Measurements of solar irradiance, both bolometric and at various wavelengths, over the last two decades have established conclusively that the solar energy flux varies on a wide range of time scales, from minutes to the 11-year solar cycle. The major question is how the solar variability influences the terrestrial climate. The Solar Electromagnetic Radiation Study for Solar Cycle 22 (SOLERS22) is an international research program operating under the auspices of the Solar-Terrestrial Energy Program (STEP) Working Group 1: `The Sun as a Source of Energy and Disturbances'. STEP is sponsored by the Scientific Committee of Solar-Terrestrial Physics (SCOSTEP) of the International Council of Scientific Unions (ICSU).