The Ambition of GreenFeedBack is to enhance knowledge of the GHG dynamics in the ecosystems and link GHG in terrestrial, freshwater and marine ecosystems to provide a solid basis for estimation of regional and global climate feedback processes taking human pressure on ecosystems into account. GreenFeedBack will study the processes in sensitive terrestrial, freshwater, coastal and marine areas of which some are hypothesized to be tipping elements in the climate system. Thus, we will primarily focus on high latitude terrestrial and freshwater systems, marine shelves and ocean areas and thereby advance the process-based representation of ecosystems in Earth System Models (ESM). The analysis will involve co-design between scientists and stakeholders. We will use data from the ICOS and ACTRIS stations in Europe and the GIOS, GEM and SMEAR network in Greenland and Finland as well as data from dedicated field and laboratory studies. The enhanced knowledge will be used to improve descriptions of the GHG processes for implementation in ecosystem models and ESMs. Hence, GreenFeedBack will improve and apply ecosystem- and Earth System models to advance our understanding of GHGs effect on climate variability over different time horizons.