Biofuel crops could affect Brazil climate

Conversion of Brazilian land for sugar plantations will help the country produce cane-derived ethanol but could lead to climate change, researchers say.

Scientists at Arizona State University and their colleagues said anticipated conversion to sugarcane plantations could lead to a 1.8-degree F decrease in temperature during the growing season followed by a 1.8-degree increase after harvest.

"When averaged over the entire year, there appears to be little effect on temperature," geographical sciences Professor Matei Georgescu said. "However, the temperature fluctuation between the peak of the growing season, when cooling occurs relative to the prior landscape, and crop harvest, when warming occurs compared to the previous landscape, of about 2 degrees C [3.6 degrees F] is considerable."

As countries worldwide look to cut dependence on fossil fuels and turn to bioethanol and other biofuels, Brazil, the second largest global producer and consumer of bioethanol, is planning a boom in sugarcane production.

Much of this expansion is expected to come at a loss of some of the country's native tropical savannas, changing the landscape's physical properties.

An increase in sugar plantations will lead to a strong seasonal temperature fluctuation, researchers said, based on sugarcane having a higher reflectivity compared to the existing vegetation and the fact that the crop will undergo an annual harvest while the savanna does not.

The study by researchers at Arizona State, Stanford University and the Carnegie Institution for Science has been published in Geophysical Research Letters.