Rapid Climate Change during the Cenozoic

Our knowledge of Cenozoic climate has been established primarily from studies of marine sediment archives. The application of sophisticated geochemical proxies to these archives has provided detailed information on various paleoclimate parameters including ocean temperature and ice-volume, as well as key forcing factors such as pCO₂. This paleoclimate database has proved extremely useful for quantitatively assessing the sensitivity of Earth's climate to a wide range of forcing including changes in continental configurations, orbital forcing, and greenhouse gas concentrations.

In this presentation, we review some of the key developments, both theoretical and observational, in our understanding of climate change during the early Cenozoic focusing on the rapid transitions, either warming or cooling. We consider whether these rapid transitions involved physical thresholds in the climate system, and explore the potential contributions of feedbacks, both physical and biogeochemical, in amplifying or damping the climatic changes during these transitions.