Causes of ice age intensification across the Mid-Pleistocene Transition

Chalk, Thomas B.; Hain, Mathis P.; Foster, Gavin L.; Rohling, Eelco J.; Sexton, Philip F.; Badger, Marcus P. S.; Cherry, Soraya G.; Hasenfratz, Adam P.; Haug, Gerald H.; Jaccard, Samuel; Martínez-García, Alfredo; Pälike, Heiko; Pancost, Richard D.; Wilson, Paul A. (2017). Causes of ice age intensification across the Mid-Pleistocene Transition. Proceedings of the National Academy of Sciences of the United States of America - PNAS, 114(50), pp. 13114-13119. National Academy of Sciences NAS 10.1073/pnas.1702143114

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Conflicting sets of hypotheses highlight either the role of ice sheets or atmospheric carbon dioxide (CO2) in causing the increase in duration and severity of ice age cycles ∼1 Mya during the Mid-Pleistocene Transition (MPT). We document early MPT CO2 cycles that were smaller than during recent ice age cycles. Using model simulations, we attribute this to post-MPT increase in glacial-stage dustiness and its effect on Southern Ocean productivity. Detailed analysis reveals the importance of CO2 climate forcing as a powerful positive feedback that magnified MPT climate change originally triggered by a change in ice sheet dynamics. These findings offer insights into the close coupling of climate, oceans, and ice sheets within the Earth System.

Item Type:

Journal Article (Original Article)

Division/Institute:

10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)
08 Faculty of Science > Institute of Geological Sciences

UniBE Contributor:

Jaccard, Samuel

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

0027-8424

Publisher:

National Academy of Sciences NAS

Language:

English

Submitter:

Samuel Jaccard

Date Deposited:

12 Dec 2017 14:32

Last Modified:

25 Oct 2019 08:59

Publisher DOI:

10.1073/pnas.1702143114

BORIS DOI:

10.7892/boris.107874

URI:

https://boris.unibe.ch/id/eprint/107874

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