Getting Serious About Urban Sustainability


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William E. Rees' presentation for the Penn IUR conference

"Re-Imagining Cities: Urban Design After the Age of Oil"

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Getting Serious About Urban Sustainability

  1. 1. Getting Serious About Urban Sustainability William E. Rees, PhD, FRSC Re-Imagining Cities: Urban Design After Oil Breakout Sessions – New Urban Forms and Strategies Regional Urban Design University of Pennsylvania, 7 November 2008
  2. 2. Framing Premise <ul><li>“ Today’s city is the most vulnerable social structure ever conceived by man” (Martin Oppenheimer). </li></ul><ul><li>Cities are threatened by: </li></ul><ul><ul><ul><li>Peak oil </li></ul></ul></ul><ul><ul><ul><li>Land degradation, soil loss, and various incipient resources shortages (e.g., ‘peak phosphorus’) </li></ul></ul></ul><ul><ul><ul><li>Climate change (e.g., rising sea levels) </li></ul></ul></ul><ul><ul><ul><li>Resultant geopolitical instability </li></ul></ul></ul>
  3. 3. Context: The Anomalous, Unsustainable Oil-Based Expansion of the Human Enterprise Continuous growth—population and economic—is an anomaly. The growth spurt that recent generations take to be normal is the single most abnormal period of human history. 2008 Population: 6.8 billion The use of fossil fuel beginning in the 19 th Century allowed the explosive growth of the human enterprise
  4. 4. Result: A World in Overshoot <ul><li>The human enterprise already exceeds global carrying capacity by 25-30%. </li></ul><ul><li>We reached ‘overshoot day’ for 2008 on 23 September. </li></ul><ul><li>For the rest of the year, humanity will live by depleting natural capital. </li></ul>Humanity’s Ecological Footprint, 1961-2005
  5. 5. As presently conceived and designed, cities are not complete (human) ecosystems (Enclosed in a bell-jar, any city would simultaneously starve and suffocate)
  6. 6. In biophysical terms, cities as presently conceived, are parasitic on the global hinterland <ul><li>“ Great cities are planned and grow without any regard for the fact that they are parasites on the countryside which must somehow supply food, water, air, and degrade huge quantities of wastes” (Odum 1971). </li></ul>
  7. 7. Redefining the Urban Ecosystem (Recognizing two discrete spatial components) <ul><li>In thermodynamic terms, ‘the city’ (defined as built-up area) is mainly a ‘dissipative structure’, a node of intense energy and material consumption and waste production. </li></ul><ul><li>The complementary production-assimilation component of the urban ecosystem lies outside of, ‘the city.’ </li></ul><ul><li>This extra-urban area—i.e., the city’s external eco-footprint —is usually two to three orders of magnitude larger than the built up area of the city. However: </li></ul><ul><li>It is an integral component of the urban ecosystem complex. </li></ul>Edward Burtynsky, Nickel Tailings
  8. 8. E.g., the twenty-nine largest cities of Baltic Europe have an eco-footprint 565-1130 times as large as the cities themselves <ul><li>Blocks on the left represent ecosystem area appropriated for resource production (biocapacity). </li></ul><ul><li>Blocks on the right represent ecosystem area appropriated exclusively for waste assimilation under two sets of assumptions. </li></ul>
  9. 9. On a finite planet, there is another really “inconvenient truth”: We must give up material growth <ul><li>“ Industrialized world reductions in material consumption, energy use, and environmental degradation of over 90% will be required by 2040 to meet the needs of a growing world population fairly within the planet’s ecological means” (BCSD 1993). </li></ul><ul><li>North Americans should be taking steps to reduce their ecological footprints by at least 80% from about 9 global average ha to an equitable Earth-share (1.8 gha). </li></ul>
  10. 10. Cities have an advantage: The Urban Sustainability Multiplier <ul><li>a high proportion of multiple-family dwelling units which reduces per capita consumption of building materials and service infrastructure. </li></ul><ul><li>a greater range of options for recycling, reuse and re-manufacturing, and a concentration of the skills needed to make these things happen. </li></ul><ul><li>greater possibilities for electricity co-generation and the use of waste process heat from industry or power plants to reduce the per capita use of fossil fuels. </li></ul><ul><li>great potential for reducing (mostly fossil) energy consumption by motor vehicles through walking, cycling, and public transit— the carless city ideal . </li></ul>’
  11. 11. Toward Functional Eco-City States (Urban Eco-Regions) <ul><li>Cities should be reconceived to include their bio-productive areas and redesigned to incorporate as much of their supportive ecosystems within their own political jurisdictions as possible. </li></ul><ul><li>Such urban-centered eco-regions would strive to maximize their self-reliance and material independence (trade as necessary but not necessarily trade). </li></ul><ul><li>Bioregionalism and perma-culture provide pre-formed philosophical and conceptual models for reintegrating heartland and hinterland. </li></ul><ul><li>Creating semi-independent eco-regions would respect the principle of subsidiarity—policy action affecting local populations and environments should always be implemented at the most local relevant planning level. </li></ul>
  12. 12. Ultimate Design Goals for Urban Eco-Regions <ul><li>Facilitate the reduction of the ecological footprints of their residents to no more than 1.8 hectares per capita. </li></ul><ul><li>Reintegrate the geography of living and employment, of production and consumption, of city and hinterland. </li></ul><ul><li>The regional eco-city, “… rather than being merely the site of consumption, might, through its very design, produce some of its own food and energy, as well as become the locus of work for its residents” (Van der Ryn and Calthorpe 1986). </li></ul><ul><li>Following this logic, urban eco-regions would gradually become less a burden on, and more a contributor to, the life-support functions of the ecosphere. </li></ul><ul><li>NB: All these points fly in the face of conventional trade theory and globalization trends. </li></ul>