Prescribed Burns May Reduce the US Carbon Footprint
Firefighters face a wildfire in Northern California. Image credit: mattspinner/Flickr
Every summer, wildfires rage across the western and southern regions of the United States. These fires threaten homes, animals, and ecosystems, and they are also responsible for something else: carbon emissions.
For decades, the primary strategies for dealing with these fires has been to prevent them at all costs then contain them when they erupt. New research, however, suggests that fighting fire with fire—clearing areas with prescribed burns—could make management easier and reduce the impact on the atmosphere.Wildfires in the United States are responsible for emitting an estimated 290 million metric tons of carbon every year. Compared to the more than six billion metric tons of total emissions, fires play only a small part of the country's annual carbon problem. What is alarming about wildfire emissions, however, is the speed at which they are created and the proportional increase they represent.
In a paper written for the National Center for Atmospheric Research, researchers Christine Wiedinmyer and Jason Neff explained:
A striking implication of very large wildfires is that a severe fire season lasting only one or two months can release as much carbon as the annual emissions from the entire transportation or energy sector of an individual state.
These fires, they said, are the "legacy of the past century of fire suppression."
A firefighter uses a torch to burn underbrush ahead of a wildfire. Image credit: mattspinner/Flickr
A New Strategy
Years of fire suppression has lead to dense forests that store large amounts of carbon. Overgrown undergrowth makes the forests more vulnerable to large fires and, as summers become hotter and drier, these wildfires are becoming increasingly common. When a wildfire tears through a forest, it has enough fuel to burn the biggest trees, which store centuries of carbon.
By setting small, controlled, fires, forest managers can clear the undergrowth; reducing the likelihood a large fire would be able to damage the biggest trees. According to research conducted using historical data and computer models, this strategy could significantly reduce the carbon emissions of forest fires in the United States.
Christine Wiedinmyer, lead author of the new study, explained:
It appears that prescribed burns can be an important piece of a climate change strategy...if we reintroduce fires into our ecosystems, we may be able to protect larger trees and significantly reduce the amount of carbon released into the atmosphere by major wildfires.
Co-author Matthew Hurteau added that "when fire comes more frequently, it's less severe and causes lower tree mortality." Small fires actually protect trees by clearing the fuel that builds on the forest floor.
Though researchers pointed out that implementing a nation-wide program of prescribed burns would be costly and logistically impractical, it could reduce annual carbon emissions by as much as 14 million metric tons and some forests would benefit from as much as a 63 percent reduction in emissions.
While prescribed burns will not solve the country's carbon problem alone, this research demonstrates how the ultimate solution will incorporate many small changes—and require that firmly entrenched strategies be revised to reflect new challenges.
Read more about forest fires:
Traditional Fire Management Helps Fight Climate Change
Tree-Powered Forest Fire Alert Network Gets Its Power From Bioenergy
Research Suggests Frequent Fires Could Help Forest Ecosystems
Giant Robot to Clear Cut Trees, Fight Forest Fires?
L.A. Demands Fire-Fighting Goats