California’s massive Park Fire—now covering nearly 400,000 acres, an area more than twice as large as New York City—started with arson. On July 24, a 42-year-old man allegedly set his car on fire, put it in neutral, and pushed it down a steep gully at a park in the city of Chico, where dry grass and brush immediately started to burn.
It was the middle of the afternoon on a day with triple-digit temperatures. Weeks of extreme heat meant the grass was bone-dry. The humidity was low, and the wind was blowing—the perfect conditions for a fire to spread. A witness called 911 immediately, and firefighters arrived quickly. But the steep terrain made it difficult to reach the fire, and by then it was too late. “Fire moving uphill, under wind, is an impossible thing to stop under the conditions of that day,” says Hugh Safford, a research ecologist at the University of California, Davis, and a former ecologist for the U.S. Forest Service in California.
The fire raced forward, burning around 5,000 acres an hour. By Friday, a day and a half later, 150,000 acres had burned. Within 72 hours, the fire had covered more than 350,000 acres. Thousands of people have had to evacuate. Hundreds of structures have been destroyed. An unknown number of wild animals have been killed. Five thousand firefighters are working on the blaze, but it isn’t even close to being contained. It’s likely to keep burning for weeks. It’s already one of the largest fires on record in California.
Climate change is only part of the problem
Huge wildfires in California are getting much more common—the number of acres burned each summer is around five times bigger than it was a few decades ago. Nine out of the 10 largest wildfires in the state’s recorded history have happened in the last decade. Not far from the Park Fire, the Dixie Fire burned 963,309 acres in 2021, and the North Complex Fire burned 318,935 acres in 2020. In 2018, the deadly Camp Fire destroyed the town of Paradise, killing 85 people. (Paradise has been rebuilding, though it was temporarily under evacuation orders again when the Park Fire began.)
One reason for the surge of large wildfires is climate change: Extreme heat dries out vegetation faster and makes fires burn more intensely. Climate change is also making nights hotter and drier; in the past, cooler temperatures and more humidity after dark helped firefighters work at night. Fire season keeps getting longer, as hot, dry conditions are present for more of the year. As climate change continues, the number of acres that burn is likely to keep growing. But climate isn’t the only reason that fires are getting much worse.
The Park Fire is burning through privately owned forests
One large chunk of the area that’s burned in the Park Fire is industrial timberland owned by Sierra Pacific Industries, the largest private landowner in the U.S. The forests are filled with relatively-densely packed trees. Timber companies plant vast swaths of trees at the same time, which means they’re the same age and size—making it easy for the fire to quickly move from one tree to another. “It burns really hot,” says Safford. “When you get wind going in a dry part of the year, those landscapes actually burn much faster than the National Forest land.” One study suggests that private timberland burns nearly twice as fast.
Like much of the rest of California, the timberland looks very different than it did before the surge of white settlers arrived in the Gold Rush in the mid-1800s. In the past, the hills in the area of the Park Fire were open, with a scattering of oak trees and ponderosa pines that were widely spaced apart. Early settlers thought it was untouched wilderness. But Native Americans living in the area regularly set low-intensity fires to clear out brush and small trees. Lightning also naturally started some fires. Because the area regularly burned and there wasn’t much fuel, fires could stay under control. Some species, like the lodgepole pine, adapted to need this type of fire (the pinecone only opens up and releases seeds when a fire heats up the resin that coats the outside). But they can’t necessarily survive the current fires that are much larger and more intense.
In the 1800s, loggers cut down ponderosa pines, which were resilient to fire. And when settlers started to suppress fires, other trees that were more susceptible to fire, like white fir, started to fill the forests. Other invasive species followed. “It’s a fundamentally different forest than it was in the mid-1800s,” says Safford. (In the wake of catastrophes like the Camp Fire, there have been some efforts to try to restore the original ecosystem in certain areas.)
Timber companies could do “prescribed burns,” or controlled fires when the conditions are lower risk, to help clear out fuel. But that often doesn’t happen. “It’s a business, so obviously the way you’re profitable is you cut as many corners as you can,” Safford says. “You cut any corner that the law will let you or that oversight will let you. And when your site hasn’t burned up for 20, 30, 40 years, you might start thinking that it’s not going to burn up.”
Ironically, we’re not burning enough
For more than a century, landowners and government forest managers have tried to stop fires as soon as they begin. Because of California’s climate, dead trees and smaller branches and plants don’t decompose as quickly as they can in more humid places. “When you remove fire, you just accumulate fuels for decades and decades and decades,” Safford says. When fires begin, they can now quickly get out of control.
After multiple catastrophic fires in recent years, the state and the U.S. Forest Service are now attempting to do more prescribed burns. (That’s taken a long time to happen: Safford says that federal agencies have know that extinguishing fires in the West was a bad idea since the 1960s, but did very little to change at that point.) Some controlled burns recently happened within the footprint of the Park Fire itself. But it’s still not happening at a large enough scale.
California, working with the Forest Service, has a goal to “treat” 1 million acres of land a year by thinning trees and using controlled burns, beginning in 2025. But they haven’t been ramping up to that goal, Safford says, and it’s fairly unlikely they’ll hit the target. The state budget is shrinking, creating another challenge. And while it’s a much bigger goal than what’s happening now, it still might be too small. Native Americans burned, on average, 4 million acres a year.
Next to the spot where the Park Fire started, the City of Chico had planned to burn a patch of particularly flammable vegetation this spring. But for a variety of reasons—a staff shortage, lack of equipment, unusually hot weather, and the difficult terrain—the project didn’t happen. There’s a small chance it might have slowed the fire down enough that firefighters could have stopped it.
What it will take to stop the Park Fire
The Park Fire is still burning wildly, and firefighters are battling in hot, dry, windy weather. As of this writing, it was only 18% contained. Firefighters have to physically “cut a line” around the perimeter, meaning they use bulldozers or other tools to cut down vegetation and trees and create a gap that the fire can’t cross. That’s happening well away from the fire for safety reasons. It could take a month, or even longer, before it’s possible to put the fire out.
On the east side of the fire, the Dixie Fire’s burn scar will stop the forward progress. “The Dixie Fire is a good example of a fire where we hated the outcome, but it’s going to limit where this fire goes,” says Safford. “We need to learn to use fire in the way that we know how to use it.” That includes choosing to let some fires burn when the conditions are right, rather than trying to extinguish them immediately.
“At some point, you’ve got to realize that the only process that is going to treat most California forests is going to be uncontrolled wildfire,” Safford says. “We don’t have a choice, because we have such limited capacity to actually actively manage fuels. Given that that’s the case, it’s better that we deal with that right now and that we begin to develop serious plans on how we are going to let fires burn on good days.”