• GFI model is used to analyze the factors of transportation carbon emissions in Beijing. • Economic development, energy intensity and population size are positive drivers. • The effect of output value of per unit traffic turnover appears as a flat “M”. • Transportation intensity is the main inhibition factor. • Energy structure has little effect on transportation carbon emissions.

Carbon emissions in China have attracted increasing world attention with rapid urbanization of this country. It is critical for the government to identify the key factors causing these emissions and take controlling measures. Consistent results have not been achieved yet although some research has been conducted on the factors leading to emissions. Meanwhile, there is still considerable room to improve the methods of previous research. Index decomposition analysis (IDA) is the main method for quantifying the impact of different factors on carbon emissions. At present, the widely used forms of IDA are primarily the Laspeyres and the Divisia index methods. Compared with the Laspeyres and the majority of the Divisia index methods, the generalized Fisher index (GFI) decomposition method can eliminate the residuals and has better factor decomposition characteristics. This paper chooses Beijing as a typical example and analyzes the factors causing carbon emissions. Based on the extended Kaya identity, we built a multivariate generalized Fisher index decomposition model to measure the impacts of economic growth, population size, energy intensity and energy structure on energy-related carbon emissions from 1995 to 2012 in Beijing. The results show that the sustained growth of economic output in Beijing was the leading factor in carbon emissions. Population size had a stimulating effect on the growth of carbon emissions during this period; the pulling effect increased after 2003 and then decreased slightly after 2011 with a cumulative effect of 165.4%. Energy intensity was the primary factor restraining carbon emissions, and the inhibition effect increased yearly. The continuous optimization of the energy structure had no obvious inhibitory effect on carbon emissions. To control carbon emissions, Beijing should continue to adjust the mode of economic development and appropriately control the population size while improving energy efficiency