In urban ecology, human settlements are seen as dynamic ecosystems whose structures are defined by the built and natural environments, population demographics, social institutions, and culture, as well as belief, economic, and political systems (1). They are dissipative structures, meaning that they require huge inputs of energy, and produce amounts of waste in proportion to the materials they consume. From reading the literature in this field, human settlements seem to be akin to parasites, in that they undermine the very ecosystems that support them. I would tend to agree with this perspective.
From this “city as ecosystem” perspective, the doctrine of sustainability has emerged, and revolves around the concept of ‘the three Es’ - Environment, Economy, and social Equity. Sustainable neighbourhood development then refers to the balanced consideration of environmental, social and economic goals, with specific objectives that include minimizing environmental impact, sustaining a high quality of life, and financing infrastructure in an equitable and efficient manner (2) – so that humans and their settlements can exist well into the future.
It should by now be quite apparent that our current space gobbling method for designing communities is environmentally (and in some instances, financially) unsustainable – see Health by Design: Part 1. However, if you need more convincing I can humour you with some extra facts and figures. In Canada for instance, passenger travel has increased by 30% (passenger km traveled per capita) from 1990 – 2008, and we travel mostly by personal passenger vehicle, not public transportation (85% of all ground-based transportation in 2008)(3). Increasing passenger vehicle use has led to an unprecedented rise in GHG emissions in Canada (and North America) – it now contributes 20% of all GHG emissions in Canada (3). Suburban sprawl also requires the continual creation of paved roadways that often disrupt and damage human communities, as well as natural ecosystems, which have the capacity to recycle harmful outputs of suburban living (4). Increasing paved surfaces also increases water runoff, which increases the chance of raw sewage flowing directly into lakes and rivers when storm sewers are overwhelmed. As an aside, New York is now having to deal with aging infrastructure and is considering going green for the environment and its pocket book. Finally, a large bulk of infrastructure funding is diverted to road repair, financing that could be spent elsewhere to improve neighbourhood liveability.
A sustainable neighbourhood design is, by its very nature, obesity preventive. The series Health by Design was originally supposed to be two posts, but I realized that I should probably more fully explain the characteristics of a sustainable neighbourhood design and how that relates to obesity prevention before I started discussing the effectiveness of the Fused Grid design. Since no one likes long posts, I’ll divide this into a series of four posts that focus on aesthetics, safety, diversity and compactness, and connectivity. This first post (coming soon) will begin with aesthetics.
(1) Grimm N, Baker LJ, Hope D. An ecosystem approach to understanding cities: Familiar foundations and unchartered frontiers. In: Berkowitz AR, Nilon CH, Hollweg KS, editors. Understanding urban ecosystems: A new frontier for science and education.New York: Springer-Verlag; 1999. p. 95-105
(2) Jabareen YR. Sustainable urban forms: Their typologies, models, and concepts. Journal of Planning Education and Research 2006;26:38-52.
(3) Environment Canada. National Inventory Report: 1990-2008 Part I. Greenhouse gas sources and sinks in Canada: The Canadian Government's Submission to the UN Framework Convention on Climate Change. Available at: http://www.ec.gc.ca/publications/492D914C-2EAB-47AB-A045-C62B2CDACC29/NationalInventoryReport19902008GreenhouseGasSourcesAndSinksInCanada.pdf
(4) Lopez R, Hynes HP. Obesity, physical activity, and the urban environment: public health research needs. Environmental Health: A Global Access Science Source 2006;5(1):25-32.