Spring agricultural fires can accelerate Arctic melting

Washington, May 27 (ANI): A research has found that agricultural fires during spring have an adverse impact on the melting Arctic, because the black carbon or soot produced by the fires can lead to accelerated melting of snow and ice.

The two-year international field campaign known as POLARCAT was conducted most intensively during two three-week periods last spring and summer and focused on the transport of pollutants into the Arctic from lower latitudes.

One surprise discovery was that large-scale agricultural burning in Russia, Kazakhstan, China, the US, Canada, and the Ukraine is having a much greater impact than previously thought.

A particular threat is posed by springtime burning - to remove crop residues for new planting or clear brush for grazing - because the black carbon or soot produced by the fires can lead to an increased melting of snow and ice.

Soot, which is produced through incomplete combustion of biomass and fossil fuels, may account for as much as 30 percent of Arctic warming to date, according to recent estimates.

Soot can warm the surrounding air and, when deposited on ice and snow, absorb solar energy and add to the melting process.

In addition to soot, other short-lived pollutants include ozone and methane.

Although global warming is largely the result of excess accumulation of carbon dioxide (CO2), the Arctic is highly sensitive to short-lived pollutants.

During the UNH workshop, a report by the Clean Air Task Force detailing some of the campaign's findings on agricultural burning and transport to the Arctic will be officially released.

"Targeting these 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," said Ellen Baum, senior scientist of the Clean Air Task Force.

"In addition, we have the know-how to control these pollutants today," she added.

The report notes that during April, at the beginning portion of the field campaign in Northern Alaska, aircraft-based researchers were surprised to find 50 smoke plumes originating from fires in Eurasia more than 3,000 miles away.

Analysis of the plumes, combined with satellite images, revealed the smoke came from agricultural fires in Northern Kazakhstan-Southern Russia and from forest fires in Southern Siberia.

The emissions from fires far outweighed those from fossil fuels, the report states.

"These fires weren't part of our standard predictions, they weren't in our models," said Daniel Jacob, a professor of atmospheric chemistry and environmental engineering at Harvard University. (ANI)