Standardizing disadvantage: How global carbon accounting methodologies undervalue China’s blue carbon assets

Developing countries host roughly 90% of global mangrove forests but face systemic barriers to international carbon market participation because measurement and methodological uncertainties compound across accounting standards. This study develops an uncertainty propagation framework that traces these uncertainties from remote sensing identification through carbon accounting to credit valuation, using China’s mangrove restoration projects as a case study. Integrating 10 remote sensing products with ground-truth validation, we quantify spatial uncertainty patterns in 2020, yielding a 3.73:1 ratio between uncertain and high-certainty mapping areas under conservative unanimous-agreement rule. These measurement uncertainties compound with methodological discrepancies across three carbon accounting standards, China Certified Emission Reduction (CCER), Verified Carbon Standard (VCS), and Gold Standard (GS), generating 2.1-fold variations in carbon reduction estimates for identical mangrove areas. We use Monte Carlo simulations to further trace how these combined uncertainties propagate through carbon pricing mechanisms, yielding market valuations spanning $0.79-$11.91 million for 2020 Chinese mangrove carbon credits across international markets. Our findings point to a mechanism by which technical measurement challenges, combined with divergence between domestic and international standards, could substantially constrain carbon market viability for developing countries with similar national contexts to China. Targeted methodological harmonization and cross-standard coordination could therefore be important for enhancing equitable market access and enabling developing countries to scale nature-based climate solutions.