“The summer often brings severe wildfires to western Canada, especially as climate change continues to dry out vegetation and heat up the atmosphere. 2021 was a particularly devastating year, with blazes destroying entire towns.
Provinces in the east — including Quebec and Nova Scotia — are somewhat more safeguarded from fires, or at least devastating ones. Air coming off the North Atlantic Ocean typically keeps the region humid and cooler, making it less likely to burn, per Reuters.
The forests out east also tend to be less flammable, Reuters notes. Unlike western forests, which are dominated by fire-prone evergreens, eastern forests also have broadleaf deciduous trees, which are less flammable (their branches start higher off the ground and their leaves contain more moisture).
But under the right conditions, even eastern forests can burn.This spring brought the right conditions across parts of the east — namely, low humidity and rainfall, and lots of heat. By the end of April, large parts of eastern Canada were abnormally dry, according to the country’s drought monitor. Some places, such as Sydney, Nova Scotia, recorded their driest April on record. When forests are dry, they ignite more easily.
“What’s unique about this year is that the forests are so dry that the fires are many times larger than they normally are,” Matthew Hurteau, a biology professor at the University of New Mexico, told Vox’s Rachel DuRose.Still, there needs to be a source of ignition. And for the fires out east, it was likely a combination of lightning strikes, people (who might, say, toss a cigarette butt out their window), and human infrastructure (such as trains, which can create sparks).”
https://www.vox.com/science/2023/6/7/23752832/canada-fires-smoke-climate-change