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