Lessons from a high-CO2 world: an ocean view from ∼ 3 million years ago
A range of future climate scenarios are projected for high atmospheric CO2 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...
Published in: | Climate of the Past |
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Copernicus Publications
2020
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Online Access: | https://doi.org/10.5194/cp-16-1599-2020 https://cp.copernicus.org/articles/16/1599/2020/cp-16-1599-2020.pdf https://doaj.org/article/113f2c2bcc8b4dddaa707dbd08a95e4b |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:113f2c2bcc8b4dddaa707dbd08a95e4b 2023-05-15T17:31:31+02:00 Lessons from a high-CO2 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 2020-08-01 https://doi.org/10.5194/cp-16-1599-2020 https://cp.copernicus.org/articles/16/1599/2020/cp-16-1599-2020.pdf https://doaj.org/article/113f2c2bcc8b4dddaa707dbd08a95e4b en eng Copernicus Publications doi:10.5194/cp-16-1599-2020 1814-9324 1814-9332 https://cp.copernicus.org/articles/16/1599/2020/cp-16-1599-2020.pdf https://doaj.org/article/113f2c2bcc8b4dddaa707dbd08a95e4b undefined Climate of the Past, Vol 16, Pp 1599-1615 (2020) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2020 fttriple https://doi.org/10.5194/cp-16-1599-2020 2023-01-22T18:19:13Z A range of future climate scenarios are projected for high atmospheric CO2 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 CO2 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 CO2. 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-CO2 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 Unknown Climate of the Past 16 4 1599 1615 |
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English |
topic |
envir geo |
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envir geo 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-CO2 world: an ocean view from ∼ 3 million years ago |
topic_facet |
envir geo |
description |
A range of future climate scenarios are projected for high atmospheric CO2 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 CO2 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 CO2. 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-CO2 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-CO2 world: an ocean view from ∼ 3 million years ago |
title_short |
Lessons from a high-CO2 world: an ocean view from ∼ 3 million years ago |
title_full |
Lessons from a high-CO2 world: an ocean view from ∼ 3 million years ago |
title_fullStr |
Lessons from a high-CO2 world: an ocean view from ∼ 3 million years ago |
title_full_unstemmed |
Lessons from a high-CO2 world: an ocean view from ∼ 3 million years ago |
title_sort |
lessons from a high-co2 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://cp.copernicus.org/articles/16/1599/2020/cp-16-1599-2020.pdf 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 |
doi:10.5194/cp-16-1599-2020 1814-9324 1814-9332 https://cp.copernicus.org/articles/16/1599/2020/cp-16-1599-2020.pdf https://doaj.org/article/113f2c2bcc8b4dddaa707dbd08a95e4b |
op_rights |
undefined |
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 |
op_container_end_page |
1615 |
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