Better understanding and attribution of land and ocean carbon sources and sinks

Forthcoming EU call topic HORIZON-CL5-2027-01-D1-12 · HORIZON Research and Innovation Actions. Part of call HORIZON-CL5-2027-01: CLIMATE. Opens 2026-11-17; next deadline 2027-03-04. Topic page: https://ec.europa.eu/info/funding-tenders/opportunities/portal/screen/opportunities/topic-details/HORIZON-CL5-2027-01-D1-12

Expected Outcome: Project results are expected to contribute to some of the following expected outcomes: - Better understanding of oceanic carbon dioxide (CO2) sources and sinks, their drivers and dynamics under different climate scenarios, including their responses to human interventions; - Better understanding of land ecosystem CO2 sources and sinks, their drivers (both natural and anthropogenic) and their evolution under future climate and land-based mitigation scenarios; - Progress on reconciling estimates of anthropogenic CO2 emissions and removals from land originating from the climate science and national emissions reporting communities; - More consistent representation and quantification of lateral transfers of carbon.

Scope: Understanding the mechanisms and drivers of land (including inland waters) and ocean carbon sinks and sources is crucial for accurate climate models and scenarios and informing climate mitigation strategies. However, significant gaps and uncertainties remain in quantifying these complex processes and their components. It is essential to better understand the roles of anthropogenic and natural drivers of carbon fluxes, in particular the surface-to-air flux. This is necessary for reconciling conceptual discrepancies among estimates and assessing the implications for future trends and mitigation potential, taking into account that mitigation actions need to be additional to natural processes and business-as-usual and that the remaining carbon budget depends, inter alia, on assumptions on sinks. Proposals are expected to address only one of the three areas identified below - which should be clearly indicated, while ensuring…