Questions about climate change are commanding societal as well as scientific interest. Climate records embedded in sediment cores from lakes and oceans, in coral reefs, and in polar ice cores are providing information about natural climatic variations and about linkages between the ocean, atmosphere, and cryosphere. Profound changes that occurred on submillennial timescales are superimposed on glacial-to-interglacial shifts in climate state. For example, marine sediment records reveal that abrupt oscillations in sea surface temperature (SSl), approaching the magnitude of glacial-interglacial transitions, occurred repeatedly between 65 and 11 kyr ago (i.e., between marine oxygen isotope stage 3 and the early Holocene). Indeed, the oceans are intimately linked with climate through thermohaline circulation. An entire subdiscipline, paleoceanography, is devoted to gleaning pertinent information from these sedimentary records.