2020 Siberian heatwave was 600 times more likely due to human activities

16 Jul 2020

Image: © Anton Petrus/Stock.adobe.com

Researchers have estimated that a heatwave in Siberia that has spanned the first half of this year would be almost impossible without human pollution.

The environment of one of the world’s most sparsely populated regions has been severely impacted by greenhouse gas emissions, according to new research. An international team of researchers working with the World Weather Attribution group was investigating the Siberian heatwave that has spanned from January to June this year, with the region experiencing unusually high temperatures of up to 38 degrees Celsius.

With “high confidence”, the researchers said the heatwave was made at least 600 times more likely as a result of greenhouse gas emissions produced by human activities. Even with the effects of the climate crisis, the heatwave was considered a very rare event and expected to only occur once every 130 years.

Without human-induced climate change, such a heatwave would only occur once in every 80,000 years.

This heatwave, the researchers said, contributed to raising the world’s average temperature to the second hottest on record between January and May. Analysing models and weather observation data from the town of Verkhoyansk, the same six-month hot spell would have been at least 2 degrees Celsius cooler if it had occurred in 1900 than today.

Based off this new data, estimates show that Siberia could expect to have average temperatures 2.5 degrees Celsius warmer in 2050 when compared with 1900, but this increase could be as high as 7 degrees Celsius.

“In places such as Siberia, a hotter climate can have devastating effects, not just on the local wildlife and people who live there, but also on the world’s climate system as a whole, for example through thawing permafrost, reduced snow cover and melting ice,” the researchers wrote.

‘Truly staggering’

In late June alone, the heat triggered widespread fires across 1.15m hectares of land releasing an estimated 56m tons of CO2, more than the annual emissions of countries such as Norway or Switzerland.

Lead author of the research and senior detection and attribution scientist at the Met Office in the UK, Andrew Ciavarella, said the findings are “truly staggering”.

“This research is further evidence of the extreme temperatures we can expect to see more frequently around the world in a warming global climate,” he said.

“Importantly, an increasing frequency of these extreme heat events can be moderated by reducing greenhouse gas emissions.”

Prof Sonia Seneviratne from the Department of Environmental Systems Science at ETH Zurich and a lead author on several IPCC reports, said it is a sign we are experiencing events that would have “almost no chance” of happening without human activities.

“We have little time left to stabilise global warming at levels at which climate change would remain within the bounds of the Paris Agreement,” she said.

Colm Gorey was a senior journalist with Silicon Republic