Remote sensing of clouds and aerosols is of vital importance in the creation of long-term uniform global records of climate-relevant parameters such as aerosol and cloud optical thickness, cloud height, particle size, liquid water path and vertical particulate matter columns. A number of unsolved problems remain in algorithms and their application. This includes remote sensing of clouds and aerosols with accounts for 3-D effects, remote sensing of polluted and mixed clouds, combination of ground-based and satellite-based remote sensing. The errors in retrievals are still large and must be reduced. This session is aimed at the discussion of current problems and trends in aerosol and cloud remote sensing using active and passive remote sensing systems.