Lidar is increasingly used for the remote sensing of atmospheric properties, and in particular for collecting information on aerosols and clouds. In his presentation, Dr. Marenco will discuss a number of scientific applications that he has been personally involved with, during ten years at the Met Office. The presentation will focus on the lidar on-board the FAAM atmospheric research aircraft, which Dr. Marenco has extensively used to study volcanic ash, mineral dust, smoke from biomass burning, and clouds: the accent is on the synergy that can be obtained between remote sensing and in situ observations, and on the validation of modelling and satellite products. The speaker will also discuss about applications of the Met Office volcanic ash network, currently consisting of 10 ground-based lidar stations, and the issues and barriers in front of the operational exploitation of spaceborne lidar.