Just as wildfire season is getting off to a heated start, a new study has found that in the last 30 years in the western United States, both the number of fires and the area that they burn have increased. The study, published by the American Geophysical Union, looked at the 17-state region stretching from Nebraska to California. It found that wildfires over 1,000 acres in size increased by about seven fires a year from 1984 to 2011. It also found that the amount of area these fires burned increased each year at about 140 square miles, or 90,000 acres, per year — an area about the size of Las Vegas and nearly the size of Denver.
The researchers assert that these trends are likely due to climate change and associated shifts in rain patterns and temperature norms, rather than local factors. The study does not directly link the findings to human-caused climate change, but it says the observations fit well with the predictions of climate models for the region.
“We looked at the probability that increases of this magnitude could be random, and in each case it was less than one percent,” Philip Dennison, an associate professor of geography at the University of Utah in Salt Lake City and lead author of the paper, said in a statement.
This is the first study to utilize high-resolution satellite data to look at wildfire trends across a variety of landscapes and ecoregions, according to the researchers. They used nine ecoregions, including forested mountains, deserts, and grasslands, and found that the rise in fire activity was strongest in areas like the Rocky Mountains, the southwest desert, and the southern plains in Texas, Oklahoma, and Kansas. According to Dennison, these are the same regions that would be expected to experience more fire activity due to climate change.
Max Moritz, a co-author of the study and a fire specialist at the University of California-Berkeley Cooperative Extension, said that the data show a strong correlation to drought-related conditions, with most areas seeing increases in fire activity also experiencing increases in drought severity.
Over the weekend, wildfires in Utah and Arizona added to the evidence that this year could be an especially long and hard wildfire season in the West. In California, additional firefighters have been called up in certain areas to prepare for an intense season after a remarkably dry winter, which is forecast to extend at least into late summer.
Wildfires are also generating some recent political heat. In February, President Obama called for shifting the costs of fighting the biggest wildfires to the same emergency fund that handles other natural disasters such as hurricanes and earthquakes. The move is intended to allow the U.S. Forest Service to avoid using their mitigation and prevention budget to pay for the costs of massive, and extremely costly, western fires.
This week U.S. Senators Jeff Flake (R-AZ) and Martin Heinrich (D-NM) will visit Arizona and New Mexico to discuss forest restoration and wildfire preparedness. “Wildfire season is here, and now is the time to get ready,” Sen. Heinrich said in a statement. “Learning about wildfire danger and being prepared can help reduce the threat of fires to our natural surroundings, our homes, and our communities.”
Senator Mark Udall (D-CO), who serves on the Armed Services Committee and the Energy and Natural Resources Committee, recently called on the military to be prepared to help out with aerial firefighting during the coming months, as contractually obligated. “The U.S. Forest Service predicts another cycle of substantial fire activity is likely in 2014, and based on lessons learned from previous fires and delays in delivery of additional U.S. Forest Service tankers, I believe that support from Department of Defense aircraft may be more critical than ever,” Udall wrote in a letter to the Pentagon.
Udall was referring to the awaited delivery of seven giant air tankers — known as “next generation” tankers — that have been ordered to provide faster and more effective retardant bombings than the current fleet. Fire-fighting supplies are already limited, and as fires tend to erupt in batches, the availability of flame retardant-dropping planes can be the difference in containing a fire before it blossoms into an inferno. Currently it appears that at most, only two of the seven new air tankers will be ready this year. As of late February, the Forest Service had less than 20 tankers, all aging and mechanically demanding. They are currently supplemented by several hundred smaller aircraft, but this is inadequate to demand. In 2012, according to reporting by the Associated Press, nearly half of the 914 calls for tanker supported went unfulfilled.