Using Antarctica's response in the mid-Pliocene warm period to understand uncertainties about long-term future sea level rise

Sea level rise represents an existential threat to coastal populations and ecosystems. The response of the Antarctic ice sheet to climate change is the highest uncertainty in future sea level projections. The primary vehicle for studying these uncertainties is through the use of ice sheet models to simulate ice sheet evolution under different emission scenarios.

However, the majority of modelling efforts to date have focused on end of the century projections. Models that have run multi-millennial simulations of the Antarctic ice sheet all either compromise on model complexity or use a grid resolution that is too coarse to robustly model grounding line retreat.

This project will conduct millennial-scale simulations of future Antarctic ice sheet evolution using the BISICLES ice sheet model, which uses Adaptive Mesh Refinement to improve resolution at the grounding line. Until recently, BISICLES was incapable of conducting multi-millennial simulations due to lacking the solid Earth processes that become relevant on these timescales.

This project will expand on previous work, which added these processes to BISICLES and used it to simulate Antarctic ice sheet evolution during the Mid-Pliocene Warm Period. It will use information from the Pliocene to put constraints on future sea level rise. It will then emulate BISICLES using a statistical model to explore the uncertainties in future sea level projections in more depth, producing full probability

distributions for sea level by 2300 and after multiple millennia.