Present-Day Warming Nearing Critical Threshold for West Antarctic Ice Sheet Stability

Communications Earth and Environment, 30 May 2025

Research analyzing the Antarctic Ice Sheet’s behavior over the past 800,000 years finds that a minimal increase in ocean temperatures above today’s levels, or even no additional warming at all if today’s temperatures continue, could trigger the irreversible collapse of the West Antarctic Ice Sheet (WAIS). Historically, WAIS has oscillated between two stable states for nearly a million years: one where it remains intact, as it is today, and another where it has collapsed entirely. These oscillations are driven by small variations in ocean temperature, which once exceeded past a critical limit, push the ice sheet irreversibly towards disintegration. Once the tipping point is crossed, returning WAIS to a new stable state requires temperatures to stay at or below pre-industrial levels for several thousand years. While ice sheet formation is incredibly slow, its destabilization can happen in just a few decades; once triggered, it sets in motion feedback loops that amplify heat absorption and ice loss, rendering it nearly impossible to halt. A stable WAIS is important not only to maintain global sea levels, but also ocean circulation patterns and weather systems.

Full Paper | Plain Language Summary from Potsdam Institute for Climate Impact Research