Climate Solutions // ISSUE # 97 // HOTHOUSE
California is experimenting with burning parts of its forest down
These ‘prescribed burns’ may reduce the risk of catastrophic wildfires by as much as 60%
The thick carpet of dry brush underfoot caught fire quickly. The color changed from brown to a fierce orange before the wind swept the flames onward, leaving only blackened scraps behind. Smoke billowed up, warming the cool November morning air and blurring the view of the surrounding mountains. Soon, the fire would flow downslope, consuming acres of the Sedgwick Reserve, a sprawling conservation and research facility in central California. And that was the goal.
“Fire on the ground!” Sarah Gibson, a local firefighter overseeing the burn, declared triumphantly. This first ignition was set as a test to ensure the fire caught and burned as expected — eagerly, but not too hot and fast. Now, the yellow-gear-clad crew had the go ahead to light up additional acres.
This was a hands-on lesson in conducting an intentionally set fire, known interchangeably as a “controlled burn” or “prescribed fire.” Research has shown that the regular application of low-intensity flames helps clear built-up plant material, reduces competition for resources among the surviving flora, destroys invasive insect colonies, and introduces new minerals into the soil, among other benefits. All of these actions can help mitigate future fires from becoming the sort of high-intensity conflagrations seen in California and across the West in recent years.
The participants joining me in the field included a mix of firefighters, Indigenous fire practitioners (skilled in fighting and lighting fires), researchers, and community members who had signed up to be part of a Prescribed Fire Training Exchange, or TREX. The Nature Conservancy and the U.S. Forest Service developed the TREX model more than a decade ago to cultivate an informed workforce to tackle this challenging — but increasingly essential — practice. The Forest Service has estimated that it can take up to a decade, if not longer, to master the prescribed fire skill set, particularly for tackling larger or more complex burns.
TREX workshops teach everything from how to plan a safe and successful burn to the part I joined to observe: how to set fire to land to make it healthier and more resilient.
The Original Architect of the Wildlands
Fire is one of the original architects of wildlands in the United States. In ancient forests, this originated from lightning strikes, which began blazes when they cracked through dry landscapes. Indigenous tribes saw how these fires breathed new life into forests and began setting their own ignitions for ecological and spiritual purposes. Before colonization, hundreds of tribes developed their own burning practices. For example, along the same stretch of the Santa Ynez Valley where the Sedgwick Reserve is located today, the Chumash people found that two of the plants they used in their diet — chia sage and red maids — thrived with regular treatments of low-intensity fire.
Over time, landscapes adapted to this application of fire. But this practice was largely erased from the land when European settlers arrived, with tribes displaced and implementation of policies prohibiting cultural burns. Anti-fire sentiment intensified further following the Great Fire of 1910, which burned through three million acres from Washington State to Northeastern Montana in just two days, killing dozens of people. With fire now viewed as a threat to burgeoning communities instead of as an asset to forest health, the U.S. Forest Service set an anti-fire precedent from the top-down. This culminated in the 1935 “10 A.M. policy,” which called for all wildfires to be contained — meaning firefighters should try to stop their uncontrolled spread — by 10 AM the day after they were first reported.
By the 1960s, researchers were already calling for the reintroduction of fire in certain ecosystems, but it would take decades and serious concerns about the health of the forest for these policies to shift in favor of not just fighting but also cultivating fire.
States in the Southeast led the charge in welcoming fire back on the landscape in the mid-20th century. Ranchers largely led the push to embrace prescribed burning, following practices their ancestors had learned from Indigenous tribes. Between 1998 and 2018, 70% of prescribed burns in the country occurred in the Southeast and were set by non-federal crews, such as state practitioners and private landowners.
Meanwhile, the rest of the U.S. is playing catch-up, as there is now a broad consensus that trying to eliminate all fire from the land was a mistake. Putting out less-extreme fires today, “ensures that remaining wildfires burn under more extreme conditions,” researchers at the University of Montana and the U.S. Forest Service wrote in the journal Nature this past March. It’s the “fire suppression paradox,” a phenomenon fire experts have been warning about since the 1990s.
Addressing this paradox means lighting more purposeful fires through both cultural burns and prescribed fires. One recent study from Stanford University found that low-intensity fires — like those cultivated in prescribed burns — reduced the risk of catastrophic fire in some California forests by 60% for at least six years. Federal and state agencies alike have called for a dramatic increase in prescribed burns, but translating those policy priorities into actual ignitions has proved to be a daunting task. Burns like the one I observed at the Sedgwick Reserve often take months, if not years, to plan. And even then, the best-laid plans are up against a changing climate that has skewed the baseline conditions and the stakes of setting fires.
The Checklist
It took a multidisciplinary team to make the Sedgwick Reserve burn happen. Some came from The Nature Conservancy and others from the reserve itself, which is owned by the University of California and has a research hub that joined in on the preparations. Members of the local fire department and a handful of retired firefighters rounded out the group. In the weeks ahead of the TREX, the group assembled in blurry squares on regular Zoom calls, sharing updates, emails, and Google doc drafts to plan out the week’s curriculum.
The rest of the preparations were a mix of fieldwork and paperwork — organizers engaged in site visits and permit processes; they rented gear and made sure a fire truck and water tanker and helicopter were available on standby. As the event drew closer, they turned their attention to the forecast. Initially, the plan was to begin burning on Thursday, November 16, but a rainy forecast threw the schedule into flux. They decided to burn that Monday instead, a day that promised brighter skies. Plus, this way, the rain could work to their advantage, providing an extra layer of moisture to ensure all embers were sufficiently doused following the fire.
This sort of last-minute shuffle was familiar to the seasoned firefighters and fire lighters. Conducting a prescribed fire requires achieving a sort of Goldilocks window: you want it hot, but not too hot; not too dry, but the rain can’t be coming down, either. Plus, there’s the wind to consider, from its strength to its direction — you need to consider where it might spread the fire and the smoke.
The morning of the burn, there were still more logistics to go over. Checklist in hand, Sarah Gibson oversaw the scene. Gibson was working toward a Burn Boss certification, which would give her the authority to plan and manage controlled burns on state- and privately-owned lands in California. It’s a program the California Department of Forestry and Fire Protection (Cal Fire) began offering in 2021 to train up its own workforce in this space. As of August 2023, California had awarded the certification to just 24 people.
“Have all permits and clearances been obtained? Yes. Have all required notifications been made? Yes. Have all pre-burn considerations and work identified and completed? Yes,” Gibson began, ticking through a list that called for considering the forecast, any amendments to the pre-written burn plan, smoke specifications, and whether there were adequate suppression resources available in case the fire starts to spread.
“We must continuously learn and adapt to changing conditions so we can be at our best to protect communities and care for the lands and natural resources we manage on behalf of the public.” - Randy Moore, U.S. Forest Service Chief
In an analysis of the barriers to implementing more prescribed fire, research group Headwaters Economics found the permitting process to be one of the most significant roadblocks. According to the group’s 2023 report, many prescribed fires languish under bureaucratic gridlock. But the abundance of caution is for a good reason — while it is rare for a prescribed fire to become a wildfire, it can be devastating when it does happen. In 2022, a Forest Service prescribed burn escaped in New Mexico, meaning it began to burn uncontrolled beyond its planned perimeter. That fire merged with another prescribed fire that had been insufficiently extinguished and reignited. The combined blaze became the most damaging and destructive wildfire in the state’s history.
The Forest Service instituted a prescribed burn “pause” that year to consider what, exactly, went wrong, and whether it was something that spoke to a broader issue within the agency’s approach to prescribed fire. In the resulting review, the Forest Service acknowledged that the conditions the day of the escaped burn had been dangerous and that they should have looked more holistically at how drought had dried the soil in the region and primed the forests to burn.
“We have decades of experience using prescribed fire. However, what we learned most during this review is that we cannot overly rely on past success,” U.S. Forest Service Chief Randy Moore wrote later that year. “We must continuously learn and adapt to changing conditions so we can be at our best to protect communities and care for the lands and natural resources we manage on behalf of the public.”
Those changing conditions were due in large part to the changing climate. One study led by climate scientist Daniel Swain found burn windows, meaning those days with the elusive Goldilocks conditions required for lighting low-intensity fires, have tightened by more than 20 days a year since the 1980s due to climate change’s impact on conditions. And as these ideal burning days are lost, the number of wildfire-risk days are on the rise.
The Prescribed Fire
Researchers with the Sedgwick Reserve estimate that the TREX burn was the first fire to graze the site in at least 75 years. This meant there was a build-up of vegetation for the fire to feed on, much of it dried brittle following years of historic drought conditions. The TREX trainees crunched across their assigned acres, stopping at times to carefully dip their drip torches towards the ground. The fuel-filled devices, which look a bit like watering cans with extra-long and skinny necks, unleashed steady streams of flames onto the ground.
As the operation continued, I was escorted further from the fire to stand with the other observers who did not have firefighting credentials — mostly researchers, some of whom had left measurement tools in the grasses and up in oak trees.
When one of the trees caught fire, resulting in a loud crackle as the flames reached the leafy branches, some of the researchers’ gasped; one murmured a drawn-out, “wow,” entranced by the spiking flames and the dataset it was creating.
But for the firefighters, this sort of fire behavior called for caution. The winds had picked up, egging on the flames and carrying some of the embers outside of the pre-designated burn area. Some of them caught outside the planned burning perimeter, creating their own ignitions known as spot fires. This was what the crew called a “slopover.” Kelly Martin, a retired wildland firefighter, explained to me that the difference between this and an escape is that the flames had not spread beyond their control. They were close by, not moving particularly quickly, and were still manageable with the resources the team had at hand.
“There is no ‘no risk’ solution; there’s also no zero fire solution,” - Daniel Swain, Climate Scientist
The constant hum of radio chatter picked up as the contingency plans were moved into action. The crew stopped adding fuel to the fire. A bulldozer cut thick lines out of the ground, forming trenches to stop the fire’s forward motion. Then, there was the whir of a helicopter overhead, which circled the scene before making a dramatic drop of water.
The fire — slopover included — was out by noon. All of that careful planning had paid off.
The Wildfire
The Sedgwick Reserve is 5,896 acres. The prescribed fire burned through about 24 of them.
In the months since, researchers have carefully monitored that small sect of land for the fire’s still-unfolding effects — the start of an observation process that will last years.
Much of the area remains blackened and has yet to re-spout. Almost none of the native plants known to follow fires have appeared. The majority of oak trees in the burned area survived, but about five percent did not, with more showing signs of significant scorching. These reactions, researchers hypothesize, are likely due to the higher intensity at which the fire ended up burning, as well as that decades-long deficit of fire in the area.
But there’s also new fire data to consider now.
On July 5, 2024, a fire sparked about 15 miles northeast of the Reserve — how exactly it started is still under investigation. The Lake Fire, as Cal Fire called it, bloomed in the summer heat, burning across more than 38,000 acres of backcountry in Santa Barbara County. More than 2,000 people were given evacuation orders as it eluded firefighters’ efforts to bring it under control. The Sedgwick Reserve staff were among the evacuees.
The staff spent multiple days prepping the reserve for the Lake Fire’s potential entrance. They showed fire crews where the water hookups were located, where their research infrastructure was located, and how to navigate the winding dirt roads and trails. Then, on July 9th, they left as the fire made its way closer.
They returned to a very different landscape.
About 3,000 acres across the northern, central, and eastern stretches of the reserve burned. Some of those areas were set ablaze by firefighters to clear it of debris that could further fuel the wildfire, but other areas bear the scars of high-intensity wildfire flames. Nikki Evans, an outreach and communications specialist for the reserve, told me this fire did not cross paths with any previous prescribed fire activity on the property. Now, the Reserve is working to quickly assemble a research team to begin quantifying the impact of the Lake Fire in addition to their ongoing prescribed fire analysis.
By July 20th, firefighters had the Lake Fire 90% contained, meaning it is considered largely under control. Days later, the Park Fire in Northern California would quickly take the Lake Fire’s title as largest fire of the year so far — and it’s still growing as I write.
Setting fires is an imperfect process, but it’s one that allows for a degree of control as our climate increasingly bends to the extremes.
“There is no ‘no risk’ solution; there’s also no zero fire solution,” Swain, the climate scientist, said in a briefing at the start of this summer. “You’re either going to see these fires as prescribed burns, early in the season usually, or as uncontrolled wildfires late in the season.”
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This edition of Hothouse is edited by Tekendra Parmar and published by Cadence Bambenek. We rely on readers to support us, and everything we publish is free to read. Follow us on Twitter or LinkedIn.
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