The massive wildfires that burned in California, Oregon, Montana, Idaho and British Columbia in 2017 exhibited a disturbing trend: a marked increase in the amount of area burned. While it may have been an exceptional year in some respects, new research predicts that years like 2017 are likely to become more common over time.
States in the interior western United States, in particular, may be faced with large increases in total wildfire area burned, potentially beyond anything that has been experienced in the past, according to the study, published in the journal PLOS ONE on December 15, 2017, as the 2017 fire season was ending.
The study projects where the greatest increases in area burned are likely to occur across the western U.S. and Canada in coming decades, suggesting that large fires years such as the recent ones in southern and northern California may become more common.
We used 34 years of climate data to calibrate area burned in 1,500 grid cells across western North America, so we could capture the different ways that seasonal climate regulates fire in different regions.
The study’s findings for western and northern North America show that about half the states and provinces are projected to have a large increase — five or more times the current levels — in total wildfire area burned.
Other states and provinces may see smaller increases, say the researchers, indicating there is no “one-size-fits-all” model. Falk said:
Ultimately, this means that the large fire seasons of recent years, such as the one just ending, are likely to occur more frequently, affecting ecosystems, communities and public safety. These will be billion-dollar fire years. We’re just not ready for fire impacts of this kind, including post-fire effects from flooding after fire.
The total cost of the 2017 fires in California alone is projected to exceed $180 billion. This includes not only the immediate costs of firefighting, but also the much larger costs of landscape rehabilitation; medical and hospital costs; insurance losses and the costs of replacing thousands of homes and other buildings; lost economic productivity from the destruction of businesses; repair and replacement of key infrastructure such as roads, power lines and dams; and weeks of lost income by employees.
Falk said that seasonal climate changes are having the effect of making the fire season longer, so there is additional time for more acreage to burn. In years when seasonal climate drives lengthy fire seasons, fire management resources may be stretched to the limit. He said:
Wildfires act as a multiplier of other forces such as climate change, exposing more and more areas not only to the immediate effects of fire, but also to the resulting cascade of ecological, hydrological, economic and social consequences.
Bottom line: A recent study projects that wildfires in the western U.S. will likely get worse.