Climate change makes freak Siberian heat 600 times likelier

Nearly impossible without man-made global warming, this year’s freak Siberian heat wave is producing climate change’s most flagrant footprint of extreme weather, a new flash study says.

International scientists released a study Wednesday that found the greenhouse effect multiplied the chance of the region’s prolonged heat by at least 600 times, and maybe tens of thousands of times. In the study, which has not yet gone through peer review, the team looked at Siberia from January to June, including a day that hit 100 degrees (38 degrees Celsius) for a new Arctic record.

Scientists from the United Kingdom, Russia, France, Netherlands, Germany and Switzerland used 70 climate models running thousands of complex simulations comparing current conditions to a world without man-made warming from the burning of coal, oil and gas. They found that without climate change the type of prolonged heat that hit Siberia would happen once in 80,000 years, “effectively impossible without human influence,” said study lead author Andrew Ciavarella, a scientist at the UK Met Office.

This study, coordinated by World Weather Attribution, was done in two weeks and hasn’t yet been put through the microscope of peer review and published in a major scientific journal. But the researchers who specialize in these real-time studies to search for fingerprints of climate change in extreme events usually do get their work later published in a peer-reviewed journal and use methods that outside scientists say are standard and proven. World Weather Attribution’s past work has found some weather extremes were not triggered by climate change.

But 2020’s Siberian heat wave stood out among the many studied, said attribution team co-lead Friederike Otto, acting director of Oxford University’s Environmental Change Institute.

“Definitely...