WILDFIRESThe Growing Challenge of Urban Wildfires

By Sara Frueh

The wildfires that burned in the Los Angeles area in January surged through highly populated areas, causing catastrophic damage. The two largest fires, the Palisades and Eaton fires, together destroyed over 16,000 homes and other buildings, killed 29 people, and displaced thousands.

Such losses are familiar to Joshua Weil, an emergency room physician who lived and worked through the Tubbs fire in northern California in 2017 — at that time the most destructive fire in the state’s history. Weil treated injuries from the fire and worked to evacuate a hospital in the city of Santa Rosa. The fire also destroyed his home.

“Living through the fire changed my life, and it changed a lot of things for my family as well,” said Weil.

He shared his experiences and insights at a recent Climate Conversations webinar that explored urban wildfires, their impacts, and lessons learned that can help communities prepare.

Multiple states — California, Arizona, Colorado, Texas, Montana, and others — are now facing increased wildfire risks, noted moderator Michael Méndez of the University of California, Irvine, whose research focuses on how climate change affects vulnerable populations.

“The best way to cope is to better understand extreme wildfire events and the methods to prepare our communities, and especially those that are most at risk and socially vulnerable,” he said.

Urban Fires Pose Unique Problems
Wildfire activity in the U.S. is increasing as climate change leads to hotter and drier conditions, according to a 2022 National Academies report.

In addition, more people are living where urban and wild lands meet, explained Christine Wiedinmyer, associate director of science at the Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder.

“We have a lot more people moving into this wildland-urban interface — moving into areas with flammable vegetation,” she said. “And when you have people in those areas, you have more likelihood of human-caused ignitions — power lines, people burning things that might create a fire.”

Wiedinmyer explained that urban fires present distinctive problems and unknowns in terms of impacts on air quality. When vegetation burns, it produces smoke containing particulate matter, greenhouse gases like carbon dioxide and methane, and other gases, she said. But with urban fires — where burning homes and garages are also generating smoke — “it’s a totally different suite of pollutants that are getting sent up there, and the impacts could be very different in terms of health and ecosystems downwind.”