Wildland fires are on the rise in the U.S. According to the National Interagency Fire Center, 2015 saw more than 68,000 wildfires burn over 10 million acres. The U.S. Forest Service reports that 2015 was also the most expensive wildfire season on record, costing $1.71 billion for the year. This total surpasses the previous record of $1.67 billion set in 2002. A total of 4,636 structures were destroyed by wildfires in 2015, including more than 2,600 homes and more than 100 commercial buildings.
Why are wildfire losses increasing?
“Changing weather patterns, increasing populations, flammable vegetation, and structures within reach of a wildfire’s flames and embers are increasing exposure to wildfire losses,” says Pat Durland of Stone Creek Fire LLC, Boise, Idaho. “With warmer summers, less rain, and milder winters, periods of seasonal fire conditions are increasing,” adds Durland. According to data compiled by the Union of Concerned Scientists from Federal Wildland Fire Occurrence Data(1) , and other published sources, the number of large wildfires in the Western U.S. has increased from approximately 140 annually in the years between 1980–1989, to 160 annually from 1990–1999, to 240 annually from 2000–2012. That’s nearly a doubling of large fires annually in those three decades. The length of the wildfire season in the West has also increased significantly from the early 1970s to today—increasing from an average of 5 months to an average of 7 months each year.
Hotter average annual temperatures are considered a key factor—snow packs melt earlier, forests and lands are drier for longer periods contributing to the ignition and spreading of wildfires.(2) As reported by the New York Times, David A. Robinson, a climatologist at Rutgers University who tracks snow cover, said that the April 2016 snow pack in the Northern Hemisphere was the lowest since records began half a century ago.(3)
Forest wildfire, temperature and the timing of spring snowmelt
In a recent scholarly article published by The Royal Society, Anthony LeRoy Westerling reports on significant research into the correlation of wildfire, temperature patterns and the timing of spring snowmelt. Westerling states that in forestland areas managed by the US Forest Service, the National Park Service and the Bureau of Indian Affairs, (which combined, includes some 70% of forest area in the western U.S.) annual large wildfire frequency is significantly correlated with spring and summer temperature. The years with more frequent large fires occur in years with warm spring and summer temperatures and early spring snowmelt dates. Fire seasons in 2003–2012 averaged more than 84 days longer than in 1973–1982, reflecting a trend (of increased length) of just over three days per year since the 1970s. Over the last four decades, the average large wildfire burn time grew from nearly six days in1973–1982, to nearly 20 days in 1983–1992, nearly 37 days in 1993–2002 and over 50 days in 2003–2012.(4)
Wildfires and the risks to populated areas
In the United States, the wildfire threat has traditionally been thought of as a “western problem” says Stone Creek’s Pat Durland, affecting the drier western states such as California, and Colorado. “Shifting weather patterns have expanded the wildfire threat in many parts of our continent,” adds Durland.
Dr. Charles Nyce, Asst. Professor of of Risk Management & Insurance at Florida State University, speaking at Loss Control Forum 2016, cites the fact that people are migrating into wildfire areas. He also noted that we are seeing more wildfire in non-traditional areas such as New Jersey and Maine.
According to Bill Gabbert, former Fire Management Officer with the National Park Service and publisher of the WildfireToday website, “The wildland-urban interface is growing. More people are living and recreating where previously there was less human activity.” says Gabbert.(5)
In May, 2016, the New York Times reported on the massive fire and related disruption and losses in Fort McMurray, Alberta, Canada: “The near-destruction of a Canadian city by a fire that sent almost 90,000 people fleeing for their lives is grim proof that the threat to the vast stands of spruce and other resinous trees, collectively known as the boreal forest, is real. And scientists say a large-scale loss of the forest could have profound consequences for efforts to limit the damage from climate change.”(6)
The article makes the point that Fort McMurray, in northern Alberta, was “particularly vulnerable as one of the largest human outposts in the boreal forest.” But, as the report continues, “the destruction of patches of this forest by fire, as well as invasions by insects surviving warmer winters, has occurred throughout the hemisphere.”
A Snapshot of Fort McMurray Losses
- Losses could reach $9.4 billion ($7.3 billion US)
- 80,000 people had to flee
- 8,000 evacuees needed to be airlifted
- 1,600+ buildings damaged
- 1 billion gallons of oil production lost daily
- 40% of entire oil sands output interrupted
Mitigating Risks and Losses
With a long-term trend toward warmer and drier springs and summers, earlier melting of annual snow packs in high-elevation areas, and continual migration of populations and accompanying residential and commercial development in areas once considered remote, the upward trend of occurrences of large wildfires appears likely to continue. But there are science-based ways to significantly decrease this risk and the related, life-threatening and enormously costly outcomes. The mitigation of wildfire risk through proven Loss Control measures is the subject of the accompanying article “Reducing Wildfire Risk.”
- Union of Concerned Scientists – http://www.ucsusa.org/global_warming/science_and_impacts/impacts/infographic-wildfires-climate-change.html#.WB3cwhIrLNA )
- Justin Gillis and Henry Fountain, NY Times, May 10, 2016 http://www.nytimes.com/2016/05/11/science/global-warming-cited-as-wildfires-increase-in-fragile-boreal-forest.html?_r=0
- Increasing western US forest wildfire activity: sensitivity to changes in the timing of spring. Anthony LeRoyWesterling Published 23 May 2016.DOI: 1098/rstb.2015.0178, The Royal Society Publishing, http://rstb.royalsocietypublishing.org/content/371/1696/20150178
- Justin Gillis and Henry Fountain, op. cit.