California Forum

Fighting wildfire from the inside out

In the wake of the Camp Fire, I’ve been reading about the work of wildfire scientist Jack Cohen. During his many years with the U.S. Forest Service, Cohen studied which houses in fire-prone areas tend to burn and which survive. His work is deeply respected and several of his videos are on YouTube. They should be required viewing for anyone living in a wildfire zone.

To his surprise, Cohen found that the houses closest to catastrophic blazes often withstood the fires even when those farther away burned. It often wasn’t the approaching flames that threatened houses the most. The bigger danger, it turns out, were the thousands of small embers, called firestarters, that blew off of fires and traveled for miles on the wind.

The discovery led to experiments in which mockups of houses were blasted with showers of firestarters in order to study their vulnerabilities.

Cohen found that houses’ immediate surroundings were more important than the condition of the surrounding forests. Conventional wisdom tends to focus on clearing brush. But wood decks, wood siding and vents through which embers can enter attics and crawl spaces all are serious vulnerabilities.

“Uncontrolled, extreme wildfires are inevitable,” Cohen says. But destroyed communities are not.


Some of Cohen’s discoveries have reached homeowners. People know the old wood-shake roofs are fire disasters in waiting. But do they know Spanish tile roofs can provide shelter for embers under their curves? Do they know vents covered with fine-mesh screens can prevent embers from entering crawl spaces and attics? Have they considered replacing wood decks with cement patios?

Richard Halsey, director of the California Chaparral Institute, suggests reversing the way we think about wildfire. Instead of focusing on backcountry wildfires, Halsey suggests Californians take steps to protect individual lives, houses and communities.

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Karin Klein Sacramento

People and policymakers — including Cal Fire — are still worried about giant walls of forest fire when they need to think about protection against tiny embers. Our biggest weapons are expansive green parks, wide streets bordering communities and houses built to withstand embers. He points to San Diego County, where a developer was persuaded to locate a golf course between houses and an adjacent wilderness area.

Donald Trump talked nonsense about rakes, but California isn’t doing much better.

Newly passed legislation would devote a significant portion of a billion dollars over five years to thinning forests and clearing brush. Cutting roads through our natural treasures so the timber industry can take more trees won’t significantly reduce the danger to Paradise or other towns like it. And the industry wants large, old-growth trees more than the younger ones even though old trees are more fire resistant.

Cutting brush brings another set of questions. What exactly is brush? Studies have found invasive annual grasses that quickly dry and burn in unpredictable patterns are a bigger fire threat than evergreen chaparral, which is native to the state.

Policymakers should be helping homeowners protect their homes from embers and installing roof sprinklers fed from reliable water sources, such as swimming pools or community water tanks.

Firefighters in Paradise saved the lives of about 150 people by having them huddle together in the middle of a parking lot. Instead of expecting people to evacuate on a couple of crammed roads, leaders should build parks with big lawns and maintain large parking lots where residents could ride out the fire if necessary.

Firestorms are no longer an aberration. They’re our future for some time to come, no matter how meaningfully we attempt to turn the tide on greenhouse gases. Gov. Jerry Brown was willing to take major steps to combat climate change, but the policy shifts needed to improve communities’ fire resilience will require even bolder commitments. It’s time for smart planning based on science rather than outmoded concepts of how fire works.

Karin Klein is a freelance journalist in Orange County who has covered education, science and food policy. She can be contacted at Follow her on Twitter @kklein100.