Carbon footprints of urban transition : Tracking circular economy promotions in Guiyang, China

Promoting urban transition is critical, particularly for China's rapid urbanization. Circular economy strategy is widely recognized as an effective way to achieve a low-carbon transition of cities through improved waste recycling and industrial symbiosis. However, the evidence of low-carbon benefit is less reported. While the carbon footprint (CFP) represents a mature tool responding to climate change concerns, limited studies have made use of CFP as a proxy for the performance of urban circular economy promotion. The aim of this paper is to investigate the CFP with a ten years span (2002–2012) of Guiyang, so as to understand how its circular economy practices have led to low-carbon benefits. Guiyang, one of China's national pilots of the Circular Economy (CE) City, the Low-Carbon City, as well as the Ecological Civilization City, has offered an ideal laboratory where the opportunities and challenges for a low-carbon urban transition can be explicitly discussed. A hybrid model that integrates an input-output (IO) approach and process-based inventory analysis is developed to distinguish between direct carbon emissions of sectors from energy consumption, and indirect carbon emissions related to upstream and downstream flows both from production and consumption perspectives. The CFP of Guiyang in 2002, 2007 (after becoming the circular economy pilot) and 2012 (with implementation of urban industrial symbiosis) are analyzed by taking the 2002 as year of business as usual (BAU) scenario. Particularly, we identify scenarios related to proposed urban industrial symbiosis. Results imply that dramatic resource saving and CFP reductions could be achieved simultaneously. Changes to the CFP in 2002, 2007 and 2012 provide critical insights into the role of circular economy in speeding up urban transition towards a low-carbon society. Finally, policy recommendations to tackle the barriers to regional low-carbon transition are proposed. We believe that this study is informative for policy makers of urban planning by shedding a light on innovative eco-industrial development and urban transition in China.