This paper gives an overview of French studies realized in the frame of the CNES (French Space Agency) working group on spaceborne lidar missions. These studies include (1) the development of forest scenery and radiative transfer models for the simulation of lidar waveforms under forest cover, (2) preliminary instrumental studies to ensure the feasibility of the scientific requirements and (3) evaluation and improvement of inversion methods to retrieve forest parameters from large footprint lidar data.