Canada wildfires and climate change
Climate change is clearly having an impact on wildfire activity across the world and especially in northern countries such as Canada, where global temperatures are rising more quickly than the global average.
The number of very hot days in Canada is expected to steadily increase over the next 75 years, which will put added stress on forests by drying them out more quickly, setting the stage for big fires.
Since the early 1980s, the number of fires in Canada has actually trended slightly lower; however, over the past 12 years, we have seen a notable increase in the number of years with a significant amount of area being burned. These larger fires are burning much more area for a longer period of time and producing massive plumes of smoke, which can travel thousands of miles away.
Canada as a whole currently averages about 8,000 fires per year. Despite the most recent 40-year trend, climate models project that number to increase to about 9,000 fires per year by the end of the century.
More than half of all wildfires in Canada are caused by lightning. This includes the large complex of fires currently burning in Quebec, which has sent large plumes of dense smoke southward into the northeastern quarter of the United States.
As Canada continues to warm this century, the range of thunderstorms will likely expand north and toward the coasts, which may result in an 80-percent increase in lightning strikes across the country by the end of the century.
Climate change is also reducing the number of days with extreme cold, especially across the western part of the country. With less extreme cold, insects such as the Pine Bark Beetle that are normally killed off in the winter are surviving the season, leading to much higher numbers during the warmer months. This beetle has caused widespread damage to the western forests, leaving strands of dried out, dead or dying evergreens, which are much more susceptible to rapidly burning compared to a healthy, living tree.
2023 so far
The fire season got off to a very early and rapid start, especially in provinces such as Alberta, Quebec and Nova Scotia.
Through week six, there has been more area burned this season in Canada compared to the 10-year average for an entire 21-week season! One of the main reasons for this was that May 2023 was much warmer than normal (see image below), especially across western Canada, where reduced snow cover and abnormal warmth led to a rapid drying of the forest floor, setting the stage for early fire growth.
In terms of the total number of fires so far this year, Canada is currently on pace with the 10-year average.