In early February, the deadliest South American forest fire in a century tore through Valparaiso, Chile, killing more than 100 people. It's been nearly six months since the deadliest U.S. fire in 100 years left 100 people dead. Flames swept through Lahaina, Maui, burning much of Hawaii's former colonial capital and forcing local residents to dive into the ocean for safety. Jumping to light a fire on a ship moored in the harbor.
Two record fire deaths in half a year may once have seemed like an ecological coincidence in world history, but this has been a year of extreme fire events and one the world has largely overlooked. In the United States, fortunately, very little land has been burned. Just 2.6 million acres, less than half the recent average. But in Canada, wildfires swept through more than twice as much forest as the country's previous modern record, and the overall burn scar was large enough to cover more than half of the world's countries. In Greece, one fire led to the largest ever evacuation, while another became the largest fire in the European Union's history. And in Australia, more than 150 million acres have burned during bushfire season. That's three times more land than burned in Canada last year and more than twice the land destroyed in Australia's “black summer” of 2019-2020, which swept through Sydney Harbour. The smoke was so bad that ferries could not navigate the seas, at least a billion animals were engulfed in flames, and panicked evacuees had to be rescued from the beach by military helicopters.
When fire historian Stephen Pyne says we are now living in a “fossil age,” this is part of what he means. Wildfires are burning twice as much tree canopy globally as they were just 20 years ago, and the world is quickly adapting to that fact. in Parts of the world as far away as Fort McMurray, Alberta; Lahaina, Hawaii; Boulder County, Colorado; And in Valparaiso, Chile, where at least 15,000 homes have now been destroyed, the new era of fires has brought about what climate scientist Daniel Swain calls a return of “urban fire storms.” Of the 10 deadliest fires on Earth since 1900, five have occurred since 2018.
How did this happen? The intuitive and traditional answer is climate change. But where people choose to live also matters. And, especially in the United States, we increasingly hear a somewhat opposing explanation that emphasizes fire suppression over warming.
The story goes like this: Beginning in the early 20th century, motivated by particularly horrific and deadly fires, Americans began a widespread effort to extinguish fires by suppressing incipient fires, no matter how remote or non-threatening. They were so successful that, over decades, vast amounts of dry forest accumulated in the landscape, which would have burned for a long time without human intervention. Instead, whenever the flame was discovered, it was ready to burn even more spectacularly. The story goes that warming is worsening these baseline conditions, but the baseline has been set by fire suppression, forest management, and the massive expansion of human settlements in what has been called the “wilderness-urban interface.” It has helped more people get much closer to the risk of fire.
In a broad sense, this story is true. For about half a century, fires were actively suppressed in the American wilderness, with the result that by the end of those decades there was a lot more of what fire scientists coolly call “fuel.”
What this tells us about the meaning and future of the thermal tax is somewhat less clear. The forest management story has been presented as a corrective to climate-focused wildfire warnings, and is hopeful in its own way. If forest policy is responsible for the dire risk of uncontrollable fires, then in theory forest policy should be able to control it without having to deal with global warming first.
But the hopeful story is at least somewhat incomplete, especially at the global level. In areas that do not use the same fire suppression principles as the United States, including Australia, Canada, Siberia, and Chile, wildfires have raged out of control.
Every wildfire ecosystem has a unique ecology and unique causal map. That is, how the density and nature of local forests have changed over time due to human and natural influences; the activity of the local timber industry and patterns of residential development; So too are changing weather patterns and the actions and responsibilities of power companies, campers and arsonists.
But there is also a simpler, more common way of thinking about conceptualizing risk. Fire scientist Mike Flannigan puts it simply as a matter of fuel load, ignition and fire weather. He says it's the last factor that largely varies from year to year, or even from decade to decade, and helps explain why, for example, 200 times more land was burned in British Columbia last year than in 2020. Suddenly, there were 200 times more trees nearby to burn.
Even in the American context, the story of fire suppression can be too simplistic. First of all, traditional estimates of fire suppression in the 20th century are quite crude and do not take into account how human construction has reduced the amount of forest available for fire. And a recent study found that the increase in burned area in California in recent decades is almost entirely due to anthropogenic climate change. However, the researchers cautioned that this increase was observed compared to background conditions resulting from fire suppression.
It's all a bit complicated. Climate scientist John Abatzoglou and forest ecologist Solomon Dobrowski said that if you gathered 100 climate scientists and forest ecologists in a bar, they would all agree on statements like “more heat, less moisture, more human environment.” “As ignitions occur and fuels increase, fire activity has increased dramatically across the western United States and beyond.” But ask 100 scientists about the relative contributions of forest management and climate change, and the consensus falls apart, they say. Climate scientists may suggest that climate change is responsible for close to two-thirds of the current fire situation, while ecologists may reverse that opinion. Estimates – 2/3 from forest management and 1/3 from climate factors.
In other words, it is not an either/or set. It's both. But that complexity is often incredibly difficult to internalize.
This tension continues even after the forest fires. On the one hand, climate-conscious progressives tend to attribute various social problems to global warming and sometimes downplay other causes. Mike Hulme, a professor of geography at Cambridge, has called this trend “climatism.” These criticisms are important. For example, you can't really talk about hurricane vulnerability in isolation from coastal development, early warning systems, local building codes, and insurance policies.
But the opposite is also true. If climate change is only one factor determining overall risk and human risk, it cannot be argued that the increasing threat posed by warming should be treated as irrelevant or trivial. It certainly would have been wiser not to build so many California homes – nearly half of all homes built in the state between 1990 and 2010 – in areas where wildfire risk is high and growing. But that doesn't reduce the risk for millions of Californians. Now the face. Perhaps controlling fires on millions of acres each year in the western United States could offset the impact of global warming on wildfires in the coming decades. That doesn't mean warming isn't important. In fact, this is one way to quantify costs.
And while it is certainly wise to grow more of what Pyne calls “good fire” and to reintroduce more fire to the landscape, in part to prevent future “bad fire,” the scale of the task given its human proportions is somewhat surprising. Development across the West: By some estimates, 20 million acres in California would have to burn to bring forests into balance, or nearly one-fifth of the state's land.
Chile also has development patterns and forestry policies that could have prevented the loss of hundreds of lives and 15,000 homes. But even in the present tense, one of the challenges of climate change is that none of us are living in that counterfactual history. Instead, we live in a time when there is a wide gap between the climate we expected and the climate we currently face, between the infrastructure we built on those expectations and the world we designed. And between the safety and preparedness standards we once had and the standards we are now revising and haphazardly improvising in the face of increasing threats.