WILDFIRESWildfires Are Much Worse Than a Sign of Climate Change
Summer headlines have screamed of climate extremes: Record temperatures, an ocean heat wave, and rampant wildfires. The fires present a dual problem: Not only are they a symptom of climate change — becoming bigger, hotter, and more common in regions where they can affect large population centers — but they also make the crisis worse. By burning vast layers of partially decomposed vegetable matter called peat, fires like those in Canada release even more greenhouse gases into the atmosphere.
Summer headlines have screamed of climate extremes: Record temperatures, an ocean heat wave, and rampant wildfires, including Canadian blazes that have funneled dense smoke into major U.S. cities.
For Loretta Mickley, a Harvard wildfire expert, the fires present a dual problem: Not only are they a symptom of climate change — becoming bigger, hotter, and more common in regions where they can affect large population centers — but they also make the crisis worse. By burning vast layers of partially decomposed vegetable matter called peat, fires like those in Canada release even more greenhouse gases into the atmosphere.
The Gazette’s Alvin Powel spoke with Mickley, who will chair a National Academies workshop next month on wildfires as a driver of greenhouse gases, about the science behind the threat. The interview has been edited for clarity and length.
Alvin Powel: How do we expect wildfires to change in the decades to come?
Loretta Mickley: The consensus is that wildfires will increase in what we call boreal regions —Siberia, northern Canada, and Alaska. With climate change, these regions are warming more rapidly than elsewhere on the globe, and the warmer temperatures will dry out the fuel, leading to increased fire activity. Fire is also predicted to increase in the western U.S. The climate in the western U.S. is historically very variable, prone to dryness, and climate models suggest that we’ll have more frequent droughts and more fire activity there.
In Australia as well as the Mediterranean, there’s also a strong view that fires will increase, again because of warmer or drier conditions under climate change. The fires in Australia in 2019-2020 and in Greece this summer are consistent with these projections.
Powel: So the general sense is more fires and shifting locations?
Mickley:Yes, but with a caveat: human activity. While human activity can ignite fires, human changes to the landscape — like roads, cities, even cropland — can impede the spread of wildfires because there’s less fuel. Efforts to suppress fires in populated regions such as the western U.S. have also played a role in this decline. In fact, in the early 2000s, observations showed that fire was decreasing over much of the globe. But there are also these emerging, climate-driven trends, and there is a consensus that out-of-control, intense wildfires will increase in some regions of the globe, imperiling people, animals, and vegetation.
