Researchers look for links among paleoclimate events



Several peculiar features appear in climate-related records at about 8000 years BP and are occasionally referred to as the 8-ka events. For example, paleolake data from intertropical Africa show a drop in water levels [e.g., Gasse and Van Campo, 1994], and the Antarctic Byrd ice-core record reveals a decrease in atmospheric CO2 of about 40 ppm [Neftel et al., 1988]. Similarly, detailed paleoceanographic studies in the northwest North Atlantic reveal a decrease in primary productivity and burial rates of biogenic carbonates at precisely 8000 years BP [Hillaire-Marcel et al., 1994], and the oxygen and deuterium values in Greenland ice show at least one sharp and short-lived decrease [Johnsen et al., 1992].