As of early August 2013, 36 wildfires were burning in eight western states and Alaska, including six in California and nine new large fires in Arizona, Idaho, Nevada, Oregon and Wyoming, according to the National Interagency Fire Center. Already this year, more than 2.5 million acres have gone up in smoke — an area bigger than Yellowstone National Park. And that’s actually a lot smaller than its been at this point in some recent years (last year, almost twice as many acres had burned by early August).

Spring and summer wildfires have always been a fact of life in the arid West. But with shrinking winter snowpack and warming spring and summer temperatures, the number and frequency of large fires has increased dramatically over the last four decades. In the more than 50 years that the NIFC has kept wildfire records, the three worst seasons have occurred within the last seven years (2006 topped the charts, followed by 2007 and 2012).

Last year, the non-profit group Climate Central analyzed 42 years of U.S. Forest Service records for 11 Western states, and found a direct correlation between heightened fire risk and rising temperatures due to climate change — a result, in part, of human-induced greenhouse gas emissions.

Produced by the Union of Concerned Scientists

Based on findings from the National Research Council, the report notes that for every degree Celsius (1.8o F) of temperature increase, the size of area burned in the western U.S. could quadruple. The Intergovernmental Panel on Climate Change, meanwhile, estimates that summer temperature in western North America, could increase between 3.6oF and 9oF by the middle of this century.

The Climate Central report found that, as compared to the average year during the 1970s, the average year from 2002 to 2011 has had:

    • 7 times more fires exceeding 10,000 acres
    • Nearly 5 times more fires exceeding 25,000 acres
    • Twice as many fires exceeding 1,000 acres — Now there are an average of roughly 100 fires per year as compared with less than 50 per year during the 1970s. In Arizona and Idaho, this rate has nearly quadrupled.
    • Twice as much land area burned by wildfires each year.
    • A burn season that begins earlier, ends later, and lasting, on average, two-and-a-half months longer.

The Flammable West: Mega-Fires in the Age of Climate Change 16 October,2017Matthew Green

  • Paul

    Climate change is a problem, but the megafires that we’ve been seeing lately are likely due to fire suppression policies of the past century which have led to an accumulation of fuel and spread of species that are poorly adapted to fire. Comparing acres burned today to a baseline in the 60’s is misleading because that was a period of unusually low burning due to fire suppression.

    • Openmindneeded

      Is that a joke?? Scientists come out and say research shows temperature increases produce more fires and you are rhyming that 50 years ago fire suppression was better than today??? Open your eyes. We are damaging the planet an scientists are proving it with facts.

      • David

        The scientist made a correlation, which does not make it a fact. The fact is that fire suppression has been allowing for fuel loads to build up for decades. The only reason that fire is a risk to ecosystems is because humans have destroyed so much habitat that wildlife is left with nowhere to run when the forest burns. The only reason people care is because homes and property are being destroyed, well if the inhabitants of the forest could speak they would tell you that that is life in the forest deal with it or move out. In conclusion fuel load has more to do with increases in fires, and people destroying habitat and insisting on saving their homes are the only reasons wildfires are now “problems” when they have always been a necessary part of the ecosystem. This not to say that climate change is not real, but when you blame all symptoms on one cause you can miss out on other equally disturbing problems.


Matthew Green

Matthew Green produces and edits The Lowdown, KQED’s multimedia news education blog, an online resource for educators and the general public. He previously taught journalism at Fremont High School in East Oakland, and has written for numerous local publications, including the Oakland Tribune and San Francisco Chronicle. Email:; Twitter: @MGreenKQED

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