Abstract: While overall the global warming with the causes and global processes connected to CO2, and its impacts on global to continental scales are well understood with a high level of confidence, there are knowledge gaps concerning the impact of many non-CO2 radiative forcers leading to low confidence in the conclusions. This relates mainly to specific anthropogenic and natural precursor emissions of short-lived GHGs and aerosols and their precursors. These gaps and uncertainties also exist in their subsequent effects on atmospheric chemistry and climate, through direct emissions dependent on changes in e.g., agriculture production, waste managements and technologies based on scenarios for future development as well as feedbacks of global warming on emissions, e.g., permafrost thaw. In addition to the atmospheric radiative forcing (gaseous or aerosols), albedo changes connected to land-use and land-cover can play a role, depending on the adaptation or mitigation measures included in different scenarios. Thus, the main goal of the EC Horizon Europe project FOCI, is to assess the impact of key non-CO2 radiative forcers, where and how they arise, the processes of their impact on the climate system, to find and test an efficient implementation of these processes into global Earth System Models and into Regional Climate Models, and finally to use the tools developed to investigate mitigation and/or adaptation policies incorporated in selected scenarios of future development targetted at Europe and other selected regions of the world. We will develop new regionally tuned scenarios based on improved emissions to assess the effects of non-CO2 forcers. Mutual interactions of the results and climate services producers and other end-users will provide feedback for the specific scenarios preparation and potential application to support the decision making, including climate policy. Present status of the project will be described, with preliminary results relevant to the conference themes briefly shown. Future selected directions will be discussed.

Keywords: climate forcers, non-CO2 forcers, aerosols, coupled climate-air quality modelling