Reducing hydro-meteorological risks through nature-based solutions: A comprehensive review of enabling policy frameworks in the European Union

The international community, particularly across the European Union (EU), is increasingly recognizing and promoting Nature-based Solutions (NBS) as long-term and sustainable measures against hydro-meteorological hazards such as flooding, coastal erosion, heat waves and landslides. Yet, scaled implementation of NBS at EU and global level presently remains a challenge due to often complex and lengthy permitting procedures. While efforts have been made to highlight the explicit and implicit role of NBS in major global and European policy frameworks, uncertainty remains when it comes to the level of coherence across government levels, from international to national and local scale. This paper attempts to address this gap by introducing an open-access online policy catalogue pertaining to the implementation of 740 NBS projects globally to mitigate the impact of hydro-meteorological phenomena. Based on a policy screening of 88 NBS projects in Europe and an in-depth analysis of the NBS permitting paths across seven Open-Air Laboratories in European countries, we examine the linkages between European and national legislation and policies. Understanding these linkages will help promote NBS mainstreaming as the NBS agenda is set at EU and global level while implementation is heavily dependent on national-scale governance. We identify a common permitting path for NBS paved by the EU in several directives, as well as some divergence in the implementation of these directives at national level which can pose significant challenges to the uptake of NBS. The NBS policy catalogue provides a valuable resource for further analysis of the NBS policy context from local to global levels towards increasing uptake and acceptance of NBS in Europe and beyond.