Thursday, October 24, 2024
Fire speed, not size, drives threat to people, infrastructure
New CU Boulder study: “Fast fires” are getting faster, more dangerous in the Western U.S.

Fast-growing fires were responsible for nearly 90 percent of fire-related damages despite being relatively rare in the United States between 2001-2020, according to a new CU Boulder-led study. “Fast fires,” which thrust embers into the air ahead of rapidly advancing flames, can ignite homes before emergency responders are able to intervene. The work, published today in Science, shows these fires are getting faster in the Western U.S., increasing the risk for millions of people.

The research highlights a critical gap in hazard preparedness across the U.S. — National-level fire risk assessments do not account for fire speed or provide insight into how people and communities can better prepare for rapid fire growth events.

“We hear a lot about megafires because of their size, but if we want to protect our homes and communities, we really need to appreciate and prepare for how fast fires move," said Jennifer Balch, CIRES fellow, associate professor of Geography, and the lead author of the study. "Speed matters more for keeping people safe.”

Balch and her colleagues were inspired to look closer at fire speed after the Marshall Fire, which destroyed more than 1,000 homes in Boulder County, Colorado, in December 2021. The fire burned less than 6,100 acres (24.7 square kilometers) but grew quickly due to a combination of dry conditions and high winds. Less than an hour after the fire was reported, it had spread to a town 3 miles (4.8 kilometers) away, eventually prompting the evacuation of tens of thousands of people. In the aftermath, Balch’s team was eager to understand how fire growth rates impact fire risk across the country.

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