Research on the development quality of China’s marine carbon sinks

Purpose This study aims to evaluate the development quality of marine carbon sinks in China’s coastal regions under the strategic background of the “carbon peak and carbon neutrality” initiative, while identifying regional disparities and multidimensional driving factors to support high-quality marine carbon sink development and advance national climate goals. Design/methodology/approach Adopting a regional coordination perspective, this research constructs a three-dimensional indicator system encompassing policy, environment and technological innovation. The study comprehensively applies integrated methodologies – the entropy weight method, kernel density estimation and the Theil index – to empirically examine the development quality of marine carbon sinks across 11 coastal provinces in China during the 2010–2022 period. Findings Analysis reveals a 21.6% aggregate improvement in comprehensive national marine carbon sink development quality across the study period, with accelerated growth observed post-2020 following the formal announcement of the “dual carbon” goals. However, significant regional disparities persist: The Southern Marine Economic Circle leads national development, capitalizing on critical marine carbon sink resources such as mangrove ecosystems; whereas the Eastern Marine Economic Circle demonstrates stable progress through industrial synergy in marine carbon sequestration; and the Northern Marine Economic Circle exhibits catch-up development constrained by limiting natural conditions. Multidimensional assessment indicates the policy dimension achieved the most pronounced improvement, the environmental dimension maintained sustained high-level stability and the technological innovation dimension experienced notable fluctuations. Regionally, the Southern Economic Circle contributes disproportionately to national heterogeneity (>55%), with Shandong Province dominating inter-provincial disparities (mean contribution rate >50%). Conversely, Tianjin exhibits minimal influence on regional differentiation. Originality/value This study innovatively proposes the concept of marine carbon sink development quality and constructs a three-dimensional evaluation index system covering the three major dimensions of policy support, environmental carrying capacity and technological innovation to scientifically evaluate the development quality of marine carbon sinks in China’s coastal areas. On this basis, the study integrates and applies the kernel density estimation and Theil index methods to conduct empirical analysis, systematically revealing the patterns of developmental disparities and dynamic evolution characteristics among different marine economic zones and their internal provinces. This provides precise empirical evidence for formulating differentiated regional coordination policies, promoting the high-quality development of marine carbon sinks to serve the national “dual carbon” goals.