Siberian heatwave made 600 times more likely by climate change, experts find

The prolonged heatwave in Siberia from January to June, which pushed overall temperatures 5 degrees Celsius (9 degrees Fahrenheit) higher than normal, would have been “almost impossible” if not for human-caused climate change, a new study has found.

Temperatures in Siberia have been above average since the beginning of the year, with the Russian town of Verkhoyansk recording a temperature of 38 degrees C (100.4 degrees Fahrenheit) in June — a record temperature for the Arctic.

The heat in the vast Russian region triggered widespread wildfires in June, associated with an estimated 56 million tons of carbon dioxide — more than the annual emissions of some industrialized nations like Switzerland and Norway.

The heat in Siberia has also accelerated the melting of permafrost. An oil tank built on the frozen soil collapsed in May, leading to one of the worst oil spills ever in the region.

In a rapid attribution study released Wednesday, a team of international researchers found that the prolonged heat like the Arctic region experienced this year would only happen less than once in every 80,000 years without human-induced climate change.

This, researchers said, would make such an event “almost impossible” in a climate that had not been warmed by greenhouse gas emissions.

Scientists found that climate change increased the chances of prolonged heat by a factor of at least 600, and warned that greenhouse gases released by the fires and melting permafrost will further heat the planet, and decrease the planet’s reflectivity from loss of snow and ice.

The Siberian heatwave has also contributed to dropping levels of sea ice, especially in the Arctic Ocean, according to the US’ National Snow and Ice Data Center. The heat has also been associated with an outbreak of silk moths, whose larvae eat conifer trees in the region, according to the Met Office.

Siberia experienced its warmest June on record — up to 10 degrees Celsius (18 degrees Fahrenheit) higher than average –according to the Copernicus Climate Change Service, a program affiliated with the European Commission.

The region tends to experience large swings in temperature month-to-month and year-to-year. But temperatures in the region have stayed well above average since 2019, which is unusual.

“The findings of this rapid research — that climate change increased the chances of the prolonged heat in Siberia by at least 600 times — are truly staggering,” Andrew Ciavarella, lead author of the research and senior detection and attribution scientist at the Met Office, said in a statement.

“This research is further evidence of the extreme temperatures we can expect to see more frequently around the world in a warming global climate. Importantly, an increasing frequency of these extreme heat events can be moderated by reducing greenhouse gas emissions,” he added.

The scientists said that, even in the current climate, the prolonged heat was still unlikely, with such extreme conditions being expected to occur less than once every 130 years.

However, without rapid cuts in greenhouse gas emissions they risk becoming frequent by the end of the century, experts warned.

This story has been updated to correct a conversion from Celsius to Fahrenheit.