Glacial cycles and carbon dioxide: A conceptual model

Abstract

The correlation between Antarctic temperature and atmospheric carbon dioxide concentration is a key feature of Quaternary climate cycles. The cycle is characterised by pronounced temporal asymmetry; with rapid increase in both temperature and CO2 at the glacial termination. Here I compare observed climate cycles with results from a simple model which predicts the evolution of global temperature and carbon dioxide over the glacial-interglacial cycle. The model includes a term which parameterises deep ocean release of CO2 in response to warming, and thereby amplifies the glacial cycle. In this model, temperature rises lead CO2 increases at the glacial termination, but it is the feedback between these two quantities that drives the abrupt warming during the transition from glacial to interglacial period.