Canada is hit hard by historic fires. Three provinces were particularly affected: Alberta, Nova Scotia and Quebec.
Canada has been confronted for weeks with hundreds of active fires spread throughout the territory, and in particular in Quebec where the situation “is apocalyptic”. A situation that is aggravated by heat and drought. The smoke from these fires has even the United States. A pollution which took the form of a fog submerging several large cities of the east coast.
>> INFOGRAPHICS. More than 360 times the area of Paris, 794 times that of Lyon… What would Canadian fires look like if they were raging in France?
Guest of franceinfo on Friday June 9, Christelle Hély, director of studies at the École Pratique des Hautes Etudes and specialist in the interaction between climate and fires, explains that according to the models, in the future “we are able to quantify that the surfaces will increase and that the number of large fires will increase”in part because of global warming.
franceinfo: How to explain that there are so many fires that are breaking out at the moment in this region of the world?
Christelle Hely: The winter in Canada was particularly light on snow, whereas the country is normally accustomed to several meters of snow for several months. When this snow melted in the spring – knowing that with rising temperatures, the melting is earlier – it produced relatively little water. The soils are therefore low in moisture and they dry out very quickly.
“In addition, the atmospheric conditions must have come into play. There is a very dry, polar air mass, which has blocked itself a little, and below, everything is dry. When it moves again, it is often pushed back by hot, humid air creates thunderstorms, so there are plenty of lightning strikes on very dry, very efficient fuel.”Christelle Hély, director of studies at the Practical School of Advanced Studies
Are these fires linked to the consequences of climate change?
In part, yes. Climate modellers and people who are, for example, at the Department of Natural Resources Canada and who do simulations, say that already, in the future, we are able to quantify that the surfaces will increase and that the number of large lights will increase.
But as the atmosphere [est plus chaud] due to warming, the dynamic is faster. We can have more frequent events. This is why we can associate this kind of event with climate change. But these systems for blocking, resuming and arriving storms still exist naturally in the climate system.
What can Canadian firefighters do in the face of so many fires over such a large area?
I would say they are doing what they can. They will, a bit like here in France, already try to contain the flanks, that is to say the sides of the fires, to try to channel them when they are too violent. We cannot act on the front of the flames, on the head of the fire. So what the firefighters do in Quebec, for example, is that they will first try to protect the villages and the communities and evacuate them if necessary.
So we can maybe slightly deviate the route of the fires, but we clearly can’t stop them. frontally?
Yes, and deviate them again… Let’s say we try to channel them a little bit.
The only way to stop these fires, what would it be? Heavy rain?
That would be it, yes. There are also very large lakes in Canada. So, if a fire encounters a large enough area without fuel, there is a chance that it will stop part of it. And then we can also have changes in the direction of the winds, so the fire could go back to something that has already burned. And there, it would be effective enough to stop it. Knowing that here, in France, for example, when there is a fire, the firefighters sometimes use what are called tactical fires, that is to say that they will carry out burns upstream of the front of flames, in front of the fire, but far enough. And at that moment, when the normal fire arrives, it arrives in an area where there is little fuel.
Source: France TV Info