Allbirds

Allbirds pioneered the use of merino wool, eucalyptus fiber (Tencel), and sugarcane foam (SweetFoam) in footwear, displaying carbon footprint labels on every product. Its 2025 Tree Flyer running shoe achieved the lowest carbon footprint of any performance running shoe at 9.4 kg CO2e. The company's mission to prove business can be a force for climate good has inspired a generation of sustainable footwear brands.