Sea level change and adaptation: linking climate services needs and territorial realities (France, Netherlands, Maldives, Greenland)

In the face of rising or falling sea levels, adaptation is unavoidable. However, the extent of the action required depends on the scale of this rise or drop, determined to within a few centimetres that people and stakeholders will have to cope with. To determine adaptation strategies, stakeholders need climate services. However, scientific information does not always coincide with users’ needs. As part of the PROTECT European programme, we focus on users’ needs in four countries: France, the Netherlands, the Maldives and Greenland. We present the context of each country, as well as the partners with whom we work in each of these countries: the Conservatoire du littoral (France), the Rijkswaterstaat (Netherlands), the Ministry of Environment (Maldives) and ASIAQ (Greenland). Based on more than thirty interviews and several workshops, we present results concerning the need for sea-level rise scenarios. We assess the extent to which the produced services meet the needs and realities of users. We note that territorial realities and the decision-making context have a strong influence on the type of needs of adaptation stakeholders. The Conservatoire du littoral favours a 'soft' approach on land with predominantly agricultural or nature conservation issues, associated with a medium-term vision, thus moving towards probabilistic scenarios. The Rijkswaterstaat, which manages areas with a high population density and strong socio-economic issues needs for their sea defence large and complex infrastructure like storm surge barriers or dams. For this purpose, they have a marked demand for long-term scenarios (100 years), a low tolerance of uncertainty and a need for higher scenarios. The Maldives sees sea rise as a major challenge and requests precise short- and medium-term scenarios, as well as data and tools enabling to measure coastal vulnerability and put in place adaptation measures, such as raising or creating islands. Finally, sea level rise is not a major concern for Greenland: other more pressing issues are caused by climate change. The local culture makes it more difficult for stakeholders to project themselves into the future, favouring a short-term approach and probabilistic scenarios. The needs for climate services also depends on the stakeholder’s level of expertise. Overall, we finally observe a request for integrated climate services, taking adaptation choices and social data into account.