Toward a Cenozoic history of atmospheric CO 2

• Published in: Science
• Main Authors: Hönisch, Bärbel, Royer, Dana L., Breecker, Daniel O., Polissar, Pratigya J., Bowen, Gabriel J., Henehan, Michael J., Cui, Ying, Steinthorsdottir, Margret, McElwain, Jennifer C., Kohn, Matthew J., Pearson, Ann, Phelps, Samuel R., Uno, Kevin T., Ridgwell, Andy, Anagnostou, Eleni, Austermann, Jacqueline, Badger, Marcus P. S., Barclay, Richard S., Bijl, Peter K., Chalk, Thomas B., Scotese, Christopher R., de la Vega, Elwyn, DeConto, Robert M., Dyez, Kelsey A., Ferrini, Vicki, Franks, Peter J., Giulivi, Claudia F., Gutjahr, Marcus, Harper, Dustin T., Haynes, Laura L., Huber, Matthew, Snell, Kathryn E., Keisling, Benjamin A., Konrad, Wilfried, Lowenstein, Tim K., Malinverno, Alberto, Guillermic, Maxence, Mejía, Luz María, Milligan, Joseph N., Morton, John J., Nordt, Lee, Whiteford, Ross, Roth-Nebelsick, Anita, Rugenstein, Jeremy K. C., Schaller, Morgan F., Sheldon, Nathan D., Sosdian, Sindia, Wilkes, Elise B., Witkowski, Caitlyn R., Zhang, Yi Ge, Anderson, Lloyd, Beerling, David J., Bolton, Clara, Cerling, Thure E., Cotton, Jennifer M., Da, Jiawei, Ekart, Douglas D., Foster, Gavin L., Greenwood, David R., Hyland, Ethan G., Jagniecki, Elliot A., Jasper, John P., Kowalczyk, Jennifer B., Kunzmann, Lutz, Kürschner, Wolfram M., Lawrence, Charles E., Lear, Caroline H., Martínez-Botí, Miguel A., Maxbauer, Daniel P., Montagna, Paolo, Naafs, B. David A., Rae, James W. B., Raitzsch, Markus, Retallack, Gregory J., Ring, Simon J., Seki, Osamu, Sepúlveda, Julio, Sinha, Ashish, Tesfamichael, Tekie F., Tripati, Aradhna, van der Burgh, Johan, Yu, Jimin, Zachos, James C., Zhang, Laiming
• Format: Article in Journal/Newspaper
• Language: English
• Published: AAAS (American Association for the Advancement of Science) 2023
• Subjects: ice core
• Online Access: https://oceanrep.geomar.de/id/eprint/59588/; https://oceanrep.geomar.de/id/eprint/59588/2/science.adi5177_sm.pdf; https://oceanrep.geomar.de/id/eprint/59588/3/science.adi5177.pdf; https://doi.org/10.1126/science.adi5177

The geological record encodes the relationship between climate and atmospheric carbon dioxide (CO 2 ) over long and short timescales, as well as potential drivers of evolutionary transitions. However, reconstructing CO 2 beyond direct measurements requires the use of paleoproxies and herein lies the challenge, as proxies differ in their assumptions, degree of understanding, and even reconstructed values. In this study, we critically evaluated, categorized, and integrated available proxies to create a high-fidelity and transparently constructed atmospheric CO 2 record spanning the past 66 million years. This newly constructed record provides clearer evidence for higher Earth system sensitivity in the past and for the role of CO 2 thresholds in biological and cryosphere evolution. Editor’s summary The concentration of atmospheric carbon dioxide is a fundamental driver of climate, but its value is difficult to determine for times older than the roughly 800,000 years for which ice core records are available. The Cenozoic Carbon dioxide Proxy Integration Project (CenCO2PIP) Consortium assessed a comprehensive collection of proxy determinations to define the atmospheric carbon dioxide record for the past 66 million years. This synthesis provides the most complete record yet available and will help to better establish the role of carbon dioxide in climate, biological, and cryosphere evolution. — H. Jesse Smith