Bush, M. B., M. Stute, M.-P. Ledru, H. Behling, P. A. Colinvaux, P. E. De Oliveira, E. C. Grimm, H. Hooghiemstra, S. Haberle, B. W. Leyden, M.-L. Salgado-Labouriau, R. Webb, 2001: Paleotemperature estimates for the lowland Americas between 30°S and 30°N at the last glacial maximum. In Interhemispheric Climate Linkages, V. Markgraf (Ed.), Academic Press, 293-306.


ABSTRACT

Paleoecological data for the lowland neotropics and subtropics between 30°N and 30°S are compiled to provide an overview of climatic conditions at the time of the last glacial maximum. A clear consensus emerges from both fossil pollen and noble gas proxies that lowland climates were ca 5°C cooler at 18,000 14C B.P. than they are now. In many records, this period appears to have been the coldest portion of the last glacial episode, but in others, periods between 33,000 and 30,000 14C B.P. and between 14,000 and 12,000 14C B.P. appear to have been somewhat cooler. These data suggest that while there was a general cooling across the lowlands, local climates were subject to periodic warmer and cooler events. More data are needed to determine the effects of such climatic oscillations on biotic assemblages in the lowland neotropics and subtropics.

Within the community of paleoclimatologists, considerable debate continues regarding the amount of precipitation reduction at the last glacial maximum. Some drying is probable, but more data and improved methods to quantify paleoprecipitation are needed to resolve the current debate.