Georgetown, CaliforniaRob York walks calmly through the quiet pines deep in California’s Sierra Nevada foothills, trailing a mix of kerosene and gas from a canister behind him onto the forest floor, which crackles alight into low flames.
“It’s nice, right?” he says to the group of locals gathered at the fire’s neatly contained edge, turning around to draw another delicate line of fire across the designated burn zone.
To many Californians, fire signifies danger. But here, on a cool, serene day in the pines, controlled flames go only where York, a scientist and forester with the University of California’s Blodgett Experimental Forest, and his colleagues direct them.
He has been out in the trees for hours, checking the humidity and wind conditions and laying the path for this small “prescribed burn”—a deliberately set fire that could help minimize the risks of uncontrolled wildfire in this stretch of forest halfway between Sacramento and Lake Tahoe.
Prescribed burns are one of the essential tools of modern fire prevention, and researchers at the Berkeley forest have spent decades experimenting with them, learning how best to use fire to clear away highly flammable underbrush and make the forest healthier. Yet even as climate change drives wildfires to more dangerous extremes, California is setting fire to only a tiny fraction of the million acres a year experts like York say is needed to lessen the severity of wildfires that have exploded in recent years, burning through many of the state’s wildly overgrown landscapes and taking lives and homes with them.
About a third of California’s 100 million acres of land is forested, so fire will always be a part of its landscape. But for York and many experts, the essential question as California confronts a future of climate-intensified fires is straightforward: “Do you want to control when and where your fires and smoke happen, with prescribed fire?” York asks. “Or do you want to wait until it comes to you, in a way you really have no control over?”
Fire belongs in forests
Contradictory as it may seem, fire is part of the natural life cycle of forests. The forests of the American West are so well adapted to flames that many species, such as the giant sequoia, even rely on fire to survive: Its seeds need fire’s intense heat to release from their cones and germinate.
Before white settlers arrived, an estimated 4.5 million acres of forest burned every year, set either by lightning or Native Americans, who used fire to manage the landscape. Both types of burns left scars in tree rings, which provide hundreds of years of historical records showing that burns occurred regularly every five to 20 years across many of the state’s forests, though smaller or gentler cultural burns not big enough to leave scars happened as often as yearly in some areas.
Those ancient forests, Native Americans and scientists say, looked much different than forests today. Then, only 40 to 60 trees per acre grew in much of the Sierra Nevada; today, hundreds of smaller trees crowd together on an acre—making forests more vulnerable to disease and pests, and primed to burn catastrophically.
“A lot of the forest—it’s five times too dense,” says Malcom North, an ecologist at the Forest Service’s Pacific Southwest Research Station, where many scientists are studying ways to keep the West’s forests healthy.
In order to get the state back on track with its historical fire patterns, researchers suggest that about one million acres should be burned every year. The reality has been more than an order of magnitude away, despite persuasive evidence that prescribed burns are effective. Last year’s Creek Fire, for example, burned explosively through parts of the Sierra Nevada. But when the blaze approached Shaver Lake, near Fresno, it ran into big swaths of land that Southern California Edison had treated with prescribed fire over the past 20 years. The fire “dropped down to the forest floor” and became controllable, says Craig Thomas, the director of the Sierra-based Fire Restoration Group, likely saving lives and property. Yet, in 2019, the last year for which figures are available, only about 118,000 acres were deliberately burned in the state.
“We are just so out of touch with fire now,” says Lenya Quinn-Davidson, a fire expert at the University of California’s Humboldt extension. “So much of our forests have this huge backlog, and we’re going to need to use prescribed fire to protect resources we care about—communities, places we love—and set larger landscapes up to thrive again.”
She estimates that some 10 million acres of the state’s forests have missed three or more natural cycles of fire.
The long history of fire—and its absence
The story of California’s relationship with fire is complex, complicated by a stew of thorny issues, ranging from chronic funding shortfalls for conducting prescribed burns to the complexities of defending the homes and businesses of the 11 million people who now live along the edge zones between settled towns and wild lands, known in fire jargon as the wildland-urban interface.
But the story starts with the practices of Native Americans, who have used fire to manage their landscapes for at least 11,000 years. For many tribes, fire was seen as a gift given by the creator; they had a responsibility to use it carefully in ways that would benefit their floral and faunal relatives.
That meant setting intentional fires frequently. Some fires cleared out underbrush so deer and other animals could move freely. Burning huckleberry bushes encouraged new shoots to grow, prized ingredients of basket weaving. Others might create a smoke-shade over streams so the temperature would drop, protecting salmon from too-warm waters.
That kind of management also helped keep landscapes resilient to changes in climate. And it kept forests clear of thick underbrush or young, spindly trees—the opposite of how many look today.
“We called it see-through,” says Ron Goode, a tribal leader for the North Fork Mono Tribe of the central Sierra Nevada who has practiced traditional burning since he was a child. “You could see straight through the trees.”
All of that changed when white settlers came West in the 1800s. They indiscriminately set fires to clear vegetation for farming and ranching, but recoiled from fire in forested areas, seeing it as dangerous and damaging to the timber they were logging. They violently ejected Native Americans from their own lands, and prevented those who remained from using fire traditionally; an 1850 law made cultural fire illegal.
“The heart of what is going on in California starts with forcible removal of Native Americans from their ancestral territories,” says Michael Wara, a fire and climate policy expert at Stanford. “There are these beautiful records of burn scars in trees like redwoods or pines, every five to 10 years until about 1850 or 1870. And then they stopped. That’s because ... part of the strategy of that forced removal was taking control of fire away from Native Americans.”
The seminal event that made people fear fire was the “Great Fire” of 1910, which burned over three million acres across Montana, Idaho, Washington, and British Columbia and killed more than 80 people.
The U.S. Forest Service was in its infancy, and in the smoldering aftermath of the fire the agency swiftly adopted an official policy to immediately and completely suppress any fire that broke out. By 1947, fire was officially declared to be “a menace to public welfare.” By the 1960s, intentional fire had been mostly eradicated from the California forest landscape.
“Smokey the Bear was too effective,” says North, the Forest Service ecologist. “A lot of the public has a view that has only slowly been changing: that fire burns up Bambi and habitat and is generally not good for the forest.”
A research revival
Meanwhile, as fire suppression became the norm across the country, a handful of scientists began to notice its unintended consequences. Harold Biswell, a Forest Service scientist who trained in Georgia, discovered that prescribed fire was used—and still is—to manage millions of acres of forest and agricultural land across the Southeast. He became convinced that wildfire danger could be mitigated with fire itself. When he moved to the University of California, Berkeley in 1947, he brought his observations about managed fire as a solution with him.
In the Sierra Nevada, Biswell’s experiments with controlled fire showed that intentional fires not only can reduce wildfire intensity, they can also improve forests’ ecological function, return forests to their formerly open, park-like state, and change water flows through the whole system.
“If you’re looking at habitat, or at watershed resilience—the answers all come back the same. They come back to establishing the natural processes, and that means fire,” says Thomas, the fire expert with the Sierra-centered Fire Restoration Council.
Support for prescribed burns slowly grew during the burgeoning environmental movement of the 1960s and 1970s as the ecological consequences became clearer, but still lagged, hindered by lack of support from some agency leaders. Prescribed fire amounted to only about 40,000 acres a year by the 2010s.
An evolving fire landscape
Even as wildfires have worsened in recent years, fear of prescribed fire persists. Private landowners, who control about 40 percent of California’s forest, worry about liability and how to safely conduct burns. Nearby communities worry about smoke and fires escaping their bounds during burns. Research led by Rebecca Miller, a fire policy expert at the University of Southern California, found that happens less than 2 percent of the time.
Cost remains a significant hurdle. California spends billions to put fires out: CALFIRE’s budget for fire suppression activities in 2021 was $1.7 billion, and after emergency allocations from the governor will top $3.6 billion. But only about one-tenth of that is directed toward fire prevention efforts, like prescribed fire, though it will get an extra $536 million this year.
Prescribed burns are also limited by the extensive planning required and a shortage of experienced workers to conduct them. Regulations about smoke, weather conditions, and safety limit the number of days burns can occur, and the paperwork alone can take months.
Smoke, for example, is demonstrably hazardous but efforts to control it are contradictory. Wildfire smoke is considered a natural emission under the Clean Air Act. But smoke from prescribed burns is tightly regulated, requiring permitting from local air resources, limits on the total amount that can be produced, and careful monitoring to make sure it doesn’t hover too intensely over nearby neighbors.
Wara says the risks and benefits need to be balanced. Wildfire smoke from 2020’s wildfires may have contributed to over 1,000 premature deaths; smoke from prescribed burns is more easily managed and often affects fewer people.
Because of all these challenges, only about 50 to 60 percent of the planned burns actually get completed in any given year, according to Miller.
Wildfires themselves may finally make the crucial difference. Since 2017, devastating wildfires including the 2018 fire that burned down the town of Paradise in northern California, have prompted California and federal lawmakers to ask for more “good fire.” Crucially, both CALFIRE and the Forest Service have agreed to vastly increase the acreage of prescribed burns: Each committed to burning 500,000 acres a year by 2025, for a total of one million acres a year—the goal researchers have identified as a good target.
Miller says achieving that could be transformative: "It demonstrates a huge commitment. That’s what we need to start getting at the deficit that has built up over decades.”
To Wara, the choice is clear. “The way we fight fire now is to let nature choose the time and place of battle,” Wara says. “And what prescribed fire does is let us choose the place and time to have that battle.”