Recent analysis from Environment and Climate Change Canada (ECCC) shows that human-caused climate change made summer heat waves two to 10 times more likely in June and July.
Using its Rapid Extreme Weather Event Attribution system, ECCC studied the record-breaking heat waves that affected the country during those two months.
The system uses one model to represent the climate of the 1800s, based on levels of atmospheric gases that existed before the Industrial Revolution, and another for the climate of today, based on observed levels of greenhouse gases and other results of human activity.
The department says several days after a heat wave, scientists can compare the number of heat waves in pre- and post-industrial era climates, and then calculate the difference between the two to find how much human activity has changed the chances of a heat wave happening.
Between July 14 and 22, the system found temperatures in southern British Columbia to be 9.2 degrees Celsius higher than average. With that result, it found the heat was two to 10 times more likely to have been the result of human influence on the climate.
Similarly, in northern B.C., the system found it was 7.2 degrees higher than average between July 17 and 22.
“Prolonged heat waves are a major contributor to more intense wildfires across Canada. The 2023 wildfires in Canada burned almost 15 million hectares of forest and cost Canadians tens of billions of dollars in damages,” the department said in a release Monday.
“Human activities, mainly greenhouse gas emissions, are causing more extreme heat events, which can drive wildfires and drought; less extreme cold; shorter snow and ice-cover seasons; thinning glaciers; and thawing permafrost.”
ECCC says the Rapid Extreme Weather Event Attribution system is still in its pilot stages but will eventually be used to analyze extreme cold temperature events and extreme precipitation as well.