What the New Yorker Got Wrong About Forests and Wildfires

Photograph Source: U.S. Department of Agriculture – Public Domain

The New Yorker recently published an article titled Trailblazing plan to fight California Wildfires that contains misinformation. I’ve had many people ask me what I thought of the piece. Given the influential nature of the New Yorker, I decided to respond here.

The writing is good. There is much that is accurate about wildfire in the article, such as the problems with the Clean Act and how it limits prescribed burning. But in many ways, the piece serves as propaganda for the Forest Service and its logging agenda.

The main problem is that the author relied upon a limited number of sources for her article, and all the sources are pro logging/thinning the forests. The on-going propaganda promoted by the Forest Service is that large fires are “catastrophic” and such blazes are demonized to justify a pro-logging agenda. One would not know that many of the statements in her article are either vigorously debated in fire ecology circles with no clear consensus.

For example, she boldly states that frequent low-intensity blazes can preclude large fires. But there are counter-arguments and research that challenges such assertions which were never mentioned. While prescribed burning and thinning may “appear” to reduce fire spread under low to moderate fire weather conditions, there is a wealth of evidence that these management prescriptions usually fail in the face of fires burning under extreme fire weather conditions.

More than 200 preeminent scientists signed a letter to Congress finding that proposed solutions to wildfire like thinning forests are ineffective and short-lived.

To quote from the scientists’ letter:

“Thinning is most often proposed to reduce fire risk and lower fire intensity…However, as the climate changes, most of our fires will occur during extreme fire-weather (high winds and temperatures, low humidity, low vegetation moisture). These fires, like the ones burning in the West this summer, will affect large landscapes, regardless of thinning, and, in some cases, burn hundreds or thousands of acres in just a few days.”

The letter goes on to say:

“Thinning large trees, including overstory trees in a stand, can increase the rate of fire spread by opening up the forest to increased wind velocity, damage soils, introduce invasive species that increase flammable understory vegetation, and impact wildlife habitat.”

There are sidebars that scientists working at Forest Service Research Stations or professors in forestry schools must observe if they want to keep their jobs and/or funding. These individuals do not fudge the data, but they start with specific questions and assumptions that beget certain conclusions.

For example, in a paper published in the Proceedings of the National Academy of Science “Adapt to more wildfire in western North American forests as climate changes” the authors concluded: “the effectiveness of this approach (logging and burning) at broad scales is limited. Mechanical fuels treatments on US federal lands over the last 15 y (2001–2015) totaled almost 7 million ha (Forests and Rangelands), but the annual area burned has continued to set records. Regionally, the area treated has little relationship to trends in the area burned, which is influenced primarily by patterns of drought and warming.”

The author of the New Yorker piece apparently is unaware of these nuances, nor did she consult with any of the many scientists who come to differing conclusions about the effectiveness of prescribed burning and thinning.

All of the people she interviewed are part of the “school” that attributes large fires to past “fire suppression” which they assert has led to “fuel build-ups”.

In her opening few paragraphs, the author describes a prescribed burn where people purposefully light fires under conditions where the fires are likely to remain small and “controlled”.

The author suggests that if we had more use of prescribed burns, large so-called “mega fires” would be snuffed out by a lack of fuel. Problem solved.

She then goes on to describe “mega fires” as “uncontrollable”. And she notes that the resulting “the cinder-strewn moonscape that mega fires leave behind is unlikely to grow back as forest.” She says the forest is “incinerated.”

So the first problem with the article occurs in the first few paragraphs where death and doom are used to describe what are large blazes. The term “mega fire” is itself pejorative suggesting that large blazes are somehow out of the ordinary or unusual and destructive. By contrast logging the forest is called “restoration.”

Never mind that high severity and the snag forests that result from them have some of the highest biodiversity in the West. They are hardly “moonscapes”.

This is due in part to the fact that most fires burn in are a mosaic of fire severity. You tend to have a quilt like patches of burned to lightly burned areas mixed with more severity burned areas. As a result, there is usually plenty plant regeneration after a blaze though it may be flowers, grasses and shrubs or different species like aspen or oaks that are favored by the opening of the forest canopy. No matter what grows back, it is not a “moonscape” for long.

Secondly, even in high severity fires, most of the tree boles remain after the blaze. They are hardly “incinerated.” Several studies suggest only around 3% of mature trees are consumed in a blaze, which is why we have snags remaining.

Furthermore, though fuels due to fire suppression might be an issue in a few specific forest types—predominately ponderosa pine forests—most of the vegetation in California as well as the rest of the West is not ponderosa pine and is characterized by long fire rotations.

For example, much of California is covered with chaparral. Chaparral tends to have long fire rotations up to a hundred years or more. And when this plant type burns, it does so naturally at high severity. Fire suppression does not influence wildfires in chaparral. Indeed, most of the larger recent fires that have burned in California are largely in chaparral ecosystems including the Thomas Fire by Santa Barbara, the Tubbs Fire by Santa Rosa, and so on.

Most of the large fires we are witnessing today are a consequence of climate change and natural climate variation, not a “disastrous buildup of forest density” as the author and her sources suggest.

First, the idea that areas with a lot of fuels are more prone to high severity fires can be challenged both scientifically and logically. The highest biomass on the West Coast is in the coastal forests of Oregon and Washington. Despite the abundance of fuels, these forests seldom burn. If fuels were the most important reason for large fires, we would expect these areas to be the center of so-called “mega fires.”

In addition, any number of studies have shown that areas that are “actively managed” (meaning logged) whether it is private timberlands or public forest tend to burn at higher severity than protected landscape where presumably the fuels are greatest.

One study that reviewed 1500 blazes around the West found the highest severity fires were in managed logged landscapes while parks and wilderness areas where there is no “active” management tended have lower severity blazes.

If you have drought, low humidity, high temperatures and most importantly, you have large fires. Since the canopy of dense forests provides shading and thus cooling of the forest floor, and also slows down wind penetration, wildfires are often slowed when they enter an old growth forest stand. By contrast, thinning the forest opens the stand to greater solar penetration (drying) and greater wind penetration, which can “fan” flames.

Keep in mind the 1910 Big Burn that raced across some 3-3.5 million acres of Idaho and western Montana occurred long before there was a “fire suppression” to create “excessive fuel.”

The author repeats the often-heard phrase that “a century’s worth of fire suppression” has created large fuel build-ups. This assertion fails to acknowledge that much of the last century between the late 1930s through the early 1980s was cool and moist due to natural climate variation. Indeed, in the 1970s there were fears that a new Ice Age might be upon us.

What happens when the climate is cool and moist? First, you get few ignitions. Second, the burns that do start, do not spread rapidly. Third, you have favorable conditions for tree germination and establishment which in turn leads to “denser” forests.

Furthermore, back in the early 1900s, all fire suppression was done by guys riding mules through what is largely wilderness. To suggest that this was an effective fire fighting force beggars the imagination. It was only after the advent of helicopters, smoke jumpers, and modern fire fighting equipment that one might be able to suggest fire suppression had a potential role in slowing fires.

But even this is hard to believe. Was there that much less fuel in 1987 in Yellowstone National Park than in 1988 when more than 1.2 million acres burned in the ecosystem? And why could firefighters control fires prior to 1988, but suddenly the same equipment, including at one point more than 10,000 firefighters failed to contain the blazes? Why did the fires suddenly stop on September 11th when it snowed?

All this is ignored by the advocates of the “century of fire suppression” proponents.

The idea that Indians burned most of the California landscape and thus precluded large blazes is another mythology she incorporated in her essay. For one thing, some research has found that Indian burning, to the degree, that it did occur, did not add significantly to the total acreage that burns naturally. Yes, in the immediate area around villages, and other high use areas, Indian burning likely exceeded the natural background fire.

Then as now, the majority of all acreage burns only when climate/weather conditions are favorable for fire spread. For instance, some 95-99% of all fires seldom burn more than 1-5 acres before they self-extinguish. In other words, whether a fire is started by lightning or humans, most fires do not spread very far.

If, however, the right conditions exist for fire spread, particularly if the wind is blowing hard, you will get a large blaze. That is why most of all acreage burned annually in the West is due to a very small number of blazes that occur during “extreme fire weather” conditions. If you don’t have these conditions, you don’t get a large blaze.

We have evolutionary evidence for this situation. For example, take sagebrush ecosystems. Most sage species must regenerate from seeds. The latest science suggests sagebrush burns anywhere from 50-400 fire rotations. If Indians were burning sagebrush ecosystems every few years as some suggest, there would be no sagebrush landscapes. And there would be no sagebrush obligate species like sage grouse, pygmy rabbits, sage sparrows and the like.

At the other end of the spectrum, higher elevation forests of spruce, fir, and mountain hemlock also burn infrequently, often hundreds of years between significant blazes, but when they do, they often burn at high severity as well.

She finishes up her piece by describing how allowing fires to burn, and/or thinning can result in higher water flows from the Sierra Nevada. A review of the assumptions by Chris Frissell and John Rhodes The High Costs and Low Benefits of Attempting to Increase Water Yield by Forest Removal in the Sierra Nevada  found that while there might be modestly higher flows in high snow years, in drought years, there was little extra water. In other words, at the time when you might want more water flows, you are unlikely to see it. Regrowth of vegetation promoted by forest removal will suck up much of the expected additional flows and countering this effect would require clearing at least 25% of a watershed every ten years—an expensive and generally impossible task.

What is obvious to anyone familiar with the scientific literature on wildfire is that while the author dutifully and accurately reported on the opinions and work of her sources, she did not realize that much of what she reported is contested or countered by other scientists and sources.

While permitting more wildfires to burn in remote areas is a positive outcome of our understanding of the important role of wildfire in forest ecology, the idea that massive thinning and burning can preclude large fires is delusional. In the end, the focus should be on reducing the vulnerability of homes and cities to fires–and this starts at the home and works outward–and preventing the construction of homes in the “fire plain”. Unfortunately, the article gives the impression that all that is needed is more management of our forests.

George Wuerthner has published 36 books including Wildfire: A Century of Failed Forest Policy