Earth's Climate History, Ice Sheets, and Sea Level Over Last Four Million Years

Lead PI: Dr. Maureen E. Raymo

Unit Affiliation: Biology and Paleo Environment, Lamont-Doherty Earth Observatory (LDEO)

August 2011 - August 2012
Project Type: Research

DESCRIPTION: The maximum elevation of the mid-Pliocene sea level is a fundamental question in the climate community. In this ABR the PI will investigate the mid-Pliocene climatic optimum and Antarctic ice volume history. This period is the last time in Earth's history when the climate was consistently warmer than the Holocene (by as much as 3 degrees above present) and CO2 levels on the order of 350-370 ppm (less than today). The sea-level change associated with this optimum are only a point of conjecture. The PI has set three tasks for herself: 1) Collect all published geological/geochemical studies of the Pliocene and write a review paper; 2) Develop a Wiki site that aims to educate students and scientists about this largely unresolved climate problem; 3) A lab based study using the Mg/Ca thermometry to isolate temperature and ocean isotopic compositional changes in a deep sea delta O18 record fro ODP site 625.

Broader impacts of the study include the development of a Wiki site for the Pliocene which could be a model for such future sites for other geological topics as well. It is hoped that the site will serve to promote research among the global community of Earth scientists. It could enhance partnerships among scientists from less developed countries through on-line sharing of data and information.

OUTCOMES: Completed an assessment of glacial-isostatic adjustment to ancient shorelines. Published a paper in Nature Geoscience. Project has been significantly expanded.


National Science Foundation (NSF)





Raymo, M. , P Hearty, R. DeConto, M. O'Leary, H. Dowsett, M. Robinson, J. Mitrovica. "PLIOMAX: Pliocene maximum sea level project," PAGES News, v.17, 2009, p. 58.

Raymo, M. E., J. X. Mitrovica, M. J. O'Leary, R. M. DeConto, and P. J. Hearty,. "Departures from eustasy in Pliocene sea-level records,," Nature Geoscience, 2011. doi:doi:10.1038/NGEO1118

Lisiecki, L. and M. E. Raymo. "Diachronous benthic d18O responses during late Pleistocene terminations," Paleaoceanography, v.24, 2009. doi:doi:10.1029/2009PA001732.

Raymo, M. E. and J. X. Mitrovica. "Collapse of polar ice sheets during the stage 11 interglacial," Nature, v.483, 2012, p. 453. doi:10.1038/nature10891


paleoclimate ice sheets biology and paleo environment sea level pliocene