Glacial cooling and climate sensitivity revisited
The Last Glacial Maximum (LGM), one of the best studied palaeoclimatic intervals, offers an excellent opportunity to investigate how the climate system responds to changes in greenhouse gases and the cryosphere. Previous work has sought to constrain the magnitude and pattern of glacial cooling from...
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Online Access: | https://doi.org/10.1038/s41586-020-2617-x |
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ftncar:oai:drupal-site.org:articles_23611 2023-10-01T03:56:38+02:00 Glacial cooling and climate sensitivity revisited Tierney, Jessica E. (author) Zhu, Jiang (author) King, Jonathan (author) Malevich, Steven B. (author) Hakim, Gregory J. (author) Poulsen, Christopher J. (author) 2020-08-27 https://doi.org/10.1038/s41586-020-2617-x en eng Nature--Nature--0028-0836--1476-4687 Cheyenne: SGI ICE XA Cluster--10.5065/D6RX99HX articles:23611 ark:/85065/d7pc35nv doi:10.1038/s41586-020-2617-x Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. article Text 2020 ftncar https://doi.org/10.1038/s41586-020-2617-x 2023-09-04T18:18:14Z The Last Glacial Maximum (LGM), one of the best studied palaeoclimatic intervals, offers an excellent opportunity to investigate how the climate system responds to changes in greenhouse gases and the cryosphere. Previous work has sought to constrain the magnitude and pattern of glacial cooling from palaeothermometers(1,2), but the uneven distribution of the proxies, as well as their uncertainties, has challenged the construction of a full-field view of the LGM climate state. Here we combine a large collection of geochemical proxies for sea surface temperature with an isotope-enabled climate model ensemble to produce a field reconstruction of LGM temperatures using data assimilation. The reconstruction is validated with withheld proxies as well as independent ice core and speleothem delta O-18 measurements. Our assimilated product provides a constraint on global mean LGM cooling of -6.1 degrees Celsius (95 per cent confidence interval: -6.5 to -5.7 degrees Celsius). Given assumptions concerning the radiative forcing of greenhouse gases, ice sheets and mineral dust aerosols, this cooling translates to an equilibrium climate sensitivity of 3.4 degrees Celsius (2.4-4.5 degrees Celsius), a value that is higher than previous LGM-based estimates but consistent with the traditional consensus range of 2-4.5 degrees Celsius(3,4). Article in Journal/Newspaper ice core OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Nature 584 7822 569 573 |
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OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
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ftncar |
language |
English |
description |
The Last Glacial Maximum (LGM), one of the best studied palaeoclimatic intervals, offers an excellent opportunity to investigate how the climate system responds to changes in greenhouse gases and the cryosphere. Previous work has sought to constrain the magnitude and pattern of glacial cooling from palaeothermometers(1,2), but the uneven distribution of the proxies, as well as their uncertainties, has challenged the construction of a full-field view of the LGM climate state. Here we combine a large collection of geochemical proxies for sea surface temperature with an isotope-enabled climate model ensemble to produce a field reconstruction of LGM temperatures using data assimilation. The reconstruction is validated with withheld proxies as well as independent ice core and speleothem delta O-18 measurements. Our assimilated product provides a constraint on global mean LGM cooling of -6.1 degrees Celsius (95 per cent confidence interval: -6.5 to -5.7 degrees Celsius). Given assumptions concerning the radiative forcing of greenhouse gases, ice sheets and mineral dust aerosols, this cooling translates to an equilibrium climate sensitivity of 3.4 degrees Celsius (2.4-4.5 degrees Celsius), a value that is higher than previous LGM-based estimates but consistent with the traditional consensus range of 2-4.5 degrees Celsius(3,4). |
author2 |
Tierney, Jessica E. (author) Zhu, Jiang (author) King, Jonathan (author) Malevich, Steven B. (author) Hakim, Gregory J. (author) Poulsen, Christopher J. (author) |
format |
Article in Journal/Newspaper |
title |
Glacial cooling and climate sensitivity revisited |
spellingShingle |
Glacial cooling and climate sensitivity revisited |
title_short |
Glacial cooling and climate sensitivity revisited |
title_full |
Glacial cooling and climate sensitivity revisited |
title_fullStr |
Glacial cooling and climate sensitivity revisited |
title_full_unstemmed |
Glacial cooling and climate sensitivity revisited |
title_sort |
glacial cooling and climate sensitivity revisited |
publishDate |
2020 |
url |
https://doi.org/10.1038/s41586-020-2617-x |
genre |
ice core |
genre_facet |
ice core |
op_relation |
Nature--Nature--0028-0836--1476-4687 Cheyenne: SGI ICE XA Cluster--10.5065/D6RX99HX articles:23611 ark:/85065/d7pc35nv doi:10.1038/s41586-020-2617-x |
op_rights |
Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
op_doi |
https://doi.org/10.1038/s41586-020-2617-x |
container_title |
Nature |
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584 |
container_issue |
7822 |
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569 |
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573 |
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1778526655126437888 |