资源环境科技发展态势分析平台

The Dansgaard-Oeschger cycles of the last glacial period are attributed to changes in the Atlantic overturning circulation. An outstanding problem is whether these are driven by a self-sustained oscillation of the Earth system, by stochastic perturbations in terms of freshwater discharges into the ocean or extremes in atmospheric dynamics, or by another driver. Their complex temporal pattern suggests that the transitions in between cold (stadial) and warm (interstadial) phases are noise induced and thus unpredictable. Here, evidence is presented that this is unlikely because the transitions can be predicted to a certain degree within a few hundred years after stadial onset from consistent trends in Greenland dust proxies. These trends could be a manifestation of the climate system reorganizing at a specific timescale. What physically determines these highly variable timescales remains unexplained. Nevertheless, constraining the dynamics underlying these abrupt climate changes is an important step to uncover their causes.