While the trends of recent years point to humans as the main culprit of forest fires in Quebec, the current ones are overwhelmingly caused by lightning. A situation “really different from what we have known in recent seasons”, confirms the spokesperson for the Society for the Protection of Forests against Fire (SOPFEU), Isabelle Gariépy.
Forest fires are still very worrying today. In western Quebec, access to the forest is still prohibited in a large portion, while all regions north of the St. Lawrence are subject to a ban on open fires.
These prohibitions could lead to believe that these fires are mainly caused by humans. And for good reason, several experts have intervened in the media in recent weeks to recall a well-known statistic from SOPFEU: in the past 10 years, 70 to 80% of fires have been induced by human activities. But when it comes to this month’s exceptional fires, for once, we are not to blame. Or at least not directly.
Hundreds of hectares burned by lightning
For the month of June 2023 alone, calculations made by The duty from SOPFEU data show that the vast majority of fires (85%) were started by lightning. And these fires are responsible for 99.98% of the hectares that have burned in recent weeks, on an area equivalent to almost a third of Lake Ontario. For the month of May, on the other hand, the statistics remained in the trends, with many fires started by humans, but which caused 200 times less damage than the lightning in June.
Why so many bans, if lightning is currently responsible for the fires? “If we advise people against going into the forest, it’s just so as not to add an additional burden to the SOPFEU teams, who are completely overwhelmed,” explains Yan Boulanger, researcher in forest ecology at Natural Resources Canada.
Contacted on this subject, SOPFEU considers that prevention remains essential. “We can’t control lightning,” says Isabelle Gariépy. “It remains that the human unfortunately still lights a lot [de feux de forêt]. And it is important to realize that this part, if we can avoid it, it can precisely help us to have fewer fires, ”she adds.
Favorable conditions
Several simultaneous factors are involved in explaining the devastation caused by lightning. “The vegetation is very dry at the moment, due to the high temperatures and the rainfall deficits that we have been experiencing since the beginning of May. These conditions are very conducive to a fire starting and spreading quickly,” says Yan Boulanger.
And the weather at the beginning of June literally set things on fire. “We had a lot of storms with very little precipitation,” says Victor Danneyrolles, professor-researcher in forest ecology at the University of Quebec at Chicoutimi (UQAC). It was these thunderstorms, conducive to lightning, that sparked many fires, he said. “The problem is that lightning often strikes far from any inhabited area, which makes it difficult to intervene quickly. »
Other fires to be expected
This combination of extreme drought, record temperatures and thunderstorms could also be repeated during the summer in Quebec, and even in the other provinces. The two experts fear in particular that Ontario will be grappling this week with forest fires similar to those that we have known here since the beginning of June.
“Conditions are very dry right now in Ontario, and there are already several fires active in this area. In the next few days, it is expected that there will be very little precipitation and very high temperatures, so the ingredients are in place for these fires to have a significant progression, and perhaps even for others to develop. trigger if ever there are thunderstorms during the week”, worries Yan Boulanger.
While lightning is the main trigger for these fires, experts point out that humans have their share of responsibility because of their role in climate change, which creates favorable conditions for forest fires.
An article published last week in the scientific journal PNAS notably demonstrated once again that the alarming increase in the area of forest burned each year in California was due “virtually entirely […] to human-induced climate change”.
This situation, which is currently exceptional, could therefore happen again in the years to come.