This process cannot be reversed, even by limiting warming to 1.5 degrees as planned in the Paris agreements, explains a study to be published in the journal Nature Climate Change, Monday October 23.
It’s a chilling conclusion. The melting of Antarctica is irreversible, according to a study published Monday, November 23 in the journal Nature Climate Change. The melting of the glacier will continue even if humans manage to limit global warming, according to British scientists from the British Antarctic Survey, the organization which operates research stations in Antarctica. These researchers more precisely analyzed the evolution of the ice.
Because Antarctica is a sensitive area, particularly its western part. The Amundsen Sea region, in the far west of the continent, is particularly exposed. “It has been suspected for decades that this is the weak point of the Antarctic ice sheetexplains Gaël Durand, research director at the Institute of Environmental Geosciences. If mechanisms of instability and withdrawal are put in place, it is in these sectors that it will play out. So this is why this region is particularly scrutinized.“
Gaël Durand’s British colleagues have calculated that the process of melting of the Antarctic ice is definitively underway. In short: whatever happens and whatever we do, it is impossible to go back. And this, even with the best-case scenario, like that of the Paris agreements, which aims to limit global warming to 1.5 degrees. This process is observed on the protective barriers of the Antarctic ice shelf, the ice shelves, which complicates its study.
“Glaciers are flowing faster and releasing more ice into the ocean.”
Gaël Durand, research director at the Institute of Environmental Geosciencesat franceinfo
“These ice shelves hold back the flow of glacierssays Gaël Durand. When we weaken these platforms, more ice goes towards the ocean. This is what we have been observing for around twenty years now thanks to satellite measurements in the Amundsen sector.“
The research director continues: “We see that these platforms are thinning due to shock intrusions into the cavity, which melt the ice more intensely than previously.“The author of the study to appear in the journal Nature Climate Change assures him : it’s as if we had lost control of the melting of the ice in West Antarctica.
The study calls for anticipating a rise in ocean levels
The consequences of this melting of Antarctic ice are likely to be seen on the coasts. Because the South Pole ice cap contains enough water to raise sea levels by five meters. Certainly the situation is not yet at this stage, but the rate of ice melting is difficult to assess, which poses a problem for adaptation. “Sea levels will rise by two meters. The question is not whether it will increase by two meters, it is when: is it in a century or is it in a few millennia.“Gaël Durand returns to the current situation:”Today, we are at a rise in sea level of 3.7 mm each year over the recent period when we add up all the components.“
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The irreversible aspect of the melting of the Antarctic ice should not distract from one of the objectives of the study: to anticipate the rise in ocean levels as much as possible. “Climate change is already hereasserts Gaël Durand. It will continue more or less strongly depending on our consumption of fossil energy. The stronger it is, the more difficult it will be to adapt and it is essential to adapt now. These are adaptation plans that take decades to put in place.“A spectacular example of adaptation is planned: the capital of Indonesia, Jakarta, will move due to repeated flooding.