A record-breaking early heat wave sweeping across the western United States is a one-in-500-year type event and almost certainly driven by human-caused climate change, experts have warned.
The heat has been toppling records throughout the week and was expected to continue into the weekend, expanding eastward from western cities.
Four locations near the California-Arizona state border registered 44.4 degrees Celsius (112 degrees Fahrenheit) on Friday, setting a new United States national record for March. The affected areas included spots near Yuma and Martinez Lake in Arizona, as well as Winterhaven and Ogilby in California.
Weather.com reported that 65 cities have already recorded new March highs, stretching from Arizona and California to Idaho.
Death Valley scorched at 40 degrees Celsius on Thursday, while San Francisco tied its historic March record at 29 degrees Celsius. In Colorado, skiers were seen on slopes without shirts as temperatures soared.
The National Weather Service issued extreme heat warnings on Friday for much of the southwest, including Los Angeles, coastal southern California, and Las Vegas. Warnings were also issued against leaving children or pets in vehicles.
The phenomenal heat arriving as winter was only just ending has alarmed climate watchers.
“This heat wave would be virtually impossible for the time of year in a world without human-induced climate change,” the World Weather Attribution network of climate scientists said in a report.
They described the event as so rare that despite overall rising temperatures, something this severe is only “expected to occur about once every 500 years.”
“These findings leave no room for doubt. Climate change is pushing weather into extremes that would have been unthinkable in a pre-industrial world,” said Friederike Otto, a professor at Imperial College London and one of the study’s authors.
Otto added: “In the US West, the seasons that people and nature were used to for centuries are disappearing, putting many, including outdoor workers and those without air conditioning, in danger. The threat isn’t distant — it is here, it is worsening, and our policy must catch up with reality.”
With the northern hemisphere officially exiting winter on Friday — the first day of astronomical spring — the soaring temperatures are wreaking havoc on wildlife across the western region. Many plants and trees are already blooming, and vegetation is growing rapidly, fueled by heavy rains in December and January.
Terry Salas, a resident in Los Angeles, told AFP the climate across the United States in recent weeks had been unusual.
“This is very unusual. We’re still in winter,” she said. “But this is global warming. The East Coast is just tornadoes and snow, and here we are, we’re sizzling.”
“We’re having summer temperatures that we never, ever had in March,” she added.
Scientists say there is overwhelming evidence that current heat waves are a clear marker of global warming, a process driven chiefly by the burning of fossil fuels.
