This book provides an updated overview of the processes determining the influence of solar forcing on climate. It discusses in particular the most recent developments regarding the role of aerosols in the climate system and the new insights that could be gained from the investigation of terrestrial climate analogues. The book's structure mirrors that of the ISSI workshop held in Bern in June 2005.

2 With a global average irradiance of 342 W/m, the Sun is by far the largest source of energy for planet Earth. In comparison, the internal energy produced by Earth 2 itself is only about 0. 087 W/m (Pollack et al., 1993), which in turn is 3. 5 times 2 larger than the 0. 025 W/m of heat produced by the burning of fossil fuels. About 31% (31 units) of the solar energy which arrives at the top of the - mosphere is re?ected back to space by scattering from clouds, aerosols, and the Earth s surface. Almost 20 units of solar radiation are absorbed in the atmosphere. The remaining 49 units are...