TiPACCs - RD4

The TiPACCs project will investigate the probability of sudden and large changes in the sea-level contribution from the Antarctic Ice Sheet that would result from passing tipping points in the marginal seas and at the grounding lines of the floating ice shelves that fringe the ice sheet. A comprehensive study of the triggering processes will reveal the likelihood of reversibility, while the study of ice-ocean feedbacks will provide insight into the threat of sudden sea-level rise. Modelling work will deliver parameter estimates of safe operating spaces, and linking these with Southern Ocean observations will contribute to the launch of early-warning indicators for dangerous levels of ocean-induced basal melting of the ice shelves. We will achieve these objectives using a suite of state-of-the art ocean-circulation and ice-flow models run by leading European research groups, greatly enhancing confidence in the results. The combination of numerical work with existing remote sensing and in-situ observations and paleo-reconstructions is ideal for defining the proximity of the simulated tipping points. With this work, we aim to provide a better understanding of key processes controlling the climate-Earth system that are critical for further improvement in climate projections and reducing uncertainty in climate sensitivity calculations. We will also assess more accurately the impacts of climate change related to the proximity, rate, and reversibility of tipping points in Antarctic climate components. Furthermore, future climate projections will benefit from our combined use of numerical models and paleo-reconstructions as they allow a better understanding of how the climate system worked during abrupt climatic transitions and under warmer or colder than present-day conditions. Thus, the project will dramatically improve our knowledge of sudden sea-level rise caused by tipping points in Antarctic climate components.

Ice-ocean interactions and effect of feedbacks on ice-sheet stability