HOLOCENE CLIMATIC INSTABILITY - A PROMINENT, WIDESPREAD EVENT 8200-YRAGO

The most prominent Holocene climatic event in Greenland ice-core proxi es, with approximately half the amplitude of the Younger Dryas, occurr ed similar to 8000 to 8400 yr ago. This Holocene event affected region s well beyond the North Atlantic basin, as shown by synchronous increa ses in windblown chemical indicators together with a significant decre ase in methane. Widespread proxy records from the tropics to the north polar regions show a short-lived cool, dry, or windy event of similar age. The spatial pattern of terrestrial and marine changes is similar to that of the Younger Dryas event, suggesting a role for North Atlan tic thermohaline circulation. Possible forcings identified thus far fo r this Holocene event are small, consistent with recent model results indicating high sensitivity and strong linkages in the climatic system .