Eocene greenhouse climate revealed by coupled clumped isotope-Mg/Ca thermometry
Abstract
Reconstructing the degree of warming during geological periods of elevated CO2 provides a way of testing our understanding of the Earth system and the accuracy of climate models. We present accurate estimates of tropical sea-surface temperatures (SST) and seawater chemistry during the Eocene (56-34 Ma before present, CO2 >560 ppm). This latter dataset enables us to reinterpret a large amount of existing proxy data. We find that tropical SST are characterized by a modest warming in response to CO2. Coupling these data to a conservative estimate of high-latitude warming demonstrates that most climate simulations do not capture the degree of Eocene polar amplification.
- Publication:
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Proceedings of the National Academy of Science
- Pub Date:
- February 2018
- DOI:
- Bibcode:
- 2018PNAS..115.1174E