Abrupt CO2 release to the atmosphere under glacial and early interglacial climate conditions

Nehrbass-Ahles, C. and Shin, J. and Schmitt, J. and Bereiter, B. and Joos, F. and Schilt, A. and Schmidely, L. and Silva, L. and Teste, G. and Grilli, R. and Chappellaz, J. and Hodell, D. and Fischer, H. and Stocker, T. F. (2020) Abrupt CO2 release to the atmosphere under glacial and early interglacial climate conditions. Science, 369 (6506). pp. 1000-1005. ISSN 0036-8075 (print), 1095-9203 (online) DOI https://doi.org/10.1126/science.aay8178

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Abstract

Bursts of carbon dioxide, released into the atmosphere and occurring on centennial time scales, were seen during the cold periods of the last glacial cycle but not in older or warmer conditions. Nehrbass-Ahles et al. present a record of atmospheric carbon dioxide concentrations retrieved from the European Project for Ice Coring in Antarctica Dome C ice core showing that these carbon dioxide jumps occurred during both cold and warm periods between 330,000 and 450,000 years ago. They relate these pulses to disruptions of the Atlantic meridional overturning circulation caused by freshwater discharge from ice sheets. Such rapid carbon dioxide increases could occur in the future if global warming also disrupts this ocean circulation pattern.Science, this issue p. 1000Pulse-like carbon dioxide release to the atmosphere on centennial time scales has only been identified for the most recent glacial and deglacial periods and is thought to be absent during warmer climate conditions. Here, we present a high-resolution carbon dioxide record from 330,000 to 450,000 years before present, revealing pronounced carbon dioxide jumps (CDJ) under cold and warm climate conditions. CDJ come in two varieties that we attribute to invigoration or weakening of the Atlantic meridional overturning circulation (AMOC) and associated northward and southward shifts of the intertropical convergence zone, respectively. We find that CDJ are pervasive features of the carbon cycle that can occur during interglacial climate conditions if land ice masses are sufficiently extended to be able to disturb the AMOC by freshwater input.

Item Type:	Article
Uncontrolled Keywords:	2020AREP; IA76
Subjects:	01 - Climate Change and Earth-Ocean Atmosphere Systems
Divisions:	01 - Climate Change and Earth-Ocean Atmosphere Systems
Journal or Publication Title:	Science
Volume:	369
Page Range:	pp. 1000-1005
Identification Number:	https://doi.org/10.1126/science.aay8178
Depositing User:	Sarah Humbert
Date Deposited:	25 Aug 2020 17:10
Last Modified:	25 Aug 2020 17:10
URI:	http://eprints.esc.cam.ac.uk/id/eprint/4867

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