The New World of Mega-fires

Mega-fires! Or, megafeux in French, as in the book Quand la Forêt Brûle: Penser La Novelle Catastrophe Écologique by Joëlle Zask (Premier Parallèle, 2019). (When the Forest Burns : Thinking about the New Ecological Catastrophe.)

Through much of my professional life, I have considered fires (in forests, prairies, and chaparrals) to be ecologically beneficial. Where to begin with the ecological benefits of fires? Fires clear away underbrush and release nutrients in the dead litter into the soil where new plants can grow back and use them. The sunlight can now reach the soil surface, warming it up earlier in the spring than would have been possible with a thick litter layer still in place. In many cases, the perennial plants that were present before the fire grow back, more vigorous than they were before. This is the case for hundreds of species of prairie plants, which maintain their thick sod of roots and underground stems. It is also true, as I have seen for the cross timbers forest of Oklahoma. As for the plants that grow back from seeds in the soil, the seeds germinate profusely, as I have seen Phacelia strictiflora do in cross-timbers forests after fires. So frequent are these fires that many plants have adapted to them even to the extent of requiring the fires to maintain their populations. My research has shown that Phacelia seeds require smoke chemicals in order to germinate; the same is true for hundreds of species around the world in fire-prone habitats such as chaparral. How can fire, which has so many ecological benefits, be bad?

Fire has long been a tool of habitat management. The whole landscape evolved with wildfires. Since the spread of western civilization, wildfires have decreased, mostly because people do not like to have their homes destroyed by fire. Ecological landscape managers have to set control burns to compensate for the decline in wildfires. This photo shows a control burn near Lake Texoma in Oklahoma in 1999.

In the absence of natural fires and control burns, dead biomass builds up under the trees and virtually assures that a fire will break out soon and be very big.

White landscape managers were not the first to use fire as a management tool. All over the world, native peoples have set fires to forests and fields to renew their growth. This was nowhere more true than with the Native peoples of North America, as I describe in my book Forgotten Landscapes.

But times are changing. In particular, global warming is changing the landscape. As Naomi Klein said in the title of her book about the economics and politics of global climate change, This Changes Everything. It has certainly changed the scientific way of thinking about fire.

Global climate change includes not only hotter temperatures but less rainfall and more wind in many areas, such as southern Europe during recent long, hot, dry, windy summers. This is not a prediction; it is something that has already happened in many parts of the world. Some of these forest fires have flames almost a hundred feet tall and that spread faster than anybody can run. The fires consume houses, including outdoor free-standing barbecue grills which are built to withstand fire: the grills simply melt.

Other human activities promote the spread of large fires. All around the world, not only in rainforests but even where I used to live in Oklahoma, native forests are cut down and replaced by tree plantations such as loblolly pine. Tree plantations, with breezy understories and with flammable, fast-growing trees, burn more readily than native forests.

The result is that, right when we need control burns more than ever, we do not dare to conduct them. There is a tremendous liability cost associated with a control burn that gets out of hand. If a private citizen loses so much as a shed to a government control burn, the land-owner will sue for lots of money. As global warming progresses, almost any control burn is guaranteed to escape and become a major fire.

A mega-fire, unlike most smaller fires, can and do sterilize the soil, so that there are no roots, stems, or seeds to grow back. The resulting moonscape will recover, but it might take many decades and suffer uncontrolled soil erosion in the meantime.

The time is coming, and in some places is already here, when there will be no such thing as a little control burn. There will be only mega-fires.

I have retired, so it is too late for me to tell my classes, forget everything I said about control burns.

Cause and Effect: The Last Refuge of Denialists, part two.

One of the most important ways in which denialists use a deliberate misunderstanding of multiple causation (see previous essay) is to ridicule global warming. In this essay, I will look at just one example of an effect of global warming that is dominating the news now (September/October 2020): the wildfires in the west, particularly in California.

Scientists are certain that global warming, primarily of human cause, is already increasing the number and severity of wildfires. Of course, global warming is not the only cause. Another factor that makes wildfires in California so big and deadly is the accumulation of dead wood in the forests. I have seen first-hand that buildup of dead wood is also a problem in the Black Hills of South Dakota, where I taught field botany for eleven years. Once a fire gets started, there is an incredible amount of fuel for it to burn. (Then, of course, yet another cause is whatever ignited the fire. It is usually lightning strikes, though in one case it was sparks from fireworks at a gender reveal party.

This is hierarchical causation: a spark starts a fire, which burns a massive accumulation of dead wood. This is multiple causation: once the fire starts, it is more likely to spread if global warming has made hot, dry conditions worse than they would otherwise have been.

But some people who deny global warming like to ignore multiple causation. They blame the dead wood, then ridicule one of the other causes, global warming.

According to an article, California has been allowing dead wood to accumulate in its forests for decades.

Why has the dead wood accumulated? Because there is no easy way for humans to get rid of the dead wood. Nature’s way of clearing away dead wood is, in fact, fire. Fire is a part of all natural ecosystems, particularly coniferous forests in California. Almost without exception, scientists claim that we need to have natural fires to reduce the accumulation of dead plant matter. In Oklahoma, where I work, fire is the best way to control the spread of red cedar.

The ash from the fire releases nutrients back into the soil, actually promoting the forest to grow back more vigorously (see my YouTube video). Some species of trees actually require fire in order to germinate, as shown in another of my videos.

The problem is that there is no safe way to start control burns, that is, small fires that burn away the wood in wild forests but not on private land holdings. It is so easy for a control burn to get out of control. If California conservation officials started a control burn, which would clear away wood and reduce the risk of future fires, and if a puff of wind sent the fire onto private land, where it destroyed a house, the state might be on the hook for millions of dollars of liability. The article linked above said that, in order to bring California forests back into a stable fire balance, it would be necessary to set fires to wild forests the equivalent of the area of Maine. There is simply no way to do this safely. Having participated in control prairie burns in the Midwest, I can tell you they are risky undertakings. We have a university class in which an expert fire manager was teaching techniques of control burns; the fire got out of control and burned a fence, for which either he or the university (or insurance) had to pay. This was a scientific expert, in a grassland. Imagine what would happen with a fire crew in a dry forest full of dead wood.

It appears to me that California has allowed wood to accumulate in its forests because of the fear of lawsuits. Anyone who lives in a fire zone, let me know: would you be happy if a control burn, which would make life better for future generations, destroyed your home?

The article took an extreme position, however. The author accused the fire control agency CalFire of letting wood build up in order to create new wildfires. Why? Because the money and the glamor comes from fighting wildfires, not from doing control burns. The firefighters get lots of hazard pay, and, friends have told me, it is nearly a carnival atmosphere. The author of the article compares it to “the Halliburton model.” This is a conspiracy theory that says Dick Cheney, who headed up Halliburton corporation, fanned the flames of the Iraq War when he was vice president of the US, in order to get billions of dollars of contracts from the federal government. I am willing to believe almost any conspiracy theory about Dick Cheney, but even I am a little skeptical about this one. Cheney starting a war to get contracts for Halliburton? I haven’t seen quite enough evidence for this.

We’re stuck between a rock (Iraq?) and a hard place. We need to burn that dead wood, but we need to avoid destroying human habitations. This is a problem created by human civilization. The Natives who lived in the forest before Smokey the Bear got there had temporary dwellings, and could usually just get up and move if they saw a fire coming. If you have a big house back in the woods (or, worse, in the chaparral), you can’t do that. You may save your life, but nothing else.

The article also says that California should adopt the model that is successful in the Southeast: namely, control burns. The author seems unaware that control burns are easier in the Southeast because it rains more, and fires are less likely to get out of control.

The denialist problem is this: Denialists say that dead wood causes wildfires and global warming (which doesn’t exist, and they ridicule it) does not. The simple fact is that both of them are causes, just waiting for that spark. Denialists should stop twisting the truth by focusing on some causes and ignoring others.