Alarm Over Siberian Heatwave

Image: A map showing places warmer (red) or cooler (blue) in May than the long-term average. Photograph: Modis/NEO/Nasa

The Guardian reported on 17 June [1] that climate scientists have said a prolonged heatwave in Siberia is “undoubtedly alarming”.

Freja Vamborg, a senior scientist at EU’s Copernicus Climate Change Service (C3S) [2], said: “It is undoubtedly an alarming sign, but not only May was unusually warm in Siberia. The whole of winter and spring had repeated periods of higher-than-average surface air temperatures.

“Although the planet as a whole is warming, this isn’t happening evenly. Western Siberia stands out as a region that shows more of a warming trend with higher variations in temperature. So to some extent large temperature anomalies are not unexpected. However, what is unusual is how long the warmer-than-average anomalies have persisted for.”

The freak temperatures have been linked to wildfires, a huge oil spill and a plague of tree-eating moths.

On a global scale, the Siberian heat is helping push the world towards its hottest year on record in 2020 [3], despite a temporary dip in carbon emissions owing to the coronavirus pandemic.

Temperatures in the polar regions are rising fastest because ocean currents carry heat towards the poles and reflective ice and snow is melting away.

Russian towns in the Arctic circle have recorded extraordinary temperatures, with Nizhnyaya Pesha hitting 30C on 9 June and Khatanga, which usually has daytime temperatures of around 0C at this time of year, hitting 25C on 22 May. The previous record was 12C.

In December, Russia’s president, Vladimir Putin, commented on the unusual heat: “Some of our cities were built north of the Arctic Circle, on the permafrost. If it begins to thaw, you can imagine what consequences it would have. It’s very serious.”

Thawing permafrost was at least partly to blame for a spill of diesel fuel in Siberia in June [4] that led Putin to declare a state of emergency. The supports of the storage tank suddenly sank, according to its operators; green groups said ageing and poorly maintained infrastructure was also to blame.