke, a former Adidas brand president, who is perhaps best known for launching Kanye West's partnership with the brand nearly a decade ago and before recent controversies, is on a mission to remove those pollutants from apparel.

In December, he unveiled a shoe that won't leave a damaging environmental footprint. In fact, it won't leave any. The shoe sold out, but it was recently restocked.

In 2021, Liedtke cofounded Unless Collective, a Portland, Oregon-based streetwear startup that doesn't use any plastics or polyester. The new shoe, called the Degenerate, will decompose at the end of its useful life.

"It's a first of its kind," Liedtke told Insider. "It's made from the elements to go out into the elements and return to the elements. It's a circular story that I think consumers will really jive on."

The sneaker solves one of the hardest problems in athletic footwear — creating a shoe that completely biodegrades — and puts pressure on industry giants to ramp up sustainability efforts. Even "sustainable" sneakers from brands like Nike tend to include polyester, which is made from plastic. The Degenerate doesn't include any plastic or petrochemicals. 

The Unless shoe, which retails for $139, was made in partnership with Natural Fiber Welding, which makes various materials from natural products, including plants and minerals.

"This is a game changer," industry analyst and ARCH-USA founder Chris Burns previously told Insider. "This is a big deal. This looks close to the 'impossible shoe,'" a reference to an aspirational shoe made entirely with plants and minerals that completely disintegrates and leaves no toxic waste.

The Degenerate includes four of Natural Fiber Welding's materials. While other brands, including Allbirds and Camper, have worked with Natural Fiber Welding, Unless is the first to build a shoe from top to bottom with its materials. 

"What's unique about what Eric has done in the footwear industry is paid attention to every single component of the shoe," Natural Fiber Welding President Steve Zika previously told Insider.

Zika called the Degenerate, which is available in black and white, a "revolutionary idea" because "the whole shoe is made out of nutrients."

Last April, Natural Fiber Welding announced an $85 million Series B investment round. Its investors include industry giants such as Ralph Lauren and Allbirds.

Liedtke said the development of the shoe required rethinking every detail of the manufacturing process. 

For instance, since the shoe doesn't include glue, it sinks lower into the sole, so it can more easily be sewn together with linen thread. Unless hired cobblers in Northern Italy to do the sewing. And instead of plastic tips for the shoelaces, Unless figured out a way to cross-stitch the ends of the laces.

"Every little thing had to be innovated," Liedtke previously told Insider. "To build a shoe without glue and without an ounce of petrochemicals has been a passion."

Industry giants, including Nike and Adidas, are working on getting more petroleum-based plastics out of athletic footwear, but it's a challenge because of the durability of plastics.

Burns said the Degenerate could put pressure on other companies, but he said there's still an education gap that needs to be closed.

"The education around sustainability is sorely missing," he said. "No brand is doing enough."

Style-wise, Burns expects the Degenerate to appeal to consumers because of its chunky sole, which Burns said is on-trend, noting its popularity in shoes like the Jordan Elevate.

"It's perfectly on trend," Burns said. "It looks great."

Now that the manufacturing process has been worked out, Liedtke said more design flourishes are to come.

"There's 1,000 things we'd like to pursue," he said.