Green Carbon: Role, Evidence, Methods, and Policy Implications

Abstract “Green carbon” — the carbon stored in terrestrial plants and soils — is a central component of the global carbon cycle and a major target for climate mitigation through conservation, improved land management, and restoration. Forests and other terrestrial ecosystems hold large carbon stocks and continue to act as carbon sinks, while soils globally represent a massive reservoir whose management can sequester additional carbon. This narrative review synthesizes current knowledge on green carbon stocks and fluxes, measurement and accounting approaches, drivers of loss and gain, co-benefits and trade-offs, and policy mechanisms (including REDD+, NDCs, and carbon markets) for mobilizing green carbon as a climate solution. The review highlights methodological challenges (measurement, permanence and leakage, and soil carbon dynamics), socioeconomic and governance constraints, and research gaps, and concludes with practical recommendations for policymakers, practitioners, and researchers. Keywords: Green carbon; terrestrial ecosystems; forest carbon stocks; soil organic carbon; carbon sequestration; land-use change; REDD+; Nationally Determined Contributions (NDCs); carbon markets; climate change mitigation