CAT-MED aims to prevent the natural risks related to climate change, thanks to the convergence of metropolitan strategies and actions. On the one hand, it proposes to identify and quantify common objectives, via indicators. These indicators will be defined on the basis of systemic approach of sustainable development. The creation of a transnational GIS will allow to evaluate the situation of each city and their evolution in real-time. For each indicator, optimal values will be defined, as convergence objectives to be reached to contribute to global warming prevention. On the other hand, CAT-MED aims to define a strategy and actions in order to concretize this convergence. Experimentation will thus be carried out jointly in all the cities. Each city will implement a “Sustainable Urban District” as pilot project, associating key actors in metropolitan groups, and connecting them at a transnational level to share operational solutions. This process will make it possible to build a common model and a methodological guide of Sustainable Urban Districts, proposing concrete answers to the diversity of Mediterranean urban problems, in order to prevent the risks related to climate change by a deep evolution of urban behaviours. CAT-MED will be narrowly followed at political level. The commitment of the elected officials to continue the convergence process on common objectives and actions will be formalized in a political charter.