After a centuries-long history of intentionally suppressing wildfires in the United States, particularly in the western part of the country, land managers now are recognizing that new strategies of coexisting with fires may be necessary—and more realistic.
Big, destructive wildfires used to be rare enough that they were remembered for decades. But over the past several years, apocalyptic images from wildfires have become a mainstay on the news in the late summer and fall: “firenados” of 100-mph-plus wind and flame, neighborhoods reduced to ashes in minutes, and eerie orange skies above scorched earth.
Thanks to the combination of fire suppression, climate change, and an increasing number of ignition sources, wildfire activity throughout the western United States has climbed steadily over the past several decades, outpacing our ability to contain it. From the 1970s to the 2010s, areas burned in large forest fires have increased by more than 1,200 percent. The giant, ferocious fires of the past several years continue the trend.
The Tunnel Fire—which in 1991 destroyed nearly 3,000 structures in Oakland—had held the record as the most destructive fire in California history for decades. But in 2017, a series of fires erupted in California’s wine country, with the Tubbs Fire breaking that earlier record in terms of structures destroyed. The same year, the Thomas Fire in Ventura and Santa Barbara Counties consumed some 280,000 acres—at that time, the largest fire in state history. Shortly thereafter, in 2018, the Camp Fire in northern California destroyed more than 18,000 structures and killed 85 people, leveling the town of Paradise. Wildfires engulfing thousands of homes now are a regular occurrence: in 2020, four fires in California reached that level of destruction.
California, the hardest hit state, has repeatedly broken its own wildfire records. But the explosion of wildfire activity has not been confined to the Golden State. The three largest fires in Colorado history occurred in 2020. Similarly, western Oregon suffered wildfires without precedent in size and ferocity; 600,000 acres burned west of the Cascade Crest in 2020—approximately 10 times the annual number of acres burned historically in that region from 1984 to 2018.
Credit: Raju Bhupatiraju / Unsplash
As heavy as property losses have been, damage to structures is not the only impact—nor the most significant—associated with wildfires.
For several weeks during the fall of 2020, as wildfires raged from the city of Los Angeles to the state of Washington, smoke blanketed much of the West Coast. Air quality ranked as the worst in the world, temporarily displacing a dozen Asian cities, with Air Quality Index numbers in Portland topping 500. (For reference, numbers above 150 are considered dangerous, even for healthy people.) And the smoke did not stay on the West Coast; it spread east across the country, with haze visible in New York. Wildfire smoke in 2021 isn’t looking much better. While Air Quality Index numbers have been more moderate thus far in major cities, the total population affected by wildfire smoke (based on daily population numbers situated within smoke plumes) as of this summer exceeded the same metric for the summer of 2020—which had been the worst of the past 15 years.
Wildfire smoke is made up of gases and fine particulate matter (also known as soot), which can be hazardous to health, especially for older people and children. Exposure to fine particulate matter—known as PM2.5, because the particles are smaller than 2.5 micrometers in diameter—is linked to lung and heart problems. Even short-term exposure to dense PM2.5 pollution can lead to increased risk of serious illness. One study estimates that wildfire smoke results in about 500 additional deaths among elderly Americans each year. Severe smoke also can disrupt business, as people seek shelter indoors from the harmful impacts of smoke. While PM2.5 pollution has declined nationally in recent decades, the western United States has seen an increase, with as much as half the region’s PM2.5 pollution now coming from wildfires.
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Wildfires also disrupt energy systems in the western United States. Several of California’s most destructive fires, including the Camp Fire, were ignited by power lines owned by Pacific Gas & Electric, the utility that distributes electricity to much of the northern part of the state. Since the Camp Fire, Pacific Gas & Electric has on several occasions responded to hot, dry wind conditions by shutting off power to hundreds of thousands of households and businesses rather than risk a repeat incident. Southern California Edison, which serves much of the southern part of the state, also has been taking no chances; for example, the company has shut down portions of its system when high winds are expected.
Given the scale of damages in an incident like the Camp Fire, these power shutdowns—known as Public Safety Power Shutoffs—may be prudent when fire danger is very high. Nonetheless, these shutoffs are extremely costly. When power is shut off, businesses and schools are forced to close, households and grocery stores can lose perishable frozen foods, and vulnerable people may lose the power they need to run medical devices. Michael Wara of the Stanford Woods Institute for the Environment estimates that a shutoff event in October 2019 cost California’s economy as much as $2.5 billion. Power supply shutoffs have to this point primarily been a California phenomenon; but in September 2020, Portland General Electric cut power to more than 5,000 Oregonians due to weather conditions that carried the threat of wildfire.
Why More Fires?
The outbreak of western wildfires is hardly just bad luck. It’s a result of our decreasing ability to prevent or control fires as several trends conspire to worsen fire conditions.
Wildfires are a natural part of many ecosystems in the western United States, which count on burns to renew the land and maintain species diversity. Historically, large amounts of land were burned every year, in part because Indigenous people used fires to maintain the landscape for productive purposes, and which to some degree accounts for the low level of wildfires over the last century.
Throughout much of the last century, federal and state land management agencies viewed wildfire as an adversary and sought to suppress fires entirely. The US Forest Service, in particular, regarded wildfire as a threat to timber harvests. In 1935, the Forest Service established the “10 AM” policy, which set the goal of extinguishing all fires by 10:00 on the morning after each fire was discovered. As the twentieth century progressed, ecologists learned more about the role of fires in healthy ecosystems, leading to changes in attitude—and policy—toward fire within management agencies. However, ending the “war on fire” has been neither easy nor immediate.
In dry forests of the western United States—like the ponderosa pine forests of the Sierras, the northern Rockies, and the east side of the Cascades—fires historically maintained ecological diversity across the landscape. Low-intensity, spontaneous fires kept the undergrowth relatively open and sustained forests that contained tall, old pines. Occasionally, more intense fires would create patches where new growth could compete with older trees for sunlight. The diverse landscape, itself a product of fires, served to regulate the threat, providing natural breaks in vegetation that could halt the spread of fires and prevent large, high-intensity fires from becoming the norm.
The history of wildfires in the United States makes it clear that we’ve been mistaken in our historic aims to suppress fires entirely, and natural burns are healthy for the ecology of the region. Therefore, we need strategies to help us coexist more safely with fires.
But, lacking periodic fires, the landscape eventually became more homogeneous. Park-like forests gave way to understories of dense vegetation, which more often carried fires high up into the forest canopy, turning low-intensity ground fires into much more dangerous crown fires. As the climate has warmed, opportunities for this kind of dangerous fire have become more frequent. Climate change has caused dry vegetation to predominate for larger portions of the year—in part because snowmelt occurs earlier—creating more opportunity for fires. In the chaparral shrublands of southern California, fire season has begun stretching into the fall, when warm Santa Ana and Diablo winds blow in from the desert, during which even a minor ignition potentially becomes a fast-spreading conflagration.
Climate change has increased fire activity even in wet parts of the Pacific Northwest. The western slope of the Cascade Range in Oregon and Washington historically was too wet to sustain wildfires. There, forests dense with fuel have been the norm, rather than sparse understories, due to a legacy of fire exclusion. But whereas the dampness of these fuel-laden forests historically minimized any fire risk, the events of last September showed that, under climate change, these forests are now potentially dangerous vectors of fire.
As we continue to better understand the underlying causes of increased wildfires, we can design better strategies for containing and minimizing the damage. The devastating consequences in recent years are, of course, one more reason to address climate change aggressively—among a long list of reasons. But the history of wildfires in the United States makes it clear that we’ve been mistaken in our historic aims to suppress fires entirely, and natural burns are healthy for the ecology of the region. Therefore, we need strategies to help us coexist more safely with fires.
Moving Forward with Forest Management
Ironically, suppressing wildfires in western US forests has led to the accumulation of flammable brush and young trees in forest understories that historically lacked tinder and had more open space. Forest managers can reduce fire risk by thinning this brush and vegetation on the forest floor, thereby minimizing the fuels that feed wildfires. This type of “fuel treatment” frequently happens through mechanical thinning projects, in which small trees or other fuels are physically removed from the forest, or through controlled burns, in which fires intentionally are set during favorable conditions to burn away the fuels from the forest floor. Removing understory vegetation in these forests reduces opportunities for low-intensity ground fires to become high-intensity crown fires, which are significantly more destructive and difficult to contain.
Fuel treatments also may reduce the negative health impacts of smoke. While controlled burns themselves emit smoke, their use can be limited to times when the emissions will not push pollution to dangerous levels and when wind is unlikely to blow smoke toward population centers. By tolerating low levels of smoke from controlled burns, we may be able to avoid the severe fire and smoke events that seriously damage health.
The outbreak of western wildfires is hardly just bad luck. It’s a result of our decreasing ability to prevent or control fires as several trends conspire to worsen fire conditions.
So, why haven’t fuel treatments solved the fire problem? A major reason is funding. Fuel treatments can be expensive, especially because pricier mechanical thinning often is needed to reduce excessive fuels before the less expensive controlled burns can be implemented safely. Another major reason is the backlog: A huge amount of land needs fuel treatments. According to the US Forest Service, up to 80 million of the agency’s nearly 200 million acres of land need forest restoration such as fuel treatments. Even spending about $350 million per year on fuel treatments, the Forest Service reaches just 1.4 million acres per year.
Fuel treatments also are subject to significant political pushback. Controlled burns do produce smoke and sometimes can be viewed as risky due to their potential for escaping the planned boundaries. Mechanical thinning projects are seen by some as logging under a different name.
Notably, the effectiveness of fuel treatments in reducing fire risk differs from place to place. In the chaparral of southern California, a recent increase in fire activity has resulted from climate change and an increase in the number of ignition sources (e.g., campers, power lines) rather than an increase in fuels. In such places, broadscale reintroduction of managed fires is not needed. Instead, those areas—and elsewhere in the western United States—need strategies for humans to coexist with the increased threat of wildfires under climate change.
Living with Fire
Regardless of our contemporary efforts, the United States is unlikely to return to the low-wildfire environment of the last century—in large part due to the combined factors of climate change and the ecological history of fires. Forest and land management can make a difference, but communities in high-risk areas also need to prioritize strategies for adapting to new realities.
Gilbert White, a twentieth-century American geographer who conducted early research on managing flood risk in floodplains, wrote that floods are acts of God, but flood losses are largely acts of man.” Similarly, the risk that wildfires pose to private property depends in large part on where and how homes are built.
A firefighting aircraft drops fire retardant on the landscape in California.
Between 1990 and 2010, the number of homes in wildland-urban interface areas grew by 40 percent across the United States. By 2050, California is expected to add about 600,000 homes in high-hazard areas. Not only will more homes be at risk in wildfire-prone areas, but the demands on fire management will grow disproportionately as a consequence: firefighters must work harder to defend homes and lives.
The most obvious fix is for communities to limit exposure by discouraging development in fire-prone areas—and encouraging development in lower-risk areas. Siting new houses out of harm’s way serves a long-term solution by displacing high-risk development. After all, buildings don’t move; new homes in high-hazard areas create risk that we then live with indefinitely.
But this solution is more easily said than done. Most cities on the West Coast have faced shortages of affordable housing in recent years, as jobs and amenities pulling new residents to these cities have not met with increased housing construction. As a result, development often gets pushed to outlying areas, where land is cheaper but fire hazards are greater. By allowing or encouraging increased density in low-hazard areas, we might see a decrease in the rate of construction in high-hazard areas.
Location isn’t everything, though. Communities can limit exposure to fire risk by requiring buildings to meet fire-resistant standards and making sure that owners maintain their properties to minimize fire risk. Building materials—such as fire-safe shingles, fire-safe tiles, and fire-resistant siding—can reduce risk of loss. Moreover, most structural losses in fires are due to embers that ignite a home or nearby vegetation: homeowners can reduce risk of damage by keeping roofs and gutters clean and by keeping areas near their home free of vegetation.
Credit: Jen Theodore / Unsplash
One way communities can ensure fire-safe buildings is through building codes. California is a leader in this regard. In 2008, the state required new homes built in high-hazard areas to meet stringent fire-safe specifications. These efforts already have made a difference. Data collected by CAL FIRE, the state’s fire management agency, indicate that within the area burned by the 2018 Camp Fire, 52 percent of homes built in high-hazard areas after 2008 were damaged or destroyed, compared to almost 80 percent of homes built before 2008.
Adapting to wildfires will require more than just reducing risk to homes; the past several years have demonstrated that fires present a variety of risks. As wildfire activity continues to rise across the western United States, smoke will become an increasing health threat. Accelerating work to restore woodlands and reduce fuels in US forests could help. However, smoke is likely to remain a serious concern in the near term. Communities can prepare by investing in air filtration systems in public buildings and schools. State and federal governments can help families purchase household air filtration systems in heavily affected areas by providing financial assistance.
Significant work can be done by the electricity sector to adapt to the threat of wildfires. According to the courts, utilities may be held liable if their electrical equipment ignites a fire. These utilities need to invest significantly in equipment and vegetation maintenance to reduce the potential for dangerous ignitions. In the meantime, utilities can avoid large-scale, disruptive shutoffs by helping create largely self-sufficient “microgrids” that allow more targeted power shutoffs in the highest-risk locations.
Given the realities of climate change and the sprawl of housing in dangerous areas, the risk of major wildfires is not going to evaporate. One way or another, people need to adapt.
No single strategy will work. Virtually all the changes we need will be costly, and some of them may be a tough sell to developers and communities. But the alternative to decisive action is predictable outcomes: more fires; more property destruction; and more damage to human health, both direct and indirect. A rational fire management policy may be expensive—but it’s much more affordable than business as usual. Between 1990 and 2010, the number of homes in wildland-urban interface areas grew by 40 percent across the United States. By 2050, California is expected to add about 600,000 homes in high-hazard areas. Not only will more homes be at risk in wildfire-prone areas, but the demands on fire management will grow disproportionately as a consequence: firefighters must work harder to defend homes and lives.
Given the realities of climate change and the sprawl of housing in dangerous areas, the risk of major wildfires is not going to evaporate. One way or another, people need to adapt.
A version of this article was published in the second quarter 2021 issue of the Milken Institute Review.
A version of this article appeared in print in the Fall 2021 issue of Resources magazine.
