Middle Eocene greenhouse warming facilitated by diminished weathering feedback.

Autor: van der Ploeg R; Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, 3584 CB, The Netherlands. R.vanderPloeg@uu.nl., Selby D; Department of Earth Sciences, Durham University, Durham, DH1 3LE, UK.; State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Resources, China University of Geosciences, Wuhan, 430074, Hubei, China., Cramwinckel MJ; Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, 3584 CB, The Netherlands., Li Y; Department of Geology and Geophysics, Yale University, New Haven, Connecticut, 06511, USA.; State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 10029, China., Bohaty SM; Ocean and Earth Science, National Oceanography Centre, University of Southampton Waterfront Campus, Southampton, SO14 3ZH, UK., Middelburg JJ; Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, 3584 CB, The Netherlands., Sluijs A; Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, 3584 CB, The Netherlands.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2018 Jul 23; Vol. 9 (1), pp. 2877. Date of Electronic Publication: 2018 Jul 23.
DOI: 10.1038/s41467-018-05104-9
Abstrakt: The Middle Eocene Climatic Optimum (MECO) represents a ~500-kyr period of global warming ~40 million years ago and is associated with a rise in atmospheric CO 2 concentrations, but the cause of this CO 2 rise remains enigmatic. Here we show, based on osmium isotope ratios ( 187 Os/ 188 Os) of marine sediments and published records of the carbonate compensation depth (CCD), that the continental silicate weathering response to the inferred CO 2 rise and warming was strongly diminished during the MECO-in contrast to expectations from the silicate weathering thermostat hypothesis. We surmise that global early and middle Eocene warmth gradually diminished the weatherability of continental rocks and hence the strength of the silicate weathering feedback, allowing for the prolonged accumulation of volcanic CO 2 in the oceans and atmosphere during the MECO. These results are supported by carbon cycle modeling simulations, which highlight the fundamental importance of a variable weathering feedback strength in climate and carbon cycle interactions in Earth's history.
Databáze: MEDLINE
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