The fog of fire

Of the weather- and climate-related perils I’ve experienced, directly or indirectly, wildfire is the most depressing. The presence of fire — its immediacy, power, and speed — is frightening.

I’ve watched, from our Colorado patio, the glow and smoke of hundreds of houses burning down. I have seen a fire in forests at the edge of town grow from ignition into a raging 10,000-acre disaster, all while doing my early afternoon chores. I have watched as the multi-acre field across the street burnt in mere minutes.

The smoke brings with it a discomforting sense of powerlessness; it evokes destruction and war. It’s depressing.

In summer 2023, many Americans learned for the first time that dense smoke events can last for weeks and months. In between the smokey days, we might see skies that are clear and blue, or we may endure weeks of pale haze.

Smoke from forests is preferable to smoke created from buildings, which deliver an industrial mixture of plastics and fuels. And if you are fortunate, you can make your living inside, in filtered air.

Canada is burning

A dark cloud of wildfire smoke rolls over the mountains of British Columbia. (Image: iStock.)

This summer’s fires in Canada are stunning. The smoke spreading over the eastern half of the United States and Canada brings an experience that millions in the West have been enduring for the past decade.

I started writing specifically about fire in relation to climate change in summer 2014. At the time we were seeing record heat in western Canada and Alaska and unprecedented millions of acres were burning. This year dwarfs 2014.

Back then, I still enjoyed narrative distance from the flames. But times have changed. Governments are implementing new building standards in the west. At home, we’ve undertaken our own mitigation efforts and other safety measures to protect ourselves. Our insurance rates have increased.

Ten years ago, no one considered the area where I live a high-risk fire zone. So what has changed?

Preventing and managing fire

A wildfire’s ingredients are fuel, heat (or “ignition”), and oxygen. The characteristics of fires are often determined by humans: How do we manage landscapes such as forests, grasslands, and cities? What are our rules of building and land-use (the location of houses and how close they are to one another)? And how do we manage fire itself – do we suppress it or use it?

Much of the current science points to management and land use as the most important factors in predicting fire. But the situation is more complicated than that. If we look at fire storms, and the explosive growth of recent fires, we find weather at the core. It is dry; it is windy.

So what about climate change?

I have listened to many debates in which people say climate change is irrelevant; they argue poor forest management is causing the increased fires. Others will counter that climate change is indeed the culprit. (I recently was (mis)quoted/represented as saying that the fires in Canada are “caused” by climate change.)

This is a false binary. Both management practices and climate change have powerful and entangled influences on fire.

Fire is endemic to nature and has long been an instrument of humans. It is generally agreed that the U.S. and Canadian approach to wildfire management in the last hundred years has led to infrequent, high-intensity fires. (Infrequent is relative to fire in either natural systems or as managed by Indigenous Tribes.)

Climate change influences fire in a number of ways, most obviously by extending the “fire season,” usually due to persistent, more intense drought. As current temperatures rise, drought becomes more extreme – drier. In addition, the onset of drought is faster now than in the past because of higher temperatures.

Climate also influences two of the basic ingredients that produce fire: fuel and heat. The warmer temperature removes water from vegetative fuels making them both easier to ignite and faster to support spread. The speed that fire races across dry grass is explosive.

Personal experience has taught me that ignition sources are everywhere. They arise from human activity, both deliberate (matches) and accidental (sparks from cars and powerlines). And we have natural sources, especially, lightning. Lightning from dry thunderstorms is the proximate cause of many of the current Canadian fires.

How can we slow or reverse this trend?

Lightning from a storm ignites a fire. (Image: iStock.)

The most obvious way to reduce the number of wildfires is to limit the availability of fuel. We can also reduce the human sources of ignition.

If we are going to reduce the availability of fuels, then we are looking first and foremost to management practices and land use. We must answer such questions as: How do we manage growing and harvesting of trees? How do we manage undergrowth? Do we graze grasslands, cut the grass? How do we revise building codes and standards, including materials and sprinkler systems?

To answer these questions, we need to align scientific research, planning, and public policy. In many cases, we know what to do, but lack the how. We need financial, scientific, political and popular support to generate, implement, and maintain the practices we know will work.

It is easy to get mired in fear and depression. But there are actions that individuals, cities, counties, states, and nations can take to reduce the threat of fire to life and property. Reducing that threat on a massive scale is more difficult. And the warming climate means that many existing management practices are deficient. Present knowledge suggests that fire in California’s Sierra Nevada, for example, will, due to changes in summer temperature, increase in number by 51 percent by 2040 (plus or minus 32 percent) and in area by 59 percent (plus or minus 33 percent).

The Canadian fires are sending us a message beyond the inconvenience and health effects of smoke. Climate change does not spare the eastern U.S. from more fire in our backyards.

We should do our best to intervene before we decide that “stop breathing” is our best option. Let’s get out in front of all this fire risk and damage. The best way to mitigate our fears (and my depression) is to know that we have robust plans, policies, and practices that will work when we put them to use.

(Lead image: U-M Biological Station Director Knute Nadelhoffer at a prescribed fire in fall 2017. “These burn plots are a time machine that allows us to look back at forests of different ages,” he says. Image credit: Roger Hart, Michigan Photography.)