If the Antarctic ice sheet ceased melting, it would take nearly 200 years to restore the lost ice, according to researchers. This finding emerges from a recent study investigating methods to slow the retreat of major Antarctic glaciers contributing to global sea-level rise.
Published last month in Communications Earth and Environment, the study titled "Sustained ocean cooling insufficient to reverse sea-level rise from Antarctica," examined ways to slow ice retreat in the Amundsen Sea Embayment of the West Antarctic Ice Sheet.
"The Pine Island and Thwaites glaciers in the Amundsen Sea Embayment represent the 'weak underbelly' of the West Antarctic Ice Sheet," said lead author Alanna Alevropoulos-Borrill, a research fellow at Victoria University of Wellington. She noted that these glaciers make the Embayment the largest contributor to sea-level rise from Antarctica, with ice loss rates expected to increase in a warming climate.
Using computer models, the study investigated the conditions necessary to halt or slow ice retreat in the Embayment and reverse sea-level rise. Nearly 200 scenarios were tested, including building undersea walls to prevent warm Southern Ocean water from accelerating ice sheet melting.
The models indicated that a cooler ocean would reduce ice loss, but reversing sea-level rise remains a daunting task. Alevropoulos-Borrill stated, "Our models showed that cooler water conditions would reduce the maximum ice loss. However, completely offsetting or reversing the region’s contribution to sea-level rise would require not just ocean cooling but also nearly two centuries of increased snowfall to rebuild the lost ice mass."
She emphasized that current melting is "already pushing the Embayment to a point of no return." The collapse of Antarctica’s two largest glaciers, along with "four smaller ice streams," could significantly contribute to global sea-level rise, potentially up to 1.2 meters globally, or as much as 3 meters if the entire West Antarctic Ice Sheet collapsed.
Alevropoulos-Borrill expressed skepticism about the effectiveness of constructing undersea walls to block warm water from the ice sheet. "Our models suggest that building submarine walls to prevent warm waters from reaching the Embayment might help mitigate the worst-case scenario, if successful. However, there will still be ongoing ice loss and global sea-level rise for decades, if not centuries."
She also mentioned recent research indicating that these submarine walls could "cause more harm than good by redirecting warmer ocean water to other vulnerable areas, accelerating their melt and increasing sea-level rise."
The research underscores the grim future for the West Antarctic Ice Sheet and the urgent need for action.
