The decoupling effect and driving factors of carbon footprint in megacities: The case study of Xi’an in western China

Abstract

China plans to pursue low-carbon development in its western megacities to control greenhouse gas emissions. Using the “2006 IPCC and the Chinese Guidelines”, the carbon footprint (CF), carbon carrying capacity, carbon deficit and carbon deficit pressure index of Xi’an were measured from 2007 to 2016. Then, the decoupling indicator was used to analyse the dynamic relationship between the urban CF and economic growth using partial least squares to explore the driving factors of CF. The results show that: (1) the CF increased from 23.34 million t CO2eq to 32.25 million t CO2eq, with average annual growth being 4.01%. The energy consumption accounts contributed 69.51%, far exceeding other accounts. (2) The carbon carrying capacity of Xi’an decreased from 7.78 million t CO2eq to 7.45 million t CO2eq, with an average annual reduction of 0.47%. The carbon deficit index fluctuated in the interval [−2.57%, 17.09%], indicating that Xi’an was in the ecological stress relief and the mildly enhanced zone. The total CF and the CF of each account exhibit a relationship of “connecting-decoupling-re-hook-re-decoupling” with economic growth. (3) The most important driver of CF growth is the per capita residential building area, while the urbanization rate restrains the growth of the CF.