Chad Hanson is an ecologist with the John Muir Project and the author of Smokescreen: Debunking Wildfire Myths to Save Our Forests and Our Climate (University Press Kentucky, May 2021).


Earlier this month, the Dixie Fire leveled most of the town of Greenville, California. I know the town well — I conducted fieldwork for my doctoral dissertation there. Thankfully, everyone survived. But the downtown is gone, along with 75 percent of the homes. 

It didn’t need to happen.

Fire has always been a concern for communities like Greenville in the northern Sierra Nevada mountains. And, for decades, the U.S. Forest Service and the timber industry told the townspeople that logging tens of thousands of acres — under the guise of “thinning” — would create “fuel breaks” to slow or even stop wildfires and prevent flames from reaching Main Street.

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Greenville became a booster for this approach to fire prevention, joining other towns in a pro-logging consortium that sent letters supporting the strategy to members of Congress. Their advocacy ultimately delivered a federal policy called the Quincy Library Group Act, which promoted a series of logging projects on national forests in the region. Proponents claim removing many or most of the trees, which they call “fuel,” is an effective fire management approach. But the Dixie Fire raced through many thousands of acres of these “thinned” forests before it razed much of Greenville. 

Wildfires can always turn tragic, but the greater tragedy in Greenville and Paradise, which was largely destroyed during the 2018 Camp Fire, and other towns is that they put their faith in logging operations miles away rather than proven, community-based fire prevention measures.

Forest thinning is gaining more media attention and is heavily promoted by some land management agencies and logging interests, but science suggests the technique more often makes fires burn hotter and faster.

The idea of felling trees and hauling them to lumber mills in the name of fire prevention has many deceptive names: fuel reduction, forest health, ecological restoration, thinning, and even reforestation. As I detail in my book, Smokescreen, the Forest Service began using these terms in the mid-1990s as the public became more aware of the horrific realities of widespread clearcutting of mature and old forests on public lands in the Pacific Northwest, and the northern spotted owl became a household name.

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The primary focus of the agency’s forest management efforts is selling public trees to private logging companies, which generates about $150 million each year. That may sound like a small portion of its $2 billion budget for land management, but logging also brings in more than $1 billion in annual Congressional appropriated funds, which generate additional revenue that goes back into the agency’s budget. As awareness of logging’s impact on forest loss and degradation began to grow, so too did public sentiment in favor of fully protecting public forests and cutting government ties with the logging business.

In a clever but cynical pivot, the USFS, the logging industry, and their political allies stopped using terms like logging, timber harvest, or timber sales, and invented benign and benevolent-sounding euphemisms. It’s a messaging strategy that continues today and is especially persuasive when voiced by PhD-holding university scientists with Forest Service appointments and funding. Rather than a credential, however, this should be seen by reporters as a conflict. Yet too often they are quoted without qualification.

Make no mistake: It is all just logging.

Proponents of thinning often cite specific locations that burned lightly, but these selective examples do not reflect the broad base of scientific evidence. For example, following the Bootleg Fire in south-central Oregon earlier this year, a representative of The Nature Conservancy claimed that a combination of thinning of “small” trees and prescribed burning effectively curbed the fire. But the Conservancy also has a conflict of interest: For years, it has conducted extensive commercial logging operations in the Sycan Marsh “Preserve,” north of Beatty, Oregon, under the banner of thinning. Thousands of mature trees have been removed under an expansive definition of “small”: up to 21 inches in diameter. Weather is always the biggest factor in fire spread, and the Bootleg Fire began in particularly hot, dry, windy conditions. Even so, according to the Forest Service’s daily rate-of-spread maps, the Bootleg fire spread fastest through Conservancy lands with extensive recent forest management, mostly thinning.

Last week, the Caldor Fire swept through a large area that had been recently logged in Eldorado National Forest in the central Sierra Nevada, under the rubric of commercial thinning. It destroyed the town of Grizzly Flats.

The forests with the most logging, of both live and dead trees, typically burn in the hottest fires, especially when extreme fire weather interacts with heavily logged landscapes.

Yes, there are exceptions, but when we look at the data on a larger scale, the pattern holds: the more trees pulled out of a forest, the more quickly and intensely a fire burns. My colleagues and I published the largest scientific study yet on this topic, analyzing three decades of data representing more than 1,500 fires that burned 23 million acres. We found that while weather and climate were the primary factors in fire intensity and spread, forest management was a significant secondary factor. As we noted in a letter to Congress, signed by 200 other scientists, “Reduced forest protections and increased logging tend to make wildland fires burn more intensely …”

Dense, mature forests tend to burn less intensely than those that have been logged because they have higher canopy cover and more shade, which creates a cooler, more moist microclimate. The higher density of trees of all sizes can act as a windbreak, buffering gust-driven flames. Thinning and other activities that remove trees, especially mature trees, reverse those effects, creating hotter, drier, and windier conditions. And, contrary to what many elected officials have portrayed, dead trees and downed logs (from drought or previous fire), which soak up and retain large amounts of water, do not increase fire intensity in subsequent burns.

Through logging, forests are often converted to open, park-like savannahs populated by flammable weeds; combustible logging debris (twigs, needles, and bark) is often left on site, and trees are planted in dense, crop-like rows that often burn hotter in the next fire.

Logged branches and tree tops are often incinerated, frequently in biomass energy facilities, and much of the remainder is incinerated as manufacturing residue at lumber mills. This emits more CO2 than burning coal for equal energy produced. The biomass industry also raises major environmental justice concerns: Many facilities are situated in communities of color — Black communities in the southeast and Latino communities in central California — and they release large quantities of toxic particulates.

Forest thinning should not be conflated with prescribed burning, which can temporarily reduce the intensity of a potential fire and will slow down its approach. Prescribed fire usually kills less than 5 percent of the mature trees in a forest canopy. The important thing is that the trees stay in the forest, even if they burn. Charred wood is a valuable habitat for woodpeckers and other cavity-nesting birds and mammals as well as the plants and insects that sustain them. Fire unlocks nutrients from leaves and pine needles and enhances a forest’s carbon sequestration and storage. In a fire, just 1 to 2 percent of the tree’s carbon is consumed and emitted. Logging is the real carbon bomb, because most of the carbon ends up in the atmosphere. The Forest Service often calls burning of logging debris piles “prescribed burning,” which is misleading.

Logging in U.S. forests now emits more CO2 annually than all sources of that greenhouse gas from the residential and commercial sectors combined. In fact, logging recently passed coal in annual U.S. greenhouse gas emissions. To argue for cutting and bulldozing forests in the name of fire prevention is a form of climate crisis denial.

What does stop fires from burning down homes and buildings is “home hardening” techniques like installing a fine wire mesh over exterior vents to prevent flaming embers from being blown into a structure and rain gutter guards to prevent dry leaves and needles from accumulating next to the roof. Creating a 100-foot perimeter of “defensible space” by removing lower limbs, dry grasses, dead needles, and leaves can deny a wildfire a path to a house.

This is not just theory; there are numerous examples of towns that implemented protections and saved 95 percent of homes, or more. Scientists have been studying such measures in the lab and in case studies, publishing research for more than 20 years. Vegetation management activities beyond 100 feet from homes provide no additional safety benefit

In Bring Your Own Brigade, a documentary film that began streaming August 20, director Lucy Walker chronicles how decades of logging in forest wildlands, distant from homes, contributed to the devastation of the town of Paradise in Northern California in 2018.

I grew up in the La Tuna Canyon area of the Verdugo Mountains in Southern California where, in the fall of 2017, a fire started during extremely hot, dry weather, with wind gusts more than 50 miles per hour. The community had gotten serious about home hardening and defensible space long before fire season began, and of the more than 1,400 homes within the fire’s path, only five burned. Three of those homes were in a remote enclave in the mountains and had escaped local fire safety monitoring.

To be fair, not every homeowner is capable of improvements or maintenance, which is why fire prevention should not be punitive. Los Angeles, for example, will fine homeowners who do not comply. Federal, state, county, and city resources and assistance should be made available to homeowners to become fire-safe.

We can’t stop fire — we’ve been trying for well over a century. Biodiversity in fact depends on the ecologically rich “snag forest habitat” that results from severely burned forest patches. It’s part of our deep evolutionary history. The heat and nutrient cycling from fire stimulates native plants, including trees, in the understory to grow. In fact, snag forests are perhaps our most threatened forests as they are frequently logged after a fire. The real concerns are the communities that are vulnerable and the emissions from logging.

It’s frustrating for an independent scientist like me to read news articles quoting scientists with undisclosed ties to industry. A couple of dozen university scientists, for example, receive large sums from the U.S. Forest Service, sometimes hundreds of thousands of dollars per year (which I have learned through Freedom of Information Act requests), and these scientists consistently promote logging in their published work.

As wildfires spread through western U.S. forests, Democratic leaders in the U.S. Senate, joined by some Republicans, have inserted several logging provisions in the name of fire management into the infrastructure legislative package, which recently passed the Senate. These would increase taxpayer subsidies for the logging, forest biomass incineration, and wood pellet industries by billions of dollars. They also include extreme rollbacks of bedrock environmental laws, including the National Environmental Policy Act, to facilitate widespread logging on public and private lands.

We’ve seen one historic, thriving mountain town after another destroyed by fires in recent years. It’s almost entirely avoidable and preventable if we focus directly on community protection. Instead, public funds are going toward chainsaws and bulldozers in the forest. That will only make climate change worse, damage wildlife habitat, and put communities at greater risk. And that’s not protecting forests or people.

The views expressed here reflect those of the author. 

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