I guess we know who the climate deniers are now. They always attack the messengers.

Heatwaves in the Arctic over the past two years have also been associated with the emergence of extreme wildfires.

The new analysis, by an international team of scientists at the World Weather Attribution network, investigates the potential influence of climate change on the prolonged heat seen across the entire Siberian region from January to June.

“Attribution” is a fast-growing field of climate science that aims to quantify the “fingerprint” of climate change on extreme-weather events, such as wildfires, heatwaves and floods.

The results show the Arctic has started to experience events that “would have been almost impossible without human-induced climate change”, says Dr Sarah Kew, study author and a climate scientist at the Royal Netherlands Meteorological Institute. She told a press briefing this week:

“The analysis shows that climate change increased the chances of the prolonged heat by a factor of at least 600. This is actually among the strongest results of any attribution study conducted so far.”

Siberian heat

The researchers analysed two significant aspects of Siberia’s 2020 heatwave. First, they analysed the prolonged heat affecting the entire Siberian region from January to June. To do this, they looked at six-month average temperatures across an area covering most of Siberia (60-75N, 60-180E).

Temperatures this year were 7.5C higher than the average in the region from 1981-2010.

Average temperatures across Siberia from January to June 2020, when compared to average temperatures from 1981-2010. Deep red indicates higher than average temperatures. Black box highlights the study area.
Average temperatures across Siberia from January to June 2020, when compared to average temperatures from 1981-2010.

Across the six-month period, Siberian temperatures were more than 5C higher than average, according to the analysis. This is particularly remarkable given Siberia usually sees its highest temperatures in July, notes Kew.

The analysis finds “with high confidence” that the January to June 2020 prolonged heat was made at least 600 times more likely as a result of human-induced climate change and would have been “impossible without human influence”.

In a world without climate change, such extreme six-month average temperatures across Siberia would only be expected around every ~ 80,000 years, the analysis says.

Second, the researchers looked specifically at the potential influence of climate change on the 38C temperature record, which occurred on 20 June at a weather station in Verkhoyansk.