The comparatively small Amundsen Basin plays a crucial role in maintaining the integrity of the huge, so-called eternal ice of the West Antarctic ice sheet. If destabilised, the entire West Antarctica ice masses could collapse completely, leading to a massive rise in sea levels.
According to researchers from the Potsdam Institute for Climate Impact Research (PIK) ocean warming is destabilising the Amundsen Basin. And only a few decades of ocean warming caused by “further greenhouse-gas emission will heighten the risk of an ice collapse in West Antarctica and more unstoppable sea-level rise,” warns IPCC sea-level expert Anders Levermann, co-author of the PIK study.
The researchers point out that once disturbed, ice masses do not respond in a linear way. Their stability can break down relatively suddenly, as is expressed by the concept of tipping elements. And the researchers fear that this area of the ice continent will be the first element in the climate system about to tip.
“In our simulations 60 years of melting at the presently observed rate are enough to launch a process which is then unstoppable and goes on for thousands of years,” says lead author Johannes Feldmann.
Sea levels could rise by at least 3 metres. And while it is a long process that would develop slowly, the researchers believe that that it’s already starting now. A sea-level rise of such a degree would destroy humankind’s heritage by consuming coastal cities — “unless we reduce carbon emission quickly,” concludes Levermann.