EEMIAN CLIMATE FLUCTUATIONS OBSERVED IN A EUROPEAN POLLEN RECORD

RECENT ice-core data from Greenland(1,2) suggest that the climate during the last interglacial period (the Eemian) was more unstable than that of the Holocene (about 10,000 years ago to the present), being characterized in particular by a series of cold episodes each lasting about 70 to 750 years. Subsequent analysis of a second Greenland ice core(3,4), however, failed to corroborate the details of these Eemian climate fluctuations, a result that may be attributable to the effects of ice flow(4). To resolve this discrepancy, it is imperative to seek alternative sources of information about the Eemian climate. Here we present climate reconstructions from pollen data from the annually laminated Eemian lake-sediment record at Bispingen(5) and from the Eemian and Holocene peat records at La Grande Pile(6). The former record indicates that an initially warm period of 2,900 yr was followed by cooling and a series oi colder episodes, one of which had winter temperatures comparable to those at the end of the preceding cold stage. The latter records show greater climate instability during the Eemian than the Holocene. These results are in broad agreement with those from the GRIP ice core, but contrast both with the GISP2 core(3,4) and with recent high-resolution marine records from the North Atlantic(7,8).