Does Antarctic glaciation cool the world?
In this study, we compare the simulated climatic impact of adding an Antarctic ice sheet (AIS) to the "greenhouse world" of the Eocene and removing the AIS from the modern world. The modern global mean surface temperature anomaly (ΔT) induced by Antarctic Glaciation depends on the backgrou...
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fttriple:oai:gotriple.eu:oai:doaj.org/article:ecac901604944b5a8727f5a56e68784c 2023-05-15T13:36:09+02:00 Does Antarctic glaciation cool the world? A. Goldner M. Huber R. Caballero 2013-01-01 https://doi.org/10.5194/cp-9-173-2013 http://www.clim-past.net/9/173/2013/cp-9-173-2013.pdf https://doaj.org/article/ecac901604944b5a8727f5a56e68784c en eng Copernicus Publications doi:10.5194/cp-9-173-2013 1814-9324 1814-9332 http://www.clim-past.net/9/173/2013/cp-9-173-2013.pdf https://doaj.org/article/ecac901604944b5a8727f5a56e68784c undefined Climate of the Past, Vol 9, Iss 1, Pp 173-189 (2013) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2013 fttriple https://doi.org/10.5194/cp-9-173-2013 2023-01-22T19:32:34Z In this study, we compare the simulated climatic impact of adding an Antarctic ice sheet (AIS) to the "greenhouse world" of the Eocene and removing the AIS from the modern world. The modern global mean surface temperature anomaly (ΔT) induced by Antarctic Glaciation depends on the background CO2 levels and ranges from −1.22 to −0.18 K. The Eocene ΔT is nearly constant at ~−0.25 K. We calculate an climate sensitivity parameter S[Antarctica] which we define as ΔT divided by the change in effective radiative forcing (ΔQAntarctica) which includes some fast feedbacks imposed by prescribing the glacial properties of Antarctica. The main difference between the modern and Eocene responses is that a negative cloud feedback warms much of the Earth's surface as a large AIS is introduced in the Eocene, whereas this cloud feedback is weakly positive and acts in combination with positive sea-ice feedbacks to enhance cooling introduced by adding an ice sheet in the modern. Because of the importance of cloud feedbacks in determining the final temperature sensitivity of the AIS, our results are likely to be model dependent. Nevertheless, these model results suggest that the effective radiative forcing and feedbacks induced by the AIS did not significantly decrease global mean surface temperature across the Eocene–Oligocene transition (EOT −34.1 to 33.6 Ma) and that other factors like declining atmospheric CO2 are more important for cooling across the EOT. The results illustrate that the efficacy of AIS forcing in the Eocene is not necessarily close to one and is likely to be model and state dependent. This implies that using EOT paleoclimate proxy data by itself to estimate climate sensitivity for future climate prediction requires climate models and consequently these estimates will have large uncertainty, largely due to uncertainties in modelling low clouds. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Sea ice Unknown Antarctic Climate of the Past 9 1 173 189 |
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English |
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geo envir A. Goldner M. Huber R. Caballero Does Antarctic glaciation cool the world? |
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geo envir |
description |
In this study, we compare the simulated climatic impact of adding an Antarctic ice sheet (AIS) to the "greenhouse world" of the Eocene and removing the AIS from the modern world. The modern global mean surface temperature anomaly (ΔT) induced by Antarctic Glaciation depends on the background CO2 levels and ranges from −1.22 to −0.18 K. The Eocene ΔT is nearly constant at ~−0.25 K. We calculate an climate sensitivity parameter S[Antarctica] which we define as ΔT divided by the change in effective radiative forcing (ΔQAntarctica) which includes some fast feedbacks imposed by prescribing the glacial properties of Antarctica. The main difference between the modern and Eocene responses is that a negative cloud feedback warms much of the Earth's surface as a large AIS is introduced in the Eocene, whereas this cloud feedback is weakly positive and acts in combination with positive sea-ice feedbacks to enhance cooling introduced by adding an ice sheet in the modern. Because of the importance of cloud feedbacks in determining the final temperature sensitivity of the AIS, our results are likely to be model dependent. Nevertheless, these model results suggest that the effective radiative forcing and feedbacks induced by the AIS did not significantly decrease global mean surface temperature across the Eocene–Oligocene transition (EOT −34.1 to 33.6 Ma) and that other factors like declining atmospheric CO2 are more important for cooling across the EOT. The results illustrate that the efficacy of AIS forcing in the Eocene is not necessarily close to one and is likely to be model and state dependent. This implies that using EOT paleoclimate proxy data by itself to estimate climate sensitivity for future climate prediction requires climate models and consequently these estimates will have large uncertainty, largely due to uncertainties in modelling low clouds. |
format |
Article in Journal/Newspaper |
author |
A. Goldner M. Huber R. Caballero |
author_facet |
A. Goldner M. Huber R. Caballero |
author_sort |
A. Goldner |
title |
Does Antarctic glaciation cool the world? |
title_short |
Does Antarctic glaciation cool the world? |
title_full |
Does Antarctic glaciation cool the world? |
title_fullStr |
Does Antarctic glaciation cool the world? |
title_full_unstemmed |
Does Antarctic glaciation cool the world? |
title_sort |
does antarctic glaciation cool the world? |
publisher |
Copernicus Publications |
publishDate |
2013 |
url |
https://doi.org/10.5194/cp-9-173-2013 http://www.clim-past.net/9/173/2013/cp-9-173-2013.pdf https://doaj.org/article/ecac901604944b5a8727f5a56e68784c |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet Sea ice |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Sea ice |
op_source |
Climate of the Past, Vol 9, Iss 1, Pp 173-189 (2013) |
op_relation |
doi:10.5194/cp-9-173-2013 1814-9324 1814-9332 http://www.clim-past.net/9/173/2013/cp-9-173-2013.pdf https://doaj.org/article/ecac901604944b5a8727f5a56e68784c |
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op_doi |
https://doi.org/10.5194/cp-9-173-2013 |
container_title |
Climate of the Past |
container_volume |
9 |
container_issue |
1 |
container_start_page |
173 |
op_container_end_page |
189 |
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