Fires are the sum of our choices
In early February, the deadliest South American forest fires in a century swept through Valparaiso, Chile, killing more than a hundred people. It had been almost six months since America's deadliest fires in a century Hundreds of people were killed when flames swept through Lahaina, Maui, burning much of Hawaii's pre-colonial capital and forcing locals to jump into the ocean for safety as the flames leapt over them and set fire to the boats moored in the harbor.
Two record-breaking episodes of fire deaths in the space of six months may once have seemed like a world-historical ecological coincidence, but it has been a year of fire extremes – and a year in which the world has largely ignored them. Fortunately, little land burned in the United States: only 2.6 million hectares, which was less than half recent average. But in Canada, fires destroyed more than twice as much forest as the country's previous modern record, with the total fire scar large enough that it could fit more than half the world's countries. In Greece, one fire has forced the country to burn largest evacuation everand another became the biggest fire in the history of the European Union. And in Australia, the bushfire season has burned more than 150 million hectares – three times more land than last year in Canada, and more than twice as much land as was destroyed during Australia's 2019-2020 “Black Summer,” when the port of Sydney was so choked with smoke that ferries couldn't navigate the waters at least a billion animals were consumed by flames, and there had to be panicked evacuees saved from the beach by military helicopter.
When fire historian Stephen Pyne says we are now living in the 'Pyrocene', this is part of what he means: bushfires are now burning Globally, there is twice as much forest cover as there was 20 years ago, and the world is quickly adjusting to that fact. In parts of the world as remote as Fort McMurray, Alberta; Lahaina, Hawaii; Boulder County, CO; and now Valparaiso, Chile – where at least 15,000 houses once stood destroyed – the new age of fire has led to what climate scientist Daniel Swain has called the return of the “urban firestorm.” Of the ten deadliest fires anywhere in the world since 1900, five have occurred since 2018.
How come? The intuitive, conventional answer is climate change. But where people choose to live also matters. And especially in the United States, you increasingly hear a somewhat contradictory statement that emphasizes fire fighting rather than warming.
That story goes something like this: Beginning in the early 20th century, Americans, motivated primarily by horrific and deadly fires, began a broad effort to suppress them by extinguishing any incipient fire – no matter how small or non-threatening. They were so successful that over many decades the landscape built up a huge amount of excess dry forest, which without human intervention would have burned long ago. Instead, it was about to burn much more spectacularly as soon as it found a spark. Warming is exacerbating these baseline conditions, the story goes, but the baseline was set by fire suppression, forest management, and the massive expansion of human settlement into what has been called the “wildland-urban interface” – which both necessitated further fire suppression and has many more people have come much closer to the risk of fire.
In broad terms this story is true. For about half a century, fires in the American wilderness were actively suppressed, with the result that at the end of those decades there was much more of what fire scientists coolly call “fuel.”
What that tells us about the meaning and future of the Pyrocene is a little less clear. The forest management story has been put forward as a corrective to the climate-focused wildfire alarm, and it is in some ways hopeful: if forest policy is responsible for the terrifying risk of out-of-control fire, forest policy should in theory also allow us to control it without first having to get a grip on global warming.
But the hopeful story is also at least somewhat incomplete, especially at the global level. Wildfires have burned out of control in places like Australia, Canada, Siberia and Chile, which do not have the same firefighting doctrine as in the United States.
Each fire ecosystem has its own ecology and idiosyncratic causal map: how the density and character of regional forests have changed over time, due to both human and natural influences; the work of the local timber industry and the pattern of residential development; changing weather patterns as well as the behavior and responsibility of energy companies, campers and arsonists.
But there are also simpler and more universal ways to conceptualize risk. Fire scientist Mike Flannigan describes it bluntly as a matter of fuel load, ignition and firefighting. It's the latter factor in particular that varies widely from year to year, he says, or even decade to decade – and helps explain why, for example, British Columbia burned 200 times as much land last year as in 2020. That's not because there were suddenly 200 times as many trees in the area were on fire.
Even in the American context, the firefighting story may be too simplistic. For starters, conventional estimates for 20th century fire suppression are fairly crude and do not take into account how human construction has reduced the amount of forested land that could burn. And recent research has suggested that the increase in burned area in California in recent decades is almost entirely due to anthropogenic climate change, although the researchers also caution that the increase has been observed against background conditions caused by fire suppression.
It's all a bit complicated. Put a hundred climate scientists and forest ecologists in a bar, climate scientist John Abatzoglou and forest ecologist Solomon Dobrowski tell me, and chances are they will all agree with a statement like “more heat, less moisture, more human-induced inflammation and more fuel have dramatically increased fire activity in the western U.S. and beyond.” But ask the hundred scientists about the relative contributions of forest management and climate change, they say, and the consensus collapses: the climate scientists might suggest that climate change contributes to almost two-thirds of our current fire situation, while the ecologists might reverse the statement . estimate — two-thirds from forest management and one-third from climate factors.
In other words, this is not an either-or set; it's both-and. But that complexity is often incredibly difficult to internalize.
This tension extends beyond wildfires. On the one hand, there is a tendency among climate-conscious liberals to attribute a wide range of social ills to global warming, sometimes downplaying other causes – a tendency that Mike Hulme, a professor of geography at Cambridge , has called 'climatism'. This criticism is important: for example, we can't really talk about hurricane vulnerability apart from coastal development, early warning systems, local building codes, and insurance policies.
But the converse is also true: we cannot pretend that, if climate change is only one factor in determining overall risk and danger to humans, we should therefore regard the growing threat of warming as irrelevant or trivial. It certainly would have been wiser not to have built so many houses in California – almost half of all buildings built in the state between 1990 and 2010 – in areas of high and growing wildfire risk, but saying this does not diminish the risk millions of Californians now face. Perhaps controlled burning of a few million acres per year in the American West could offset the impact of global warming on wildfires in the coming decades. That doesn't mean warming doesn't matter; in fact, it is a way to quantify costs.
And while it is certainly wise to reintroduce some more fire to the landscape—to cultivate more of what Pyne calls “good fire,” in part to prevent future “bad fire”—the scale of that work is somewhat staggering, considering the rate of human development in the west: According to some estimates20 million acres in California must be burned to rebalance the forest, a landmass covering nearly a fifth of the state.
There are also in Chile development patterns And forest policy that could have prevented the loss of those hundred lives and those 15,000 homes. But one of the challenges of climate change, even in the present, is that none of us live in a counterfactual history. Instead, we live in a timeline where vast gaps have opened up between the climate we expected and the climate we now face, between the infrastructure we built based on those expectations and the world we could have to create. and between the standards of safety and preparedness we once had and the standards we are now revising and haphazardly improvising in the face of increasing threats.