In January 2019, the journal Nature Communications published a review that analyzed the state of permafrost globally and warned that its average temperature has increased in recent years by around 0.3 ° C. If, for example, the average temperature global increase one more degree, it is estimated that an amount of permafrost equivalent to the area occupied by India would be lost.
The loss of permafrost, that layer of the earth’s subsoil that is permanently frozen and that supports ecosystems as valuable as the taiga or tundra, is a phenomenon that greatly worries scientists, since this system plays a very important role in the global climate.
With climate change, a kind of vicious cycle takes place that feeds itself, since carbon dioxide is trapped in the permafrost. In fact, the amount of carbon retained in it is not negligible, since it is estimated to be approximately twice that contained in the atmosphere. As temperatures rise, part of the permafrost thaws, causing the release of carbon dioxide which in turn contributes more and more to global warming.
The Climate Change Initiative of the European Space Agency (ESA) has published a series of maps that give us an idea of the magnitude of the melting of permafrost in the Arctic and how it has evolved over a 14-year time series (2003 -2017).
It must be taken into account that permafrost can be divided into two strata, and that the most superficial of them tends to periodically thaw and freeze due to the usual seasonal variations , so the study of the phenomenon simply by means of satellite photos would fall short . For this reason, the work has been completed with in situ measurements of the permafrost temperature at the subsoil level with the idea of obtaining a more complete view of what is happening and being able to develop reliable climate models that allow us to understand what can happen in future scenarios.
The images are, without a doubt, impressive, but it is still too early to draw conclusions. “Although the maps provide useful information regarding interannual variability over a 14-year period, it is not possible to draw conclusions about climate trends ,” explains Annett Bartsch, director of ESA’s CDI permafrost project. “We will have to wait to have permafrost maps that cover a complete time series of at least thirty years.”
Economic, social and environmental consequences
The consequences of the thawing of permafrost will not only have an effect on the global climate. For example, it is estimated that more than 60% of Russian soil is on permafrost, and many populations in Siberia, Canada and Alaska settle on it, so their houses and buildings are in danger of collapsing.
Another structure that is threatened by the thawing of permafrost is the Svalbard World Bank, also called ‘the vault of the end of the world’, which serves as a warehouse for more than a million seeds from all over the planet. In fact, in recent years millions of euros have been invested in making various improvements that make the construction more resistant to the climatic events that are expected in the near future.
