## 1 Introduction  
A recent review provides a comprehensive overview about climate change effects in the Baltic Sea region [1]. Examples are increasing air and water temperatures, longer warm and cold spells, reduced snow and ice in winter, increasing risks of heavy precipitation and droughts, and changes in solar radiation, cloudiness, river discharge and salinity. These changes cause multiple problems and threats, not only for the flora and fauna in coastal and marine ecosystems, but also for society [1]. For coastal areas, climate-change-induced sea level rise is the main problem. The sea level rise in the Baltic Sea is close to the global average of 3-4 mm per year, with significant differences between Baltic regions and depending on the assessed time period. The sea level will continue to rise at an increasing rate and in 2100 may be 1 m higher compared to the 1990s [1]. The south-western Baltic Sea faces an additional problem: a sinking coast by about 0.5 mm per year [2] resulting from glacial isostatic subsidence. Therefore, climate change and sea level rise are an increasing problem, especially for the south-western Baltic Sea coast. The Baltic Sea is a micro-tidal sea, with a tidal range of about 0.2 m only. Storm surges in the western Baltic frequently cause increased sea levels of 1-1.5 m, with a maximum sea level above 3 m observed in 1872. Extreme sea levels become more frequent with rising mean sea level [3] and are a hazard for the low-lying coasts of the southwestern Baltic Sea region. Climate change at the southern Baltic Sea coast requires fast adaptation. In general, adaptation has to take place not only on a local scale but also integrated at large scales to avoid a shift of risks from one area to another [4]. Therefore, coasts need effective and comprehensive climate change and sea level rise adaptation planning. However, presently the list of short-comings is long: legal frameworks are partly lacking [5], and while many strategic plans exist, e.g., [6; 7], strategies, infrastructures and coordination hubs are often perceived as weak and insufficient [8; 9]. In England, for example, the existing national coastal change adaptation policies, specifically Coastal Change Management Areas, are hardly designated at a local level [10]. Another example is New Zealand, where Boston and Lawrence [11] consider current planning, regulatory and funding frameworks as ill-equipped. Spatial planning provides the umbrella for climate change adaptation. In European Union (EU) member states, spatial planning is influenced by a variety of legislations and policies, including the directives on Strategic Environmental Assessment and Environmental Impact Assessment, the Birds and Habitats Directives, the Water Framework and the Floods Directive. Spatial planning for the coastal zone specifically was originally intended to be part of the Maritime Spatial Planning (MSP) Directive (2014/89/EU), combining Integrated Coastal Zone Management (ICZM) and MSP. However, in the process of adopting the directive, the coastal waters were excluded due to diverging political interests [12]. Therefore, spatial planning for the coastal zone is not directly regulated by EU legislation but only influenced by the above-mentioned policies, which can hamper coherent planning across borders [13]. However, one region in the EU--the Baltic Sea--can be regarded as a forerunner in policies development and implementation because of a long tradition in cross-country cooperation through the Baltic Marine Environment Protection Commission (HELCOM), a key institutional actor. For many coastal regions, sets of climate change adaptation measures exist. For example, [PERSON] et al. [14] review 51 measures suitable for parts of the French coast. However, a lack of public support for coastal adaptation hampers implementation [15] and, in case of implementation, assessment of the outcomes and impacts of the adaptation measures is lacking [16]. Here, ecosystem services assessment approaches could be beneficial and could complement planning.