Application of life cycle thinking towards sustainable cities: A review

Abstract

Defining sustainable cities is not straightforward. The main issues involved in urban sustainability are buildings, energy, food, green areas and landscape, mobility, urban planning, water and waste; and their improvement is promoted through different strategies. However, a quantitative method, such as life cycle thinking (LCT), is essential to evaluating these strategies. This paper reviews LCT studies related to urban issues to identify the main research gaps in the evaluation of these improvement strategies. The review identifies the main sustainability strategies associated with each urban issue and compiles articles that deal with these strategies through LCT, including environmental life cycle assessment (LCA), life cycle costing (LCC), social LCA (S-LCA) and life cycle sustainability assessment (LCSA), as well as integrated analyses with combined tools. Water, waste and buildings are the urban issues that accounted for a larger amount of studies. In contrast, a limited number of papers assessed urban planning and energy (excluding energy in buildings). Strong interrelations among urban issues were identified, most of them including water. In terms of methods, 79% of the studies exclusively applied life cycle tools (i.e., LCA, LCC, S-LCA or LCSA). Within this group, the environmental dimension was the focus of 84% of the papers. Single environmental indicators (e.g., global warming) were common in 20% of the analyses, highlighting the need to integrate more impact categories to prevent trade-offs. In the field of social and sustainability assessment, there is a need for methodological advances that foster their application in urban areas. Further research should cover the thematic and methodological gaps identified in this paper, such as developing models that assess complex urban issues, generating comprehensive LCT studies and promoting multi-indicators. Life cycle tools might benefit from revising the methodology with stakeholders to optimize the understanding and communication of life cycle results for policy-and decision-making processes.

Multi‐functionality of nature‐based and other urban sustainability solutions: New York City study

“…Berardi et al's () comprehensive review of green roof benefits encourages more cross‐disciplinary, interresource studies. Petit‐Boix et al () further state that “as green areas are multi‐functional systems, studies should consider a complete set of impacts and benefits to estimate their real contribution to urban sustainability.” Oberndorfer et al () call for assessments that consider the aggregate benefits of GI, not only compare the environmental costs between infrastructure options.…”

Integrating lifecycle assessment and urban metabolism at city level: Comparison between Spanish cities

“…Moreover, an exponential population growth of around 2.5 billion people is projected all over the world by 2050, with an associated trend toward urbanization (Pincetl, Bunje, & Holmes, ; United Nations, ). Thus, urban areas can be considered to be hotspots facing multiple environmental problems at several scales, linked to the demand for resources (energy, food, fossil fuels and water, among other goods) and the generation of pollution in sustaining their citizens (Dias, Lemos, Gabarrell, & Arroja, ; Petit‐Boix et al., ). The identification of a broad framework that captures the energy and material flows related to an individual urban area is therefore critical.…”

“…There are concerns that urbanization may be an important driving force of unsustainable resource demands (Satterthwaite, ). An urban population also requires additional services for its subsistence, such as cultural, economic, educational, and institutional factors (Petit‐Boix et al., ; Phillis, Kouikoglou, & Verdugo, ). Urbanization involves economic advantages for businesses (since the majority of private investment is concentrated in urban areas) that can give rise to environmental advantages, although these depend on the choices made by the inhabitants regarding resource use and waste generation (Satterthwaite, ).…”

Applying the SDGs to cities: business as usual or new dawn?

“…Cities have been and are using indicators to a larger or lesser degree to assess the development of social issues [21,22] and environmental conditions [23] as well as economic development [22]. During the last two decades there have been many attempts by international organisations and cities themselves, as well as private and interest groups, to develop indicators and indicator sets to monitor cities' sustainable development [24], accompanied by a proliferation of different monitoring methods [12,25].…”