Antarctica in the Eemian

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Importantly, the most comprehensive published high-latitude (≥40° S) network of quantified sea surface temperature (SST) estimates suggests an early LIG (∼130 ky) warming of 1.6 ± 0.9 °C relative to present day, providing an upper limit on the sensitivity of the Antarctic ice sheet to ocean temperatures.

For the 2 °C warmer than present day ocean temperature scenario (comparable to reconstructed estimates), with no additional atmospheric warming, our model predicts a contribution to GMSL rise of 3.8 m in the first millennium of forcing. The loss of the Filchner–Ronne Ice Shelf within 200 y of warming triggers a nonlinear response by removing the but- tressing force that stabilizes grounded ice across large parts of the WSE and the EAIS (most notably the Recovery Basin). Ongoing slower ice loss subsequently occurs around the margins of East Antarctica, producing a sustained contribution to sea level rise. Even for relatively cool ocean-forced runs, we find the shelves collapse quickly between the 200-y intervals. Indeed, during the warmer ocean model runs, the shelves disappear too quickly to observe the relevant processes on the timescale covered by the snapshots. For instance, under the scenario of 2 °C linear warming, the ice shelves disappear within 600 y of forcing (when temperatures reached between +0.4 and +0.8 °C).

Indeed, recent work has proposed that if mass loss comparable to recent decades is maintained for as little as 60 y, the WAIS could be irrevocably destabilized over subsequent millennia through the collapse in the Amundsen Sea sector, overcoming any isostatically driven rebound.

Early Last Interglacial ocean warming drove substantial ice mass loss from Antarctica
Chris S. M. Turney, Christopher J. Fogwill, Nicholas R. Golledge, Nicholas P. McKay, Erik van Sebille, Richard T. Jones, David Etheridge, MauroRubino, David P. Thornton, Siwan M. Davies, Christopher Bronk Ramsey, Zoë A. Thomas, Michael I. Bird, Niels C. Munksgaard, Mika Kohno, JohnWoodward, Kate Winter, Laura S. Weyrich, Camilla M. Rootes, HelenMillman, Paul G. Albert, Andres Rivera, Tas van Ommen, Mark Curran, Andrew Moy, Stefan Rahmstorf, Kenji Kawamura, Claus-Dieter Hillenbrand, Michael E. Weber, Christina J. Manning, Jennifer Young, Alan Cooper
Proceedings of the National Academy of Sciences Feb 2020, 201902469; DOI:10.1073/pnas.1902469117