In June 2021, a record-breaking heat wave scorched the Pacific Northwest.

High temperatures in Portland are usually in the seventies that time of year. But in 2021, they reached more than 110 degrees. Hundreds of people died across the Pacific Northwest and British Columbia.

“Many people do not realize that heat waves are actually one of the deadliest natural hazards,” says Sjoukje Philip of the Royal Dutch Meteorological Institute.

She’s part of the World Weather Attribution Initiative, a group that analyzes extreme weather events.

The researchers estimate that this year’s heat wave in the Pacific Northwest was about a one-in-a-thousand-year event, so it was extremely unlikely.

“Yet it would have been virtually impossible without human-induced climate change,” Philip says.

And if global warming continues, such extreme heat waves could grow more common.

The researchers found that if average global temperatures rise to about 3.5 degrees Fahrenheit above pre-industrial times, an event like this would occur roughly every five to 10 years in that future world.

So Philip says there’s an urgent need to limit global warming and make sure that a once-in-a-thousand-year heat wave remains extremely rare.

Reporting credit: Sarah Kennedy/ChavoBart Digital Media