What about wildfires?

Firefighters are dealing with unprecedented conditions. Four times as many large forest fires burn in the U.S. West every year compared to 30 years ago.(1),(2) If that wasn’t enough, the fire season is more than two and a half months longer, about a 40 to 50 percent jump.(3),(4),(5)

“You won’t find [climate change skeptics] on the fire line in the American West anymore… We know what we’re seeing and we’re dealing with a period of climate… that’s different from anything… ever seen in our lifetimes.”
– Tom Boatner, U.S. Chief of Fire Operations, October 2007

For a sense of scale, the 2012 wildfires burned areas nearly twice the size of New Jersey. NASA and leading fire ecologists are not surprised by the recent upswing: Climate change creates conditions for more frequent, large wildfires.(6),(7) Within a few decades, as forests dry further, over half of the Western forests could be lost.(8)


Large wildfires and the climate change connection
Climate change is a major reason large wildfires are happening more often.(9),(10),(11) Warmer temperatures, heat waves and drought dry out forests. Parched forests, similar to campfire kindling, catch fire more easily and help fuel fires.(12),(13),(14) According to the U.S. Chief of Fire Operations, some wildfires in years past have been so large that they simply cannot be put out.(15)

“The fires in California and here in Arizona are a clear example of what happens as the Earth warms, particularly as the West warms, and the warming caused by humans is making fire season longer and longer with each decade.”
– Jonathan Overpeck, Professor at the University of Arizona, 2014

“Wildfire will increase throughout the United States, causing at least a doubling of area burned by the mid-21st century”

– U.S. Department of Agriculture, 2012

“Recent fires… serve as a grim portent for what we expect to see more of in the future.”

– Tom Tidwell, U.S. Forest Service Chief, February 2013

Warmer temperatures also shrink spring snowpack and leave the forest drier throughout the entire summer. Studies of the Sierra snowpack, a main source of Western water, show as much as a 90% reduction is realistic by the end of the century if greenhouse gases are not reduced.(16)


Wildfire fighting costs on the rise
The manpower and scale of resources needed to fight wildfires is perhaps best represented by the cost. Annual wildfire-fighting costs doubled from just 20 years ago, as large wildfires became more common. Since 2000, the cost of fighting wildfires averages about $1.7 billion each year.(17)


Source: National Interagency Fire Center

Large-scale wildfires turn a natural phenomenon into a long-term problem
Wildfires occur naturally and many would happen without human influence. Small natural wildfires aren’t all bad. They help remove dead wood that fuels larger-scale fires, and they return nutrients into the soil and restore balance to habitats.(18),(19),(20) Large wildfires, however, impose immediate and long-term damages on the environment. They burn through fertile layers of soil, robbing trees of the nutrients needed to regrow. Burned areas also repel water, creating dangerous flash-flood conditions.(21)

“A good rule of thumb is if you can look uphill from where you are and see a burnt-out area, you are at risk.”
– National Weather Service, April 2014

Wildfire smoke exposure is also a threat to people. According to the Centers for Disease Control (CDC) smoke can harm eyes, respiratory systems, worsen heart and lung diseases.(22) Indirect exposure to smoke can even be fatal, contributing to hundreds of thousands of deaths each year.(23)


Wildfires strain water resources
Wildfire damages continue long after the final flame is extinguished. Wildfires may seem only like a problem for people and animals that live near forests, they actually pose big risks for all Americans. The U.S. depends on forests for freshwater: About 3,600 public water systems and 80% of U.S. freshwater resources come from forest land.(23) Pollution from wildfires contaminates our water systems. Burned forests drain ash, sludge, and even microorganisms into our rivers and reservoirs.(24) Public water supplies can take years and millions of dollars to completely rebound.(25)

“Water-quality concerns are greater after a fire than they are during a fire.”
– Stacy chesney, Denver Water spokeswoman, July 2012

Restoring water quality often requires massive intervention, from dredging reservoirs to reforestation. Relying on trees and soils to naturally recover can take a thousand years, a luxury cities cannot afford.(26)



  1. Wildfires Increasing: Climate Central
  2. Fire Costs: National Interagency Fire Center



  1. National Academy of Sciences
  2. World Resource Institute: Western US Wildfires
  3. CBS: Age of Megafires
  4. ClimateCentral: Wildfires 2012
  5. Science Magazine
  6. NASA
  7. CBS: Age of Megafires
  8. CBS: Age of Megafires
  9. NASA
  10. Science Magazine
  11. USA Today
  12. Texas Tech University
  13. Northern Arizona University
  14. National Wildlife Federation
  15. CBS: Age of Megafires
  16. University of California, San Diego
  17. National Interagency Fire Center: Suppresion Costs
  18. California Forestry Association
  19. California Department of Forestry and Fire Protection
  20. Fish and Wildlife Service
  21. NOAA
  22. CDC: Protect Yourself from Wildfire Smoke
  23. CDC: Wildfires
  24. US Geological Survey: Wildfire
  25. US Geological Survey: Wildfire
  26. Denver Post