Interglacial instability of North Atlantic Deep Water ventilation

Atlantic Meridional Overturning Circulation (AMOC) and the related process of North Atlantic Deep Water (NADW) have been thought to be stable during warm, interglacial periods. Galaasen et al. report that episodes of reduced NADW over the past 500,000 years actually have been relatively common and occasionally long-lasting features of interglacials and that they can occur independently of the catastrophic freshwater outburst floods normally thought to be their cause (see the Perspective by Stocker). This discovery implies that large NADW disruptions might be more likely than we have assumed in the warmer climate of the future. Science , this issue p. [1485][1]; see also p. [1425][2] Disrupting North Atlantic Deep Water (NADW) ventilation is a key concern in climate projections. We use