Even if we were to reach net zero tomorrow, our past emissions have locked us into inevitable sea level rise due to the long term effects of global warming on oceans and the cryosphere. It is therefore essential to understand the extent of this rise and how to both mitigate and adapt to it.
The publication of the 1st European Assessment Report on Sea Level Rise – a collaboration between nine countries, and around 60 scientific and non-scientific European experts from a variety of backgrounds – marks a critical milestone in the collaborative efforts of the Joint Programming Initiatives for Connecting Climate Knowledge for Europe (JPI Climate) and for Healthy and Productive Seas and Oceans (JPI Oceans), with key input from CMCC experts, the Report provides essential insights to guide policymakers, coastal planners, and practitioners in addressing the multifaceted challenges of rising seas.
In what ways does the 1st European Assessment Report on Sea Level Rise provide innovative insight for policymakers, coastal planners, and practitioners in addressing the multifaceted challenges of rising seas?
The 1st European Assessment Report on sea level rise (SLR) is a key resource of practical scientific insights for climate change adaptation and mitigation as it provides regional specificity, assessing projections and drivers of SLR impacts for policymakers.
The report goes beyond rising waters, and explores compound floods, flood-erosion patterns, and shoreline changes, proposing solutions such as nature-based approaches. Besides, it also provides a comprehensive approach to the risks related to rising sea levels through an analysis that encompasses marine spatial planning options, methodologies for assessing risk, and considerations of risk perception.
Are there some key findings that you believe will influence coastal management policies across Europe?
The analysis focused on three key aspects of SLR that are relevant for shaping coastal management policies and their implementation: information and data, impacts, and strategies for adaptation and decision-making in the management of coastal zones.
Regarding information, the Report confirms that there is insufficient climate data at the local level (particularly estuaries and human-activity zones). There is also a lack of localized, high-resolution data for sea level projections which would enable better understanding of extreme events. As for the impacts, the report points out that there is a need to assess combined effects of hazards, such as floods, erosion, salt intrusion as well as to systematically catalogue historical events and share knowledge across European regions and sea basins. Finally, on adaptation and decision-making, the report flags the need for clarity in adaptation methods (including nature-based solutions), cross-country policy comparison, and the crucial role of community engagement.
What are some of the solutions that emerged?
The interaction of adaptation responses to SLR and vulnerability factors, such as income, education or access to services and infrastructures, has been highlighted as an important aspect to be considered in order to avoid the reproduction of inequitable outcomes.
The report delivers recommendations for further investment and coordinated action to overcome local knowledge gaps, as uncertainty in projections, impact chains, and adaptation effectiveness hampers informed decision-making. It also recommends focusing on remote sea-level rise drivers, as monitoring and understanding ice sheet collapse is vital, with proactive mitigation strongly advised; local impacts, identifying interconnected challenges in infrastructure, urbanization, land loss, and adaptation demand coordinated assessments and investments; and linking adaptation planning, governance, and financial management as diverse local contexts reveal interconnected challenges, emphasizing the need for multi-level discussions on solutions to prevent them from becoming barriers to implementation.
In what ways is stakeholder input critical to the report?
Over the three year design and implementation phase of the 1st European Assessment report of the joint JPI Climate/JPI Oceans Sea Level Rise Knowledge Hub (KH-SLR) the input by stakeholders was sought for from the onset and played a critical role to frame the report in the view of its user orientation. The user engagement process started with a stakeholder survey followed by sea basin specific workshops, and Sea Level Rise Conference in Autumn 2022.
The survey involved over 200 interested actors across Europe in coastal planning and relevant research and was conducted to assess the availability and use of SLR information, impacts of SLR, and adaptation strategies and policy implications of SLR. Following the survey, four scoping workshops in the five European sea basins were conducted in 2022. These played a pivotal role in the process of identifying the requirements of policy-makers, coastal planners, and stakeholders at large.
The insights gathered from these workshops were instrumental in designing the key themes related to SLR drivers, impacts, and policy options for each of Europe’s major sea basins to be addressed in the Report.
When talking about SLR research, what is the relationship between local impacts and global trends?
SLR is a global concern for low-lying coastal areas, including many European coasts. Despite the global nature of SLR, European sea basins face disparities in impacts but also in understanding and applying sea level science, evaluating its impacts, and devising effective adaptation strategies at the local and regional scales.
SLR adaptation is context-specific to the extent that it involves regional and local nuances at multilevel scales, while information gaps primarily revolve around regional–local data and information on SLR projections and uncertainties. Sea level rise is a chronic hazard that is addressed in the governance of environmental and economic development of European coastal regions in all surrounding sea basins.
The mean rate of European absolute sea level rise slightly exceeds the global mean trend and is accelerating. Regional variability is large, with lower relative sea level rise in some Baltic regions due to vertical land movements and the effects of loss of land ice masses. Higher relative rates of sea level rise are expected in the southern areas.
Sea level rise has several coastal impacts, such as the increased likelihood of floods, shoreline retreat via coastal erosion, and freshwater shortages due to saltwater intrusion. Other human interventions can exacerbate these impacts, such as reduced sediment supplies due to streamflow obstructions, urbanization, and habitat loss in exposed coastal areas, lack of sustainable groundwater strategies, or aging coastal infrastructure.
The levels of sea level rise considered in the management of coastal developments vary across countries and depend on socioeconomic developments in coastal areas, environmental constraints, and options to take measures against negative sea level rise impacts.
What are some of the most critical knowledge gaps when it comes to addressing SLR effectively and how should they be addressed to support future strategies and analyze trade-offs?
The report has identified adaptation measures that are suitable to addressing SLR effectively. These measures, however, are generally subject to trade-offs that should be considered when planning coastal adaptation.
In particular, while “accommodate measures” offer benefits such as cost-effectiveness and immediate relief, the financial cost of implementing these measures can be a challenge for some communities. “Protect measures” provide important risk reduction benefits. However, they can severely disrupt natural coastal processes and harm marine life. Even soft protection or “advance measures” can have similar, localised ecological effects: for example they may alter sediment transport patterns unintentionally lead to erosion in neighbouring regions. While sea walls provide coastal protection, they can also exacerbate erosion by affecting the entire ecosystem and thus diminishing the ability of the system to respond naturally to different conditions. These measures may also impact cultural heritage sites and alter coastal areas in addition to requiring high maintenance costs.
Lastly, “retreat measures” potentially displace entire communities and can involve substantial loss of assets and economic activities. In order to accurately analyse existing trade-offs, it is important to understand the effectiveness and feasibility of these measures.
The Report identified a critical gap in the literature and information in this regard. In particular, there is a need to scientifically assess the effectiveness and feasibility of individual measures particularly in context-specific cases. Such a research gap, if addressed, could advance knowledge to support effective coastal adaptation action.
The Report concludes that the effectiveness and flexibility of current adaptation plans and strategies are uncertain. Hence, these findings suggest that the literature review can be expanded to include more studies and that more research is needed to learn about the trade-offs of implementing each of these measures.
Are there universal solutions to SLR adaptation and in what ways does adaptation have to be context specific?
Addressing SLR is inherently context-specific due to governance frameworks and institutions related to the issue. Many countries have mainstreamed sea level rise in national and regional policies for climate adaptation as well as in (marine) spatial planning and environmental conservation.
However, approaches to coastal adaptation policies vary among countries at the national level according to institutional arrangements and geographical and social circumstances.
Although SLR is already affecting and is expected to affect almost all European coastal countries and has been identified as a major hazard by almost all European countries with coastlines, only a few countries include specific measures to adapt to SLR in their coastal adaptation policies. This indicates that in some sea basins there is still a gap between the recognition of SLR risks and necessary adaptation measures to address those through policies at the national level.
In what ways are you working with CMCC and JPI Climate to help make scientific information easily accessible and tailored for policy responses?
CMCC and JPI Climate have been working on initiatives such as the Knowledge Hub on Sea Level Rise to ensure periodic update of reports and creating a networking platform to facilitate the exchange, synthesis, integration, and generation of knowledge customized in accessible formats that are understandable to various stakeholders.
The intention is to convey scientific and socio-economic developments in an aggregated manner, tailored to current themes and debates in policy and public discussions. In the case of the 1st Assessment Report by the KH-SLR, one of the outcomes was precisely to provide accessible and updated knowledge tailored to users across European basins, addressing the needs of policy-makers, coastal planners, and stakeholders, given that there is need to tailor SLR information to different application domains, involving diverse stakeholders and institutions that needed specific information on the topic for improved preparedness.
This collaboration is anchored in the Equinox Process established by JPI Climate which aims to accelerate the development and transfer of climate knowledge to policy for urgent action. Equinox acknowledges that actors in the public and private sector need access to current, authoritative scientific information. With Equinox, JPI Climate aims to establish a process to systematically update this scientific information, framed by the challenges of climate neutrality, climate resilience and transition and transformation. Equinox also aims to contribute to future work of the IPCC.
The upcoming European Climate Change Adaptation Conference (ECCA) 2025 organised by CMCC and MAGICA project together with JPI Climate in Rimini on June 16-18 recognises the Protection of Coastal Areas as one of the key theme of the Conference and it will provide an additional platform of engagement and discussion at European level around this topic.
In addition CMCC also provides education, training, exchange, and knowledge transfer on climate change through the Advanced Training and Education Center (ATEC) and Future Earth School (FERS) on sea level rise and coastal adaptation.
References
Galluccio, G., Hinkel, J., Fiorini Beckhauser, E., Bisaro, A., Biancardi Aleu, R., Campostrini, P., Casas, M. F., Espin, O., and Vafeidis, A. T.: Sea Level Rise in Europe: Adaptation measures and decision-making principles, in: Sea Level Rise in Europe: 1st Assessment Report of the Knowledge Hub on Sea Level Rise (SLRE1), edited by: van den Hurk, B., Pinardi, N., Kiefer, T., Larkin, K., Manderscheid, P., and Richter, K., Copernicus Publications, State Planet, 3-slre1, 6, https://doi.org/10.5194/sp-3-slre1-6-2024, 2024 .
van de Wal, R., Melet, A., Bellafiore, D., Camus, P., Ferrarin, C., Oude Essink, G., Haigh, I. D., Lionello, P., Luijendijk, A., Toimil, A., Staneva, J., and Vousdoukas, M.: Sea Level Rise in Europe: Impacts and consequences, in: Sea Level Rise in Europe: 1st Assessment Report of the Knowledge Hub on Sea Level Rise (SLRE1), edited by: van den Hurk, B., Pinardi, N., Kiefer, T., Larkin, K., Manderscheid, P., and Richter, K., Copernicus Publications, State Planet, 3-slre1, 5, https://doi.org/10.5194/sp-3-slre1-5-2024, 2024.
