Global warming: Antarctica is racing

Antarctica is warming more than models predicted

Global warming: Antarctica is racing

Antarctica is warming more than models predicted. This is the sad conclusion of scientists. The rate of warming of the southern continent, twice as fast as the rest of the world, is much greater than estimated by climate models, write researchers in a study published Thursday in the scientific journal Nature Climate Change after analyzing dozens of ice cores.

Scientists based in France, Germany and the United Kingdom used data from 78 cores taken in Antarctica, tracing climate change back 1,000 years. This method makes it possible to compensate for the lack of data from the white continent, where few weather stations are present and where satellite data is incomplete.

Concerning warming in Antarctica, “the results we obtain are 20 to 50% greater than the predictions of climate models,” explains Mathieu Casado, of the climate and climate sciences laboratory, to Agence France-Presse. environment (LSCE) of the CNRS, main author of the study.

“With our reconstructions from ice cores, we predict a warming of between 0.22 and 0.32°C per decade” for Antarctica, while “climate models predict a value of 0.18°C C per decade,” he says. In other words, the warming in Antarctica is "virtually twice the value of the global average", he adds.

Climate change is more marked at the poles due to an already known phenomenon called polar amplification, with the melting of snow and ice which reflect sunlight. But Antarctica was theoretically much less affected by this phenomenon as it is made up of a thicker layer of ice. This warming would be due to complex reasons linked to the quality of the snow and “atmospheric circulation”, indicates Mathieu Casado. The authors conclude their study with the need for paleoclimatologists, statisticians and modelers to work together to reconcile models and observations regarding the poles in order to avoid such differences between predictions and reality.

But, beyond that, Mathieu Casado wonders if climate models do not also underestimate other phenomena, opening the door to other research. “This is not something that we were able to estimate in the study but a priori these are the same climate models used to evaluate future changes in sea levels, for example, according to gas emissions scenarios Greenhouse effect. So we wonder how much of an impact that will have on those predictions as well,” he said.