A new modeling study, published in the journal Nature Climate Change, suggests that the East Antarctic Ice Sheet may be more resilient to extreme long-term warming than previously estimated. Increased snowfall, greater cloud cover, and changes in atmospheric circulation could partially offset ice loss—even under very high carbon dioxide concentrations.
Researchers from the IBS Center for Climate Physics at Pusan National University in South Korea conducted idealized simulations with different atmospheric CO2 levels, spanning 100,000 years using a coupled global climate–ice-sheet model. Unlike conventional studies that prescribe atmospheric and oceanic conditions, the model allowed climate and the Greenland and Antarctic ice sheets to evolve together.
The results reveal striking regional contrasts. Sustained global warming above approximately 2°C relative to preindustrial conditions leads to major long-term ice loss from the marine-based West Antarctic Ice Sheet. Greenland retreats progressively and disappears completely when warming exceeds approximately 6°C. The terrestrial East Antarctic Ice Sheet, however, remains comparatively stable even at warming levels exceeding 10°C in the simulations (Figure 1).
The researchers traced this unexpected resilience to atmospheric processes. Warmer air will carry more moisture toward Antarctica, while a poleward shift in the Southern Hemisphere westerly winds strengthens moisture transport toward the continent. Much of this additional precipitation falls as snow over the high East Antarctic interior, increasing ice accumulation.
At the same time, greater cloud cover reduces the amount of sunlight reaching the ice surface, helping to suppress melting. Together, these effects substantially moderate East Antarctic ice loss in the coupled simulations.
"Our results demonstrate that the long-term future of an ice sheet cannot be understood from temperature alone," said YUN Kyung-Sook, the study's lead author. "Changes in snowfall, clouds, winds, and ocean temperatures all interact with the evolving ice surface."
The findings do not suggest that Antarctica is immune to climate change. The simulations indicate significant warming-induced ice loss from the West Antarctic Ice Sheet, which could accelerate global sea-level rise. Additionally, parts of East Antarctica are also retreating. However, East Antarctica's interior responds differently: increased snowfall and clouds offset some ice loss, leading to a different overall response.
When the researchers excluded the warming-induced changes in precipitation and sunlight, the modeled Antarctic Ice Sheet lost about 70% of its volume under the strongest forcing. In the fully coupled simulation, which included these atmospheric responses, the loss was approximately 20%.
"These results highlight why fully coupled climate–ice-sheet models are essential for estimating long-term climate instabilities and sea level rise," said Axel TIMMERMANN, co-author and Director of the IBS Center for Climate Physics. "Simplified climate forcing may overlook regional processes that strongly influence whether an ice sheet retreats, stabilizes, or survives."
The study provides a new perspective on ice-sheet tipping points and humanity's long-term climate legacy. The authors caution that their model has relatively coarse spatial resolution and cannot fully represent localized processes beneath ice shelves or at individual outlet glaciers. Higher-resolution simulations will be needed to determine how these atmospheric stabilizing effects interact with regional ocean-driven melting.
