High tide of the warm Pliocene: Implications of global sea level for Antarctic deglaciation

We obtained global sea-level (eustatic) estimates with a peak of similar to 22 m higher than present for the Pliocene interval 2.7-3.2 Ma from backstripping in Virginia (United States), New Zealand, and Enewetak Atoll (north Pacific Ocean), benthic foraminiferal delta O-18 values, and Mg/Ca-delta O-18 estimates. Statistical analysis indicates that it is likely (68% confidence interval) that peak sea level was 22 +/- 5 m higher than modern, and extremely likely (95%) that it was 22 +/- 10 m higher than modern. Benthic foraminiferal delta O-18 values appear to require that the peak was <20-21 m. Our estimates imply loss of the equivalent of the Greenland and West Antarctic ice sheets, and some volume loss from the East Antarctic Ice Sheet, and address the long-standing controversy concerning the Pliocene stability of the East Antarctic Ice Sheet.