Sugarcane ‘can help in cooling climate’

Sugarcane reflects sunlight back into space and "exhales" cooler water.

Updated: Apr 18, 2011, 14:11 PM IST

London: Sugarcane, grown in Brazil to power automobiles as an alternative to gasoline, has a double benefit - if cultivated in massive scale, it also helps in cooling the climate.

Researchers from the Carnegie Institution`s Department of Global Ecology found that sugarcane crops help lower the temperature of the surrounding air by reflecting sunlight back into space and "exhaling" cooler water.

The study is the first to quantify the direct effects on the climate from sugarcane expansion in areas of existing crop and pastureland of the Cerrado, in central Brazil.

Scott Loarie and his team used data from hundreds of satellite images over 733,000 sq miles.

They measured temperature, reflectivity (also called albedo), and evapotranspiration—the water loss from the soil and from plants as they exhale water vapor.

"We found that shifting from natural vegetation to crops or pasture results in local warming because the plants give off less beneficial water. But the bamboo-like sugarcane is more reflective and gives off more water—much like the natural vegetation,” said Loarie.

It`s a potential win-win for the climate—using sugarcane to power vehicles reduces carbon emissions, while growing it lowers the local air temperature," he added.

The scientists found that converting from natural vegetation to crop/pasture on average warmed the Cerrado by 1.55 degree Celsius, but that subsequent conversion to sugarcane, on average, cooled the surrounding air by 0.93 degree Celsius.

The study is published in the 2nd issue of Nature Climate Change, posted online April 17.