Lessons from a high-CO 2 world: an ocean view from ∼ 3 million years ago
A range of future climate scenarios are projected for high atmospheric CO 2 concentrations, given uncertainties over future human actions as well as potential environmental and climatic feedbacks. The geological record offers an opportunity to understand climate system response to a range of forcing...
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Copernicus Publications
2020
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Online Access: | https://doi.org/10.5194/cp-16-1599-2020 https://doaj.org/article/113f2c2bcc8b4dddaa707dbd08a95e4b |
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ftdoajarticles:oai:doaj.org/article:113f2c2bcc8b4dddaa707dbd08a95e4b 2023-05-15T17:31:36+02:00 Lessons from a high-CO 2 world: an ocean view from ∼ 3 million years ago E. L. McClymont H. L. Ford S. L. Ho J. C. Tindall A. M. Haywood M. Alonso-Garcia I. Bailey M. A. Berke K. Littler M. O. Patterson B. Petrick F. Peterse A. C. Ravelo B. Risebrobakken S. De Schepper G. E. A. Swann K. Thirumalai J. E. Tierney C. van der Weijst S. White A. Abe-Ouchi M. L. J. Baatsen E. C. Brady W.-L. Chan D. Chandan R. Feng C. Guo A. S. von der Heydt S. Hunter X. Li G. Lohmann K. H. Nisancioglu B. L. Otto-Bliesner W. R. Peltier C. Stepanek Z. Zhang 2020-08-01T00:00:00Z https://doi.org/10.5194/cp-16-1599-2020 https://doaj.org/article/113f2c2bcc8b4dddaa707dbd08a95e4b EN eng Copernicus Publications https://cp.copernicus.org/articles/16/1599/2020/cp-16-1599-2020.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-16-1599-2020 1814-9324 1814-9332 https://doaj.org/article/113f2c2bcc8b4dddaa707dbd08a95e4b Climate of the Past, Vol 16, Pp 1599-1615 (2020) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2020 ftdoajarticles https://doi.org/10.5194/cp-16-1599-2020 2022-12-31T02:36:39Z A range of future climate scenarios are projected for high atmospheric CO 2 concentrations, given uncertainties over future human actions as well as potential environmental and climatic feedbacks. The geological record offers an opportunity to understand climate system response to a range of forcings and feedbacks which operate over multiple temporal and spatial scales. Here, we examine a single interglacial during the late Pliocene (KM5c, ca. 3.205±0.01 Ma) when atmospheric CO 2 exceeded pre-industrial concentrations, but were similar to today and to the lowest emission scenarios for this century. As orbital forcing and continental configurations were almost identical to today, we are able to focus on equilibrium climate system response to modern and near-future CO 2 . Using proxy data from 32 sites, we demonstrate that global mean sea-surface temperatures were warmer than pre-industrial values, by ∼2.3 ∘ C for the combined proxy data (foraminifera Mg∕Ca and alkenones), or by ∼3.2 –3.4 ∘ C (alkenones only). Compared to the pre-industrial period, reduced meridional gradients and enhanced warming in the North Atlantic are consistently reconstructed. There is broad agreement between data and models at the global scale, with regional differences reflecting ocean circulation and/or proxy signals. An uneven distribution of proxy data in time and space does, however, add uncertainty to our anomaly calculations. The reconstructed global mean sea-surface temperature anomaly for KM5c is warmer than all but three of the PlioMIP2 model outputs, and the reconstructed North Atlantic data tend to align with the warmest KM5c model values. Our results demonstrate that even under low- CO 2 emission scenarios, surface ocean warming may be expected to exceed model projections and will be accentuated in the higher latitudes. Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Climate of the Past 16 4 1599 1615 |
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 E. L. McClymont H. L. Ford S. L. Ho J. C. Tindall A. M. Haywood M. Alonso-Garcia I. Bailey M. A. Berke K. Littler M. O. Patterson B. Petrick F. Peterse A. C. Ravelo B. Risebrobakken S. De Schepper G. E. A. Swann K. Thirumalai J. E. Tierney C. van der Weijst S. White A. Abe-Ouchi M. L. J. Baatsen E. C. Brady W.-L. Chan D. Chandan R. Feng C. Guo A. S. von der Heydt S. Hunter X. Li G. Lohmann K. H. Nisancioglu B. L. Otto-Bliesner W. R. Peltier C. Stepanek Z. Zhang Lessons from a high-CO 2 world: an ocean view from ∼ 3 million years ago |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
A range of future climate scenarios are projected for high atmospheric CO 2 concentrations, given uncertainties over future human actions as well as potential environmental and climatic feedbacks. The geological record offers an opportunity to understand climate system response to a range of forcings and feedbacks which operate over multiple temporal and spatial scales. Here, we examine a single interglacial during the late Pliocene (KM5c, ca. 3.205±0.01 Ma) when atmospheric CO 2 exceeded pre-industrial concentrations, but were similar to today and to the lowest emission scenarios for this century. As orbital forcing and continental configurations were almost identical to today, we are able to focus on equilibrium climate system response to modern and near-future CO 2 . Using proxy data from 32 sites, we demonstrate that global mean sea-surface temperatures were warmer than pre-industrial values, by ∼2.3 ∘ C for the combined proxy data (foraminifera Mg∕Ca and alkenones), or by ∼3.2 –3.4 ∘ C (alkenones only). Compared to the pre-industrial period, reduced meridional gradients and enhanced warming in the North Atlantic are consistently reconstructed. There is broad agreement between data and models at the global scale, with regional differences reflecting ocean circulation and/or proxy signals. An uneven distribution of proxy data in time and space does, however, add uncertainty to our anomaly calculations. The reconstructed global mean sea-surface temperature anomaly for KM5c is warmer than all but three of the PlioMIP2 model outputs, and the reconstructed North Atlantic data tend to align with the warmest KM5c model values. Our results demonstrate that even under low- CO 2 emission scenarios, surface ocean warming may be expected to exceed model projections and will be accentuated in the higher latitudes. |
format |
Article in Journal/Newspaper |
author |
E. L. McClymont H. L. Ford S. L. Ho J. C. Tindall A. M. Haywood M. Alonso-Garcia I. Bailey M. A. Berke K. Littler M. O. Patterson B. Petrick F. Peterse A. C. Ravelo B. Risebrobakken S. De Schepper G. E. A. Swann K. Thirumalai J. E. Tierney C. van der Weijst S. White A. Abe-Ouchi M. L. J. Baatsen E. C. Brady W.-L. Chan D. Chandan R. Feng C. Guo A. S. von der Heydt S. Hunter X. Li G. Lohmann K. H. Nisancioglu B. L. Otto-Bliesner W. R. Peltier C. Stepanek Z. Zhang |
author_facet |
E. L. McClymont H. L. Ford S. L. Ho J. C. Tindall A. M. Haywood M. Alonso-Garcia I. Bailey M. A. Berke K. Littler M. O. Patterson B. Petrick F. Peterse A. C. Ravelo B. Risebrobakken S. De Schepper G. E. A. Swann K. Thirumalai J. E. Tierney C. van der Weijst S. White A. Abe-Ouchi M. L. J. Baatsen E. C. Brady W.-L. Chan D. Chandan R. Feng C. Guo A. S. von der Heydt S. Hunter X. Li G. Lohmann K. H. Nisancioglu B. L. Otto-Bliesner W. R. Peltier C. Stepanek Z. Zhang |
author_sort |
E. L. McClymont |
title |
Lessons from a high-CO 2 world: an ocean view from ∼ 3 million years ago |
title_short |
Lessons from a high-CO 2 world: an ocean view from ∼ 3 million years ago |
title_full |
Lessons from a high-CO 2 world: an ocean view from ∼ 3 million years ago |
title_fullStr |
Lessons from a high-CO 2 world: an ocean view from ∼ 3 million years ago |
title_full_unstemmed |
Lessons from a high-CO 2 world: an ocean view from ∼ 3 million years ago |
title_sort |
lessons from a high-co 2 world: an ocean view from ∼ 3 million years ago |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/cp-16-1599-2020 https://doaj.org/article/113f2c2bcc8b4dddaa707dbd08a95e4b |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Climate of the Past, Vol 16, Pp 1599-1615 (2020) |
op_relation |
https://cp.copernicus.org/articles/16/1599/2020/cp-16-1599-2020.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-16-1599-2020 1814-9324 1814-9332 https://doaj.org/article/113f2c2bcc8b4dddaa707dbd08a95e4b |
op_doi |
https://doi.org/10.5194/cp-16-1599-2020 |
container_title |
Climate of the Past |
container_volume |
16 |
container_issue |
4 |
container_start_page |
1599 |
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1615 |
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1766129256829550592 |