Getting Serious About Urban Sustainability

Transcription

1 Getting Serious About Urban Sustainability William E. Rees, Ph.D. University of British Columbia School of Community and Regional Planning Planning Sustainable Cities Lecture Series University of Calgary 12 February, 2007

2 In the background there are Different Ways of Perceiving What the scientist s and the lunatic s theories have in common is that both belong to conjectural knowledge. But some conjectures are much better than others (Karl Popper, The Problem of Induction)

3 Ecological View: Planet Earth is Like a Ship: Carrying Capacity = Plimsoll Mark We know enough not to load a ship beyond its cargo capacity as indicated by the Plimsoll mark/line. Why do we think we can get away with overloading the earth?

4 The modern view there is no real problem! According to Lawrence Summers then Chief Economist, World Bank (1991) There are no... limits to the carrying capacity of the earth that are likely to bind any time in the foreseeable future. There isn t a risk of an apocalypse due to global warming or anything else. The idea that we should put limits on growth because of some natural limit, is a profound error and one that, were it ever to prove influential, would have staggering social costs.

5 Which Leads to the Conventional View of Sustainability (Un)Sustainability is a temporary problem due to unsophisticated technologies and market failure. Technology exists now to produce in virtually inexhaustible quantities just about all the products made by nature, and: We have in our hands the technology to feed, clothe, and supply energy to an ever-growing population for the next seven billion years (J. Simon 1995).

6 Problem: Efficiency = Sustainability Much of what is proposed in the name of sustainability today smart growth, green buildings, hybrid vehicles, life-cycle analysis, internalizing the externalities, etc., assumes that sustainability is a problem that can be solved through improvements in economic and technological efficiency. Efficiency gains are necessary but are by no means sufficient. On their own, all such measures simply make techno-industrial society more efficiently unsustainable.

7 This is an overloaded ship sinking inefficiently

8 This is an overloaded ship sinking efficiently (but sinking just the same and possibly faster)

9 Re-Thinking Sustainability Something is sustainable if can safely remain in its present state or maintain its present course indefinitely. Like pregnant, the term sustainable is an absolute. Something is either sustainable or it is not. To speak sensibly about sustainability one must specify both context and contextually relevant criteria.

10 On Urban Sustainability: Questions to Ponder - #1 Is the smoke-belching factory city below much like those of 19 th Century Britain or present day China sustainable?

11 On Urban Sustainability: Questions to Ponder - #2 Is modern Vancouver, with its crystalline air, urban green-spaces and general feel-good atmosphere sustainable?

12 Both these questions are meaningless taken out of context Assertions for the sake of argument: The 19 th Century European factory city was at least biophysically sustainable; the 21 st century factory city in China is not. Both are considerably more sustainable than seemingly pristine Vancouver or Calgary. (The latter are among the least sustainable cities on the planet.)

13 Sustainability Depends on Constantly Evolving Context Smoke-bound factory cities, however miserable for their inhabitants, would be at least biophysically sustainable if there weren t very many of them. For example, despite their apparent filth and pollution, 19 th Century industrial cities in the aggregate remained within global carrying capacity. The modern world has already overshot global carrying capacity. Modern factory cities indeed all contemporary cities are therefore contributing to the erosion of natural capital and are unsustainable by definition.

14 Point: Context Matters Another example: One could adopt behaviours and patterns that would be sustainable if they were universal, but No person, no lifestyle, no building, no city, no country can be sustainable if she/it is part of a system that is not, in the aggregate, sustainable.

15 Biophysical Criteria for Sustainability Cities are potentially sustainable if their aggregate demand on supportive ecosystems is less than the productive capacity (carrying capacity) of those systems. That is, our urbanizing world must not: consume self-producing and replenishable natural capital (renewable resources) faster than they can be produced in nature. generate toxic or ecologically active waste faster than it can be assimilated or neutralized by nature.

16 An Ethical Criterion for Sustainability The life-styles of individuals or populations are sustainable only if they could be extended to the entire human family without putting the aggregate human enterprise beyond global carrying capacity.

17 The City as Biophysical Entity We usually think of cities as areas dominated the built environment and characterized by high human population densities. Cities are also centers of culture/intellectual activity, hotbeds of political activity, seats of governments. Jane Jacobs trumpeted cities as the engines of national economic growth. All this is true, but we usually forget that cities as complex, self-organizing systems, are also biophysical entities.

18 As presently conceived, cities are parasites on the global hinterland 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) Great cities can produce the wealth of nations only by first consuming the products and services of an increasingly global hinterland, i.e., the ecosphere.

19 The city as currently defined is not a complete (human) ecosystem enclosed in a bell-jar, a city would simultaneously starve and suffocate.

20 The ecological space effectively appropriated by cities can be measured using eco-footprint analysis The ecological footprint of any specified population is the area of land and water ecosystems required, on a continuous basis, to produce the resources that the population consumes, and to assimilate the wastes that the population produces, wherever on Earth the relevant land/water may be located.

21 Eco-Footprints Vary with Income The average per capita ecological footprints of residents of high-income countries range between four and ten hectares (10 to 25 acres). The residents of the poorest countries survive on less than half a hectare.

22 Equivalence-Adjusted Per Capita Eco- Footprints of Selected Countries (2001 Data) United States Australia Canada United Kingdom Belgium Germany Spain Netherlands Japan Hungary Mexico Brazil Thailand China Indonesia Nigeria Peru India Ethiopia Mozambique Pakistan Bangladesn World Country Eco-Footprint (hectares)

23 The Global Picture: A World in Overshoot (2001 data) Billions of Hectares Area of Productive Ecosystems on Earth Estimated Global Ecological Footprint Available and Appropriated Biocapacity

24 Societies in overshoot reduce their future carrying capacity Overshoot represents an ecological deficit, the difference between human demand and biophysical capacity One Planet Living Whenever a population grows beyond carrying capacity, the environment is rapidly degraded and future carrying capacity is reduced. Think: climate change, ozone depletion, sea level rise, deforestation, fish stock collapses, desertification, etc.

25 Missing: Four Phantom Planets If today s entire world population enjoyed the same consumer lifestyles as residents of North America, it would take four additional Earth-like planets to accommodate everyone sustainably! Problem: Good planets are hard to find.

26 Another Inconvenient Truth Since wealthy urbanites enjoy energy- and materialintensive (consumer) lifestyles, high-income cities impose enormous ecofootprints on the earth. Two thirds of resource consumption and pollution is attributable to consumption in the world s rich cities alone.

27 Cities everywhere have enormous ecological deficits The twenty-nine largest cities of the Baltic states of Europe have an eco-footprint times as large as the cities themselves. Hong Kong s eco-footprint is at least 303 times the total land area of the Hong Special Administrative Area (1097 km 2 ) and 3020 times the built-up are of the city (110 km 2 ). Tokyo s eco-footprint is about 302 times larger than the region, 3.8 times the area of Japan and represents 1.6 times the nation s domestic biocapacity.

28 Reducing the Entropic Burden of Cities Constructing, operating and maintaining the built environment accounts for about 40% of the materials used, and 33% of the energy consumed, by the global economy. Private consumption by urbanites accounts for much of the rest. It is the responsibility of every moral agent to work toward sustainability with equity. Sustainability requires policy directed toward massive reductions of both public and private consumption. (Overall target: 80-90% reduction of energy/material throughput by 2050)

29 Sustainability implies the end of material growth in the developed world 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; Getting Eco-Efficient ) To avoid a [potentially catastrophic] mean global temperature increase above 2 C degrees, the world must reduce carbon emissions by 90% by (Tyndall Centre for Climate Change Research 2006)

30 What this Means for Canadians Canadians need an average of 7.6 gha per capita to satisfy their consumer lifestyles. A fair Earth-share today is equivalent to 1.8 global average hectares (gha). As wealthy consumers Canadians are as responsible as anyone for the current unsustainable state of the planet. Growing more efficiently is not enough. For sustainability with equity we should be taking steps to reduce our ecological footprints by at least 75% to our equitable Earth-share (1.8 gha).

31 The Good News We have the technology today to enable a 75%-80% reduction in energy and material consumption without compromising quality of life. Moreover: Sustainable cities will have cleaner air, safer streets, greater accessibility, more urban amenities, better public transit, lower housing costs, stronger neighbourhoods, and a greater sense of community than would otherwise obtain. By reducing pressure on agricultural lands, more compact sustainable cities would also enhance local food security. Greater self-reliance generally would reduce the population s ecological footprint on distant hinterlands.

32 Rethinking the City as Complete Human Ecosystem If 99%+ of the land that supports cities lies outside their boundaries, shouldn t we redefine what we mean by urban land in a whole-systems framework? A city-as-(eco)system would be an urban region comprising both the built environment and as much as possible of the population s supportive hinterland. Ideally, it would be politically organized as a modern regional-scale city-state. Bioregionalism and permaculture provide pre-formed philosophical and conceptual models for human ecosystem planning.

33 The Political Conundrum (Think Kyoto) What is ecologically necessary for sustainability is said to be politically unfeasible but what is politically feasible is ecologically irrelevant. Problem: On an ecologically full earth, trading off the ecosphere for further growth is no longer a sustainable option. If strong sustainability cannot survive the political process then society will not survive the political process.