Unveiling the competitive dynamics between economic development and CO2 emissions in China's urban clusters: insights from structural characteristics, technological changes, and efficiency optimization

To clarify the competitive dynamics between economic development and CO2 emissions in urban clusters. This article explores the decoupling status and driving factors of China's major urban clusters by constructing a comprehensive decomposition model incorporating the decoupling index, LMDI, and PDA methodologies. Findings reveal that (1) during 2006-2019 the overall decoupling status of China's eight urban clusters underwent five distinct phases and was dominated by weak decoupling. The Yangtze River Delta exerted the most significant inhibitory effect on overall carbon decoupling. (2) Among the structural factors, population size, economic development, and population agglomeration hindered overall carbon decoupling, while the urban cluster's economic structure effect facilitated it. For technology and efficiency factors, the potential CO2 emission intensity played the most prominent role in promoting carbon decoupling. Additionally, efficiency factors and the technology efficiency gap all played positive roles. Conversely, the reduction and production technology did not contribute to carbon decoupling within the sample period. (3) During 2006-2019, each urban cluster exhibited a state of weak decoupling but with noticeable variations in low-carbon development pathways and driving factors. Additionally, all 135 cities within urban clusters sustained a state of weak decoupling, indicating that the emission reduction efforts have effectively avoided economic costs.