Carbon flow of urban system and its policy implications: The case of Nanjing
Rongqin Zhao, Xianjin Huang, Taiyang Zhong, Ying Liu, Xiaowei Chuai
Renewable and Sustainable Energy Reviews 33(2014)589–601
Abstract: China is now in the process of rapid urbanization. City's operating efﬁciency was directly determined by the scale and efﬁciency of energy consumption and ﬂow. The pattern, scale and efﬁciency of urban carbon ﬂow are not only important indicators that reﬂect urban efﬁciency and sustainable development, but also important references in the formulating low-carbon and sustainable energy polices for cities. Through establishing atheoretical framework and calculation method, this paper studied the carbon ﬂows of Nanjing urban system in three different levels. It shows that urban production and transportation system, urban living system, rural production system and rural living systems are the major part of urban system in the carbon ﬂow. The carbon ﬂows between Nanjing and the external system, was much higher than the carbon ﬂows among different internal subsystems. If the embodied carbon is taken into account, carbon ﬂow from the urban to rural system of Nanjing was clearly greater than the ﬂow in the opposite direction. With economic development and the implement of energy-saving and emission reduction policy, the carbon productivity and carbon ﬂow efﬁciency in Nanjing has improved signiﬁcantly since 2000. Fossil energy consumption, urbanization, agricultural activities, rural life demands and trade are key factors with major impact on urban carbon ﬂows in Nanjing. Therefore, adjusting industrial structure, urban expansion control, and developing renewable energy are main measure storealize sustainable development of Najing city. Furthermore, the dual urban–rural structure in Nanjing brought large exchanges of products and embodied carbon between urban and rural areas, indicates that urban carbon ﬂow and its efﬁciency was highly inﬂuenced by urban rural structure, which will further aggravate carbon ﬂow burden of urban systems.
Keywords: Carbon ﬂows; Energy consumption; Energy efﬁciency; Embodied carbon; Urban system