LATE QUATERNARY TEMPERATURE-CHANGES SEEN IN WORLD-WIDE CONTINENTAL HEAT-FLOW MEASUREMENTS

Analysis of more than six thousand continental heat flow measurements as a function of depth has yielded a reconstruction of a global averag e ground surface temperature history over the last 20,000 years. The e arly to mid-Holocene appears as a relatively long warm interval some 0 .2-0.6 K above present-day temperatures, the culmination of the warmin g that followed the end of the last glaciation. Temperatures were also warmer than present 500-1,000 years ago, but then cooled to a minimum some 0.2-0.7 K below present about 200 years ago. Although temperatur e variations in this type of reconstruction are highly smoothed, the r esults clearly resemble the broad outlines of late Quaternary climate changes suggested by proxies.