The permafrost in Siberia, Alaska and Canada is not only melting, but also becoming warmer – the average temperatures of the frozen-over soil in the Arctic Circle have increased by an average of 0.4 degrees Celsius over the last ten years. This is written by Russian and foreign researchers in the journal Nature Communications.
‘We simply state that the soil temperatures in most wells have increased. We did not try to disclose the reasons for this or give predictions for the future,’ commented Andrei Abramov, a scientist from the Institute of Physico-Chemical and Biological Problems of Soil Science, RAS in Pushchino.
In recent years, climatologists have seriously worried that the warming of the Arctic will lead to the rapid disappearance of all permafrost reserves that have arisen in the soil of Siberia, Alaska and the polar regions of Canada during the last glaciation. According to current forecasts, about a third of the permafrost in the southern regions of Siberia and Alaska will disappear by the end of this century.
The melting of the permafrost, as scientists now believe, will release a huge amount of organic matter, frozen into the soil and accumulated there over millions of years of glaciation. These plant and animal remains will begin to rot, releasing methane and carbon dioxide into the atmosphere, as well as burning during natural fires, which will further accelerate global warming.
Abramov and his colleagues, including many other Russian scientists, are not interested in how quickly the permafrost area is reduced, but in a somewhat different, but related problem – how quickly its temperature changes.
Similar information is important for climatologists and soil scientists for several reasons. First, they make it possible to more accurately predict how fast the permafrost will melt in the future. Secondly, it depends on how fast the organic matter decomposes, frozen in the not yet melted soil or freed of ice relatively recently.
Until 2009, as the researchers note, such observations were not made, which is why there was no consensus in the scientific community about what caused the permafrost to thaw – air warming or other processes, whether the soil warms and how this temperature rises. is, will affect her condition in the future.
Russian soil scientists and their foreign colleagues have filled this gap by drilling more than 150 wells in different parts of the Arctic, Antarctic and in the mountains of Asia, where there are permanent or temporary layers of permafrost today.
As it turned out, the permafrost has become noticeably warmer in all corners of the world, but these changes were far from the same. For example, in the mountains, the temperatures of the frozen soil increased by 0.19 degrees Celsius, whereas in some parts of Yakutia they were almost an order of magnitude higher – 1.15 degrees.
Interestingly, the “southern” deposits suffered from global warming more than the Arctic reserves of frozen ground – the temperature of the first ones increased by 0.1 degrees Celsius more.
Comparing these trends with how air temperatures changed in those points of the Arctic and mountains where the mines were drilled, scientists did not find a clear connection between the processes in the atmosphere and in the soil. On the other hand, the permafrost warming rate in general corresponded to how quickly a particular region of the Arctic or mountains was warming.
Regardless of what caused this effect, similar results of observations, as scientists note, suggest that the temperatures of the frozen soil will continue to increase in the coming years.
How exactly this will affect her condition is not yet clear – thawing of permafrost is still being inhibited by the fact that some of the heat is “eaten up” by ice when turning from a solid state into liquid water. Nevertheless, the authors of the article suggest that this process will accelerate the decomposition of organic matter and global warming.