Dear EarthTalk: Why are wildfires on the increase and what can be done to stop them from happening? -- Sandy Heffran, Albuquerque, N.M.
There's no question that wildfires are on the increase across the American West and other fire-prone regions of the world, and most environmental leaders agree that global warming is largely to blame. In a recent study published in the journal Geophysical Research Letters, researchers from the University of Utah analyzed a database of large wildfires in the western U.S. between 1984 and 2011 and found a significant increase in the number of large fires and/or the area covered by the blazes. From Nebraska to California, the number of large wildfires increased sevenfold per year over the study period, with the total area burned increasing by 90,000 acres a year on average.
"Wildfire trends in the West are clear: There are more large fires burning now than at any time in the past 40 years and the total area burned each year has also increased," Alyson Kenward of the nonprofit Climate Central said. "Over the same span, average spring and summer temperatures across 11 Western states have increased by more than 1.5 degrees Fahrenheit, contributing to the higher fire risks." What worries Kenward and others is that the latest climate model projections show temperatures rising an additional 2 to 4 degrees Fahrenheit over the next few decades (and as much as 8 degrees by 2100).
According to the National Wildlife Federation, the hotter temperatures we are already experiencing increase fire risks for several reasons. For one, drier, hotter conditions increase evaporation rates and encourage desertification. Also, as snowpacks melt earlier and summer temperatures rise to new heights, the length of the "fire season" is extending. Meanwhile, warming-induced insect infestations and other problems are ravaging many forests, turning once teeming ecosystems into tinderboxes. And the increased frequency of lightning as thunder storms become more severe only exacerbates the situation.
Not everyone agrees that global warming is causing the increase in wildfires. Professor David B. South of Auburn University points the finger at forest management and fire suppression practices over the last century that have allowed "fuels" to build up on forest floors, making the fires that do get started that much harder to quell or contain.
"Policymakers who halt active forest management and kill `green' harvesting jobs in favor of a `hands-off' approach contribute to the buildup of fuels in the forest," South told the Senate Environment and Public Works Committee in May 2014. "This eventually increases the risk of catastrophic wildfires," he said, adding that blaming carbon dioxide emissions for increased fire risk would be "simply unscientific."
Regardless of who is right, we can all help reduce or prevent wildfires. According to Smokey Bear, the federal government's mascot for wildfire prevention since the 1940s, those of us living in or visiting fire-prone areas should take extra precautions when burning anything outdoors. The campfire safety page of Smokey Bear's website outlines how to build and extinguish campfires properly to minimize wildfire risks, and provides lots of other relevant tips on how to stay vigilant. You can also help reduce the risk of wildfire by reducing your carbon footprint (drive and fly less, plant trees) and speaking up for legislation and other actions that help reduce greenhouse gas emissions.