Climate change can make wildfires spread, but it’s not the only factor
(SACRAMENTO) -- Two major wildfires in California have burned more than 150,000 acres so far this year and almost 100 large fires are burning across the country.
Is climate change making wildfires worse?
After several record-breaking wildfires in California last year, Gov. Jerry Brown said the severe fires were the "new normal" for the state and said that years of drought and rising temperatures from climate change contributed to the worsening fire season.
Before the Carr Fire broke out near Sacramento, the area was facing its hottest July on record and temperatures had been above-average for months, according to the Los Angeles Times.
While rising temperatures may not spark a wildfire, the heat contributes to the factors that make fires more likely and more severe, including droughts that dry out more plants and trees that become the fuel that helps fires spread further and more quickly.
Noah Diffenbaugh researches the connection between climate and extreme weather as a professor of Earth System Science at Stanford University. He said the longer fire season in California is related to climate change because global warming caused by greenhouse gas emissions have increased the average temperature by almost 2 degrees Fahrenheit.
"We're getting warmer and warmer conditions around the globe but certainly here in California and in the western United States we're getting earlier melting of snowpack," Diffenbaugh told ABC News' Brad Mielke on the "Start Here" podcast. "That means that when those warm conditions happen in the summer and fall all the vegetation is even more dried out and that means that when lightning strikes when a spark from a from a car or a campfire hits the ground that the vegetation is more dried out there's more fuel available."
Multiple studies have found a connection between rising temperatures and the severity of wildfires, but other research suggests that other factors are at play as well. One study published last year said that many studies that connect climate change and wildfires don't account for the unique factors in smaller geographic areas.
That study, published by the Proceedings of the National Academy of Science, found that climate change had less of an effect in areas that were more populated because people can both start fires where they wouldn't normally occur or can reduce the risk of wildfires by managing the land.
The researchers found that in some cases the way people manage or develop land in a specific area can even counteract the increased risk associated with rising temperatures or drought.
"Climate change may indeed be a concern for those areas with strong fire-climate relationships. However, our results suggest that, in some areas, anthropogenic (or human-caused) factors diminish the influence of climate on fire activity," the authors wrote in the study, saying that humans' influence on fires needs to be a larger part of the conversation about the connection between fires and climate change.
The U.S. Forest Service has been warning of the increasing costs related to fighting these wildfires for years, saying that it had to borrow money from programs intended to prevent fires to pay for fire suppression. The U.S. Department of Agriculture, which includes the Forest Service, said that 2017 fire season cost more than $2 billion, making it the most expensive fire season on record.
A record-setting 129 million trees on 8.9 acres were dead at the end of 2017 because of the state's drought, according to the U.S. Forest Service and California fire and forestry agency.
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