| Carbon emission is closely related to economic development,and how to achieve economic decarbonization has become one of the key issues urgently needed to be solved on the road of carbon peak and carbon neutral development in China.The decoupling effect of economic development and carbon emissions is an important indicator to measure the level of economic decarbonization.For the decoupling effect about China,scholars mostly studied it from the national level or provincial level and analyzed the driving factors indirectly,the cities’ decoupling effect and its influencing factors are not clear yet.In addition,the carbon emissions related with social and economic activities mainly come from the production process,while the carbon emission efficiency is an indicator to reflect the relationship between economic development and carbon emissions by taking the production process into consideration.Improving the carbon emission efficiency is an important way to promote economic decarbonization.For the carbon emission efficiency about China,several scholars have studied its deferences among cities with different geographical location,economic development level,urbanization level and so on,lacking of the research that combining decoupling effect to carbon efficiency.The carbon emission efficiency of Chinese cities and how to improve it are not yet clear.Therefore,by taking 284 cities in China as the research object,this dissertation researched the decoupling effect and carbon emission efficiency from the city-level to advance economic decarbonization.The main contents and results are as follows:(1)Based on Tapio decoupling theory,the decoupling effect of carbon emissions from economic growth was analyzed at China’s city?level,finding that strong decoupling,weak decoupling,expansion coupling and expansion negative decoupling were the main decoupling status for Chinese cities.Then the driving factors of decoupling effect were studied directly by decomposing the decoupling effect with LMDI decomposition method.The results showed that energy structure and energy intensity were the main reasons for the difference of decoupling effect among cities with different decoupling status.Improving efficiency to optimize energy structure and reduce energy intensity is crucial to promote the decoupling between economic development and carbon emissions.(2)Using the super-efficiency SBM-DEA model,this dissertation analyzed the carbon emission efficiency of Chinese cities from a static perspective.The results showed that carbon emission efficiency level of Chinese cities was mainly concentrated in the range of 0.2 to 0.6,and strong decoupling cities were most likely to reach the effective level.Secondly,this dissertation divided Chinese cities into strong decoupling cities,weak decoupling cities,expansion coupled cities and expansion negative decoupling cities based on decoupling effect,and then studied the influencing factors of carbon emission efficiency of those kinds of cities,respectively.The results showed that economic development level and population size were the main factors to improve the carbon emission efficiency,public transport facility was the main factor to reduce the carbon emission efficiency,while industrial structure,consumption tendency and foreign direct investment were the main factors that leading to the difference of carbon emission efficiency of cities with different decoupling status.Developing green economy and providing population quality are important ways to improve the carbon emission efficiency of Chinese cities.(3)Using the DEA-Malmquist index model,this dissertation studies the dynamic changes of carbon emission efficiency of Chinese cities,from the dynamic perspective,finding that the carbon emission efficiency index of Chinese cities showed an overall trend of growth,and the number of cities with increasing carbon emission efficiency year by year kept increasing.In addition,combined with decoupling effect,the driving factors of dynamic change of carbon emission efficiency were studied by decomposition analysis method.The results showed that technological change and pure technological efficiency change can inhibit and promote the growth of carbon emission efficiency respectively,and they were the main factors for the difference of carbon emission efficiency index between strong decoupling cities and expansion negative decoupling cities.The mean fluctuation of scale efficiency change index was small,and its effect on dynamic change of carbon emission efficiency was not obvious.Promoting regional and trans-regional cooperation,to improve the scale efficiency of strong decoupling cities and weak decoupling cities,and advance the technological progress of expanding coupled cities and expanding negative decoupling cities,is of great significance to realize the year-by-year increase of carbon emission efficiency of Chinese cities. |
