The United Nations and global blue carbon governance: a policy and practice review of frameworks, challenges, and possible pathways

As a potentially important component of natural climate solutions, blue carbon is increasingly bridging climate change mitigation and adaptation with biodiversity conservation. This Policy and Practice Review provides comprehensive coverage and a balanced overview of the global blue carbon governance landscape, focusing on the United Nations system. The analysis systematically examines the policy interfaces and coupling mechanisms between blue carbon governance and five key international instruments: the United Nations Framework Convention on Climate Change (UNFCCC), the Convention on Biological Diversity (CBD), the Ramsar Convention on Wetlands, the 2030 Agenda for Sustainable Development (SDGs), and the Sendai Framework for Disaster Risk Reduction. Based on this assessment, this review identifies four structural bottlenecks hindering effective UN-led governance: (1) conceptual and accounting discrepancies between “coastal blue carbon” and emerging “broad-sense blue carbon” definitions; (2) insufficient cross-convention synergy, leading to fragmented regulations and high transaction costs; (3) inadequate implementation of the Common But Differentiated Responsibilities (CBDR) principle, particularly for coastal developing countries and small island nations; and (4) persistent funding and capacity gaps throughout the entire lifecycle of blue carbon projects. In response, this review proposes three actionable recommendations for institutional reform: (1) establishing a “minimum consistency standards package” with cross-institution mutual recognition within the UN system; (2) developing “nationally integrated blue carbon policy packages” aligned with Nationally Determined Contributions (NDCs), National Biodiversity Strategies and Action Plans (NBSAPs), Ramsar designations, and national disaster reduction strategies; and (3) implementing the CBDR principle through concrete pathways for mandatory funding and technology transfer