Once considered a distraction, scientists now say using technology—and nature—to remove CO2 from the atmosphere is not only possible: It’s a must.
By Craig Welch, January 17th, 2019, nationalgeographic.com
At McCarty Family Farms, headquartered in sun-blasted northwest Kansas, fields rarely sit empty any more. In a drive to be more sustainable, the family dairy still grows corn, sorghum, and alfalfa, but now often sows the bare ground between harvests with wheat and daikon. The wheat gets fed to livestock. The radishes, with their penetrating roots, break up the hard-packed surface and then, instead of being harvested, are allowed to die and enrich the soil.
Like all plants, cereal grains and root vegetables feed on carbon dioxide. In 2017, according to a third-party audit, planting cover crops on land that once sat empty helped the McCarty farms in Kansas and Nebraska pull 6,922 tons of carbon dioxide from the atmosphere and store it in the soil across some 12,300 acres—as much as could have been stored by 7,300 acres of forest. Put another way: The farm soil had sucked up the emissions of more than 1,300 cars.
“We always knew we were having a sizable impact, but to have empirical numbers of that size is inspiring to say the least,” says Ken McCarty, who runs the farms with his three brothers.
Moves like this are among a host of often overlooked steps that scientists now say are crucial to limiting the worst impacts of climate change.
From planting more trees and restoring grasslands to using sophisticated machines with fans and filters to capture CO2 from ambient air, these far-ranging steps are all aimed at one thing: Sucking greenhouse gases from the sky.
The machines to do that are still cumbersome and expensive. But managing forests and grasslands and farms with an eye toward atmospheric carbon removal is often a matter of doing what we already know how to do, only better.
“We know how to deal with forests; we know how to store carbon in soil,” says Richard Birdsey at Woods Hole Research Center. “These are strategies that are ready right now—things that can basically be deployed immediately.”