Decomposition and attribution analysis of the transport sector's carbon dioxide intensity change in China

Understanding the factors driving changes in transport carbon dioxide (CO2) intensity and the contributions of different regions to each factor helps inform targeted emissions reduction policies. This paper provides a comprehensive approach, combining index decomposition analysis (IDA), production-theoretical decomposition analysis (PDA) and attribution analysis (AA), to decompose the changes in transport CO2 intensity into nine factors and identify the contributions of different regions to the individual factors. Energy-related and transport-related factors are considered simultaneously and some new factors are created to provide additional insights for exploring changes in transport CO2 intensity. An empirical study of the transport sector across 30 Chinese PARs (provincial administrative regions) resulted in three key findings. First, the effect of potential transport energy intensity and the effect of the economic output technology were the major drivers for the reduction in transport CO2 intensity, while the effect of potential transport intensity and the effect of energy utilization technology were the major factors that increased the transport CO2 intensity. Second, due to the diverse transport sector characteristics of the 30 PARs, their contributions to the four driving factors for the transport CO2 intensity mitigation varied. Third, specific policy implications in terms of energy conservation and transport management policy were proposed for the 30 PARs.