Managed Retreat: Preparing Coastal Cities for Sea Level Rise

By 2100, sea levels could rise by more than a meter without drastic reductions in our greenhouse gas emissions, according to the latest IPCC report. This global average encompasses diverse local realities, and many uncertainties remain regarding the exact pace and magnitude of the phenomenon. While coastal cities attract a growing population and concentrate numerous activities, they are confronted with coastal erosion, marine submersions, loss of land, flooding, erosion, salinisation of soils, and the degradation of ecosystems. One thing is certain: they must adapt immediately and sustainably.

Several adaptation solutions are possible and can be combined in space and time to meet local needs: hard and soft protections, accommodation, nature-based solutions, or even relocation. Also known as managed retreat, this strategy, although complex to implement, will sometimes be inevitable. Unlike emergency management, managed retreat is defined as a planned effort to permanently relocate people, assets, and infrastructure away from areas at risk.

Because of its complexity, managed retreat is a topic which attracts much debate and resistance among both the populations concerned and policy and decision makers. To better anticipate, design, and implement this adaptation strategy, it is essential to bring about changes in narratives and to work towards a shared understanding of the issues and the methodologies that can accompany its deployment.

With this in mind, the Ocean & Climate Platform, as part of the Sea’ties project, publishes a special report on “Managed Retreat: Preparing Coastal Cities for Sea Level Rise“. Intended for policymakers, and key stakeholders involved in the adaptation of coastlines, this special report proposes an in-depth analysis of managed retreat and methods for its implementation, illustrated and incarnated by the voices of experts and from the field.