The long–term sea–level commitment from Antarctica
The evolution of the Antarctic Ice Sheet is of vital importance given the coastal and societal implications of ice loss, with a potential to raise sea level by up to 58 m if melted entirely. However, future ice-sheet trajectories remain highly uncertain. One of the main sources of uncertainty is rel...
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ftcopernicus:oai:publications.copernicus.org:tcd115131 2023-11-12T04:00:58+01:00 The long–term sea–level commitment from Antarctica Klose, Ann Kristin Coulon, Violaine Pattyn, Frank Winkelmann, Ricarda 2023-10-09 application/pdf https://doi.org/10.5194/tc-2023-156 https://tc.copernicus.org/preprints/tc-2023-156/ eng eng doi:10.5194/tc-2023-156 https://tc.copernicus.org/preprints/tc-2023-156/ eISSN: 1994-0424 Text 2023 ftcopernicus https://doi.org/10.5194/tc-2023-156 2023-10-16T16:24:16Z The evolution of the Antarctic Ice Sheet is of vital importance given the coastal and societal implications of ice loss, with a potential to raise sea level by up to 58 m if melted entirely. However, future ice-sheet trajectories remain highly uncertain. One of the main sources of uncertainty is related to nonlinear processes and feedbacks of the ice sheet with the Earth System on different timescales. Due to these feedbacks and the ice-sheet inertia, ice loss may already be triggered in the next decades and then unfolds delayed on multi-centennial to millennial timescales. This committed Antarctic sea-level contribution is not reflected in typical sea-level projections based on mass balance changes of Antarctica, which often cover decadal-to-centennial timescales. Here, using two ice-sheet models, we systematically assess the multi-millennial sea-level commitment from Antarctica in response to warming projected over the next centuries under low- and high-emission pathways. This allows bringing together the time horizon of stakeholder planning with the much longer response times of the Antarctic Ice Sheet. Our results show that warming levels representative of the lower-emission pathway SSP1-2.6 may already result in an Antarctic mass loss of up to 6 m sea-level equivalent on multi-millennial timescales. This committed mass loss is due to a strong grounding-line retreat in the Amundsen Sea Embayment as well as a potential drainage from the Ross Ice Shelf catchment and onset of ice loss in Wilkes subglacial basin. Beyond warming levels reached by the end of this century under the higher-emission trajectory SSP5-8.5, a collapse of the West Antarctic Ice Sheet is triggered in the entire ensemble of simulations from both ice-sheet models. Under enhanced warming, next to the marine parts, we also find a substantial decline in ice volume of regions grounded above sea level in East Antarctica. Over the next millennia, this gives rise to a sea-level increase of up to 40 m in our experiments, stressing the importance of ... Text Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ross Ice Shelf Copernicus Publications: E-Journals Antarctic The Antarctic East Antarctica Amundsen Sea West Antarctic Ice Sheet Ross Ice Shelf Wilkes Subglacial Basin ENVELOPE(145.000,145.000,-75.000,-75.000) |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
The evolution of the Antarctic Ice Sheet is of vital importance given the coastal and societal implications of ice loss, with a potential to raise sea level by up to 58 m if melted entirely. However, future ice-sheet trajectories remain highly uncertain. One of the main sources of uncertainty is related to nonlinear processes and feedbacks of the ice sheet with the Earth System on different timescales. Due to these feedbacks and the ice-sheet inertia, ice loss may already be triggered in the next decades and then unfolds delayed on multi-centennial to millennial timescales. This committed Antarctic sea-level contribution is not reflected in typical sea-level projections based on mass balance changes of Antarctica, which often cover decadal-to-centennial timescales. Here, using two ice-sheet models, we systematically assess the multi-millennial sea-level commitment from Antarctica in response to warming projected over the next centuries under low- and high-emission pathways. This allows bringing together the time horizon of stakeholder planning with the much longer response times of the Antarctic Ice Sheet. Our results show that warming levels representative of the lower-emission pathway SSP1-2.6 may already result in an Antarctic mass loss of up to 6 m sea-level equivalent on multi-millennial timescales. This committed mass loss is due to a strong grounding-line retreat in the Amundsen Sea Embayment as well as a potential drainage from the Ross Ice Shelf catchment and onset of ice loss in Wilkes subglacial basin. Beyond warming levels reached by the end of this century under the higher-emission trajectory SSP5-8.5, a collapse of the West Antarctic Ice Sheet is triggered in the entire ensemble of simulations from both ice-sheet models. Under enhanced warming, next to the marine parts, we also find a substantial decline in ice volume of regions grounded above sea level in East Antarctica. Over the next millennia, this gives rise to a sea-level increase of up to 40 m in our experiments, stressing the importance of ... |
format |
Text |
author |
Klose, Ann Kristin Coulon, Violaine Pattyn, Frank Winkelmann, Ricarda |
spellingShingle |
Klose, Ann Kristin Coulon, Violaine Pattyn, Frank Winkelmann, Ricarda The long–term sea–level commitment from Antarctica |
author_facet |
Klose, Ann Kristin Coulon, Violaine Pattyn, Frank Winkelmann, Ricarda |
author_sort |
Klose, Ann Kristin |
title |
The long–term sea–level commitment from Antarctica |
title_short |
The long–term sea–level commitment from Antarctica |
title_full |
The long–term sea–level commitment from Antarctica |
title_fullStr |
The long–term sea–level commitment from Antarctica |
title_full_unstemmed |
The long–term sea–level commitment from Antarctica |
title_sort |
long–term sea–level commitment from antarctica |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-2023-156 https://tc.copernicus.org/preprints/tc-2023-156/ |
long_lat |
ENVELOPE(145.000,145.000,-75.000,-75.000) |
geographic |
Antarctic The Antarctic East Antarctica Amundsen Sea West Antarctic Ice Sheet Ross Ice Shelf Wilkes Subglacial Basin |
geographic_facet |
Antarctic The Antarctic East Antarctica Amundsen Sea West Antarctic Ice Sheet Ross Ice Shelf Wilkes Subglacial Basin |
genre |
Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ross Ice Shelf |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ross Ice Shelf |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2023-156 https://tc.copernicus.org/preprints/tc-2023-156/ |
op_doi |
https://doi.org/10.5194/tc-2023-156 |
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1782329067330076672 |