About half of the current sea-level rise stems from land ice – glaciers and the Antarctic and Greenland ice sheets – with most of the rest originating in warming of the ocean. In comparison to pre-industrial levels, global sea-levels have so far risen by more than 20cm. Over the last decades sea-level rise has been accelerating, and understanding it’s future evolution is of great importance to coastal communities worldwide.
In the newly published paper led by Tamsin Edwards from King’s College London, with contributions from the TIPACCs-members Nicolas Jourdain (Université Grenoble Alpes/CNRS), Ronja Reese and Ricarda Winkelmann (Potsdam Institute for Climate Impact Research), nearly 900 model simulations from 38 international groups were combined to explore the land ice contribution to sea level in the 21st century.
The study finds that if global warming is limited to 1.5°C, melting of ice until the end of this century could be halved in comparison with current emission pledges. Greenland ice sheet losses would reduce by 70%, and glacier losses by 50%. Projections for the Antarctic Ice Sheet show similar mass loss for different emission scenarios because it is currently unclear whether snow falling in the interior could offset melting at the coasts. However, under a ‘pessimistic’ storyline, with much more melting than snowfall, Antarctic ice losses could be five times larger.
This study highlights that new observations and modelling are necessary to improve the understanding of Antarctica’s future. Research on interactions and tipping points of the Antarctic Ice Sheet and the Southern Ocean, central to TiPACCs, provide important insights on melting of the ice sheet and it’s future evolution.
Weblink to the paper: https://www.nature.com/articles/s41586-021-03302-y