Mercator Ocean International Contributes to First Report on Sea Level Rise in Europe by JPI Climate and JPI Oceans

Sea level rise is one of the most evident and potentially devastating effects of climate change, presenting considerable risks to coastal communities, ecosystems, and infrastructure. The implications for Europe’s economy and biodiversity highlight the critical need for easily actionable scientific information to inform targeted policy responses. With over 70 leading climate and marine scientists, Angélique Melet, senior scientist at MOi, contributed to the first European Assessment Report on Sea Level Rise, developed over three years through the Knowledge Hub on Sea Level Rise (KH-SLR). Her expertise was instrumental in two key chapters: “Sea Level Rise in Europe: Observations and Projections” and “Sea Level Rise in Europe: Impacts and Consequences“.

A Comprehensive Assessment of European Sea Level Rise

As a collaborative effort of the Joint Programming Initiatives for Connecting Climate Knowledge for Europe (JPI Climate) and for Healthy and Productive Seas and Oceans (JPI Oceans), this milestone publication was overseen by nine European countries including Belgium, France, Germany, Ireland, Italy, the Netherlands, Norway, Spain, and Sweden. Spanning three years of dedicated effort — from initial scoping with stakeholders to conducting surveys, regional workshops, and a European conference — this report serves as a crucial platform for informing policymakers about coastal changes throughout Europe. It focuses on both regional and local sea level changes, providing practical scientific insights for climate change adaptation and mitigation strategies.

Key features of the Report are provided in a Summary for Policy Makers and include:

Knowledge Gaps: Stakeholders from government and academia identified gaps in regional sea level rise projections, uncertainties surrounding shoreline erosion, emerging threats like saltwater intrusion, and the need for effective adaptation strategies.
Sea Level Rise Projections: The report outlines projections over European seas under different emission scenarios, highlighting how these vary regionally across Europe.
Impacts on Coastal Regions: The report examines the vulnerability of diverse regions, from the Arctic to the Mediterranean, detailing the effects of sea level rise on infrastructure, ecosystems, and local economies.
Adaptation Strategies: Recommendations include resilience-building approaches such as nature-based solutions, coastal defence mechanisms, and urban planning that integrates future sea level rise projections.

As co-chair of Task Group 3 on “Physical science” for the JPI Knowledge Hub on Sea Level Rise, Angélique Melet contributed her expertise alongside other European scientists. Furthermore, she served as coordinating lead author for two crucial chapters: “Sea level rise in Europe: Observations and projections” and “Sea level rise in Europe: Impacts and consequences”. Her work provides critical insights into past, present, and future changes in sea level rise across Europe.

Objectives and Knowledge Gaps

A primary objective of this report was to identify knowledge gaps in sea level rise data availability and adaptation plans. Key findings of the Chapter on Objectives and Knowledge Gaps include:

Insufficient climate data for local areas,
Need for localized high-resolution data for sea level projections,
Better understanding of extreme events required,
Need for long-term projections and characterized uncertainties,
Current adaptation plans need reinforcement in terms of effectiveness and flexibility.

Sea Level Rise in Europe: Observations and Projections

This chapter provides a comprehensive overview of observed and projected sea level rise in Europe. It highlights that European sea level trends are slightly above the global mean, with regional variations due to factors like vertical land motion. Projections for the 21st century indicate continued rise, with some areas experiencing rates below or above the global mean. The chapter about Observations and Projections emphasizes the need for high-resolution regional projections and addresses uncertainties in future scenarios.

Impacts and Adaptation Strategies

The report thoroughly examines the impacts and consequences of sea level rise across European coastal regions, focusing on three primary hazards: coastal flooding (including compound flooding from marine, pluvial, and fluvial sources), coastal erosion, and saltwater intrusion. These impacts are becoming more frequent and severe, leading to cascading effects on ecosystems, infrastructure, and socio-economic systems. Coastal erosion results in habitat loss, increased flood risks, and tourism losses, while saltwater intrusion causes freshwater loss, soil and crop damage, and threatens drinking water resources.

A chapter also discusses how these impacts vary across different European basins and presents a variety of adaptation and mitigation strategies, acknowledging regional and national differences. It emphasizes the importance of mapping these impacts to inform communities about potential changes to their living conditions. Additionally, the report addresses the challenges in quantifying and projecting these impacts, highlighting the need for improved regional assessments and flexible adaptation strategies to effectively respond to the evolving threats posed by sea level rise.

Decision-Making Principles and Governance Challenges

The report provides guidance on adaptation measures in European basins and presents approaches for supporting coastal adaptation decision-making. It acknowledges the complexity of coastal governance, which requires integrating policies across multiple scales and domains. It presents a mix of soft and hard measures, emphasizing flexible approaches for long-term resilience. While all European countries are working on adaptation, the report highlights accommodate measures as most discussed, followed by protect, advance, and retreat strategies, primarily focusing on mitigating coastal flooding and erosion.

Major governance challenges identified include:

Addressing time horizons and uncertainty,
Cross-scale and cross-domain coordination,
Equity and social vulnerability considerations, such as income, source of livelihood, access to services and infrastructures, age, education, physical isolation, mental health, …

Relative mean sea level rise by 2100 with regards to 1995-2014. — Figure: Relative mean sea level rise by 2100 with regards to 1995-2014, in meters, under two contrasted socio-economic scenarios: SSP1-2.6, with low emissions of greenhouse gases, leading to a warming of 1.8°C by the end of the century (2081-2100) wrt the pre-industrial era (1850-1900), and SSP5-8.5, with very high emissions of greenhouse gases, leading to a warming of 4.4°C by the end of the century (2081-2100) wrt the pre-industrial era (1850-1900). From Melet et al. (2024): Sea Level Rise in Europe: Observations and Projections.

For more information

Report directed by Nadia Pinardi (UN Ocean Decade Centre for Coastal Resilience, CoastPredict Programme) and Bart van den Hurk (co-chair of IPCC Working Group II)
To download the full report or read by chapter: 1st Assessment Report of the Knowledge Hub on Sea Level Rise (SLRE1)
To read the Brochure for Summary for Policymakers: Key Insights on Assessment Report on Sea Level Rise in Europe
For more information about the Knowledge Hub on Sea Level Rise, please visit: Home – KHSLR