CO2 pumped out of tailpipes in New York City traffic could eventually be sucked up by an air capture plant in the desert in Australia or North Africa.

Carbon Engineering, a Canadian startup, is designing massive walls of fans that suck carbon dioxide out of the air and turn it into things we need–like more fuel.

Because carbon dioxide is everywhere, the air capture plants could be built anywhere in the world and still help reduce global concentrations. “A direct air capture plant can be built wherever land is cheap and there is a demand for the CO2 produced,” says Geoff Holmes, Carbon Engineering’s business development manager.

While trees naturally do the same thing as the company’s machines, planting enough trees to deal with the world’s carbon problems would take at least 1,000 times more land–and the trees would have to live in areas that might be needed for agriculture. The smog-sucking machines are more efficient and can go in deserts.

The technology works by pulling air over a special carbon-absorbing liquid that traps CO2 and turns it into a salt. While it’s not quite as easy as trapping carbon directly at a source like the smokestack on a coal power plant–where concentrations are far higher–it’s possible (though less efficient). And it’s important, because most emissions come from moving sources like cars.

“Only about 40% of our total emissions come from large flue stacks, and the other 60% results from what we call ‘diffuse and mobile’ sources that can be difficult to tackle at source,” says Holmes. “Capturing them back from the atmosphere may be a key way to help manage these diffuse emissions.”

The captured CO2 can be stored underground, used in the oil industry to make something called “low carbon crude,” or turned into low-carbon synthetic fuels that can replace something like jet fuel.