The Integrated Carbon Observation System (ICOS) is a fully operational European Landmark research infrastructure providing standardised high-precision observations on greenhouse gases and their fluxes. The ICOS infrastructure is currently covering 16 countries with 170 stations. In this project, we will work with new users for ICOS data from satellite and modeling communities and prepare products for policymakers. We are improving sustainability of ICOS by streamlining the data pipelines and strengthening the community engagement including new members. In addition to data, ICOS is producing protocols and processes, which are now needed for the global greenhouse gases (GHG) initiative coordinated by World Meteorological Organization (WMO), thus strengthening the European leadership in it. NUBICOS will focus on four specific objectives: 1. The cooperation between ICOS and the remote sensing community will be deepened. 2. The value chain from observations to climate services will be improved. 3. The internal engagement of ICOS and the identity of the ICOS community will be strengthened. 4. The global cooperation of ICOS, particularly in the WMO framework, will be intensified.