Climate models

Increased snowfall will offset sea level rise due to melting Antarctic ice sheet


The Jakobshavn Glacier, Greenland. Credit: Thomas Overly

A new study predicts that any rise in sea level on the world’s southernmost continent will be countered by increased snowfall, coupled with a warmer polar atmosphere. Using modern methods to calculate projected changes in sea level, the researchers found that the two ice caps in Greenland and Antarctica react differently, reflecting their very distinct local climates.

The article, recently published in Geophysical research letters, is based on the new generation of climate models that are used in the recently released Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), examining scientific, technical and socio-economic information regarding the change climate.

The project brought together more than 60 researchers from 44 institutions to produce, for the first time, community projections based on the processes of sea level rise from ice caps. This particular paper focuses on one aspect of the overall project, namely how the new generation of climate model projections used in current IPCC assessments differs from the first generation in its impact on ice caps.

Professor Tony Payne, director of the School of Geographical Sciences in Bristol, said the team was trying to establish whether the sea level rise predicted by the new generation of climate models was different from the previous generation. “The new models generally predict more warming than the previous generation, but we wanted to understand what this means for the ice caps. ” he said. “The increased warming of the new models is causing the Greenland ice sheet to melt more and sea level to rise by a factor of around 1.5 at 2100.

“However, there is little change in the predicted sea level rise from the Antarctic ice sheet. This is because the increase in mass loss triggered by warmer oceans is countered by mass gain by the increased snowfall that is associated with the warmer polar atmosphere.

Recent findings suggest that society should predict sea level rise and match virtually all previous estimates of sea level rise, as scientists expect the sea level to rise. tides continue to increase well beyond 2100, most likely at an accelerating rate.

Professor Payne added: “It is difficult to predict the mass budget of the ice caps from estimates of global warming and many of the processes involved require further attention.

“Finding out that warmer climates do not affect Antarctica’s mass budget, in particular, deserves a closer look as it is based on big changes in snowfall and the balancing of marine melting. “

“One of the main things to take away from this, interestingly, is that the response of two ice caps and the impact of global warming on them are different and depend heavily on their local conditions,” Prof. Payne said.

Reference: “Future Sea Level Change Under Coupled Model Intercomparison Project Phase 5 and Phase 6 Scenarios From the Greenland and Antarctic Ice Sheets” by Antony J. Payne, Sophie Nowicki, Ayako Abe-Ouchi, Cécile Agosta, Patrick Alexander, Torsten Albrecht, Xylar Asay-Davis, Andy Aschwanden, Alice Barthel, Thomas J. Bracegirdle, Reinhard Calov, Christopher Chambers, Youngmin Choi, Richard Cullather, Joshua Cuzzone, Christophe Dumas, Tamsin L. Edwards, Denis Felikson, Xavier Fettweis, Benjamin K. Galton-Fenzi , Heiko Goelzer, Rupert Gladstone, Nicholas R. Golledge, Jonathan M. Gregory, Ralf Greve, Tore Hattermann, Matthew J. Hoffman, Angelika Humbert, Philippe Huybrechts, Nicolas C. Jourdain, Thomas Kleiner, Peter Kuipers Munneke, Eric Larour, Sébastien Le clec’h, Victoria Lee, Gunter Leguy, William H. Lipscomb, Christopher M. Little, Daniel P. Lowry, Mathieu Morlighem, Isabel Nias, Frank Pattyn, Tyler Pelle, Stephen F. Price, Aurélien Quiquet, Ronja Reese, Martin Rückamp, ​​Nicol e-Jeann e Schlegel, Hélène Seroussi, Andrew Shepherd, Erika Simon, Donald Slater, Robin S. Smith, Fiammetta Straneo, Sainan Sun, Lev Tarasov, Luke D. Trusel, Jonas Van Breedam, Roderik van de Wal, Michiel van den Broeke , Ricarda Winkelmann, Chen Zhao, Tong Zhang and Thomas Zwinger, May 4, 2021, Geophysical research letters.
DOI: 10.1029 / 2020GL091741


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