We have analyzed the geological and geomorphological materials about the early history of the relief formation in the region. We reviewed the evolution of the lakes in the south of Eastern Siberia in the late Pleistocene and Holocene. Chronological table shows the natural events of the late Pleistocene and Holocene Siberia. We performed cartographic modeling of ice sheets and lake basins in Eastern Siberia that appeared and disappeared over the past 180 thousand years as well as statistical modeling of climatic changes, taking into account variations in the Earth's orbital parameters (Milankovitch cycles), and solar activity. Special attention is devoted to the current state of the Baikal, we show the role of climatic changes in the variations of standing height of its level. Based on an analysis of historical materials and data of hydrological monitoring we have identified the periods and studied the dynamics of lake level fluctuations. In the end, we made an attempt to look into the near future conducting of the lake lens and the development of its exogenous processes. With the simple approach of mathematical statistics we made a preliminary forecast of geo-ecological state of the environment of the Baikal region up to 2050.