Environment and Climate Change Canada says it is now able to publicly identify links between extreme heat events and climate change within days of the weather event occurring.
The federal weather service says scientists are now able to estimate the extent to which man-made climate change has played a role in heat waves or extreme heat events within a week of them occurring.
Friederike Otto, an internationally renowned climate researcher and one of the world leaders in the science of weather causes, said that Meteorological Canada will be the first in the world to publish a rapid analysis of the heatwave event.
“We’ll be the first (weather agency) to actually do this,” he said.
“It’s about time, and it’s great that they’re doing this.”
The science of analyzing the factors that cause weather has existed for many years and combines meteorology, weather observations, and climate science.
Science doesn’t say whether climate change caused a particular weather event, but rather estimates the statistical likelihood that climate change caused a particular weather event and the degree to which it exacerbated that event. It can also show the opposite — that climate change did not play a major role in a particular weather event.
“The question of ‘Was it climate change or was it not?’ cannot be answered,” Otto told CBC News.
for example, Paper cited by Environment and Climate Change Canada The ECCC concluded that the heat wave that hit British Columbia, Washington and Oregon in June 2021 would have been 150 times less likely to have occurred in the absence of human-induced climate change.
The paper said that human-induced global warming made extreme rainfall events that caused flooding in British Columbia about 45% more likely in November 2021.
The ECCC will launch a pilot project that will allow scientists to study heat waves in Canada through computer modelling.
The ministry says it will run computer models when such a heatwave occurs, comparing two scenarios: one in which the heatwave is caused by climate change, and one in which the heatwave would occur without climate change.
The department says it is working to expand the system to include extreme cold weather and rainfall.
Climate causation science was born in part out of journalists’ questions about the connection between climate change and certain weather phenomena, but climate scientists such as Simon Donner of the University of British Columbia have been unable to definitively answer these questions.
Donner likens it to a cancer diagnosis.
“We know that smoking causes lung cancer, but doctors can’t tell us which cigarettes cause cancer,” Donner said.
“We know that climate change will cause more heat waves, more heavy rains and more storm surges. But we can’t look at a heat wave and say, ‘That’s because of climate change.'”
Climate scientists have changed their approach to such questions by looking for models that define the likelihood that climate change will affect certain weather events, he said.
“So everything is affected by climate change, so the real question is how likely is this event or how unusual is it?” he said.
Nathan Gillette, a research scientist at Environment and Climate Change Canada, said weather attribution reports could be used by businesses and governments during extreme weather events that damage infrastructure, such as the atmospheric river event that washed away a bridge in British Columbia in 2021.
“When rebuilding a bridge in the aftermath of a disaster, it’s useful to know whether the probability of that event has increased due to human-induced climate change and is expected to increase in the future,” Gillette said.
“If we can provide results days after an event, rather than months or years later, it’s more likely to increase public interest in understanding the impacts of climate change.”
Gillette contributed to a weather attribution report released in December 2022, concluding that the June 2021 heat dome in British Columbia “would have been at least 150 times less frequent in the absence of anthropogenic climate change.”
The town of Lytton recorded the highest temperature ever recorded in Canada, at 49.6°C, during a heatwave on June 30, 2021. A wildfire ravaged the town the following day, destroying most of the buildings. The 60s died They took refuge from the flames in a trench.
Megan Fandrich lost her cafe in Lytton and said she welcomed promises of a rapid analysis following the incident.
“We hope this helps Canadians overcome the distance they feel between themselves and the impacts of climate change,” Fandrich told CBC.
“I hope it helps overcome the apathy they feel that nothing we do right now will make a difference.”
