During the Last Interglacial (LIG; 129–116 thousand years before present), the Antarctic ice sheet (AIS) was 1 to 7 m sea level equivalent smaller than at pre-industrial. This study assesses the climatic impact of partial AIS melting at the LIG by forcing a coupled climate model with a smaller AIS and the equivalent meltwater input around the Antarctic coast. Results show that changes in surface elevation induce surface warming over East Antarctica (2–4 °C), and sea surface temperature (SST) increases in the Weddell and Ross Seas (up to 2 °C). Meltwater forcing causes a high-latitude SST decrease and a subsurface ocean temperature increase (up to 2 °C in the Ross Sea). The combined effects of a smaller AIS and enhanced meltwater input lead to larger subsurface warming and greater Antarctic warming than each perturbation alone.

David K. Hutchinson, Laurie Menviel, Katrin J. Meissner, Andrew McC. Hogg