Green Low-Carbon Transition Efficiency in China's Yangtze River Economic Belt: A Global Super-Efficiency SBM Analysis with Implications for Land Use Management

Urban green low-carbon transition requires land use planning that coordinates construction-land development, redevelopment, and ecological protection. This study evaluates transition efficiency in 108 cities in China’s Yangtze River Economic Belt during 2012–2023 using a global super-efficiency slacks-based measure model with undesirable outputs. Inputs comprise labor, electricity, construction land, capital stock, and water supply; desirable outputs include real GDP (gross domestic product) and a green-space-based carbon-sink proxy; undesirable outputs comprise wastewater, sulfur dioxide, dust, and carbon dioxide emissions. Temporal, distributional, regional, spatial, and city-typology analyses reveal initial fluctuations, subsequent adjustment, and recent recovery. Under the baseline land-data treatment, the 2023 rebound accompanies wider dispersion, with the proportion of observations scoring 1.3000 increasing from 6.48% in 2022 to 22.22% in 2023. Improvement is therefore concentrated in the upper tail. A comparison of reported scores through 2022 also identifies recovery between 2021 and 2022, although it does not isolate the frontier effects of extrapolated 2023 construction-land inputs. The lower reaches and eastern subregion generally outperform the middle reaches and central subregion. Global Moran’s I is small and mostly insignificant, suggesting limited basin-wide spatial association. The coexistence of leading, catching-up, and lagging cities supports differentiated land use governance. Policy implications include linking discretionary construction-land quotas to verified green low-carbon performance, prioritizing redevelopment of underused land, and applying watershed-specific controls consistent with ecological protection red lines.