Joint Seminar: Hysteresis Behavior of the Greenland Ice Sheet in a Coupled Earth System Model
The Greenland Ice Sheet (GrIS) is projected to disappear abruptly and irreversibly under continuous global warming. To date, the threshold temperature for its retreat and regrowth as well as the governing processes remain unclear. I composed a systematic set of transient and equilibrium simulations using the novel fully-coupled atmosphere–ocean–vegetation–ice-sheet–solid-earth model MPI-ESM/mPISM/VILMA to investigate the hysteresis behavior of the GrIS. The transient simulations show hysteresis behavior of the GrIS. Until a global-mean temperature anomaly of +2.4 to +2.6 °C, mass loss of the GrIS is small and limited to the coastal areas. Beyond this critical threshold, the GrIS disintegrates abruptly. In contrast, strongly delayed regrowth happens stepwise. A full regrowth is only achieved once the global temperature anomaly drops below -1.4 to -1.2 °C. Additionally, I find three nested hysteresis loops that exist at intermediate temperature anomalies. In this talk, I will also explore whether these critical transitions in the GrIS retreat and regrowth can be predicted with early warning signals. My results suggest that we are approaching a critical threshold beyond which the GrIS is irreversibly lost over the next millennia.
Datum
23.09.2025
Uhrzeit
15:15 h
Ort
- Bundesstr. 53, room 022/023
- Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg
Chair
- Marie-Luise Kapsch