Under a White Sky: The Nature of the Future

by Elizabeth Kolbert

So much have we altered the atmosphere that one out of every three molecules of CO2 loose in the air today was put there by people.

In either case, the math is punishing. To stay under 2°C, global emissions would have to fall nearly to zero within the next several decades. To stave off 1.5°C, they’d have to drop most of the way toward zero within a single decade. This would entail, for starters: revamping agricultural systems, transforming manufacturing, scrapping gasoline- and diesel-powered vehicles, and replacing most of the world’s power plants.

The office was almost entirely bare, except for a few New Yorker cartoons on the theme of nerd-dom, which, Lackner told me, his wife had cut out for him. In one of the cartoons, a couple of scientists stand in front of an enormous whiteboard covered in equations. “The math is right,” the first scientist says. “It’s just in poor taste.”

Lackner became convinced that a fusion reactor was, at a minimum, decades away. Decades later, it’s generally agreed that a workable reactor is still decades away.

A few years after the original conversation, they produced an equation-dense paper in which they argued that self-replicating machines could satisfy the world’s energy needs, and, more or less at the same time, clean up the mess humans had created by burning fossil fuels. They called the machines “auxons,” from the Greek αυξάνω, meaning “grow.” The auxons would be powered by solar panels and, as they multiplied, they’d produce more solar panels, which they’d assemble using elements, like silicon and aluminum, extracted from ordinary dirt. The expanding collection of panels would produce ever more power, at a rate that would increase exponentially.

This same array could also be put to use scrubbing carbon. A Nigeria-sized solar farm would, they calculated, be sufficient to remove all the carbon dioxide emitted by humans up to that point. Ideally, the CO2 would be converted to rock, much the same way my emissions had been converted in Iceland.