The large ice sheets in Greenland and Antarctica hold together so much ice, that it could raise the global mean sea level by more than 65m, if melted completely. In both ice sheets self-amplifying feedback mechanisms have been identified, with associated temperature thresholds beyond which the ice sheets become unstable and collapse. This makes them classical examples of tipping elements in the climate system. With the help of numerical ice sheet models coupled to climate or Earth system models, we can gain a better understanding of the involved mechanisms and the competing feedbacks to constrain the relevant thresholds and possible change rates, once they tip. Sea-level rise is a threat to many coastal communities and ecosystems worldwide and needs to be mitigated up to a rate that allows for the global society today and future generations to adapt to.
Key research objectives
- Comprehensive understanding of key processes including sub-shelf melting, surface mass balance changes, iceberg calving, ice-shelf buttressing
- Further development of the Parallel Ice Sheet Model (PISM) and the Ice Shelf Cavity Model (PICO)
- Configuration and coupling of PISM within the Potsdam Earth Model POEM
- Reconstruction / modelling of the glacial-interglacial history of the Antarctic Ice Sheet
- Projections of future sea-level contributions from Greenland and Antarctica
- Role of extreme events for the ice-sheet mass balance
- Assessment of the long-term stability, critical thresholds and tipping dynamics of the Greenland and Antarctic ice sheets
