What do crop fires in Asia have to do with the melting Arctic? Quite a lot, it turns out. For two years, scientists – including UNH’s Jack Dibb of the Institute for the Study of Earth, Oceans and Space (EOS) – looked at how pollutants from “down south” affected the Arctic. Known as POLARCAT, the field campaign sought to measure “short-lived” airborne pollutants in the Arctic and determine how they contribute to the dramatic changes underway in the vast, climate-sensitive region.

To the scientists’ surprise, large-scale agricultural burning in Russia, Kazakhstan, China, United States, 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 accelerated melting of snow and ice. Soot might account for up to 30 percent of Arctic warming to date, by some estimates; it warms surrounding air and, when it falls on ice and snow, absorbs solar energy to speed melting.

“These fires weren’t part of our standard predictions, they weren’t in our models,” says Daniel Jacob, a professor of atmospheric chemistry and environmental engineering at Harvard. Jacob, along with Dibb, flew in NASA’s DC-8 “flying laboratory” to sample plumes of air over Arctic regions in Alaska and Canada.

Scientists from around the world will convene at the University of New Hampshire next week (June 2-5) to discuss these findings. 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.

“We’re in agreement that these short-lived pollutants are critical in the Arctic. This meeting is to discuss what we learned from this massive undertaking and what we as a scientific community can recommend to help address the problem,” says Dibb.

For more information on POLARCAT visit www.polarcat.no.

Tags: climate change, pollution, UNH, unhnews