On greenhouse and icehouse climate regimes over the Phanerozoic

Throughout the Phanerozoic and more, the Earth has experienced cold and hot periods, which are typically associated with long-lasting (hundreds of million years, Ma) greenhouse and icehouse climate regimes. Now, most published sea-level curves report two main maxima in the Cretaceous and Ordovician superimposed on a multitude of short-term fluctuations. The big humps are shown to be predominantly the results of the plate tectonic configuration, not icehouse and greenhouse regimes, suggesting that the small oscillations are related to continental ice variations. From this point of view, it can be inferred that polar ice caps are present almost all the time, and climate regime changes appear much more frequent and shorter than usually considered and are not well-documented from glaciogenic deposits. Relying on short-term oscillations, the volume of continental ice can be retrieved over the Phanerozoic.