Nature Geoscience, Published online: 02 June 2026; doi:10.1038/s41561-026-02003-3 Analysis of particles within a coastal Antarctic ice core reveal a shift in atmospheric dynamics and ice-free terrain related to ice loss during the Last Interglacial. Climate simulations with a reduced Antarctic ice extent agree with the ice core record, suggesting that the Ross Ice Shelf and West Antarctic Ice Sheet are vulnerable to a warmer climate.