Climate Change Affected by Forest Fires

Airborne Particles in Soot Rise to Interact with Clouds

Aug 16, 2008

Climate change is affected when soot from forest fires interacts with clouds as the aerosols rise, first causing them to heat up and later produce a cooling effect.

Scientists have found that since the mid-1980’s there has been an increasing incidence of forest fires in the United States. The result is a change of climate which is affected when soot from forest fires interacts with clouds as the aerosols rise, first causing them to heat up and later producing a cooling effect.

Climate change may have affected forest fires as long as 300 million years ago when the atmosphere was rich with oxygen when everything burned repeatedly. As time went on, human-set fires joined lightning-set fires, including those used as controlled burning. During the 1987-2003 period, 7 times more fires occurred than in the previous 17 years. New findings point to climate change as the primary driver of recent increases in large forest fires.

Climate change has been tracked through a study done by the Laboratory of Tree-Ring Research at the University of Arizona in Tucson, Arizona. The research was funded by the National Oceanic and Atmospheric Administration, the U.S. Forest Service and the California Energy Commission. The scientists involved in the study found sharp spikes in carbon dioxide and methane, the two major gases blamed for trapping heat in the atmosphere. Now the wildlife season starts earlier, fires last longer and the fire season ends later. The year-to-year changes in wildfire frequency appear to be linked in annual spring and summer temperatures and to the timing of the spring snowmelt.

Climate change is affected by the soot that is released into the air from forest fires that range from California to the Amazon to Siberia and Indonesia. Soot, collectively known as aerosols, rise into the atmosphere where interaction with clouds happens. The clouds reflect the sun’s energy back into space, cooling the upper atmosphere and trapping heat underneath, warming the Earth’s surface.

Climate change will continue as researchers suggest that more severe fires could change forest composition so drastically that the western forests, which currently store atmospheric carbon dioxide, could become a source of atmospheric Co2 which would further warm the climate and exacerbate the fire problem.

An accurate model of the intricate relationship between clouds and aerosols has been a key missing piece in the picture of human-induced climate change. The scientists believe their findings may help both climate modelers and policy makers to understand the true climate consequences of burning trees or sooty industrial fuels.

University of Arizona Alumnus. Global Warming Update: More Large Fires Linked to Climate Change. Fall, 2006. http://www.uagrad.org/Alumnus/gw/tree.html

Running, Steven W. “Is Global Warming Causing More, Larger Wildfires?” Science: August 18, 2006

Swetnam, Thomas W. Fire and Climate History in Western America from Tree Rings. New Scientist: Science Highlights: June 2007

The copyright of the article Climate Change Affected by Forest Fires in Climate Change is owned by Martha R. Gore. Permission to republish Climate Change Affected by Forest Fires in print or online must be granted by the author in writing.