Climate change linked to human activity brought on heatwave

The heatwave which has hit Siberia over the last six months would have been “effectively impossible” without climate change caused by humans, scientists have found.

The region has been experiencing unusually hot conditions since the beginning of 2020, while June saw a new reported record high Arctic temperature of 38C at Verkhoyansk, Russia.

A rapid analysis of the conditionsfoundtheprolongedheat over the region since January was made at least 600 times more likely to occur because of human activity driving global warming.

It is the strongest result of any study by the World Weather Attribution initiative in attributing extreme events to climate change, the team behind the analysis said.

Siberia’s heatwave, with temperatures 5C warmer than average in the past six months, has caused widespread wildfires, pumping millions of tonnes of carbon dioxide into the atmosphere which will further drive warming.

It is also melting permafrost – permanently frozen ground – which caused the collapse of a fuel tank and huge oil spill in May, and is causing an outbreak of the pest Siberian silk moth.

The high temperatures in the Arctic are helping drive 2020 to being one of the hottest years on record.

The team of scientists from around the world, including from the Met Office and Oxford University in the UK, applied methods previously used to analyse the impact of human-caused climate change on other extreme events, including storms and heatwaves in the UK, to assess its role in the Siberian heat.

They ran computer simulations to compare today’s world with 1C of global warming to the climate, as it would have been without human activity putting greenhouse gas emissions into the atmosphere that warm the world.

They examined average temperatures through the six months from January to June over a large region spanning most of Siberia, and also lookedatdailymaximumtemperatures in June in the town of Verkhoyansk.

Even with climate change, such a period of heat would be very unlikely, occurring once every 130 years. But without humans causing global warming, it would be almost impossible, taking place just once in 80,000 years.

Dr Friederike Otto, acting director of Oxford’s Environmental Change Institute, and co-lead of the World Weather Attribution initiative, said: “This study shows again just how much of a game changer climate change is with respect to heatwaves. Given that heatwaves are by far the deadliest extreme weather events in most parts of the world they must be taken very seriously.”