Clearing grasslands to make way for biofuels may seem counterproductive, but University of Wisconsin-Madison researchers show in a study today (April 2, 2015) that crops, including the corn and soy commonly used for biofuels, expanded onto 7 million acres of new land in the U.S. over a recent four-year period, replacing millions of acres of grasslands.
The study — from UW-Madison graduate student Tyler Lark, geography Professor Holly Gibbs, and postdoctoral researcher Meghan Salmon — is published in the journal Environmental Research Letters and addresses the debate over whether the recent boom in demand for common biofuel crops has led to the carbon-emitting conversion of natural areas. It also reveals loopholes in U.S. policies that may contribute to these unintended consequences.
“We realized there was remarkably limited information about how croplands have expanded across the United States in recent years,” says Lark, the lead author of the study. “Our results are surprising because they show large-scale conversion of new landscapes, which most people didn’t expect.”
The conversion to corn and soy alone, the researchers say, could have emitted as much carbon dioxide into the atmosphere as 34 coal-fired power plants operating for one year — the equivalent of 28 million more cars on the road.