Analysis of regional decoupling relationship between energy-related CO2 emission and economic growth in China

China has become the biggest CO2 emitter in the world. In China, economic development in different regions is not the same. Thus, it is necessary to study the regional decoupling relationship between energy-related CO2 emission and economic development. Considering the regional difference of economic development, energy consumption and CO2 emission, provincial regions in China are divided into seven economic bands. The Tapio decoupling method is adopted to calculate the decoupling index in the seven regions over the study period 1996-2013. Furthermore, the WCDM is developed to study the driving factors governing the decoupling state. The result showed that decoupling development differed in each economic band; North-East and North-West, showed a better trend and a worse one, respectively, than the others. Economic factor showed a stable trend of negative effect, and energy intensity factor was the crucial factor to accelerate the process of CO2 emission decoupling. Only in Yangtze River delta, economic band had structural factor shown a positive effect during the research period, and emission efficiency factor was not stable and showed a negative effect in most years in every region.