Evaluation of key node groups of embodied carbon emission transfer network in China based on complex network control theory

Abstract

China has committed to enhancing its national efforts to peak CO2 emissions by 2030. Rather than applying broad emission reduction measures nationwide, a more efficient strategy involves focusing on select provinces and sectors as pioneers in emission reduction. This targeted approach is expected to drive broader, nationwide progress towards the carbon emission reduction goal, thereby improving the effectiveness of emission reduction policies. This study integrates complex network control theory with input–output modeling to develop a detailed analysis of the embodied carbon emission (EC) transfer network at the province-sector level in China for the year 2017. By examining the network’s characteristics and identifying key nodes for control, the study arrives at several notable findings: (1) EC transfers predominantly flow from central and northern provinces to the economically vibrant southeast provinces, and from energy-intensive sectors towards services, manufacturing, and others. (2) The network’s structure follows a scale-free distribution, indicating that a limited number of provincial sectors are central to the network, managing a majority of EC transfers and thus playing a crucial role. (3) Utilizing complex network control theory, an algorithm was developed to identify optimal control nodes, aiming to minimize the costs associated with emission reduction. This approach identified 287 provincial sectors, about one-third of the total, while keeping abatement costs below one-fourth of potential expenses. (4) The identified crucial control nodes consist of approximately 38% source nodes and 20% isolated nodes. Sectors downstream of these source nodes, such as sec04, sec05, and sec22, show significant node strength and betweenness centrality, enhancing the spread of emission reduction impacts. (5) When compared to other node selection strategies, the algorithm not only achieves complete network control but also minimizes abatement costs effectively. This research offers valuable insights for policymakers on the dynamics of interregional trade and EC management. It supports the formulation of a strategic, long-term plan for collaborative emission reduction across provinces and sectors, aligning with China’s environmental commitments.