The study is part of the 3rd United Nations Ocean Conference (UNOC) to be held in Nice in June 2025, the main theme of which is « Accelerating action and mobilising all stakeholders to conserve and sustainably use the oceans ». This study is not intended to present an exhaustive list of coastal risk management Solutions. The International Union for Conservation of Nature (IUCN) estimates that more than 60% of the world's population lives on the coast, with 3.5 billion of people living within 150 kilometers of the coast. Coastal cities are increasingly vulnerable to coastal risks, which are aggravated by climate change. In the short/medium term, adapting them will require a combination of solutions. In the event of definitive situations, managed retreat must be envisaged for these vulnerable areas.