The European Union's regions and cities believe that developing a macro-regional strategy for the Mediterranean basin would allow to tackle jointly the necessary green and digital transitions, as well as socio-economic, migratory and security challenges. Climate change, environmental deterioration, the proliferation of extreme weather events, water scarcity, loss of biodiversity and food security do not know any borders and are a serious threat to the three shores of the Mediterranean. The European Committee of the Regions points out in its opinion that a macro-regional strategy would help dev...