Overview
- The study, published in May 2026, used a 3-million-year paleoclimate simulation from the IBS Center for Climate Physics combined with a Penn State ice-sheet–ice-shelf model to recreate Antarctic ice behavior.
- Results show that after the Mid-Pleistocene Transition about 1 million years ago the Antarctic ice sheet entered a new dynamical regime that reacted more strongly to climate forcing.
- Researchers identify a critical atmospheric CO2 level near 240 parts per million below which the amplitude of Antarctic ice-volume changes increased sharply.
- The model attributes the shift to colder glacial ocean temperatures reducing sub-shelf melt, lower global sea levels that allowed slow bedrock uplift, and coastal thickening that reinforced ice growth.
- Combined with contemporaneous May 2026 studies showing ocean-driven and sub-ice-channel melting can rapidly accelerate local loss, the findings underline that Antarctic responses can be nonlinear and may make near-term sea-level projections too conservative.