Spatial Network Analysis of CO2 Emissions in Major Cities in China: Regional Structures and Influencing Factors

China’s rapid industrialization and urbanization have led to significant and imbalanced CO2 emissions, putting pressure on achieving sustainable development goals. This study analyzed the CO2 emissions of 31 major cities in China from different sectors (total, power, industry, and transport) from 2019 to 2022. This study constructs a city-scale CO2 emission correlation model to achieve nationwide and urban fine-scale research on CO2 emission spatial networks from different sectors. This study revealed the following: (i) there is an increasing correlation among regions in China, and collaborative governance is crucial; (ii) there are differences in the structure, characteristics, and roles of CO2 emission networks from different sectors; (iii) China’s CO2 emission network is mainly concentrated in the northern and eastern regions, which play an important role in emission reduction; and (iv) the impact factors have different effects on CO2 emissions from different sectors, and we should actively contribute to promoting emission reduction. Correctly understanding the spatial characteristics and influencing factors of CO2 emissions can help us formulate targeted and efficient emission reduction policies.