The unpredictable response of Greenland and Antarctic ice sheets to global warming adds uncertainty to projections of future sea level rise. Current estimates anticipate that average global sea level could rise between 0.3 and 1.6 metres by the end of this century, potentially exceeding 15 metres by the year 2300, according to the latest IPCC (Intergovernmental Panel on Climate Change) assessment report. These extreme scenarios factor in ice sheet instability mechanisms that could cause sea level to rise much faster than is currently being planned for – and present a future potential risk to the world’s coastal communities. To improve the projections of future, and potentially abrupt ice sheet collapse as well as the resulting sea level rise, precise satellite observations are essential for enhancing computer models. These improved models will better reflect the processes driving ice sheet behaviour and help to better estimate how close we are to a critical threshold or tipping point resulting from a full or partial collapse of the ice sheet.
This is the focus of a new research project, Cryotipping, which is contributing to ESA’s Climate Change Initiative. The project led Dr Inés Otasaka of Northumbia University, UK is combines satellite observations – including ice velocity and surface elevation change – with ice sheet models to detect signs of ice sheet instability in a key glacier of Antarctica and investigate its future behaviour.
Satellite records to date shows that ice sheets are thinning and flowing faster than before, highlighting the urgency of this research. The team is investigating three potential mechanisms that could lead to partial collapse of the ice sheet: marine ice sheet instability, marine ice cliff instability and surface elevation melt instability.
Understanding these processes is critical to reduce risks and avoid the severe consequences of more frequent flooding, storm surges, and potential population relocation for coastal communities.
Read more about the exact mechanisms and their potential impact on sea levels: https://theconversation.com/three-things-that-might-trigger-massive-ice-sheet-collapse-267275