Climatic fluctuations during the last glacial:
Driven by the study of long ice cores extracted from the Greenland and the Antarctic ice sheets, great advances have been made in the understanding of Earth’s climate system over the last decades. The Greenland ice cores, which partly reveal an annual layering, provide evidence for numerous short and abrupt climate changes especially for the last ice age (110,000 to 11,700 years before present).
The frequent Dansgaard-Oeschger cycles, which occur in close connection to the less frequent Heinrich events, contrast with the Younger Dryas as a single event.
The more frequently occurring cycles and events, in particular, which last from a few centuries up to 1,500 years, point to a close linkage between the atmospheric and the oceanic circulation which very likely controls the turning-on and turning-off of the Atlantic Meridional Overturning Circulation and the change between warm and cold phases.
Recognizing that drastic climate changes can occur within just a few decades, casts a new (worrisome) light on the extent and rapidity which future climate changes might have.