Rapid Reductions in North Atlantic Deep Water During the Peak of the Last Interglacial Period

Limited Stability Deep ocean circulation is thought to be stable during warm, interglacial periods. Galaasen et al. (p. 1129 , published online 20 February) constructed a highly resolved record of North Atlantic Deep Water production during the last interglacial period, around 128,000 to 116,000 years ago. The findings reveal large, centennial-scale reductions—in contrast to the prevailing paradigm. These changes occurred in an ocean warmer than that of today, but in a temperature regime similar to that expected because of global warming, raising the possibility that future ocean circulation, regional climate, and CO 2 sequestration pathways could be impacted.