Insensitivity of alkenone carbon isotopes to atmospheric CO 2 at low to moderate CO 2 levels
Atmospheric p CO 2 is a critical component of the global carbon system and is considered to be the major control of Earth's past, present, and future climate. Accurate and precise reconstructions of its concentration through geological time are therefore crucial to our understanding of the Eart...
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ftdoajarticles:oai:doaj.org/article:05f1c31f9be14e5fadebfcb7cb3466bb 2023-05-15T16:38:58+02:00 Insensitivity of alkenone carbon isotopes to atmospheric CO 2 at low to moderate CO 2 levels M. P. S. Badger T. B. Chalk G. L. Foster P. R. Bown S. J. Gibbs P. F. Sexton D. N. Schmidt H. Pälike A. Mackensen R. D. Pancost 2019-03-01T00:00:00Z https://doi.org/10.5194/cp-15-539-2019 https://doaj.org/article/05f1c31f9be14e5fadebfcb7cb3466bb EN eng Copernicus Publications https://www.clim-past.net/15/539/2019/cp-15-539-2019.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-15-539-2019 1814-9324 1814-9332 https://doaj.org/article/05f1c31f9be14e5fadebfcb7cb3466bb Climate of the Past, Vol 15, Pp 539-554 (2019) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2019 ftdoajarticles https://doi.org/10.5194/cp-15-539-2019 2022-12-31T10:15:44Z Atmospheric p CO 2 is a critical component of the global carbon system and is considered to be the major control of Earth's past, present, and future climate. Accurate and precise reconstructions of its concentration through geological time are therefore crucial to our understanding of the Earth system. Ice core records document p CO 2 for the past 800 kyr, but at no point during this interval were CO 2 levels higher than today. Interpretation of older p CO 2 has been hampered by discrepancies during some time intervals between two of the main ocean-based proxy methods used to reconstruct p CO 2 : the carbon isotope fractionation that occurs during photosynthesis as recorded by haptophyte biomarkers (alkenones) and the boron isotope composition ( δ 11 B ) of foraminifer shells. Here, we present alkenone and δ 11 B -based p CO 2 reconstructions generated from the same samples from the Pliocene and across a Pleistocene glacial–interglacial cycle at Ocean Drilling Program (ODP) Site 999. We find a muted response to p CO 2 in the alkenone record compared to contemporaneous ice core and δ 11 B records, suggesting caution in the interpretation of alkenone-based records at low p CO 2 levels. This is possibly caused by the physiology of CO 2 uptake in the haptophytes. Our new understanding resolves some of the inconsistencies between the proxies and highlights that caution may be required when interpreting alkenone-based reconstructions of p CO 2 . Article in Journal/Newspaper ice core Directory of Open Access Journals: DOAJ Articles Climate of the Past 15 2 539 554 |
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Directory of Open Access Journals: DOAJ Articles |
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language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
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Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 M. P. S. Badger T. B. Chalk G. L. Foster P. R. Bown S. J. Gibbs P. F. Sexton D. N. Schmidt H. Pälike A. Mackensen R. D. Pancost Insensitivity of alkenone carbon isotopes to atmospheric CO 2 at low to moderate CO 2 levels |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Atmospheric p CO 2 is a critical component of the global carbon system and is considered to be the major control of Earth's past, present, and future climate. Accurate and precise reconstructions of its concentration through geological time are therefore crucial to our understanding of the Earth system. Ice core records document p CO 2 for the past 800 kyr, but at no point during this interval were CO 2 levels higher than today. Interpretation of older p CO 2 has been hampered by discrepancies during some time intervals between two of the main ocean-based proxy methods used to reconstruct p CO 2 : the carbon isotope fractionation that occurs during photosynthesis as recorded by haptophyte biomarkers (alkenones) and the boron isotope composition ( δ 11 B ) of foraminifer shells. Here, we present alkenone and δ 11 B -based p CO 2 reconstructions generated from the same samples from the Pliocene and across a Pleistocene glacial–interglacial cycle at Ocean Drilling Program (ODP) Site 999. We find a muted response to p CO 2 in the alkenone record compared to contemporaneous ice core and δ 11 B records, suggesting caution in the interpretation of alkenone-based records at low p CO 2 levels. This is possibly caused by the physiology of CO 2 uptake in the haptophytes. Our new understanding resolves some of the inconsistencies between the proxies and highlights that caution may be required when interpreting alkenone-based reconstructions of p CO 2 . |
format |
Article in Journal/Newspaper |
author |
M. P. S. Badger T. B. Chalk G. L. Foster P. R. Bown S. J. Gibbs P. F. Sexton D. N. Schmidt H. Pälike A. Mackensen R. D. Pancost |
author_facet |
M. P. S. Badger T. B. Chalk G. L. Foster P. R. Bown S. J. Gibbs P. F. Sexton D. N. Schmidt H. Pälike A. Mackensen R. D. Pancost |
author_sort |
M. P. S. Badger |
title |
Insensitivity of alkenone carbon isotopes to atmospheric CO 2 at low to moderate CO 2 levels |
title_short |
Insensitivity of alkenone carbon isotopes to atmospheric CO 2 at low to moderate CO 2 levels |
title_full |
Insensitivity of alkenone carbon isotopes to atmospheric CO 2 at low to moderate CO 2 levels |
title_fullStr |
Insensitivity of alkenone carbon isotopes to atmospheric CO 2 at low to moderate CO 2 levels |
title_full_unstemmed |
Insensitivity of alkenone carbon isotopes to atmospheric CO 2 at low to moderate CO 2 levels |
title_sort |
insensitivity of alkenone carbon isotopes to atmospheric co 2 at low to moderate co 2 levels |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/cp-15-539-2019 https://doaj.org/article/05f1c31f9be14e5fadebfcb7cb3466bb |
genre |
ice core |
genre_facet |
ice core |
op_source |
Climate of the Past, Vol 15, Pp 539-554 (2019) |
op_relation |
https://www.clim-past.net/15/539/2019/cp-15-539-2019.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-15-539-2019 1814-9324 1814-9332 https://doaj.org/article/05f1c31f9be14e5fadebfcb7cb3466bb |
op_doi |
https://doi.org/10.5194/cp-15-539-2019 |
container_title |
Climate of the Past |
container_volume |
15 |
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2 |
container_start_page |
539 |
op_container_end_page |
554 |
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1766029336464326656 |