A Stellar View on Solar Variations and Climate

Abstract

Accurate reconstruction of solar irradiance variations is important for assessing human and natural contributions to climate change. Fluctuations in the Sun9s brightness, measured directly by space-borne radiometry over the past two 11-year sunspot cycles, seem too small to drive climate. Recent reconstructions of solar irradiance extending back to the 17th century have assumed that larger, multidecadal irradiance variations occur, similar to those detected on other Sun-like stars. In their Perspective, Foukal et al . discuss the recent retraction of this stellar evidence and of the solar irradiance reconstructions based on it, which has important implications for the relative roles of various forcing factors in climate change.