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 (Δ T ) induced by Antarctic Glaciation depends on the backgr...
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ftdoajarticles:oai:doaj.org/article:ecac901604944b5a8727f5a56e68784c 2023-05-15T14:05:04+02:00 Does Antarctic glaciation cool the world? A. Goldner M. Huber R. Caballero 2013-01-01T00:00:00Z https://doi.org/10.5194/cp-9-173-2013 https://doaj.org/article/ecac901604944b5a8727f5a56e68784c EN eng Copernicus Publications http://www.clim-past.net/9/173/2013/cp-9-173-2013.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-9-173-2013 1814-9324 1814-9332 https://doaj.org/article/ecac901604944b5a8727f5a56e68784c Climate of the Past, Vol 9, Iss 1, Pp 173-189 (2013) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2013 ftdoajarticles https://doi.org/10.5194/cp-9-173-2013 2022-12-31T05:20:11Z 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 (Δ T ) induced by Antarctic Glaciation depends on the background CO 2 levels and ranges from −1.22 to −0.18 K. The Eocene Δ T is nearly constant at ~−0.25 K. We calculate an climate sensitivity parameter S [Antarctica] which we define as Δ T divided by the change in effective radiative forcing (Δ Q Antarctica ) 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 CO 2 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 Directory of Open Access Journals: DOAJ Articles Antarctic Climate of the Past 9 1 173 189 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 A. Goldner M. Huber R. Caballero Does Antarctic glaciation cool the world? |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
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 (Δ T ) induced by Antarctic Glaciation depends on the background CO 2 levels and ranges from −1.22 to −0.18 K. The Eocene Δ T is nearly constant at ~−0.25 K. We calculate an climate sensitivity parameter S [Antarctica] which we define as Δ T divided by the change in effective radiative forcing (Δ Q Antarctica ) 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 CO 2 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 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 |
http://www.clim-past.net/9/173/2013/cp-9-173-2013.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-9-173-2013 1814-9324 1814-9332 https://doaj.org/article/ecac901604944b5a8727f5a56e68784c |
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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