Andy Ridgewell and colleagues at the University of Bristol say that growing crops such as wheat, maize and barley already cools the planet because many cultivated plants reflect more sunlight into space than natural vegetation.

Using a global climate model, they found that by being more selective in which crops to grow, and modifying some to reflect more light, summertime temperatures could be kept down by 2 degrees Fahrenheit across much of the American Heartland and the middle latitudes of Eurasia.

Writing in the journal Current Biology, the team stressed that unlike growing biofuels, cultivating more reflective plants could be achieved without disrupting food production, either in terms of yield or the types of crops grown.

“The idea is you could continue to grow maize, for example, but you could grow a variety that has a bigger climate benefit,” Ridgewell said.

He and his team say that selecting plants for their cooling properties is far more practical than other proposed geo-engineering schemes, such as dumping iron into the oceans or placing mirrors in space to divert sunlight.

Photo: University of Bristol