Apparently, pumping carbon dioxide into volcanic basalts is a pretty effective carbon capture technique. Back in 2012, scientists began an experiment in Iceland called the CarbFix Project. Since then, they've been injecting tons of carbon dioxide waste from a geothermal plant in the country into basaltic rock 1,600 feet underground. According to results they've recently published in Science, 95 percent of the gas they store underground turn into solid carbonate minerals within only two years. Even better, the team doesn't have to turn the gas into liquid first.