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Abstract:The global urban transition increasingly positions cities as important influencers in determining sustainability outcomes. Urban sustainability literature tends to focus on the built environment as a solution space for reducing energy and materials demand; however, equally important is the consumption characteristics of the people who occupy the city. While size of dwelling and motor vehicle ownership are partially influenced by urban form, they are also influenced by cultural and socio-economic characteristics. Dietary choices and purchases of consumable goods are almost entirely driven by the latter. Using international field data that document urban ways of living, I develop lifestyle archetypes coupled with ecological footprint analysis to develop consumption benchmarks in the domains of: food, buildings, consumables, transportation, and water that correspond to various levels of demand on nature's services. I also explore the dimensions of transformation that would be needed in each of these domains for the per capita consumption patterns of urban dwellers to achieve ecological sustainability. The dimensions of transformation needed commensurate with ecological carrying capacity include: a 73% reduction in household energy use, a 96% reduction in motor vehicle ownership, a 78% reduction in per capita vehicle kilometres travelled, and a 79% reduction in air kilometres travelled.

Washington, D.C.-As the world continues down the path of unmitigated and unsustainable development, it is becoming increasingly clear that we have successfully pushed ourselves out of the stable geological era of the Holocene and into the more volatile and unpredictable Anthropocene. Nevertheless, many remain blissfully unaware

Ecological footprint analysis (EFA) can be used by cities to account for their on-going demands on global renewable resources. To date, EFA has not been fully implemented as an urban policy and planning tool in part due to limitations of local data availability. In this paper we focus on the material consumption component of the urban ecological footprint and identify the ‗component, solid waste life cycle assessment approach' as one that overcomes data limitations by using data many cities regularly collect: municipal, solid waste composition data which serves as a proxy for material consumption. The approach requires energy use and/or carbon dioxide emissions data from process LCA studies as well as agricultural and forest land data for calculation of a material's ecological footprint conversion value. We reviewed the process LCA literature for twelve materials commonly consumed in cities and determined ecological footprint conversion values for each. We found a limited number of original LCA studies but were able to generate a range of values for each material. Our set of values highlights the importance for cities to identify both the quantities consumed and per unit production impacts of a material. Some materials like textiles and aluminum have high ecological footprints but make up relatively smaller proportions of urban waste streams than products like paper and diapers. Local government use of the solid waste LCA approach helps to clearly identify the ecological loads associated with the waste they manage on behalf of their residents. This direct connection can be used to communicate to citizens about OPEN ACCESS Sustainability 2013, 5 1961 stewardship, recycling and ecologically responsible consumption choices that contribute to urban sustainability.

Although many cities are engaged in efforts to calculate and reduce their greenhouse gas (GHG) emissions, most are accounting for "scope one" emissions i.e., GHGs produced within urban boundaries (for example, following the protocol of the International Council for Local Environmental Initiatives). Cities should also account for the emissions associated with goods, services and materials consumed within their boundaries, "scope three" emissions. The emissions related to urban consumption patterns and choices greatly influence overall emissions that can be associated with an urban area. However, data constraints and GHG accounting complexity present challenges. In this paper we propose one approach that cities can take to measure the GHG emissions of their material consumption: the solid waste life cycle assessment (LCA) based approach. We used this approach to identify a set of materials commonly consumed within cities, and reviewed published life cycle assessment data to determine the GHG emissions associated with production of each. Our review reveals that among fourteen commonly consumed materials, textiles and aluminum are associated with the highest GHG emissions per tonne of production. Paper and plastics have relatively lower production emissions, but a potentially higher impact on overall emissions owing to their large proportions, by weight, in the consumption stream.