When it comes to controlling greenhouse gases, forests are a big help. And scientists think if we plant more trees, the very ground they stand on could absorb even more carbon.
In a first-of-its-kind study, researchers combined satellite imagery with 15,000 soil measurements. They found reforested topsoil could absorb up to 21 million metric tons of carbon a year — or about 10 percent of all carbon absorbed by reforested land.
Currently, the U.S. is reforesting a combined swath of land larger than California. But we have a long way to go if we want to use reforestation efforts to fix our climate. Only about 7 percent of all forestlands that can be replanted have actually been replanted.
And researchers stressed that if we want topsoil, trees and other carbon sinks to help, we need to take action sooner rather than later. Nature has been absorbing less and less carbon for more than 20 years, and it's expected to stop completely around 2050.
