Below a global temperature rise of 2°C, the glaciers of the Weddell Sea will not be irreversibly affected by warm water currents by the end of the century. Foresight.
In the southern Weddell Sea, the world’s second largest ice shelf will remain protected from rapid melting if the Paris Agreements are respected. This is the finding of a study by the Alfred-Wegener-Institut, published on February 28 in the journal Communications Earth & Environment. The deep currents of warm water that circulate around Antarctica at 1,600 meters only flow up into the Weddell Sea in fits and starts, through the foothills of the continental shelf : a seasonal phenomenon. These water intrusions fill the Filchner Trough and reach the bases of the ice shelves, where melting increases. A normal process, but what happens if the temperature rises?
The study explores the evolution of currents according to the socio-economic scenarios our societies will follow. In the best-case scenario, if the Earth’s average temperature remains below 2°C (Paris Agreement), intrusions will be more frequent and the average temperature of the Weddell Sea will rise by 0.5°C by 2100. The more pessimistic the scenarios, the higher the temperature of the Weddell Sea – by 1°C and beyond – and the more “the cold waters of the continental shelf that currently fill the through will be replaced”, explains Vanessa Teske, climatologist at the Alfred Wegener Institute. In this case, the ice masses will destabilize and reach a point of no return from 2040 onwards, considerably increasing the rate of sea-level rise. “Only the scenario in line with the 2°C climate target (SSP1-2.6) does not appear to be leading to a regime shift in the Filchner Trough for the time being”, she concludes.
Camille Lin, PolarJournal
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