Climate change threatens coastal areas of the North Sea and the Baltic Sea primarily through accelerated sea-level rise, increasing storm surges, and increasing winter rainwater discharge. Accelerating sea-level rise and changes in hydrological cycles are likely to affect coastal ecosystems and may restrict the efficiency of existing protective measures in the future. Therefore, the collaborative research project COMTESS will perform an inter- and transdisciplinary investigation of four land management scenarios, applied to a North Sea and a Baltic Sea coastal region. COMTESS will quantify and evaluate the performance of multiple ecosystem functions and services in each scenario in socio-economic and ecological terms.