CLIMATE-CHANGE SCENARIOS - COMPARISONS OF PALEORECONSTRUCTIONS WITH RECENT TEMPERATURE-CHANGES

Paleoclimatic reconstructions for the Mid-Holocene, Eemian, Mid-Plioce ne and the Last Glacial Maximum are used to test the paleoanalog hypot hesis and develop a regional climate change scenario based on a linear scaling by one parameter - the mean Northern Hemispheric temperature change with respect to present, Delta T-NH. The empirical verification of the paleoanalog hypothesis is extended to a cold epoch for zonal m eans and to regional distributions of temperature in warm epochs. The best agreement among the scaled paleoanomalies from different epochs i s obtained if the seasonal temperature anomalies are scaled with Delta T-NH Of the corresponding season. Preferential areas are identified w here the paleoanalog hypothesis works relatively well; these areas coi ncide with the areas of the most pronounced warming. It is shown that the geographical distributions of the winter temperature anomalies ove r land in the paleodata are similar to those in the 1980-1990 period. From the three warm epochs, a paleodata-based scenario is deduced for the spatial distribution of temperature in a future climate, on the sc ale of continents. The conditions under which scenarios based on paleo data can be applied are discussed.