A company in Finland called Rens has created waterproof sneakers using old coffee grounds. They’ve got plenty of material to work with. More than 23 million tons of coffee waste is produced globally every year, with only 5% of that coffee waste getting recycled. Experts say coffee grounds produce methane as they break down. Methane is a greenhouse gas scientists say is 30 times more harmful than carbon dioxide. Rens says after sneakers, they want to branch out into clothing.