Human-caused climate change made nearly all of Canada’s worst heat waves more likely: Report

As cooler weather finally blows its way across the nation, a report from Environment Canada is reminding Canadians that just because the air is chillier, does not mean the impacts of climate change are not present.

“As the global climate continues to warm because of increasing greenhouse gas concentrations in the atmosphere, Canada is warming at roughly double the global average rate,” a news release from Environment and Climate Change Canada (ECCC) notes, adding that from 1948 to 2023, the annual average temperature in Canada increased by two degrees. “Spring and summer are becoming hotter, and this means earlier snowmelt, dangerous heat waves, and conditions that are ripe for wildfires.”

Over the summer, scientists with the ECCC analyzed the devastating heat waves that impacted Canadians. From coast to coast, historical temperature records were broken, making 2024 the hottest year on record. The scientist found that anthropogenic, or human-caused, climate change made almost all of Canada’s worst heat waves hotter and more likely.

From June to September, ECCC climate scientists analyzed 37 of the hottest heat waves in 17 regions across Canada. They determined that of these heat waves, human-caused climate change made five of them more likely to occur, 28 of them much more likely to occur, and four of them far more likely to occur. More likely is defined as one to two times higher, much more likely as two to 10 times, and far more likely as at least 10 times.

Often labelled as “once in 100 year” climate events, rising temperatures are making floods, forest fires and other natural disasters much more common, leading to much higher recovery costs. 2020, 2021, 2022, and 2023 all rank in the top 10 years based on insurance claims, surpassed only by the 2016 Fort McMurray fires, the 2013 flooding in Calgary and Toronto, and the 1998 Quebec ice storm.

According to StatsCan data, between 1983 to 2008, insurers spent approximately $400 million per year on catastrophic claims. Since 2009, the yearly average has risen to almost $2 billion, a 400 per cent increase.

Starting this winter, the ECCC will be able to use its Rapid Extreme Weather Event Attribution system to analyze the connection between human-caused climate change and the odds of extreme cold temperature events. Work is also underway to develop the system to analyze extreme precipitation. This capability is expected to come online in 2025.