IGPP Seminar Series

Contrasting Climate Effects of Fire in Boreal and Tropical Regions

by James T. Randerson
Earth System Science Department University of California, Irvine

Abstract

The contemporary global distribution of fire emissions reflects a combination of factors linked with ecosystems, the hydrological cycle, and human activity. Humans are increasingly appropriating aspects of the fire regime in many biomes, using fire as a tool in deforestation, pasture maintenance, agriculture, and logging. Compared with other carbon loss pathways from terrestrial ecosystems, fire is unique because its consequences for the climate system are amplified via multiple agents, including the production of methane and ozone greenhouse gases, aerosols, black carbon deposition on snow and sea ice, and changes in surface albedo. Here I assess recent trends in global fire activity using an 11 year time series derived from satellite observations. I then present evidence that increases in fire within boreal forests may slow climate warming (by means of a negative feedback loop) whereas increases in fire within tropical forests may accelerate climate warming.
Tuesday, 04 December 2007
3853 Slichter Hall
Refreshments at 3:45 PM
Lecture at 4:00 PM