Environmental nexus paradigm: Toward a unified framework for sustainable governance

The concept of the environmental nexus developed within environmental science to tackle connected challenges across resource, ecological, and social systems. As environmental issues become more complex—driven by climate change, ecosystem loss, and resource competition—traditional single-dimensional countermeasures have proven inadequate. The nexus paradigm marks a key transition toward systematic, cross-sector environmental governance. This study conducts a comprehensive review of environmental nexus research over the past decade (2015-2025), tracing its conceptual shifts, methodological diversification, and expanding policy relevance. In response to unresolved issues in this field such as conceptual ambiguity, fragmented data, and isolated governance, we propose a five-layer integrative framework of environmental nexus. The framework comprises: (1) interdisciplinary theoretical foundations rooted in systems ecology, socio-ecological resilience, and planetary boundaries; (2) a diverse methodological toolkit including coupled system models, decision-support methods, participatory tools, and AI-enhanced analytics; (3) dynamic data integration supported by multi-source fusion, shared indicators, and real-time feedback loops; (4) multi-level governance strategies for institutional coordination, stakeholder inclusion, and equity embedding; and (5) sustainability actions aligned with climate, biodiversity, and development targets. This framework advances the environmental nexus as both an academic foundation and an actionable pathway for supporting integrated, just, and adaptive environmental governance in an era of accelerating complexity.