The heat and record-breaking temperatures recording in Siberia over the last few months are made possible by climate change.

On June 20, all Arctic heat records were shattered in the Russian city of Verkhoyansk when the thermometer hit 38 degrees Celsius. The extreme heat followed a months-long period (which began as early as January) during which temperatures in Siberia were generally more than 5 degrees Celsius higher than normal.

Climate change?

The fact that the temperatures are so high for so long is exceptional. And it raises the question of whether we are seeing climate change in action here. Probably, according to researchers.

Using computer simulations, researchers show that the persistent heat in Siberia would have been unthinkable without the global warming caused by human activities.

The researchers used a large set of computer simulations for their analysis to simulate two situations. One in which the climate is as it is today: so about 1 degree (Celsius) warmer than in pre-industrial times. And one where the climate is not influenced by humans. The simulations reveal that the sustained heat that consumed Siberia between January and June in the latter scenario – in which man had not warmed the Earth – would occur only once every 80,000 years. And with that, such a period of sustained heat in the area is actually impossible in a climate that has not warmed by greenhouse gas emissions, the researchers argue.

A global problem

Simulations of the current (warmed) climate were found to increase the chance of a long period of persistent heat in Siberia some 600 times. However, the researchers point out that the persistent heat in Siberia is quite unusual even in the current climate; It’s something that’s based on the simulations less than once every 130 years. But, the scientists warn, if we don’t reduce our emissions and the Earth warms further, we’ll see such warm periods more often. “This study shows once again the impact climate change has on heat waves,” said researcher Friederike Otto. “Since heatwaves are by far the deadliest extreme weather events in many parts of the world, we need to take them very seriously. If emissions continue to increase, we need to think about how to deal with it globally – and even in Arctic communities, something that seem completely unnecessary not so long ago.”

Snowball effect

Researchers are concerned that the persistent heat in Siberia will also lead to more warming. For example, the heat has already led to huge wildfires, releasing an estimated 56 million tons of CO2 in the atmosphere. To put that in perspective, that is more than the annual emissions of a country like Switzerland. The high temperatures also lead to the melting of permafrost, from which greenhouse gases are also released.

The research once again makes clear how urgent the climate change problem really is. “These results show that we are beginning to experience extreme events that we would otherwise – if we had not left our mark on the climate system – almost no chance of happening,” says researcher Sonia Seneviratne. “There is still very little time to allow warming to stabilize at a level within the limits of the Paris climate agreement. In order to limit global warming to 1.5 degrees Celsius, a temperature where we still have an increased chance of such periods of extreme heat, we need to halve our CO2 emissions by 2030.”