Curr. Biol. doi:10.1016/j.cub.2008.12.025 (in the press)

Credit: JOY SINGARAYER

Cultivating only crop varieties that have a high capacity for reflecting sunlight could lower regional temperatures by as much as 1 °C during summertime, shows new research.

A team from the University of Bristol, UK, led by Andy Ridgwell tested whether a 'bio-engineering' approach involving the careful selection of crop varieties could be used to mitigate surface warming. The team used a global climate model to simulate the warming that would result from doubling atmospheric carbon dioxide concentrations and heightening albedo, or solar reflectivity, of vegetation over specific cropland areas. Their results show that increasing the albedo of vegetation in these areas by 20 per cent could result in regional summertime cooling of up to 1 °C across much of mid-latitude Eurasia and North America. This would cancel out up to one-fifth of the regional seasonal warming caused by a doubling of atmospheric carbon dioxide.

The authors say that, unlike growing biofuels, choosing the more reflective crop varieties would not disrupt global food production. They note that further temperature reductions could be achieved by genetic modification of plants for high albedo.