Less than a week after an atmospheric river took aim at British Columbia, dumping several inches of rain that washed away highways, sparked landslides and flooded homes and businesses, more extreme precipitation is set to fall across the region.
Much of the province on Canada's West Coast was still underwater from last week's record-setting deluge of rain, which cut off several towns, forced the evacuation of thousands of residents and left at least four people dead. More than 5 inches of rain fell Tuesday night into Wednesday morning in parts of British Columbia, and more is on the way.
The unprecedented rainfall is at least partially caused by climate change. For every degree Celsius of temperature rise, the atmosphere holds 7 percent more moisture. When conditions are right, that moisture can be unleashed, as has been seen across the globe this year, including record-setting deluges in New York and Michigan.
Since preindustrial times, the Earth has warmed 1.2 degrees Celsius (2.2 degrees Fahrenheit), and at the current rate that humankind continues to add greenhouse gases to the atmosphere, more warming is all but guaranteed, and with it, further disruptions to the water cycle.
Extreme rainfall is just one of the consequences of climate change that are being felt in British Columbia and portions of neighboring Washington state. This summer a heat dome descended over the region, killing almost 600 people in British Columbia — the deadliest single weather event in Canadian history — and more than 110 in Washington. Wildfires sparked by the heat leveled whole Canadian towns. The record-breaking heat wave also resulted in a mass die-off of approximately 1 billion marine animals along the Canadian coast.
"This is what climate change looks like," Merran Smith, executive director of the policy institute Clean Energy Canada, told the Toronto Star. "It is a clear call to action — right now."
With rivers still rising and flash flooding continuing in much of British Columbia, numerous roadways have been left impassable.
From #BCstorm flooding impacts to assessment to recovery - we're collecting the transportation story in photos.
Check it out here: https://t.co/cjRfONjK4B#HopeBC #Malahat #Coquihalla #Lytton pic.twitter.com/25YVUkH1b7
— BC Transportation (@TranBC) November 24, 2021
"Infrastructure decisions in Canada are not accounting for a changing climate," Ryan Ness, research director for climate adaptation at the Canadian Institute for Climate Choices, told the Canadian Broadcasting Corporation.
While portions of the Pacific Northwest had been in the grip of a drought that has affected most of the Western U.S., the atmospheric rivers that have flowed through the region are now bringing the opposite problem.
"Seattle has recorded a whopping 8.40 inches of rainfall so far in November, which is 174 percent of normal through Nov. 23," AccuWeather meteorologist Alyssa Smithmyer said, adding that the next round of rain is set to hit the city on Thanksgiving.
Officials in British Columbia are working to roll out a new rating system to alert the public about the threat posed by atmospheric rivers.
"It will help us improve not just our notification but our response, and help local governments, too, which are on the ground at the frontlines, so that's all-important," the province's Deputy Premier Mike Farnworth told CTV.
While scientists have long warned about the possible consequences of rising global temperatures, the speed at which they have unfolded over the past few years has caught many residents, as well as public officials, off guard. But not everyone in British Columbia has been surprised at the havoc being unleashed by climate change.
In 2019, Canada's then-Gov. General Julie Payette singled out climate change as the defining challenge of the coming decades.
"Canada's children and grandchildren will judge this generation by its action — or inaction — on the defining challenge of the time: climate change," she said.
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