Canada increasingly vulnerable to climate change

Canada is known for its breathtaking landscapes, its lakes, forests, parks, animals, or its remarkable and distinct seasons. In this country which is 20 times the size of mainland France, nature reigns supreme. But the Canadian postcard catches fire.

“Global warming has made extreme weather conditions behind the raging fire season in eastern Canada this year at least seven times more likely,” according to a study published Tuesday, August 22 by the World Weather Attribution (WWA). international scientific network.

In just a few years, climate disasters have exposed the country's vulnerabilities to global warming. Canada has gained 1.7°C since the 1950s. In the North, the average annual temperature has even increased by 2.3°C. According to Environment Canada's 2019 report, the world's second largest country is warming twice as fast as the global average.

As explained to Le Figaro Yan Boulanger, co-author of the WWA study published on Tuesday and scientific researcher in forest ecology at Natural Resources Canada, Canada is a Nordic country, affected by Arctic amplification. This is a phenomenon that means that the further we go towards northern latitudes, the greater the warming. This amplification is mainly caused by melting ice — a process that is increasing in the Arctic by 13% per decade.

Since the ice is melting, the sun no longer reflects on it. Its rays therefore directly warm the air and the oceans. The hotter it is, the more the ice melts and the more the ice melts, the hotter it will be.

In its 2021 report, the IPCC announces that temperatures in northern regions of Canada could therefore increase very significantly compared to the global average, particularly in winter. The Expert Panel predicts an increase in snowfall in January and February accompanied by less extreme cold weather. Conversely, summers are expected to be hot. Heat waves will become more intense and frequent and a sharp increase in summer forest fires is expected. This year 2023 is a good illustration of this.

More than 15 million hectares have already burned this year, an absolute record. According to the Department of Natural Resources Canada, this is more than 10 times greater than the average area burned per decade. Among other reasons, the country started burning early, in May. “Global warming is making the climatic fire season longer; it starts earlier in the spring and ends later in the fall,” laments the AAW scientist.

The very hot and dry conditions in Canada made the fuels very flammable. But the forests in the north of the country, the boreal forests, are also particularly sensitive to fires. Mainly made up of conifers (pines, firs, etc.), they burn more easily than hardwood species (maples, oaks, etc.).

These repeated fires plunge Canada into a vicious circle. When they burn, plants release all the carbon dioxide accumulated over the years. And the burnt boreal forests, very old, were heavily loaded with CO2. In total, this year's fires have released the equivalent of more than a billion tonnes of CO2. But this released CO2 will not be able, or very little, to be absorbed by the new forests which will grow back, because they will take time before being able to support it. In short, the more the territory burns, the more it becomes younger. And the more it burns, the more CO2 it emits and the less it can absorb.

Yan Boulanger recalls that “fire is a major natural disturbance in Canada; ecosystems are adapted to it”. But up to a point, because the country could well face regeneration accidents. After the passage of the fire, certain species of plants can regenerate relatively easily, “the problem is that when the fires become too frequent, we exceed the resilience of the boreal forest”.

Not only is the country burning, but Canada's warming involves many other weather phenomena. The 2021 heat dome in British Columbia remains in the memory. It killed at least 130 people and Canada recorded a new all-time heat record that year, at 49.5°C.

Flooding is also very common at the end of winter; exceptionally high temperatures cause snow and ice to melt faster. The water flow rates then become too high. At the beginning of May 2023, the excess of 10 ° C in places above the normal for the season, triggered floods in the West and forced the evacuation of homes in Alberta.

Less cold winters sometimes also mean earlier snowmelt. A certain humidity then sets in and the return of the rains. But winter is not always over; a sudden return of cold can freeze this humidity and create an ice storm. That of last April, especially in Montreal, caused a lot of damage and killed 3 people. Hundreds of thousands of homes were without power for several days.

Yan Boulanger asserts that since the 1950s, extreme weather phenomena have multiplied and intensified and that "the country and the communities will have to learn to adapt and live with the very changing climate".

According to him, this suggests making arrangements so that the risk of fire around cities and infrastructure is limited. “The fuels around the communities should be reduced or changed; change the vegetation so that it is less flammable”. Better detection and quantification of the risks of forest fires is also a major challenge. In 2029, the "fireguard mission" will be operated: a satellite will be sent to detect fires more quickly in Canada.

These climatic upheavals will have real repercussions on the country's economy. Some sectors will have to adapt, such as the forestry industry or agriculture, which are very affected.