Halve the land ice contribution to sea level rise by following the Paris Agreement target of limiting warming to 1.5°C

6.5.2021 8:34

New research from a large international community of scientists predicts that, if we meet the Paris Agreement target of limiting global warming to 1.5°C instead of continuing with the current contributions to mitigating climate change, sea level rise this century from the melting of ice could be halved. Greenland ice sheet losses would reduce by 70%. The exact sea level rise contribution from Antarctica is less clear, as uncertainties are higher.

Since 1993, in addition to thermal expansion of oceans, land ice has contributed to around half of all global sea level rise and this contribution is expected to increase as the world warms. A new study, ‘Projected land ice contributions to twenty-first-century sea level rise’, published in Nature explores the contribution to sea level in the 21st century arising from the world’s glaciers and the Greenland and Antarctic ice sheets.  It combines the research of more than 80 authors from 38 international research groups and brings together both computer models and statistical techniques to make predictions for the latest socio-economic scenarios.  The research informs the Intergovernmental Panel on Climate Change's Sixth Assessment report which will be published later this year.


A simulation of Antarctica ice flow velocity. Image: Rupert Gladstone

Co-authors Dr Rupert Gladstone of the Arctic Centre at the University of Lapland and Dr Thomas Zwinger of the CSC – IT Center for Science, collaborated with researchers from Tasmania to contribute to the new study. Their research was funded by the Academy of Finland and they used CSC’s supercomputers in their simulations.

– We use the computer model Elmer/Ice to simulate Antarctica´s Ice Sheet. Our simulations comprise the study’s most advanced contribution in terms of representing the flow and deformation of ice.  This is especially important where land ice starts to float on the sea, says Thomas Zwinger. 

 – Our contribution builds on almost two decades of development by Dr Thomas  Zwinger and his colleagues resulting in the world’s most sophisticated computer model for simulating ice dynamics at all scales, Rupert Gladstone adds.  

– Uncertainties for Antarctica’s sea level contribution are very high, because it is currently unclear whether increasing snowfall in the cold interior of the ice sheet will offset increased mass loss at the coasts.  If mass loss dominates, a total sea level rise of over half a metre by 2100 due to melting land ice globally cannot be ruled out, says Rupert Gladstone. 

Contact details

Rupert Gladstone, Arctic Centre, University of Lapland
email: rupert.gladstone@ulapland.fi 
telephone: +49 15258784656

Thomas Zwinger, CSC – IT Center for Science
email: thomas.zwinger@csc.fi 
telephone: +358503819538