The Physics Behind Biogeochemical Glacial-Interglacial CO2 Variations

The atmospheric concentration of CO2 has undergone significant and fairly regular changes on a time scale of 100 kyr during the at least last four glacial-interglacial cycles. We present a novel coupled physical-biogeochemical mechanism for these variations. Unlike previous studies, we do not arbitrarily specify the behavior of the physical climate system in order to invoke a biogeochemical mechanism. We also explain the continuous time evolution between glacial and interglacial states rather than treat them as two steady states, and are able to model explicitly for the first time the amplification of the glacial-interglacial variability of the physical climate system by the ocean biogeochemistry.