An international team of researchers led by Laurent Orgogozo, lecturer at the University of Toulouse and member of the Geosciences Environment Laboratory, has modeled the consequences of global warming on permafrost. The results were published last December in the Scientific Journal The cryosphereshow that thawing of these frozen soils will increase significantly around 2100, significantly affecting both local ecosystems and the global climate.
Can you remind us of the importance of permafrost?
What is permafrost and what are the consequences of global warming?
Permafrost, also called permafrost in French, is that soil that we encounter all year round in cold areas, at all high latitudes. This permafrost is rapidly triggering global warming with enormous consequences for human activities and natural environments. These are several: land instability at the local level; Global climate impacts, particularly through greenhouse gas emissions; And modification of the Albédo, that is, the ability of terrestrial surfaces to reflect sunlight. There is a very important connection between soil and life. The change in permafrost also implies consequences for vegetation: for example, the line of trees will go to the north. This is one of the aspects that our group is trying to maintain with the scientific community.
How works PermafoamYour simulator to describe the effects of global warming?
I developed Permafoam more than ten years ago. This digital model uses supercomputers that make it possible to simulate the way permafrost evolves according to rainfall, the rise in temperatures and the conditions of the terrain. From a methodological point of view, we used an open source tool and supercomputers.
In Siberia, the Dégel du Pergélisol will increase by more than 60% around 2100. Were you surprised by this result?
This is a study interested in a very precise case of central Siberia, where permafrost is present everywhere. This is an area we were interested in because it has the data we need to inform our model. Our study predicts what will happen in this location around 2,100, but the IPCC offers different scenarios. We covered the four main substances. I expected there to be a significant impact on this area, and in fact I expected there to be a significant impact on this area, and indeed our analyzes confirm an impressive 65% increase in thawed thickness. In the case of the most intense global warming scenario, it is as if we have moved the permafrost layer 350 kilometers south, so it is very important.
On the other hand, your study shows that the total disappearance of permafrost will not happen…
Many models predicted its complete disappearance, but that will not be the case. In order to deal with the consequences of the Dégel du Permafrost, it is important to accurately anticipate the extent of this phenomenon. This is why we developed these high-resolution studies.
Who is this study for?
These results will be published in the cryosphere. It targets two main communities: permafrost specialists and climate modelers.
Will your simulator only be placed locally?
We cannot deal with the problem on a global scale, but we can look at areas representative of regions such as the large peat devices in Western Siberia or Scandinavia. We will try to achieve specific results in these locations. In the future, we would like to continue these approaches and in particular use artificial intelligence to further improve our predictions. We have three other study locations in Eurasia.
Is it possible to study permafrost in the Pyrenees?
There is enough permafrost in the Alps to be an economic problem. In the Pyrenees it would be a potential study object.
What impact does this unfreezing have on our daily lives?
Large amounts of natural resources come from permafrost areas. However, the Dégel threatens vital infrastructure, particularly in Norilsk, north of the Arctic Circle. This could disrupt the global supply of nickel, an essential material in many everyday objects. If its extraction becomes impossible, the cost of nickel will fly away, affecting regions such as Occitania, where this metal plays a central role in various uses.
Even if global warming stops, your simulations show that thawing will continue…
Imagine that in the year 2100 there is no more warming due to the thermal inertia of the environment. A current hypothesis suggests that thermal equilibrium will be reached by this date. We show that this hypothesis is false and can no longer be used. This is bad news from the perspective of the impact of global warming on permafrost, and it is bad news for model manufacturers.