Why fire is our best tool against megafires

American Indians have burned the West for millennia. Their knowledge could save it.

To live in many parts of the American West today is to live with wildfires. And to suppress those fires is only to delay, and worsen, the inevitable.

The gargantuan wildfires that have scorched states like California, Washington, Oregon, and Colorado recently are vivid reminders of this fact.

A number of unique factors this year combined with long-term trends to create the devastating and unprecedented fires of 2020. But a major reason for the massive scale of the destruction is that natural fires and burning practices first developed by Indigenous people have been suppressed for generations.

Wildfires are essential to many Western ecosystems, restoring nutrients to the soil, clearing decaying brush, and helping plants germinate. Without these fires, vegetation in woodlands, grasslands, and chaparral shrublands accumulates, so more fuel is available to burn, especially when a megadrought keeps drying the fuel out, year after year. A debt to the landscape starts to mount, and when it comes due, there is hell to pay.

“If we’re not using fire in the same way that this landscape evolved with over millennia, then we could be creating a situation where we’re creating a further imbalance,” said Don Hankins, an environmental geographer at California State University Chico and a Plains Miwok Indigenous fire practitioner.

So a key part of the strategy to reduce the growing threat from wildfires is to burn parts of the landscape on purpose.

This is much easier said than done. It’s costly, it can be dangerous, and it demands a sophisticated and granular understanding of the land. But American Indians have used burning practices across much of the West for thousands of years, building up a vast reservoir of knowledge of when and how to start fires to protect themselves and to increase the bounty of the land.

Much of this burning stopped when European settlers arrived and drove American Indians away from their ancestral homes and deprived those that remained of their culture. Now there’s a growing movement to bring these practices back to the landscape, with Indigenous practitioners in the lead in places like California. But it requires confronting an ugly past and facing a future of growing wildfire risk.

Why Indigenous burning practices are a powerful way to mitigate wildfire risk

To understand how we arrived in this era of extreme wildfires across the Western United States, scientists have studied patterns like those in tree rings to get a sense of the history of fires across the West.

“It shows that a lot of these areas burned a lot, anywhere from every two years to every 15 years,” said Eric Knapp, a research ecologist at the United States Forest Service’s Pacific Southwest Research Station. “If you haven’t burned in a long time — some of these places haven’t seen fire in recorded history, or since 1910 — that’s a lot of fire debt.”

Eric Knapp/USFS

The US Forest Service has even tabulated estimates for how often fires have historically occurred across ecosystems like sage scrub and ponderosa pine forests. These records, plus what we know about how fires were suppressed since the 1800s, point toward how much American Indians in the Western US engineered the landscape with their burning practices for thousands of years. European settlers arrived and saw a landscape that had been methodically cultivated, like forests with trees spaced far apart and with little leaf litter on the ground. But they often failed to recognize it as such.

“There’s this idea — the idea I was raised with — that this wilderness is untrammeled by man,” Knapp said. “The more work I’ve done in this field, the more strongly I believe that there was a pretty strong human imprint on this landscape.”

The gap between historical levels of burning and the current fires also illustrates how much more fuel is now available to burn in dangerous megafires. However, there’s more to paying off this fire debt than lighting a match.

Bill Tripp is the director of natural resources and environmental policy for the Karuk Tribe Department of Natural Resources. The Karuk Tribe’s territory is in Northern California and reaches into Oregon. Tripp, a member of the tribe and an Indigenous fire practitioner, explained that every bit of the landscape has its own terroir when it comes to fire, a unique set of traits in a given region that can influence a blaze. The ideal conditions for a burn depend on the mix of plants, sunlight, soil, and weather conditions. They can change from day to day, and from one hillside to another.

Carlos Avila Gonzalez/The San Francisco Chronicle via Getty Images

And these deliberate fires are not just about reducing wildfire risk, as is often the case with prescribed burns from government or private land managers. These Indigenous burns serve cultural purposes, like maintaining trails, helping food plants grow, and providing materials for building and crafts. Such fires don’t just hinge on “when” and “how,” but on “why,” which in turn demands sophisticated local insight. For practitioners, it’s not just a tactic, but a way of thinking about how they interact with the natural world.

“The Karuk people have historically been dependent on the food, fiber, and medicinal resources that come off the greater landscape,” Tripp said. “We’re still dependent on those today.”

When done right, these Indigenous-prescribed fires have natural breaks built in as they spread from one type of vegetation to another. Rather than having hundreds of thousands of acres suddenly engulfed in flames, Indigenous burning practices can create a mosaic of areas that can readily burn surrounded by areas that are more resistant to ignition. Those breaks can be areas that have previously burned, thereby having less fuel, or plants that retain more moisture and are less likely to catch on fire.

There are ecological benefits, too. A well-timed burn can also restore the biodiversity of the species of plants and animals in places where invasives have become dominant. For example, invasive grasses like ripgut brome and shrubs like Spanish broom in parts of California can outcompete local vegetation, but quickly turn into highly flammable tinder when it gets hot.

A robust mix of native plant and animal species can instead make an ecosystem more resilient to shocks like drought and extreme heat, as well as speed up recovery after a fire.

Frontiers in Ecology and the Environment

“In California, in our foothill and valley ecosystems, we’ve got a lot of nonnative grasses,” Hankins said. “If we think about the seasonal timing of when it’s appropriate to remove those species with fire and favor native species in their place … we can still achieve the fuel reduction but then we’re shifting the dynamics in favor of native species.”

The Indigenous-prescribed fires can be slower and less intense than natural or inadvertent fires, creeping along the forest floor rather than tearing through tree canopies. The trees and plants that remain become more resistant to future fires.

Over time, with frequent controlled fires, the landscape starts to shift to a healthy mix of species. The fires become easier and safer to conduct, and eventually the risks of a devastating wildfire start to go down.

Halting Indigenous burning practices was part of a deliberate strategy to eradicate American Indians

When European settlers arrived in the Western United States, they intervened to stop American Indian burning practices, but not just out of fear of fire. Instead, according to Tripp, cultural burning practices were blocked as a deliberate tactic to threaten the survival of Indigenous people like the Karuk Tribe.

“It became part of the policy to remove that connection to the food systems well before fire suppression became a policy,” Tripp said. “When you’re going through a cycle of genocide and people are trying to remove the Indigenous component from a place, that [Indigenous burning practice] becomes a logical target.”

Laws in states like California stripped Indigenous people of their rights and prevented them from practicing their culture, including burning. As late as the 1930s, Karuk people were actively stopped, and even shot, for trying to conduct burns.

Fire exclusion policies also stemmed from a misguided impulse to improve the region’s ecology. Prior to the 20th century, forests like those in the Sierra Nevada were far less dense, with trees spaced much further apart. “The relative openness of forests was attributed to frequent fire, which many early foresters saw as a negative,” according to a 2012 study from the US Forest Service. “It was believed that if fire could be kept out the forest could support many more trees. This became one of the main arguments for suppressing fire.”

With the suppression of natural fires and indigenous burning practices, some sections of the forest grew to be anywhere from twice as dense to 10 times as dense as they were when fires were more frequent, increasing the likelihood of what’s known as a “stand-replacing fire.” These are massive blazes that can wipe out almost all of the living trees in an area, including towering overstory trees. When there’s a drought, more trees means there’s less water to go around, leading to drier and more flammable vegetation.

Today, the Karuk Tribe can only conduct burns on the tiny sliver of their ancestral lands across California and Oregon that is privately held and not part of federal land.

More than 135,000 acres of Karuk ancestral territory burned in the fires this year. But Tripp said that this could also be an opportunity to begin a regime of controlled burns in those areas. “We need to be putting some strategic placement of follow-up burning,” he said.

Vast swaths of land across the West are overdue for a fire

The question now is how to scale up these Indigenous burning practices across federal, state, and private land and develop an appreciation for the knowledge behind them. Even with the record-breaking blazes across the United States in recent years, there are still millions of acres of wildlands that have yet to burn and could still be devoured in megafires. And as the climate changes, more areas will become primed to ignite.

With controlled burns, the plants that could fuel a massive uncontrollable fire are depleted in smaller, easier to manage bursts. Many small fires can help prevent devastating megafires.

Burning is also just one of several ways to reduce the risks of dangerous wildfires alongside measures like mechanically removing vegetation and building fire breaks.

Bringing these tactics to all the places they’re needed stands to be a costly endeavor, and the investment is far short of where it needs to be. Already the federal government, which manages huge swaths of land in the Western United States — including 57 percent of the land in California — is struggling to implement its existing prescribed burning plans.

The US Forest Service conducts fire mitigation work, including controlled burns, across roughly 1 million acres of land per year across the whole country. But the agency has an 80 million-acre backlog built up after years of fire suppression and inadequate budgets, with 50 million acres “at high risk of wildfire, insects, and disease.”

Over the summer, the State of California reached an agreement with the US Forest Service to conduct fire mitigation treatment across 1 million acres in the state per year. That’s a big step up. Currently, California land managers conduct controlled burns on 125,000 acres per year across state, federal, and private lands. By comparison, Florida, a much smaller state, permits about 2 million acres of controlled burning each year.

And California has a lot of fuel it needs to eliminate. “An estimated 20 million acres of forestland in California with high wildfire threat may benefit from fuels reduction treatment to reduce the risk of wildfire,” according to a 2018 state report.

Carlos Avila Gonzalez/The San Francisco Chronicle via Getty Images

Carlos Avila Gonzalez/The San Francisco Chronicle via Getty Images

For Indigenous fire practitioners like Hankins and Tripp, the aim now is to build a framework from the bottom up to support Indigenous cultural burning practices within and beyond the bounds of Indigenous lands. The Karuk Tribe, for instance, has launched the Endowment for Eco-Cultural Revitalization and is raising funds to help teach people about the culture around burning and to support burning practices over the long term.

“It’s not lost, it’s all still ingrained in our culture,” Tripp said. “If we wait a couple more generations, it might get lost. If we don’t start acting soon to revitalize the knowledge, practice, and belief systems, then a lot more than just information about our practices will be lost. We’ll be looking at large-scale biodiversity collapse as well. And we’re already starting to see it.”

Deploying Indigenous knowledge to reduce fire risks would also require recognition of tribal sovereignty over their ancestral areas, returning land to American Indian communities, and a frank accounting of what was lost and stolen over more than a century of settlement and colonization.

At the same time, when land managers start strategically deploying fire and thinking carefully about all the factors at play, they often come to practices and results that resemble Indigenous burning.

Jared Dahl Aldern, an environmental historian and lead researcher at the West on Fire Project, highlighted the recent example of a 15,000-acre plot of land managed by Southern California Edison near Shaver Lake. The area survived the recent Creek Fire near Fresno with much less destruction than adjacent federal land, becoming an island within a nearly 350,000-acre megafire. Prior to the blaze, the power utility deployed controlled burns, forest thinning, and timber harvests to help protect its assets on the land from wildfire.

“While they didn’t draw on a lot of Indigenous knowledge or consult with tribes in terms of figuring out how to do their land management, I call it a process of convergent evolution of their forestry practices because they ended up in the same place as historically what forest conditions were under an Indigenous fire regimen,” Aldern said.

But land managers don’t have to reinvent the wheel when it comes to strategically deploying fire; by partnering with and following the lead of American Indian fire practitioners, they can build on an existing foundation of knowledge.

Prescribed burns are essential for reducing wildfire risk. But we need to do even more.

As important as it is to reduce the amount of vegetation that can readily burn, fuel is not the only driver of massive, destructive wildfires. The record-breaking 2020 fire season — which is still not over — is a case in point.

Many factors converged to create such a devastating year for wildfires in 2020. A series of unusual weather events, from a searing heat wave to a rare dry lightning storm to high winds to extraordinarily low humidity, left much of the West ready to burn.

But other long-term factors are at play as well. People have continued to build into the wildland-urban interface, where suburbs meet shrubland. Across the United States, the number of homes in these regions has grown rapidly over the last two decades. And more homes continue to be built. One study found that, based on current trends, 645,000 homes in California will be in “very high” wildfire severity zones.

Frederic J. Brown/AFP via Getty Images

Since the vast majority of wildfires are ignited by humans, this can increase the likelihood of sparking a new blaze, increase the damage of the blazes that do occur, and lengthen the fire season.

Humans are also continuing to destabilize the climate. With the emissions of heat-trapping gases from burning fossil fuels, the planet is warming. That’s upping the frequency and intensity of extreme heat events and is increasing aridity in many parts of the West, making grasses and trees more likely to ignite.

California in particular is still experiencing the effects of a drought that stretched from 2011 to 2017. That drought, exacerbated by climate change, helped dry out forests and leave trees vulnerable to pests like bark beetles, fueling a die-off of more than 140 million trees across the state, potentially adding more fuel to fires.

There’s also risk in conducting controlled burns. Even a well-managed fire can behave in unpredictable ways, or winds can suddenly shift and drive embers over fire breaks and six-lane highways. Fires can even generate their own weather, and rising temperatures are making it harder to safely conduct controlled burns, whether by American Indians or by other land managers. There’s also the problem of air pollution stemming from wildfires; deliberate blazes also have to take steps to reduce the smoke exposure of people who live downwind.

In addition to restoring fire to the land, some of the existing vegetation may have to be removed in other ways. That can take the form of forest thinning, where trees in a given region are selectively removed to reduce fire risk.

Some forest thinning can yield salable products and generate money. But forest thinning is different from logging in that reducing wildfire risk is the priority. In fact, some forms of logging can increase fire risks, as hardy, fire-resistant trees give way to fast-growing, fast-drying plants.

People will also have to use fire-resistant building materials for their homes and construct a defensible perimeter around property. In some cases, people may have to retreat from high-fire-risk areas altogether. And humanity will also have to take aggressive action to limit greenhouse gas emissions in order to stave off the worst consequences of climate change.

Just like there’s no single cause of the increase in destructive wildfires in recent years, there’s no single fix. And since this situation took more than a century to develop, it will take decades to start making progress on a solution. However, without concerted action now, the risks will only get worse. There is a debt to be paid — both to the landscape and to American Indians — and restoring Indigenous burning practices is a small step toward paying off both.

Help keep Vox free for all

Millions turn to Vox each month to understand what’s happening in the news, from the coronavirus crisis to a racial reckoning to what is, quite possibly, the most consequential presidential election of our lifetimes. Our mission has never been more vital than it is in this moment: to empower you through understanding. But our distinctive brand of explanatory journalism takes resources. Even when the economy and the news advertising market recovers, your support will be a critical part of sustaining our resource-intensive work. If you have already contributed, thank you. If you haven’t, please consider helping everyone make sense of an increasingly chaotic world: Contribute today from as little as $3.