GLACIALS INTERGLACIALS IN VOSTOK - CLIMATE AND GREENHOUSE GASES

The main message coming from long term ice core records may be the clo se association between changes in the atmospheric composition, and gla cial/interglacial changes. When compared with the preanthropogenic lev els, the Vostok paleorecords show lower CO2 and CH4 concentrations and significant variations in aerosols of both terrestrial and oceanic or igins. These changes, in particular those associated with greenhouse g ases, may account for about half of the temperature change over the la st climatic cycle. Although the interplay between the physical atmosph eric and oceanic systems and the biosphere has still to be clarified, this finding may provide a clue to help in the prediction of future gr eenhouse gases induced warming. In view of available paleodata, a warm ing of 3-4-degrees-C, at equilibrium, may be a realistic figure for a doubling of CO2 concentrations or its equivalent.