Wildfires and Climate

Wildfires and Climate Laser Talk

Question: How are wildfires connected to climate change?

Answer:  Wildfires, while not strictly ‘weather’ events themselves, are certainly affected by weather. Climate change alone cannot cause a wildfire but can increase the likelihood that one will start and, that if it does, it will be more intense, more widespread and longer-burning. [1]

Global warming magnifies the threat of wildfires in two ways. First, snow melts earlier in the spring but then starts to fall later in the autumn. This extends the dry season, allowing forests to dry out sooner and for a longer time. Second, global warming increases the frequency and duration of heat waves that intensify and expand dry conditions, turning green vegetation into easily ignited tinder. [2,3,4,5] A July 2019 paper stated that “warming‐driven fuel drying is the clearest link between anthropogenic climate change and increased California wildfire activity to date.” [6]

Over the last four decades, the number of wildfires in the U.S. has not changed much, but the acreage burned from those fires has more than doubled, and the cost, just since 2004, has exploded by a factor of 35. [7] This has occurred despite better forest management and fire suppression policies that should decrease the acreage burned. The fact that the opposite is true strongly suggests that the impact of climate change is outrunning efforts to mitigate the damage, rising costs, and danger to life that we are bearing from wildfires.

So, what’s the bottom line? There is strong evidence that destruction from wildfires across the U.S. has increased massively over the last 40 years, a trend that is consistent with a longer fire season exacerbated by higher seasonal temperatures due to global warming. The impact of climate change on wildfires is costing us tens of billions.

In a Nutshell: Global warming is drying out forests and grasslands, extending fire seasons and overwhelming the ability of states and countries to contend with wildfires. This is already costing us tens of billions of dollars just in the U.S.

  1. “Is Global Warming Fueling Increased Wildfire Risks?” Union of Concerned Scientists (Accessed 1 Oct 2017).
  2. Buis, A. “The Climate Connections of a Record Fire Year in the U.S. West.” Ask NASA Climate (22 Feb 2021).
  3. “Wildfires and Climate Change.” Center for Climate and Energy Solutions (Accessed 1 Oct 2017).
  4. Ma, M. “New report: State of the science on western wildfires, forests and climate change.” University of Washington, UW News (02 Aug 2021).
  5. Abatzoglou, J.T. and A.P. Williams. “Impact of anthropogenic climate change on wildfire across western US forests.” Natl. Acad. Sci. 113:42, 11770-11775 (18 Oct 2016).
  6. Williams, A.P., et al. “Observed impacts of anthropogenic climate change on wildfire in California.” AGU100, American Geophysical Union (15 July 2019).
  7. “Facts + Statistics: Wildfires.” Insurance Information Institute (accessed 22 Oct 2021).

This page was last updated on 10/23/2021 at 12:17 CDT.