Glacial cycles and carbon dioxide: A conceptual model

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.