Siberian heat wave that caused an oil spill made more likely by climate change

Extreme temperatures from January to June 2020 led to wildfires and thawing permafrost

an aerial image showing where oil spilled near the Ambarnaya River

Thawing, unstable permafrost led to the collapse of a fuel tank in the Russian mining city of Norilsk on May 29, 2020. It spilled at least 21,000 metric tons of oil. That oil appears red in this satellite image of the Ambarnaya River, taken on May 31.


An intense heat wave gripped Siberia during the first half of 2020. Temperatures far higher than normal across this northern stretch of Russia would have been impossible without human-caused climate change. That’s the finding of a new study.

The study’s authors, part of the World Weather Attribution Network, relied on the fairly new field of attribution science. Climate change made the prolonged heat in the region at least 600 times more likely, they find. It may have been as much as 99,000 times more likely.

“We wouldn’t expect the natural world to generate [such a heat wave] in anything less than 800,000 years or so,” said Andrew Ciavarella. He’s a climate scientist with the U.K. Met Office in Exeter, England. He spoke July 14 in a news conference. It’s “effectively impossible without human influence.”

The new study was posted online July 15. It examined two aspects of the heat wave. The first was the persistence and intensity of average temperatures across Siberia this past January to June. The second was daily maximum temperatures during June 2020 in Verkhoyansk. This is a remote town in Siberia.

Verkhoyansk made international headlines earlier this year. Although north of the Arctic Circle, it logged a record high temperature of 38° Celsius (100.4° Fahrenheit) on June 20.

The record was just one extreme in a larger and long event in this region. The heat led to a series of human and natural disasters. They included wildfires across Siberia. There also was the collapse of a fuel tank in the mining city of Norilsk. Sagging permafrost led to the tank spilling oil, which polluted the Ambarnaya River. The health of people in the region suffered from the heat, too.

The researchers gathered data from Siberian weather stations. They assessed the rarity of the temperatures these logged and trends in local temperatures. Then they compared these with hundreds of climate simulations. Those computer models used different scenarios of greenhouse-gas warming. 

Had such a hot spell occurred in 1900 instead of 2020, it would have been at least 2 degrees C (3.6 degrees F) cooler on average, the researchers found. In Verkhoyansk, climate change amped up June temperatures by at least 1 degree C (1.8 degrees F) relative to 1900. And such heat waves are likely to become more common in the near future. By 2050, temperatures in Siberia could rise by between 2.5 degrees C (4.5 degrees F) to as much as 7 degrees C (12.6 degrees F) compared to 1900, the report finds.

Carolyn Gramling is the earth & climate writer at Science News. She has bachelor’s degrees in geology and European history and a Ph.D. in marine geochemistry from MIT and the Woods Hole Oceanographic Institution.

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