Carbon emission efficiency network formation mechanism and spatial correlation complexity analysis: Taking the Yangtze River Economic Belt as an example

The spatial correlation of carbon emissions poses new challenges to constructing ecological civilisation and sustainable development in the Yangtze River Economic Belt. This study explains the formation mechanism of the carbon emission efficiency network and attempts to explore its structural complexity and spatial directivity. It focuses on the carbon emission efficiency network's structural entropy, node efficiency, hierarchy, connection symmetry, and transmission characteristics. The main conclusions are as follows: (1) The carbon emission efficiency of the Yangtze River Economic Belt has significantly improved, and the gap between cities is narrowing, but there is gradient differentiation on the provincial spatial scale that exhibits a strong Matthew effect; (2) There is an imbalance in carbon emission efficiency, which is primarily reflected in spatial distribution and hierarchical structure. Low-efficiency cities have played an important role in promoting the spatial evolution of carbon emission efficiency in the Yangtze River Economic Belt, but they have not completely changed the imbalance in carbon emission efficiency; (3) Supporting sub-networks and basic sub-networks have emerged as critical groups in promoting the complexity of carbon emission efficiency network structures, and have formed distinctive network structures in different basins of the Yangtze River; (4) The overall convergence of the carbon emission efficiency network has improved, and it exhibits preference attachment characteristics. The connection symmetry has been reduced from 5 to 7 times to 1 to 3 times, and the situation of unilateral unequal connection has been alleviated. Finally, this study puts forward some policy suggestions to improve carbon emission efficiency from the aspects of low-carbon technology research and development and carbon emission rights market construction.