Droughts in Asia aggravating global warming

Scientific Blogging: In the rainforests of equatorial Asia, a link between drought and deforestation is fueling global warming, finds an international study that includes a UC Irvine scientist. The study, analyzing six years of climate and fire observations from satellites, shows that in dry years, the practice of using fire to clear forests and remove organic soil increases substantially, releasing huge amounts of climate-warming carbon dioxide into the atmosphere.

In 2006, the climate on the fast-developing islands of Borneo and Sumatra and in New Guinea and other parts of equatorial Asia was three times drier than in 2000, but carbon emissions from deforestation were 30 times greater – exceeding emissions from fossil fuel burning.

"Land managers respond to the drought by using fire to clear more land. In dry years, they burn deeper into the forest, which in turn releases more carbon dioxide," said James Randerson, climate scientist at UCI and co-author of the study, published online the week of Dec. 8 in the Proceedings of the National Academy of Sciences.

The findings, Randerson says, illustrate why limits on deforestation should be a critical part of future climate agreements. Global warming modelers typically consider climate and land use separately when assessing how changes will affect greenhouse gas emissions. The results also indicate that forecasting drought may be important when countries in this region allocate resources to combat illegally set fires and clearing….

Smoke from agricultural and forest fires burning on Sumatra (left) and Borneo (right) in late September and early October 2006 blanketed a wide region with smoke that interrupted air and highway travel and pushed air quality to unhealthy levels. This image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on October 1, 2006, shows places where MODIS detected actively burning fires marked in red. Smoke spreads in a gray-white pall to the north.