To Offset Greenhouse Gas Damage Caused From California Wildfires During 2001-2007, State's 14 Million Cars Would Need To Be Locked In Garages For 3½ Years, Study Finds  

By Mike Dubrasich, Executive Director of the Western Institute for the Study of the Environment

A raging wildfire can burn out of control for a long period of time, but eventually it will be extinguished.  However, the effects of that wildfire can linger for years and be a prime contributor to global warming.   A study by Dr. Thomas M. Bonnicksen, Professor Emeritus of Forest Science at Texas A&M University, released today found that California's increasing wildfire crisis is causing more destruction and undoing much of the progress California is making to fight global warming.

Dr. Bonnicksen, who holds a Ph.D. in forestry from the University of California, Berkeley, and has studied California forests for more than 30 years, is author of America's Ancient Forests: from the Ice Age to the Age of Discovery (John Wiley, 2000).   This report, entitled "Impacts of California Wildfires on Climate and Forests," chronicles how the wildfires that scorched California from 2001 to 2007 seriously degraded the forests in the state and contributed to global warming.

The report notes that political and economic obstacles to managing and restoring forests contribute to causing the wildfire crisis.   Emissions from the last seven years of wildfires documented in this study are equivalent to adding an estimated 50 million more cars onto California's highways for one year, each spewing tons of greenhouse gases.  To offset this damage, all 14 million cars in California would have to be locked in garages for 3½ years to make up for the global warming impact of these wildfires.  

From 2001 to 2007, fires burned more than 4 million California acres and released an estimated 277 million tons of greenhouse gases into the atmosphere, resulting from combustion and the post-fire decay of dead trees.  That is an average of 68 tons per acre.   This study and previous studies use a new computer model, the Forest Carbon and Emissions Model (FCEM), to estimate greenhouse gas emissions from wildfires and insect infestations, and opportunities to recover these emissions and prevent future losses.  

"Our most important question is: Can we recover from our mistake of letting forests become unnaturally overcrowded with trees and vulnerable to catastrophic wildfires?" said Dr. Bonnicksen, "the answer is yes, if we care about restoring our forests and fighting global warming."   

There are many other harmful effects of these wildfires as well, including killing wildlife, polluting the air and water, and stripping soil from hillsides.  Ironically, the greenhouse gases they emit are wiping out much of what is being achieved to reduce emissions from fossil fuels to battle global warming.  

"While California's actions to reduce global warming are significant, reducing the number and severity of wildfires may be the single most important action we can take in the short-term to lower greenhouse gas emissions and really fight global warming," Bonnicksen said.  

Some public forests in California have more than 1,000 trees per acre when 40 to 60 trees per acre would be natural.  These dense forests contain small trees that can carry fire into the canopy, and heavy concentrations of woody debris lying on the ground intensify the flames, which helps increase the size and severity of forest fires.  Reducing the number of all sizes of trees per acre by thinning is effective in helping prevent crown fires in forests.  

Yet that is only part of the wildfire tragedy.   During the seven years covered by this study, California wildfires deforested about 882,759 acres of public and private land.  Only an estimated 120,755 acres were replanted.  That means about 762,004 acres of forest was converted permanently to brush because no live trees remain standing to provide seed for a new forest.  That is an average loss of 109,000 acres of forests each year, or the equivalent of nearly four times the area of San Francisco.  

California's forests are dwindling due to permanent deforestation from wildfire.  In addition, the estimated 134 million tons of carbon dioxide (CO2) released by fires and the decay of dead trees from forests that were permanently converted to brush from 2001 to 2007 will continue to worsen global warming.  

Harvesting dead trees to prevent them from releasing CO2 from decay, storing the carbon they contain in long-lasting wood products, and using the money from the sale of the wood to replant a young forest that absorbs CO2 through photosynthesis, is the only way to restore deforested areas and recover this greenhouse gas from the atmosphere, Dr. Bonnicksen said.  He added that this is done routinely on private industrial forestland but rarely on public forestland.  Therefore, he said, it is critical to expedite and increase the harvesting of fire-killed trees and replanting of young trees on public forests destroyed by wildfire. 

The immensity of greenhouse gas emissions from California's wildfires and the permanent loss of huge areas of forest are a warning.   The report emphasizes that every effort must be made to reduce the amount of fuel in public and private forests to prevent catastrophic wildfires.  That means managing forests to make them healthy, productive, and resistant to crown fires.   Major constraints to managing and thinning private forests are government regulations and the high cost of Timber Harvest Plans (THPs). 

Solving this problem by streamlining regulations and reducing THP costs on private forests, and expediting environmental reviews for thinning and timber harvesting on public forests, could dramatically reduce wildfires and greenhouse gas emissions.   Data used in this report come from a variety of government and other sources.  They include the U.S. Forest Service Pacific Southwest Region Ecosystem Planning Staff, U.S. Forest Service Region 5 Silviculturalist, California Department of Forestry and Fire Protection (CAL FIRE), and the National Interagency Fire Center (NIFC).

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Bonnicksen Report on California Wildfires