Climate change influences the hydrodynamical, morphological and ecological state of coastal waters and estuaries. It is of great importance for society and policy-makers to gain knowledge about the expected types and extent of changes in these systems. The Estuarine and Coastal Science Association (ECSA) called for a conference in 1999 to discuss scientific, policy and socioeconomic aspects of this topic. This CR SPECIAL documents a diversity of contributions as well as results of intensive discussions.