Spatial correlation investigation of carbon emission efficiency in the Yangtze River Delta of China: The role of low-carbon pilot cities

• Low-carbon pilot cities in the YRD strengthen regional CEE through integration. • Trade openness speeds low-carbon tech adoption and improves CEE correlations. • Economic collaboration in similar cities enhances low-carbon tech sharing. • Reduced energy structure disparities enhance the spatial connection of urban CEE. • Nanjing, Suzhou, and key cities should lead low-carbon pilot efforts in YRD. Mitigating urban carbon emissions is vital for global sustainable development. Low-carbon city pilot programs are key in China’s transition to a low-carbon economy, enhancing energy efficiency, shifting to sustainable energy, and promoting industrial restructuring. This study addresses the radiative and driving effects of these programs on non-pilot cities using Social Network Analysis (SNA) and Quadratic Assignment Procedure (QAP) regression to explore the spatial correlation of carbon emission efficiency (CEE) among cities in the Yangtze River Delta (YRD). Results show that since 2010, CEE spatial correlations have strengthened due to regional integration and pilot initiatives. Core cities like Shanghai, Nanjing, and Suzhou exhibit significant spillover effects, fostering regional low-carbon development. Peripheral cities benefit from these effects, highlighting the importance of core-periphery dynamics. Key factors influencing CEE spatial correlations include geographical proximity, trade openness, economic development, technology development activity, and energy structure, with trade openness enabling access to low-carbon technologies and policy alignment. The study suggests strategically selecting future pilot cities to optimize CEE, focusing on pivotal and economically open cities to enhance regional collaboration and improve carbon reduction efforts across the YRD.