New research published in Nature shows how changes in ocean circulation can cause rapid changes in global climate and CO2. The research illustrates the mechanism for "deglaciation" which begins with a warming-induced slowdown of North Atlantic ocean circulation, and then quickly induces warming and CO2 release from the Southern Ocean. The resulting warming-circulation-CO2 feedback can literally end an Ice Age in a few thousand years. As Dr. Jeff Severinghuas writes in a commentary article in Nature:
"There are implications of potential relevance to future climate. First, it is difficult to explain the demise of the ice sheets without the added heating from CO2, confirming that this gas has killed ice sheets in the past and may do so again. Second, the predicted slowdown of Atlantic circulation in the coming century may cause an additional release of CO2 from the ocean that adds to the human-made CO2, a biogeochemical feedback that is not considered in current climate projections.