AGRICULTURAL FIRES AND ARCTIC CLIMATE CHANGE: A SPECIAL CATF REPORT ________________________________________________________________________________________________ ASHLEY PETTUS MAY 2009 CATF is a nonprofit organization dedicated to reducing atmospheric pollution through research, advocacy, and private sector collaboration. This work was supported by ClimateWorks and benefitted from the time and assistance of Madhura Kulkarni, Johann Goldammer, Amber Soja and Stefania Korontzi. However, the opinions expressed are solely those of the Clean Air Task Force. Cover photo reprinted with permission from Larry Moore MAIN OFFICE 18 Tremont Street Suite 530 Boston, MA 02108 617.624.0234
[email protected] www.catf.us Agricultural Fires and Arctic Climate Change 2 Executive Summary Over the past century, the Arctic has been warming at nearly twice the rate of the rest of the planet. While increases in carbon dioxide and other greenhouse gases account for much of this steep warming trend, the Arctic is also highly sensitive to short-lived pollutants—gases and aerosols that travel north from lower latitudes, impacting the Arctic climate in the near term. Black carbon aerosol, or soot, which is produced through incomplete combustion of biomass and fossil fuels, accounts for as much as 30 percent of Arctic warming to date, according to recent estimates. Springtime deposits of black carbon pose a particular threat to the Arctic climate because of their potential to accelerate melting of snow and ice. Agricultural fires, intended to remove crop residues for new planting or clear brush for grazing, contribute a significant portion of the black carbon from biomass burning that reaches the Arctic in spring. Remote sensing of fires in non-forest lands, combined with analysis of chemical transport models and fire emissions databases, reveal that concentrations of black carbon from agricultural burning are highest in areas across Eurasia—from Eastern Europe, through southern and Siberian Russia, into Northeastern China—and in the northern part of North America’s grain belt.