Sea Level Rise in Europe: Adaptation Measures and Decision Making Principles

Abstract. Sea level rise (SLR) will increasingly impact European countries in the coming decades, posing challenges for coastal decision-making and the design and implementation of adaptation measures to address coastal risks. This chapter aims to provide guidance for the design and implementation of adaptation policies in European basins, and does so by, first, assessing the state-of-the-art of SLR adaptation measures in Europe, and second, presenting approaches suitable for supporting coastal adaptation decision making and addressing uncertainty. Assessment of SLR adaptation in Europe is carried out by developing a typology of measures based on the IPCC classification of accommodate, protect, advance, and retreat responses to SLR, supplemented with sub-types measures socio-economic, physical and technological, nature- and ecosystem-based characteristics. Surveying relevant literature measures being implemented in Europe are identified and characterised according to their effectiveness and location within the European sea basins. We find that adaptation strategies on Europe’s coasts constitute a mix of hard and soft measures, planning measures, policy developments, and stakeholder and community engagements. Across all basins, a common theme is the shift towards a combination of traditional engineering solutions with soft measures, including nature-based solutions, integrating local communities into decision-making processes and emphasizing the importance of continuous monitoring and flexible management strategies. At the sea basin level, Baltic countries are incorporating SLR projections into their spatial planning and land-use regulations, and progress has also been made on marine environment conservation. In the North Sea Basin, SLR information has been integrated into coastal planning at national and sub-national levels in most countries, and countries are implementing different mixes of hard and soft protection measures. In the Mediterranean Sea Basin, SLR information is being mainstreamed through the development of national adaptation plans. Prominent protection measures are coastal reforestation and dunes and marsh restoration, while insurance is emerging as an accommodation measure. In the Black Sea Basin, emphasis is on early warning systems, and upgrading and modernizing existing coastal infrastructure to enhance resilience. In the Atlantic Ocean Basin, an emerging focus of adaptation measures is on nature-based solutions and improved spatial planning. Finally, coastal adaptation decision-making literature is then review and provides an overview of the common characteristics of coastal adaptation decisions and key aspects to be considered in coastal adaptation decision making, i.e., considering multiple criteria and interests, implementing low regret and flexible options, keeping future options open, factoring SLR into decisions that need to be made today, and revisiting decisions iteratively and monitoring.