The GEO-TREES initiative, a new action of the intergovernmental Group on Earth Observations (GEO), is hiring a Project Coordinator. GEO-TREES supports the establishment and development of a global activity of in situ biomass reference measurement sites, to validate satellite-based forest biomass observation instruments. These sites will provide, at global scale, high-quality, georeferenced data (forest census, terrestrial, and airborne lidar) to support global space-based forest biomass mapping. The project coordinator will be responsible for ensuring communication between the participating scientists (remote sensing and ecology), creating links with other potential partners (funders), and helping with the technical implementation of the research programme.