Enabling climate action: A nexus approach for delivering co-benefits across biodiversity, water, food, and health.

Climate response options rarely affect biodiversity, water, food, and health in uniform ways. This comparative analysis examines why technically viable response options generate uneven cross-nexus outcomes, and how governance and justice conditions shape whether these outcomes become durable co-benefits. Anchored in the IPBES Nexus Assessment, the analysis synthesizes evidence from fifteen response options spanning land, ocean, energy, urban, industrial, and societal transitions. Ecosystem-centered and demand-side pathways more consistently produce synergies because they work through ecological functions that connect several nexus elements. Infrastructure- and technology-centered options deliver mitigation and health gains, but their wider effects are more context-dependent and often shaped by land use, water demand, biodiversity risk, tenure, access, and benefit-sharing. These patterns do not arise from technical design alone. By integrating nexus governance with Earth System Justice, the analysis indicates how cross-sectoral coordination, distributive equity, procedural inclusion, accountable finance, and knowledge pluralism can shape legitimacy and durability. Climate action is more likely to deliver sustained system-wide benefits when institutions align ecological interdependencies with social rights and responsibilities. Otherwise, promising interventions may remain partial, contested or short-lived.