Gert-Jan Nabuurs is professor European forest resources at Wageningen University and Research. His expertise is European scale forest resource analyses, carbon sequestration under climate change. He is IPCC Coordinating lead Author in the Sixth Assessment Report for Agriculture and Forestry. In this talk, Gert-Jan shared his long-standing experiences in gathering ground-based data for European inventories, alongside the challenges related to non-open data and introduces virtuous examples connecting EO with field monitoring for European forests.