Explain the problem of greenhouse gases to a little kid, and her solution might be a set of giant fans that suck them out of the air and bury them underground. Such a fanciful fix is real--in fact, it's the business model of Carbon Engineering, a startup with audacious ambitions based in scenic Squamish, British Columbia.

Scientists have known how to remove carbon dioxide from the air for decades. The problem has been making that process economically feasible. But 10 years ago, founder David Keith, then a physicist at the University of Calgary, developed a direct air capture system that not only isolates carbon more efficiently, but also turns it into synthetic fuels, first by converting CO2 into pellets of calcium carbonate. The pellets are then heated to produce pure CO2 gas that is converted into synthetic, carbon-neutral fuel for trains, ships, and planes. Captured carbon that isn't used for fuel can be pushed underground to extract oil.

Powered by an investment from Bill Gates, the company began producing fuel at its pilot plant near Vancouver in 2017. Perhaps not surprisingly, Chevron and Occidental Petroleum participated in Carbon's most recent, $68-million funding round. The company will look to raise even more money to build its first full-scale plant--which, at a price of around $500 million, would offset the annual carbon emittance of 250,000 vehicles. That's why CEO Steve Oldham sees another potential client: governments. "One day," he says, "they'll realize that we have to do pure sequestration to solve the climate problem. When that happens, the costs will come down--and our technology will be ready."