Achi news desk-
The deadly heat dome that smothered the Pacific Northwest in record high temperatures for weeks in 2021 was exacerbated by climate change, a new study suggests, and intensified North America’s wildfire season that year – a possible model of summers to come.
The study, published on Monday in Communications Earth and Environment, concluded that the heat dome in June and July 2021 was 34 per cent larger and lasted 59 per cent longer than a similar event without global warming. – wide As a result, the sweltering temperatures across British Columbia, Washington and Oregon were linked to fires that accounted for up to a third of the total area burned across the continent that year.
Researchers looking back at the last 40 years of data also found that the 2021 heat dome was 36 percent stronger and almost 40 percent larger than the next largest such event, which took place in the summer of 2003.
“Looking at the trends … we see that these events are becoming more intense,” said Piyush Jain, lead author of the study and a research scientist with the Canadian Forest Service and Natural Resources Canada.
The 2021 heat dome lasted for 27 days, from June 18 to July 14, and was directly responsible for hundreds of deaths across western Canada and the United States, including more than 600 deaths in BC alone.
The town of Lytton, BC, recorded the highest temperature ever seen in Canada at the center of the phenomenon—49.6 degrees Celsius—and was completely destroyed by wildfires that broke out a day later.
Jain, who lives in Edmonton, said he also experienced unusually high temperatures that summer which told him he was experiencing an “exceptional” climate event.
“We had a day where it was 38 degrees Celsius, which is the only time it’s been that hot in all the time I’ve lived here for 15 years now,” he said.
The email you need for the day’s top news stories from Canada and around the world.
In the United States, Seattle and Portland, Ore., repeatedly broke maximum temperature records on consecutive days in late June 2021, according to the US National Oceanic and Atmospheric Administration (NOAA). Other states that were technically outside the heat dome, including California and as far east as Montana, also broke or tied their own heat records for that period.
That summer also saw an exceptionally severe wildfire season, which the new study says was “unequivocally exacerbated by the presence of the heat dome.” About 3.2 million hectares burned across North America in July 2021 alone, according to researchers, the highest area recorded in one month over the previous 20 years.
Smoke from the fires in Canada and the United States spread as far east as New Brunswick and New York City.
The researchers found that 21 percent of the land burned in North America that year was due to fires and fires during and within the heat dome. That figure rose to 34 per cent when including fires that started within 10 days of the incident.
The “widespread and simultaneous” wildfires across the Pacific Northwest and beyond also strained firefighting resources, the study said, and kept national emergency preparedness levels at their highest in Canada and the U.S. States for record-breaking periods of time (50 and 69 days, respectively).
Jain said the issue of resources under pressure was also seen during the 2023 wildfire season, which once again broke records for the area burned – this time for an entire season in North American history. As more regions that normally share firefighting crews face their own fire risks at the same time, the harder it will be to fight them effectively, he said.
“That is a concern going into the future that under a warming climate we may see even more limited firefighting resources,” he said.
The study builds on an earlier method developed by Jain and other researchers to track extreme weather events and their severity over time. That research determined a trend of increasing high pressure systems due to thermodynamic warming of the atmosphere due to anthropogenic, or human-caused, climate change.
Without that trend, the new study concluded, the 2021 heat dome would have been about two-thirds the size and 59 percent shorter — nearly 16 fewer days of extreme heat.
The study adds to a growing field of research to confirm climate change that other scientists say is important to build on.
“Even though we know in the future climate model that we’re going to have a warmer climate, we’re going to have more intense heatwaves, we still have a lot of uncertainty about how the processes contributing to those events,” said Lualawi Admasu, a PhD student studying atmospheric science at the University of British Columbia.
“So these studies come together to give us a more holistic view of, what are the processes that are important, in this particular case of fire weather. … That’s very important to the climate change (research) community.”
Jain said it was also important for him to “connect the dots” through science to underscore what more and more people are gathering: that the warming climate is directly contributing to more extreme weather events and fire risk.
“If we can make these connections between these extreme events and climate change, it could inform policy,” he said.
“I think it’s important to keep getting this message out so we can have a better understanding in our societies that this is what’s really going on.”
& copy 2024 Global News, a division of Corus Entertainment Inc.
