Determining differences in regional carbon emissions and the factors that affect these differences is important in the realization of differentiated emissions mitigation policies. This paper adopts the Theil index and the partial least square-variable importance of projection (PLS-VIP) method to analyze the change characteristics, regional differences and causes of carbon emissions, as well as the extent to which various factors influenced carbon emissions in China’s eight economic regions in 2005–2017. The results indicate that (1) during the study period, carbon emissions in the eight economic regions displayed a rigid uptrend with a phased characteristic. The growth rates of carbon emissions were different across the studied regions. (2) The overall difference in regional carbon emissions showed an increasing trend, mainly owing to increasing interregional differences. (3) The extent of the influence and explanatory ability of each factor on regional carbon emissions and discrepancies in carbon emissions were different. Population size, economic development, and energy intensity were found to be the three main factors influencing regional carbon emission changes. Industrial structure and urbanization were also contributors to regional differences in emissions. The influence of energy structure on regional carbon emissions and its explanatory power were weak on the whole, but its elastic coefficients and VIP values changed significantly. Finally, regionally targeted proposals for emissions mitigation are offered.

Facing the growing problem of carbon emission pollution, the scientific and reasonable division of environmental management power between governments is the premise and institutional foundation for realizing China’s carbon emission reduction target in 2030. In this article, we directly assess the degree of environmental decentralization according to the allocation of environmental managers among different levels of government. By incorporating fiscal decentralization indicators, the provincial panel data and dynamic spatial econometric model are used to empirically test the impact of environmental decentralization on carbon emissions from a spatial perspective. The results show that (1) China’s provincial carbon emissions have significant inertia dependence and spatial path dependence. The increase (decrease) of provincial carbon emissions will lead to the increase (decrease) of carbon emissions in neighboring regions. (2) At the national level, environmental decentralization, environmental administrative decentralization, and environmental monitoring decentralization significantly reduce China’s carbon emissions, while environmental supervision decentralization and fiscal decentralization significantly increase carbon emissions. Similarly, the interaction of environmental decentralization and its decomposition indicators and fiscal decentralization also significantly promotes carbon emissions, and the impact is related to the types of environmental management decentralization. (3) The carbon emission effects of environmental decentralization in different regions are heterogeneous. The inhibition effect of environmental decentralization, environmental administrative decentralization, and environmental monitoring decentralization on carbon emissions in the western region is significantly greater than that in the eastern and central regions, but the inhibitory effect of the interaction of environmental decentralization and its decomposition index and fiscal decentralization on carbon emissions in the eastern region was significantly stronger than that in the central and western regions. The above results provide theoretical support for China to construct a differentiated carbon emission environmental management system from two aspects of regional differences and environmental management power categories.

Facing the growing problem of carbon emission pollution, the scientific and reasonable division of environmental management power between governments is the premise and institutional foundation for realizing China's carbon emission reduction target in 2030. Although existing studies have focused on the relationship between Chinese decentralization and carbon emissions, most of them are based on fiscal decentralization indicators to depict China's environmental decentralization, lacking of systematic analysis and empirical test of institutional factors affecting carbon emissions from the perspective of environmental management. In this paper, we directly assess the environmental decentralization degree according to the allocation of environmental management personnel among different levels of government. By incorporating fiscal decentralization indicators, the provincial panel data and dynamic spatial econometric model are used to empirically test the impact of environmental decentralization on carbon emissions from spatial perspective. The study found that: (1) China's provincial carbon emissions have a significant positive spatial autocorrelation, showing a clear trend of high-high, low-low aggregation, and the carbon emissions of the previous period and the current have an obvious positive relationship. (2) At the national level, environmental decentralization, environmental administrative decentralization and environmental monitoring decentralization significantly reduce China's carbon emissions, while environmental supervision decentralization and fiscal decentralization significantly aggravate carbon emissions, which means that China's current environmental decentralization systems are generally conducive to carbon emission governance. The interaction between fiscal decentralization and environmental decentralization with its decomposition indicators significantly promotes carbon emissions, and its impact is related to the category of environmental decentralization, indicating that when local governments have greater environmental management power and fiscal autonomy, the combination of the two will push up carbon emissions. (3) The carbon emission effects of environmental decentralization in different regions are spatially heterogeneous. In the central region, environmental decentralization, environmental administrative decentralization and environmental supervision decentralization can promote carbon emissions apart from environmental monitoring decentralization. In the western region, the carbon emission suppression effect of environmental decentralization, environmental administrative decentralization and environmental monitoring decentralization is stronger than the eastern region, but the inhibitory effect of fiscal decentralization and environmental decentralization with its decomposition index interaction on carbon emissions in the eastern region is significantly better than the central and western regions. The above results provide policy ideas and theoretical support for the construction of the environmental management system with long-term carbon emission control in China in terms of regional differences and categories of environmental management power.