Rather than questioning the primary role of the
atmospheric CO2, our modelling results allow us to put forward that the
atmospheric CO2 is not the whole story and that, owing to the overwhelming effect and interplay between the paleogeography, the water cycle and the
seasonal response, the climate system may undergo subtle climatic changes (as the 4 °C global warming simulated here between the Aptian and the Maastrichtian runs).
Warming of sea surface temperatures and alteration of ocean chemistry associated with anthropogenic increases in
atmospheric carbon dioxide will have profound consequences for a broad range of species, but the potential for
seasonal variation to modify species and ecosystem
responses to these stressors has received little attention.