sustainable cities and communities

Despite being a fundamental concept to build sustainable cities and communities, the concept of urban metabolism is applied to very few cities globally largely owing to data constraints (Kennedy et al. 2007; Minx et al. 2011). Apart from it’s application to the specific cities such as the study by Newman (1999) on Sydney and 5 cities by Goldstein et al. (2013), there are very few studies which applied the concept of extended metabolism to many number of cities. Applying this concept to a larger number of cities where consistent data is available provides further insights whether large cities are more eco-efficient in comparison to smaller cities and the crucial role population density, economic structure and affluence play in determining a city’s eco-efficiency. Moreover, such an exercise will enable policy makers to identify best performing cities in terms of their metabolic efficiency. This procedure, which is characterized by systematic search for efficient procedures and best practices for complicated problems leading to enhanced performance, is often referred to as “Benchmarking” in operations research (Dattakumar and Jagadeesh 2003; Elmuti and Kathawala 1997; Moriarty 2011). The concept of benchmarking so far has been applied to cities to identify best practices with respect to urban competitiveness (Arribas-Bel et al. 2013; Charnes et al. 1989; Jiang and Shen 2013; Kresl and Singh 1999), urban infrastructure service delivery (Fancello et al. 2014; Matas 1998; Pina and Torres 2001) and urban energy consumption and GHG emissions (Ahmad et al. 2015; Dhakal 2009; Hillman and Ramaswami 2010; Keirstead 2013; Kennedy et al. 2009; Sovacool and Brown 2010).

Since cities are primary drivers of global environmental change (Pincetl et al. 2012; Seto and Satterthwaite 2010), benchmarking eco-efficiency of cities could foster peer-to-peer learning of good practices for sustainable urban development between local policy makers. Further, a study by Marans (2015) depicted that the quality of life and liveability has a strong influence on urbanites’ perception. Therefore, there is a need to relate urbanites’ perception about the quality of life with eco-efficiency of cities to understand whether the most eco-efficient cities are well perceived by their citizens and to identify the crucial factors determining urbanites’ perception about quality of life.

Urban metabolism and factors influencing eco-efficiency in cities
Being a fundamental concept in developing sustainable cities, urban metabolism practically involves large scale quantification of energy and resource flows in cities (Kennedy et al. 2011). The seminal work of Wolman (1965) on city metabolism lead to copious research in this field. Kennedy et al. (2011) highlighted how this study resulted in two non-conflicting schools of urban metabolism. One school addresses urban metabolism in terms of energy equivalents from a systems ecology perspective. The other describes urban metabolism in terms of life cycle assessments of material flow analysis from an industrial ecology perspective. Both these schools on urban metabolism involve city scale quantification of inputs and outputs of materials, natural resources and energy balances.