Aerosol radiative effects are an important aspect of the climate system that has both anthropogenic and natural contributions. Today, more and more high quality data of aerosol optical properties, aerosol humidification, size distributions, aerosol light absorption and aerosol extinction vertical profiles have become available through international cooperation such as ACTRIS, GAW and NOAA networks. At the same time exhaustive global aerosol model results from multiple groups have been assembled in the AeroCom database. This session shall focus on radiative properties and effects of light-absorbing aerosols like black and brown carbon, mineral dust, and biomass burning aerosol, and on model evaluation using the aerosol observations.