Towards low carbon urban agglomerations: spatiotemporal characteristics and influencing factors of carbon emission intensity and network linkages in China’s urban agglomerations

• BTHUA has the highest carbon emission intensity level. • Carbon emission linkages shows “dense in the east, sparse in the west” pattern. • Combining SDM and QAP model to reveal differences in the influencing factors of carbon emissions. • Detailed carbon emission reduction policy recommendations were proposed for each UA. Facing mounting climate challenges driven by rising CO 2 emissions, China—now the world’s largest emitter—must balance economic growth with decarbonization, making its urban agglomerations key arenas for low-carbon transition. This study explores the spatiotemporal characteristics and influencing factors of carbon emission intensity (CEI) and carbon emission network linkages in China’s major urban agglomerations (UAs), aiming to support the transition to low-carbon cities. Using spatial econometrics and QAP network analysis, we uncover significant spatiotemporal heterogeneity and spatial spillover effects across UAs. The results show that carbon emissions grew rapidly before 2013 and slowed thereafter, with the YRDUA having the highest total CE and the CCUA the lowest. CEI exhibits fluctuating trends, with BTHUA at the highest level and CCUA at the lowest. Notably, carbon emission linkages follow a “dense in the east, sparse in the west” pattern, with different UAs showing different characteristics of monocentric, dual-centric or dense network. The study highlights the complex interactions between carbon emissions and various socioeconomic and geographical factors, showing that inter-city distance significantly impacts emission linkages. Based on these findings, the paper offers policy recommendations for regionally coordinated emission reduction strategies, emphasizing the importance of respecting each UA’s development endowments. This research contributes new insights into urban carbon governance in China and provides actionable strategies for achieving low-carbon urban agglomerations.