Decomposition and Decoupling of Transportation CO2: A Comparison of Areas with Different Economic Development in China

The gap between relatively developed and less developed areas in China has become more evident with economic development. However, only a few investigations have compared factors of transportation CO2 emissions in relatively developed and less developed areas at the micro level. Factors differ for transportation CO2 emissions between areas. To assess their differences, we select Guangdong and Guangxi provinces in China as examples. This study conducted a decoupling research between transportation CO2 emissions and economic output based on the Logarithmic Mean Divisia Index (LMDI) decomposition and Tapio decoupling model during 2000-2017. The LMDI model successfully quantified the effects of six factors, focusing on technology-related factors, i.e., research and development (R&D) efficiency and per capita R&D expenditure. Different factors of transportation CO2 emissions in the two provinces were then compared. Results were as follows: (1) Four decoupling states appeared in the two areas. (2) Per capita R&D expenditure was the primary contributor to increased CO2 emissions, followed by population size. Relative to those in Guangdong, the two effects were weaker in Guangxi. (3) Energy intensity was the major inhibitor of CO2 emissions in Guangdong, followed by R&D efficiency. The two effects can reduce CO2 emissions in Guangxi, although the inhibitory effects were relatively small. (4) Freight transportation intensity in Guangdong increased CO2 emissions, whereas it decreased CO2 emissions in Guangxi due to the extremely weak inhibitory effect. Finally, the study provides valuable suggestions for the development of low-carbon transportation in different areas.