A Pervasive Millennial-Scale Cycle in North Atlantic Holocene and Glacial Climates

TLDR

North Atlantic deep‑sea cores show that abrupt climate shifts punctuated the otherwise stable Holocene. During each event, cool, ice‑bearing waters from north of Iceland were advected as far south as Britain, atmospheric circulation above Greenland changed abruptly, and the timing of Holocene and last‑glacial shifts matched a ~1470‑year cycle, indicating that the Holocene events are the latest expression of a pervasive millennial‑scale climate cycle amplified by the North Atlantic thermohaline circulation.

Abstract

Evidence from North Atlantic deep sea cores reveals that abrupt shifts punctuated what is conventionally thought to have been a relatively stable Holocene climate. During each of these episodes, cool, ice-bearing waters from north of Iceland were advected as far south as the latitude of Britain. At about the same times, the atmospheric circulation above Greenland changed abruptly. Pacings of the Holocene events and of abrupt climate shifts during the last glaciation are statistically the same; together, they make up a series of climate shifts with a cyclicity close to 1470 ± 500 years. The Holocene events, therefore, appear to be the most recent manifestation of a pervasive millennial-scale climate cycle operating independently of the glacial-interglacial climate state. Amplification of the cycle during the last glaciation may have been linked to the North Atlantic's thermohaline circulation.