Solar variability and climate change

The variability of solar radiation is a key factor influencing the terrestrial climate. In the last few decades space-borne measurements of solar irradiance have revealed evidence of a correlation with the 11 yr solar activity cycle, although the amplitude of these changes is too small to produce significant climate variation through direct heating. However, solar activity also shows variations on larger scales that are clearly related to several climate indicators. Various feedback mechanisms are currently being explored that could amplify different internal patterns of the climate system. Finally, the influence of solar variability on the terrestrial climate is compared to that originating from other natural and anthropogenic sources, and predictions for the future are outlined.