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 approximately 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 (super 18) O values, and Mg/Ca-delta (super 18) O estimates. Statistical analysis indicates that it is likely (68% confidence interval) that peak sea level was 22 + or - 5 m higher than modern, and extremely likely (95%) that it was 22 + or - 10 m higher than modern. Benthic foraminiferal delta (super 18) O 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.