Natural and Climatic Changes in West Siberia During the First Third of the Next Century

A prognostic scenario of natural and climatic changes in West Siberia is tentatively proposed for 2025, when CO2 concentration in the atmosphere is expected to increase, due to the anthropogenic factor, to the values typical of the climatic optimum of the last, Kazantsevo, interglacial period. This scenario is supported by paleogeographic reconstructions of the above optimum according to the principle of paleoclimatic analogies. Identification and interregional correlation of the time frame corresponding to the Kazantsevo optimum have been made on a chronostratigraphical basis and detailed stratigraphical subdivision of the Kazantsevo stratum. The paleoclimatic characteristic of the optimum is supported by palynological and other data. Climatic diagrams and schematic maps have been compiled for vegetation, soil cover, and annual temperatures. Deviations of temperatures of the Kazantsevo optimum from modern values have been calculated. A quite stable tendency toward warmer winter seasons is predicted leading to general warming of the Siberian climate in the first third of the 21st century.