Klaus Lackner’s lab at Arizona State University looks as if an artificial Christmas tree exploded. Seemingly every surface is covered by white shreds of material, some small, some large, some slim, some thick. They look like plastic, but have the feel of stiff leather. And they are, according to Lackner, the head of the university’s Center for Negative Carbon Emissions, our best hope for avoiding catastrophic climate change.  

Lackner’s resin strips absorb carbon dioxide when they’re dry and release it when they’re wet. In cooperation with the Dublin-based company Carbon Collect and his colleagues at Arizona State, he wants to build an artificial forest in the desert: 1,200 CO2-eating columns, each up to 30 feet tall, that could capture 100 tons of carbon dioxide per day — the equivalent of sucking up the emissions of about 8,000 cars. The white shreds will form the leaves of the “mechanical trees,” passively absorbing CO2 as the wind passes through them. 

artificial forest carbon capture
A rendering of Klaus Lackner’s proposed artificial forest. Photo courtesy Arizona State University

The plan only seems radical until you consider the alternative. “The CO2 emissions that are already in the atmosphere make it increasingly unlikely that we will stay under two degrees Celsius of global warming,” the soft-spoken German physicist says. “It’s not a problem that will go away on its own. Therefore the capturing and storing of CO2 is unavoidable. It is too late now to argue whether we need to eliminate CO2 or not. We must get it out of the atmosphere.”

Of course, carbon-absorbing machines were invented millions of years ago. They’re called trees and plants, and they exist throughout the world. So why not simply plant more of them?

klaus lackner carbon capture
Klaus Lackner. Photo courtesy Arizona State University

“The resin binds CO2 more efficiently than any other material,” says Lackner. “Each column is 1,000 times more efficient than a tree.” Wind speed determines exactly how much CO2 the resin binds. Once it is saturated with CO2, which takes about 30 minutes, the columns fold like an accordion into water, where the CO2 is washed off for storage or reuse. Then the process begins again.

“We use almost no energy; the columns stand in the wind just like a tree,” says Lackner. “Unlike other methods, we need no ventilators, no propellers. Because we need only water, we are ten times cheaper than comparable techniques.” As a result, he hopes to use the captured CO2 to produce fuel at a competitive price. Lackner and Carbon Collect will build the first columns this year at the campus of Arizona State’s Global Futures Laboratory in Tempe. 

In 1999, Lackner became the world’s first scientist to suggest CO2 could be captured from the air to manage its climate impact. For many years, he had to explain why capturing carbon was even necessary. Now the consensus among scientists and engineers is that not only is it necessary, it’s mission critical.