The present knowledge of the aerosol distribution is far from sufficient to properly estimate the role of aerosols in changes of the global and regional environmental conditions and climate. Improving the observation system for aerosols will contribute to almost all areas of societal benefits listed in the GEOSS Implementation Plan.
Since it is in particular the information on the vertical distribution that is lacking, advanced laser remote sensing is the most appropriate tool to close the observational gap. This was demonstrated by the systematic quantitative aerosol profiling performed within the European Aerosol Research Lidar Network (EARLINET).
With EARLINET, Europe has taken the lead in this area: the improvement of continuing observations and methodological developments are urgently needed to provide the multi-year continental scale data set necessary to assess the impact of aerosols on the European and global environment and to support future satellite missions.