28 June 2012
Definition: There are several ways to define sustainability. One, attributed to the “Brundtland Commission” considers sustainability to be the ability to satisfy current needs without compromising the ability of future generations to meet their needs. This definition rests on intergenerational equity. The second generation focuses on equity at the current moment, and holds the needs of classes, ethnic groups, or nations who are less empowered, to have a legitimate stake in the satisfaction of needs. A third definition can also be identified. It focuses on the capacity of people to live within the capacities of ecosystems to support them. This, in a sense, is the most fundamental definition of sustainability. It hews very close to the ordinary definition of sustainability in the sense of sustenance or support.
Examples: Applying the concept of sustainability to urban systems requires some caution. From an environmental standpoint, no urban area is strictly sustainable. Large urban areas, including suburbs, and their non-agricultural exurbs, do not supply their own food, cleansing capacities, or other environmental benefits (see Ecosystem Services). However, city, suburban, exurban systems that contribute toward their food needs, environmental cleansing, carbon storage, and pollution reduction, for example, can be said to be more sustainable than those which do not make the same kinds of contributions. Urban sustainability is thus a relative condition.
Why important: No activity that claims a benefit to sustainability can be narrowly construed. All definitions of sustainability from the 1980s on, recognize that sustainability has three inextricably linked components – economic, social, and environmental. Thus, people often speak of a “triple bottom line” in making any decision, so that the health of the economy, of the environment, and of social equity are all supported by decisions and actions that enhance sustainability. None of the three aspects of sustainability trumps the others. Given that urban sustainability is a relative condition, there are many activities and strategies cities, suburbs, and urbanized exurbs can make toward sustainability.
For more information:
Williams, D.E. 2007. Sustainable Design: Ecology, Architecture, and Planning. Wiley, Hoboken NJ.Curwell, S., M. Deakin, and M. Symes, editors. 2005. Sustainable urban development, volume 1: the framework and protocols for environmental assessment. Routledge, New York.