The Antarctic ice sheet is the largest source of uncertainty in projections of global mean sea-level change. This is due to our limited understanding of key physical processes at the interface between the ice sheet, the atmosphere, the ocean and the solid Earth. Both West and East Antarctic ice sheets are projected to retreat rapidly with substantial ice loss, potentially contributing several meters to global sea level rise within centuries under a warming climate. Geological evidence shows that past sea level variations involved Greenland, West Antarctic ice sheets, and also some sectors of East Antarctic ice sheet. Our understanding of the missing processes is improving with time, and identifying the drivers of tipping points from past to future requires a multi-disciplinary approach. It is critical to integrate the knowledge across time and spatial scales to provide reliable actionable science, to help decision makers and practitioners co-design adaptation strategies to mitigate risk and damages, and to inform the public. This session welcomes contributions from both observation and modeling perspectives, and from paleo to future, from earth science to policy, that focus on (i) the drivers of Antarctic ice sheet instabilities and tipping points, i.e., ice sheet, ocean, atmosphere and solid earth interactions, (ii) integration between sea level projections and damages, new decision making scenarios, (iii) societal impacts.
Robert Nicholls, Gael Durand, Jonathan Wille