The study proposes to develop a diagnostic test for the verification and validation of the origin of warm episodes in Earth's history. An isotopic approach will be applied to the Cenozoic record to understand the mechanisms responsible for changes in the polar temperatures. Latitudinal oxygen-isotopic profiles from planktonic foraminifera will provide independent tests for the validity of changes in deep-water circulation and/or varying trace gas concentrations as mechanisms for the climatic shifts from the warm Eocene to the glacial-interglacial cycles of Plio-Pleistocene.
