Modeling the glacial-interglacial cycles in response to astronomical and CO2 forcings

Several models were designed and many modeling experiments were performed to validate the hypothesis that long-term climate change is driven by change in the solar energy received at the top of the atmosphere and that the astronomical parameters describing the orbit and inclination of the Earth are a pacemaker of the climate. Earth system model of intermediate complexity (EMICs) were used to simulate long-term variations of the climate. They are forced by the time variation in the distribution of the insolation and by scenario of atmospheric CO2 concentration. Here we will discuss the ability of several of them to simulate successfully the entrance into glaciation around 2.75 Myr BP, the late Pliocene-early Pleistocene 41-kyr cycle. the emergence of the 100-kyr cycle around 900 kyr BP and the glacial-interglacial cycles of the middle and late Pleistocene. We will also present some projections for the future climate.