## 1 Introduction
### Background
Although progress on adaptation by EU member states has been slow, the large majority have already adopted a range of adaptation policies (Figure 3). These include climate change laws, which are at different stages of preparation, development, and implementation [8; 37]. According to [PERSON] et al., around 76% of European countries have adopted a NAS, and 61% have developed a NAP [9]. Figure 3: EU member countries with a NAS [National Adaptation Strategy] and/or NAP [National Adaptation Plan]. EU member countries without national adaptation instruments are color-coded in striped blue (non-coastal countries), while non-EU countries are shown in light gray. The map reflects the current status of national adaptation instruments as of 2024. Figure 2: Number of strategic instruments for climate change adopted by coastal EU member countries in the years 2005 to 2024. The trend shown considers the adoption of new instruments and the renewal or update of previously existing instruments during the period analyzed. The effects linked to climate change are not manifested in the same way through space and time. In Europe the diversity of climates, ecosystems, and socioeconomic characteristics plays a significant role. The north may benefit due to the interaction of multiple factors associated with rising temperatures, such as a reduction in energy demand or an increase in tourism. In contrast, southern Europe is particularly vulnerable to the worsening of extreme climate events such as droughts and floods [8; 36]. Among the most widely studied effects are the risks associated with the rising mean sea level and both river and coastal flooding [24; 38]. Recent examples include the floods caused by Storm Gloria in 2020, which severely affected the Mediterranean coasts, as well as those resulting from a cut-off low (COL) in October 2024 in the same region [39; 40]. Most studies have concentrated on Western Europe, where the Netherlands and Germany have greater adaptation capacities and resources to implement measures [30]. Nonetheless, in recent years, there has been an increase in policies, legal frameworks, and funding dedicated to adaptation and mitigation across the European continent [8]. In general, global adaptation efforts show heterogeneous progress and require greater coherence to address impacts effectively. While the European Climate Law (2021) urges member states to evaluate the implementation of adaptation strategies and plans, the European Court of Auditors considers these assessments ineffective due to the poor quality and limited comparability of the available data [28; 41]. Consequently, there is a notable lack of systematic, comparative studies that integrate both strategic instruments and concrete measures implemented by coastal EU member states. Although fragmented reports and national case studies exist, few academic contributions have addressed this issue from a cross-cutting perspective that combines multiple geographical scales, methodological approaches, and types of adaptation actions. The aim of this study is to assess and analyze different adaptation instruments by considering implementation capacities in coastal EU member countries. The objective is to provide a comprehensive analysis of strategic instruments and to offer a clear perspective on current adaptive capacities and areas for improvement within the context of coastal management. This work also aims to identify institutional, economic, and territorial inequalities and examine the structural factors underlying disparities between countries and regions. Ultimately, it seeks to provide a synthesis of good practices and emerging trends that could serve as a guide for improving public policy and fostering intergovernmental cooperation.