Heatwaves in Siberia are increasing and could cause additional methane emissions. While the risks remain low at present, scientists warn that this threat needs to be closely monitored, especially if the climate crisis worsens in the coming years.
Faced with unprecedented episodes of high temperatures, Siberia is currently prey to fires, particularly in Yakutia, located in the northeast of the Russian province. It's a worrying phenomenon, especially since it is occurring in one of the coldest areas of the world.
After facing the world's most extreme heat wave in 2020, Siberia has released methane emissions from permafrost. This famous layer of ice covering part of the Earth is one of the world's largest carbon sinks, but it is melting rapidly as a result of global warming. One of the greatest dangers of melting permafrost is the release of astronomical amounts of greenhouse gases, such as carbon and methane.
While the size of carbon stocks and the extent of possible methane emissions from the Arctic are still subject to considerable uncertainty, scientists behind a new report warn of the need for continued research and monitoring of this potential "climate bomb."
Indeed, in the most pessimistic scenario, significant amounts of methane could be released if the climate crisis were to worsen, with devastating effects on the planet. "We observed a significant increase in methane concentration starting last summer. This remained over the winter, so there must have been a steady flow of methane from the ground," said geology professor Nikolaus Froitzheim of Rhenish Friedrich Wilhelm University of Bonn, Germany, who led the research, published in Proceedings of the National Academy of Sciences.
Based on satellite data from the Taimyr Peninsula in northern Siberia, the study identified the presence of limestone rocks containing significant amounts of methane, trapped by permafrost. In this area, atmospheric methane concentrations increased significantly during and after the 2020 heat wave.
"We suggest that gas hydrates in fractures and pockets of the carbonate rocks in the permafrost zone became unstable due to warming from the surface. This process may add unknown quantities of methane to the atmosphere in the near future," warn the study authors.
According to estimates from a Canadian study, published in 2017, the warming power of methane could potentially be 84 times greater than that of carbon dioxide over a period of 20 years. Emissions of this greenhouse gas into the atmosphere are mainly related to agricultural activity and fossil fuels.
