A joint project of SCOR and PAGES whose primary goals are to quantify climate and chemical variability of the ocean on time scales of oceanic and cryospheric processes, determine the sensitivity of the ocean to identified internal and external forcing functions, and determine the ocean's role in controlling atmospheric CO2. A global programme including at least 30 dedicated oceanographic expeditions from 1994–2004 is planned to answer questions concerning how changes in ocean properties controlled the evolution of global heat transfer through to deep and surface ocean and so modified the climate, how changes in ocean circulation, chemistry, and biological activity have interacted to generate the observed record of pCO2 over the past 300 Ka, and how close continental climate has been linked to ocean surface and deep water properties.