Christoph Gebald and Jan Wurzbacher

Last September, Climeworks co-founders Christoph Gebald and Jan Wurzbacher switched on the world’s largest direct-air carbon-­capture plant—a huge machine in Iceland that, over the course of a year, can pull the equivalent of 870 cars’ annual emissions from the air. When they founded Climeworks in 2009, Gebald and Wurzbacher initially faced skepticism, but now they are working on another facility that will be nine times as large, which they plan to have ready within two years. The company has generated a lot of excitement, with investors pouring in $650 million in April, and Microsoft signing a 10-year agreement in July to pay Climeworks to remove atmospheric CO2. But carbon removal is still controversial among environmentalists for its potential to distract from the urgent need to cut global emissions, without which carbon-­sucking machines can’t possibly make a difference in averting catastrophic climate change. “People think if we’re successful, they can skip [emissions] reduction,” says Gebald. “This does not work.”

Write to Alejandro de la Garza at alejandro.delagarza@time.com.