Abstract
The solar radiation reaching the earth surface supports life on the earth and a small change in intensity would change the earth climate to a large extent. The observed surface solar radiation shows a decreasing trend from the 1950s to 1980s and an increasing trend since then (Global dimming and brightening, GDB). This transition can affect any surface physical processes and climate changes, such as global warming, the hydrological cycle, the cryosphere, and the terrestrial biosphere. Since GDB is recognized under both cloudy and cloud-free skies, the changes in clouds and aerosols, especially anthropogenic aerosols, are considered to be one of the key factors. In this paper, observational evidences, causes, General Circulation Model (GCM) simulations, and impacts of GDB are reviewed.
