The Community–Environment–Health Nexus: Connecting Community-Led Climate Action to Health Co-Benefits

Background: Climate action initiatives primarily target environmental outcomes, but their potential for health co-benefits through green and blue space contact remains understudied. Understanding these secondary outcomes could inform dual-purpose programming addressing climate and health challenges. Methods: This retrospective analysis examined 32 community-led climate action projects funded through Edinburgh Communities Climate Action Network (ECCAN) and their GreenLight programme (2024–2025). Projects spanned energy, transport, food, circular economy, and green space themes, with no formal health evaluation framework. Data were extracted from final reports covering 3195 direct participants. Results: Despite health not being a primary objective, 21 of 32 projects (66%) reported secondary health and wellbeing outcomes. Projects involving direct nature contact showed the strongest co-benefits: nine of ten high-nature-contact projects reported health benefits, compared to two of eight low-nature-contact projects. Notable outcomes included 94% of participants reporting increased willingness to engage in future community activities and 76% reporting mental wellbeing improvement following community garden workshops. Blue space engagement demonstrated particular significance for mental health and social cohesion. Conclusions: Green and blue space engagement in climate action projects consistently produces secondary health outcomes. We propose the Community–Environment–Health Nexus (CEHN) framework to understand how community-led environmental action generates synergistic health co-benefits.