Study: Wildfires emit more global warming gases than thought
A new study has found that California wildfires emit more greenhouse gases than previously believed largely through the post-fire decay of dead wood, a finding that is raising questions about how effective the state’s forests are at storing carbon and slowing global warming.
The study by Thomas Bonnicksen, a retired forestry professor at Texas A&M University, found that four major wildfires – from the Fountain fire near Redding in 1992 to the Angora blaze at Lake Tahoe last year – are responsible for the release of 38 million tons of greenhouse gases into the atmosphere, far more than the 2 million tons the state estimates that fires produce on average each year.
“Up until now, we have not fully appreciated the magnitude of the impact of wildfires on climate change,” Bonnicksen said. “This is a very important part of the problem.”
His study, which is not peer-reviewed and has been found lacking by some, is one of a flurry of reports that have begun to explore the critical role that forests play in regulating carbon dioxide, the principal atmospheric gas responsible for global warming. Traditionally, forests have been viewed as green reservoirs of landlocked carbon, soaking up and storing CO2 from the atmosphere in their leaves, needles, roots and soil.
Bonnicksen’s study casts that view into question. Forests today are so overcrowded with spindly, unhealthy trees – partly the result of decades of fire suppression – that as they burn and decay they are turning into an actual source of greenhouse gas pollution.
His study, for example, estimates emissions from just one blaze alone last year, the Moonlight fire in Plumas County, at more than 19.6 million tons, three-quarters of which are expected to occur over the next century as trees killed by the fire decay. That much carbon is roughly equivalent to the emissions from 3.6 million cars for a year.
Overall, California fires are producing so much CO2, he said, that they will defeat the state’s pioneering efforts to respond to climate change by reducing emissions elsewhere.
“No matter what anybody does in California to reduce greenhouse gas emissions, as long as these forests are burning, they are wasting their time,” Bonnicksen said. … [more]
For the full text of Dr. Bonnicksen’s reports, see W.I.S.E. Forest and Fire Science [here]
Regarding the “not peer reviewed” comment in the Sac Bee story above, a great many experts contributed to Dr. Bonnicksen’s reports. From FCEM Report 2:
The author gives special thanks to Dr. Bruce Krumland, consultant in statistical design and analysis, forest inventory, and modeling, and Klaus Scott, Air Pollution Specialist, California Air Resources Board (CARB), for their review, analysis, and suggestions in the development of FCEM. Thanks also to Dr. Mark Nechodom, USDA Forest Service Sierra Nevada Research Center and Dr. Chris Dicus, Wildland Fire & Fuels Management, California Polytechnic State University (Cal Poly), San Luis Obispo, for their helpful comments and suggestions. Thanks also to Neva Lowery, Emissions Inventory staff (CARB) and Richard Bode, Chief Emissions Inventory Branch (CARB), for taking time for consultation on estimating greenhouse gas emissions.
The author thanks Martha Beninger, Applied Forest Management; James Ingram and Elaine Gee, Eldorado National Forest; Karen Jones, Tahoe National Forest; Rich Wade and David Harcus, Sierra Pacific Industries; Mike Aguilar, Mason, Bruce, & Girard; Keith Crummer, Plumas County Fire Safe Council; Ryan Tompkins, Plumas National Forest; Ike Riffel, Shasta Forest c/o W.M. Beaty & Associates, Inc.; and the Fire and Resource Assessment Program (FRAP), California Department of Forestry and Fire Protection, for their assistance and willingness to share data.