EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Has the (West) Antarctic Ice Sheet already tipped?

Ronja Reese1,2, Julius Garbe2,3, Emily A. Hill1, Benoît Urruty4, Kaitlin A. Naughten5, Olivier Gagliardini4, Gael Durand4, Fabien Gillet-Chaulet4, G. Hilmar Gudmundsson1, David Chandler6, Petra M. Langebroek6, and Ricarda Winkelmann2
Ronja Reese et al.
  • 1Department of Geography and Environmental Sciences, Northumbria University, Newcastle, UK
  • 2Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, Potsdam, Germany
  • 3Institute of Physics and Astronomy, University of Potsdam, Potsdam, Germany
  • 4Univ. Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, 38000 Grenoble, France
  • 5British Antarctic Survey, Cambridge, UK
  • 6NORCE Norwegian Research Centre, Bjerknes Centre for Climate Research, Bergen, Norway

Observations of ocean-driven grounding line retreat in the Amundsen Sea Embayment in Antarctica raise the question of an imminent collapse of the West Antarctic Ice Sheet. Here we analyse the committed evolution of Antarctic grounding lines under the present-day climate. To this aim, we run an ensemble of historical simulations with a state-of-the-art ice sheet model to create model instances of possible present-day ice sheet configurations. Then, we extend the simulations to investigate their evolution under constant present-day climate forcing and bathymetry. We test for reversibility of grounding line movement at different stages of the simulations to analyse when and where irreversible grounding line retreat, or tipping, is initiated.

How to cite: Reese, R., Garbe, J., Hill, E. A., Urruty, B., Naughten, K. A., Gagliardini, O., Durand, G., Gillet-Chaulet, F., Gudmundsson, G. H., Chandler, D., Langebroek, P. M., and Winkelmann, R.: Has the (West) Antarctic Ice Sheet already tipped?, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-14469,, 2023.