Long-term processes on the sun controlling trends in the solar irradiance and the Earth's surface temperature

The instrumental measurements and indirect data on the variation in solar a ctivity and irradiance are used to study the long-term trend in the Earth's global surface temperature. The found relationship between the variations in the solar magnetic fluxes and interplanetary magnetic field makes it pos sible to ascertain the tendency toward a variation in the total solar irrad iance and its impact on the Earth's global surface temperature. It is shown that the decrease in the global temperature in 1950-1970 may have been be due to a combined effect of the 90- and 210-year cycles of solar activity.