Driving Factors of Transportation CO2 Emissions in Beijing: An Analysis from the Perspective of Urban Development

There is a coupling relationship between the development of urban transportation and cities: Urban growth leads to increase in the demand for urban transportation and consequently, a lot of transportation emissions. Therefore, an in-depth understanding of the mechanism behind the driving effect of urban development on transportation emissions is a crucial prerequisite for coordinated development of low-carbon urban transportation and cities. Based on the oil product allocation method, this paper estimates the transportation emission in Beijing from 1995 to 2016. Then based on the understanding of the driving mechanism, this paper applies the urban allometric scaling law to analyze the relationship between city size and transportation emission. Finally, the driving mechanism is analyzed using the STRIPAT model. The results reveal a superlinear relationship between transportation emission in Beijing and the expansion of the city, as the former outgrew the latter. Population size, urbanization, economic size, industrial structure, spatial scale and infrastructure construction are positive driving factors of transportation emission, whereas progress of energy technologies as a negative driving factor can restrain the growth of transportation emission. Urbanization has the most significant impact on urban transportation emission, and economic size contributes the most to the growth of transportation emission. Based on the results, we make a few policy recommendations for low-carbon urban transportation of Beijing, which include: improving transportation efficiency in the process of urbanization; promoting energy conservation and emission reduction while pursuing economic development so as to decouple transportation emission from urban development; restricting unordered urban expansion and updating the concept of transportation infrastructure supply; and developing energy technologies to improve energy efficiency.