There are discussed the problems, which have the paramount importance for understanding of the nature of climate changes in XX century, and main physical processes, responsible for these changes. There are considered the possible role of solar activity in climate changes at the Earth in last and future. There are shown, physical mechanisms, which can provide for solar activity influence on the earth’s climate and weather reduces to the regulation of the energy flux coming from the Earth into space. The special attention is devoted to the mechanism of the solar activity effect on climate characteristics of troposphere by atmosphere electricity. The main causes, which lead to essential changes of the atmospheric electric field at the polar latitudes of the Earth in the time of the heliogeophysical disturbances (the solar cosmic rays fluxes of charged particles precipitating from the magnetosphere during the heliogeophysical disturbances the disturbed magnetosphere convection during the magnetic storms), are analyzed.