“There have been other studies on the increase in the number of forest fires, in their average size,” explains the lead author of the study published Monday in the journal Nature Ecology
With 20 years of satellite data, Australian researchers assessed extreme fires, which represent just 0.01% of total wildfires. Among this group, fires in 2023 are twice as frequent as those in 2003. “Six of the last seven years are among the most extreme,” Cunningham says.
Before 2003, there was no comparable satellite data to assess fire intensity. Last summer’s forest fires in Quebec’s Far North fell into this category.
Martin Girardin, a Canadian Forest Service researcher who published last winter in the journal Communications Earth
“They looked at the intensity of the energy released by forest fires,” says Mr. Girardin. We’re talking about the 99.99th percentile, it’s really extreme. It is interesting that these more intense fires are increasing. »
Fires release the most CO2 into the atmosphere, because they can burn humus down to non-organic soil, Cunningham said. And they have a disproportionate effect on ecosystems. The Australian megafires of 2019 and 2020, for example, wiped out 2.8 billion invertebrates and the entire range of 116 plants, according to a 2021 study cited by Cunningham.
According to the forest classification used by Mr. Cunningham, the north of the province – along a line running roughly from Tadoussac to Rouyn-Noranda – is made up of boreal forest and taiga, the category most affected by the increase in extreme fires: they are seven times more frequent than 20 years ago.
Southern Quebec is in a category that has seen almost no increase in these extreme fires.
In western Canada, there is another category of forests particularly affected by increasing extremes, with a frequency 11 times higher.
Boreal forests are also found in Russia. “[The situation] is roughly similar in Russia and North America,” says Cunningham.
Potentially, but in the case of forests far north, they are often not fought, notes Mr. Cunningham. “This is one of the paradoxes of fighting forest fires: the more quickly we suppress fires, the more fuel they leave behind which accumulates, and the greater the risk of further fires. more intense. »
Mr. Girardin believes that fires this intense are rarely fought. “Once a fire gets very, very intense, there’s nothing you can do, you have to remove the equipment and the firefighters, it’s too dangerous. Even planes can’t do anything about it. »
In Australia, authorities are considering using herbivores, such as kangaroos and rabbits, to eat vegetation and limit available fuel. “It gives one more argument for the preservation of these species,” says Cunningham.
A recent Canadian study showed progress in calculating the direction of fire spread, notes Mr. Girardin. And there are controlled burning programs, to further limit the amount of fuel available. “But you can’t do that in the big wilderness areas where most of the big fires occur. »
