Disentangling the drivers of future Antarctic ice loss with a historically-calibrated ice-sheet model
We use an observationally-calibrated ice-sheet model to investigate the future trajectory of the Antarctic ice sheet related to uncertainties in the future balance between sub-shelf melting and ice discharge on the one hand, and the surface mass balance on the other. Our ensemble of simulations, for...
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ftunivbruxelles:oai:dipot.ulb.ac.be:2013/367836 2024-02-11T09:55:21+01:00 Disentangling the drivers of future Antarctic ice loss with a historically-calibrated ice-sheet model Coulon, Violaine Ann Kristin, Klose Kittel, Christoph Edwards, Tamsin L Turner, Fiona Winkelmann, Ricarda Pattyn, Frank 2023-07-27 1 full-text file(s): application/pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/367836 https://dipot.ulb.ac.be/dspace/bitstream/2013/367836/3/egusphere-2023-1532.pdf en eng https://dipot.ulb.ac.be/dspace/bitstream/2013/367836/3/egusphere-2023-1532.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/367836 1 full-text file(s): info:eu-repo/semantics/openAccess The Cryosphere Discussions Sciences exactes et naturelles info:eu-repo/semantics/article info:ulb-repo/semantics/articlePeerReview info:ulb-repo/semantics/openurl/article 2023 ftunivbruxelles 2024-01-17T23:23:41Z We use an observationally-calibrated ice-sheet model to investigate the future trajectory of the Antarctic ice sheet related to uncertainties in the future balance between sub-shelf melting and ice discharge on the one hand, and the surface mass balance on the other. Our ensemble of simulations, forced by a panel of CMIP6 climate models, suggests that the ocean will be the primary driver of short-term Antarctic mass loss, initiating ice loss in West Antarctica already during this century. The atmosphere initially plays a mitigating role through increased snowfall, leading to an Antarctic contribution to global mean sea-level rise by 2100 of 6 (-8 to 15) cm under a low-emission scenario and 5.5 (-10 to 16) cm under a very high-emission scenario. However, under the very high-emission pathway, the influence of the atmosphere shifts beyond the end of the century, becoming an amplifying driver of mass loss as the ice sheet's surface mass balance decreases. We show that this transition occurs when Antarctic near-surface warming exceeds a critical threshold of +7.5 °C, at which the increase in surface runoff outweighs the increase in snow accumulation, a signal that is amplified by the melt–elevation feedback. Therefore, under the very high-emission scenario, oceanic and atmospheric drivers are projected to result in a complete collapse of the West Antarctic ice sheet along with significant grounding-line retreat in the marine basins of the East Antarctic ice sheet, leading to a median global mean sea-level rise of 2.75 (6.95) m by 2300 (3000). Under a more sustainable socio-economic pathway, we find that the Antarctic ice sheet may still contribute to a median global mean sea-level rise of 0.62 (1.85) m by 2300 (3000). However, the rate of sea-level rise is significantly reduced as mass loss is likely to remain confined to the Amundsen Sea Embayment, where present-day climate conditions seem sufficient to commit to a continuous retreat of Thwaites Glacier. info:eu-repo/semantics/published Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet The Cryosphere The Cryosphere Discussions Thwaites Glacier West Antarctica DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) Antarctic The Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet East Antarctic Ice Sheet Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
institution |
Open Polar |
collection |
DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) |
op_collection_id |
ftunivbruxelles |
language |
English |
topic |
Sciences exactes et naturelles |
spellingShingle |
Sciences exactes et naturelles Coulon, Violaine Ann Kristin, Klose Kittel, Christoph Edwards, Tamsin L Turner, Fiona Winkelmann, Ricarda Pattyn, Frank Disentangling the drivers of future Antarctic ice loss with a historically-calibrated ice-sheet model |
topic_facet |
Sciences exactes et naturelles |
description |
We use an observationally-calibrated ice-sheet model to investigate the future trajectory of the Antarctic ice sheet related to uncertainties in the future balance between sub-shelf melting and ice discharge on the one hand, and the surface mass balance on the other. Our ensemble of simulations, forced by a panel of CMIP6 climate models, suggests that the ocean will be the primary driver of short-term Antarctic mass loss, initiating ice loss in West Antarctica already during this century. The atmosphere initially plays a mitigating role through increased snowfall, leading to an Antarctic contribution to global mean sea-level rise by 2100 of 6 (-8 to 15) cm under a low-emission scenario and 5.5 (-10 to 16) cm under a very high-emission scenario. However, under the very high-emission pathway, the influence of the atmosphere shifts beyond the end of the century, becoming an amplifying driver of mass loss as the ice sheet's surface mass balance decreases. We show that this transition occurs when Antarctic near-surface warming exceeds a critical threshold of +7.5 °C, at which the increase in surface runoff outweighs the increase in snow accumulation, a signal that is amplified by the melt–elevation feedback. Therefore, under the very high-emission scenario, oceanic and atmospheric drivers are projected to result in a complete collapse of the West Antarctic ice sheet along with significant grounding-line retreat in the marine basins of the East Antarctic ice sheet, leading to a median global mean sea-level rise of 2.75 (6.95) m by 2300 (3000). Under a more sustainable socio-economic pathway, we find that the Antarctic ice sheet may still contribute to a median global mean sea-level rise of 0.62 (1.85) m by 2300 (3000). However, the rate of sea-level rise is significantly reduced as mass loss is likely to remain confined to the Amundsen Sea Embayment, where present-day climate conditions seem sufficient to commit to a continuous retreat of Thwaites Glacier. info:eu-repo/semantics/published |
format |
Article in Journal/Newspaper |
author |
Coulon, Violaine Ann Kristin, Klose Kittel, Christoph Edwards, Tamsin L Turner, Fiona Winkelmann, Ricarda Pattyn, Frank |
author_facet |
Coulon, Violaine Ann Kristin, Klose Kittel, Christoph Edwards, Tamsin L Turner, Fiona Winkelmann, Ricarda Pattyn, Frank |
author_sort |
Coulon, Violaine |
title |
Disentangling the drivers of future Antarctic ice loss with a historically-calibrated ice-sheet model |
title_short |
Disentangling the drivers of future Antarctic ice loss with a historically-calibrated ice-sheet model |
title_full |
Disentangling the drivers of future Antarctic ice loss with a historically-calibrated ice-sheet model |
title_fullStr |
Disentangling the drivers of future Antarctic ice loss with a historically-calibrated ice-sheet model |
title_full_unstemmed |
Disentangling the drivers of future Antarctic ice loss with a historically-calibrated ice-sheet model |
title_sort |
disentangling the drivers of future antarctic ice loss with a historically-calibrated ice-sheet model |
publishDate |
2023 |
url |
http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/367836 https://dipot.ulb.ac.be/dspace/bitstream/2013/367836/3/egusphere-2023-1532.pdf |
long_lat |
ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Antarctic The Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet East Antarctic Ice Sheet Thwaites Glacier |
geographic_facet |
Antarctic The Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet East Antarctic Ice Sheet Thwaites Glacier |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet The Cryosphere The Cryosphere Discussions Thwaites Glacier West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet The Cryosphere The Cryosphere Discussions Thwaites Glacier West Antarctica |
op_source |
The Cryosphere Discussions |
op_relation |
https://dipot.ulb.ac.be/dspace/bitstream/2013/367836/3/egusphere-2023-1532.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/367836 |
op_rights |
1 full-text file(s): info:eu-repo/semantics/openAccess |
_version_ |
1790595090187550720 |