Bordeaux Métropole and the University of Bordeaux are co-developing a new governance model for climate transition — shifting from top-down planning to horizontal coordination that harnesses local knowledge and cross-sector collaboration. The initiative centres on "Les Rencontres des Transitions" (Transition Encounters), an annual event bringing together public authorities, researchers, associations, and businesses to co-create projects rolled out across the metropolitan area. ABCD uses iterative learning to identify and support grassroots transition projects, building a durable, citizen-powered structure for collective climate action. In Year 1, the first joint edition of Rencontres des Transitions (October 2024) brought together 90 participants and generated six projects across carbon neutrality, ecocitizen mobilisation, and water pollution — now being implemented. A "Science Shop" (Boutique des Sciences) is also being developed to bridge scientific and citizen knowledge through association networks.