While many shoes are made from natural fibers like cotton or leather, athletic shoes take a different approach. Needing to be breathable and moisture-wicking, makers of running shoes often opt for synthetic fibers derived from petroleum-based materials. In other words, those sporty joggers are not environmentally friendly. Synthetic materials are toxic to produce, and when they've been worn out by your workouts, they'll stick around in a landfill for a long time after.
That's where brands like Allbirds comes in. The San Francisco shoe startup catapulted to popularity two years ago with its stylish, minimalistic, and sporty shoes that had the tech sect and the fashion world swooning. But there's more to this brand than meets the eye. Instead of being constructed out of synthetic fibers with a rubber soul, Allbirds' shoes were composed of a fine merino wool upper and a base made from castor bean oil, a natural substitute for plastic and rubber.
The wool is not only breathable and wicking, it's also one of the most sustainable natural fibers out there. Sheep are part of the natural carbon cycle, consuming the organic carbon stored in plants and converting it to wool—50 percent of the weight of wool is pure organic carbon. Plus Allbirds sources its wool from sustainably and ethically raised sheep in New Zealand. All of this has given Allbirds street credit as not only a stylish brand, but a green one.
Now the company is taking that reputation to the next level with its newest collection of sneakers. While they look similar to the wool classics, the Allbirds Tree Collection is made from—you guessed it—trees. Using wood pulp derived from eucalyptus trees, the manufacturers spin the material into a fiber and knit it into a mesh fabric that feels like a cotton-polyester blend, according to Wired.
The process requires just five percent of the water needed to produce a typical pair of shoes, and the trees themselves are sustainably harvested—the company had the supply chain certified to ensure it was environmentally friendly.
Allbirds cofounder Tim Brown told Glamour that he hopes the new collections keeps the company's environmental message going while also challenging ideas that some shoe lovers have about sustainable footwear.
"What’s fantastic about this Tree launch is that it’s another moment to sort of show that sustainable materials can be used," Brown stresses. "They can be used not just because it’s the right thing to do, but because they can make better products."
Allbirds is just one of many companies making shoes out of alternative and eco-friendly materials. Portugal-based NAE is making shoes out of used airbags and tires; Veerah is making trendy pumps out of apple peels; Rothy's shoes are made from recycled water bottles; and even Nike is turning wasted leather into "Flyleather" sneakers.