Nature Communications, 20 May 2022

Warming in the tropical Pacific Ocean served as the main driver behind the melting of the West Antarctic Ice Sheet ten thousand years ago; and similar conditions today may cause its destabilization. Rising ocean temperatures in the tropics can shift westerly wind currents to the south and generate “atmospheric rivers” that push warm air toward the poles. Together, these factors lead to warming and intense periods of rainfall over West Antarctica. High temperatures and moist conditions then trigger widespread melting across the surface of the ice, producing meltwater ponds and increasing the vulnerability of floating ice shelves to fracturing. Such wind and ocean current conditions are similar to the ones that surround Antarctica today. Over the past two decades, widespread melting across the Amundsen region has increased Antarctica’s contribution to sea-level rise. Future warming and increasing precipitation brought by strengthened atmospheric rivers could contribute further to accelerated thinning and retreat of glaciers in the West Antarctic Ice Sheet. These findings emphasize the importance of global atmospheric patterns on the stability of the West Antarctic Ice Sheet, as well as the urgency of reducing emissions to curb temperatures and reduce its future contributions to sea-level rise.