May 28, 2009

Agricultural fires impact arctic ice melt

Researchers from the United States and around the world have determined springtime agricultural fires have a significant impact on the melting of arctic ice.

The scientists are to meet at the University of New Hampshire next week to discuss findings from the most ambitious effort ever undertaken to measure short-lived airborne pollutants in the Arctic Circle.

The two-year international project known as Polarcat focused on the transport of pollutants into the arctic from lower latitudes.

Among other findings, the researchers learned large-scale agricultural burning to remove crop residues or clear brush for grazing in Russia, Kazakhstan, China, the United States, Canada and Ukraine is having a much greater impact than previously thought because of the black carbon or soot the fires produce.

The scientists said soot, produced through incomplete combustion of biomass and fossil fuels, may account for 30 percent of arctic warming since soot warms the surrounding air and, when deposited on ice and snow, absorbs solar energy and adds to the melting process.

Targeting such emissions offers a supplemental and parallel strategy to carbon dioxide reductions, with the advantage of a much faster temperature response, and the benefit of health risk reductions, researcher Ellen Baum said.

More information about Polarcat is available at www.polarcat.no.