As the climate warms over the next four decades, portions of Montana and Wyoming are at ground zero for larger areas burned by wildland fires and an increase in air pollution from those fires.
The forecasts come from a recently released study done for the Environmental Protection Agency by Harvard's School of Engineering and Applied Sciences. It was published in the June 18 issue of the Journal of Geophysical Research. The study used a moderate-warming scenario of about 3 degrees by 2050 to arrive at its conclusions.
"The EPA wanted this information as one more indicator of what happens in the future," said Jennifer Logan, a senior research fellow at the Harvard school. "It's another indicator of what happens with climate warming."
Graphics accompanying the research show areas of Montana and Wyoming facing up to a 200 percent increase in wildfire areas burned and an 80 percent increase in organic carbon aerosols - air pollution from fires. Based on yearly temperature and precipitation, the fires and air pollution would vary. But overall, the researchers found an upward trend.
"These are unexplored effects of climate change," said Loretta Mickley, a research associate at the Harvard school who focuses on climate change and smog.
A decrease in summertime air quality could worsen visibility in national parks including Yellowstone and Glacier. And it could affect people with lung and heart conditions such as asthma and chronic bronchitis, the researchers said.
Mickley said that although the EPA has done a significant job of cutting emissions, climate change is working against the agency's best efforts.
"The U.S. is constantly cleaning up cars and power plants and factories, but something like an increase in wildfires could put a monkey wrench in those plans," Mickley said. "It's a climate penalty in the efforts to clean our air."
The study, the first from three years of funding from the EPA, focused on the Northern Rockies and Pacific Northwest because there was an extensive database available on fires compiled by Anthony Westerling of the University of California, Merced, Logan said. Future studies will look at the Southwest, California and possibly Canada and Alaska.
Wildland fires have increased in size, frequency and intensity since the mid-1980s in the United States, and climate change has been partly to blame. Warmer weather extends the length of the fire season, leaves fuels more dried out and has allowed pests such as pine beetles to thrive and kill more trees, producing more fuel.
"What climate change will do is amplify the problem of wildfires," Mickley said. "Climate change can feed the fires that do start."
According to the 2009 Quadrennial Fire Review, "in the first half of this decade (2000-04) the average annual acres burned by wildland fire reached the 7-8 million range. ... Looking to the end of this decade, there is a high likelihood that wildland fire activity could exceed this new baseline and move up as high as 10-12 million acres due to the effect of climate change on wildland ecosystems."
The scenario of more and bigger fires coupled with dirtier air seems unavoidable, if the researchers' predictions are correct. Even extensive logging couldn't be done quickly enough to remove fuels.
"If we see the changes we predict, it's not going to look so good," Mickley said.
Contact Brett French at firstname.lastname@example.org or at 657-1387.