Spatial connection strength and endogenous and exogenous interactive driving factors of carbon efficiency in China's metropolitan areas with higher energy consumption

Investigating the spatial effects and driving factors of carbon efficiency is meaningful for the sustainable development of metropolitan areas. However, research on the spatial connection strength and endogenous and exogenous interactive driving factors for metropolitan areas' carbon efficiency are limited. This research studies the carbon efficiency in China's metropolitan areas within year 2003–2019. The spatial connection strength using the gravity model with the “dual” driving factors and the geographical detector are analyzed. The results show that: 1) Shanghai metropolitan area performs well and promotes the development of neighboring cities, but Shenyang and Taiyuan metropolitan areas have negative effects on the neighboring cities; 2) The interaction between land resource consumption and pollution index, energy consumption and economic development level is the main endogenous driving factor with the determinant force values of 0.712, 0.674 and 0.634. Energy consumption is a secondary endogenous factor. Capital input, labor input and pollution play weaker roles. 3) Openness degree and education development level and their interaction are the main exogenous driving factors of carbon efficiency in China's metropolitan areas with the determinant force value of 0.673. Based on the results of interactive driving factors of China's metropolitan areas, this paper gives policy suggestions accordingly.