[ Murdoch University logo and link to homepage ]
SEARCH| MURDOCH| INDEX| PEOPLE

Institute for Sustainability and Technology Policy

 

 


SUSTAINABILITY AND HOW IT RELATES TO CITIES

By Professor Peter Newman
Director, Institute for Sustainability and Technology Policy Murdoch University Perth, Australia

The Concept of Sustainability

'Sustainable Development' or 'Sustainability' for short is easily understood at its most basic level. It simply means that in a global context any economic or social development should improve not harm the environment. This concept will guide our case studies and, as will be shown below, sustainability has developed from a global political process over the last three decades of the 20th century into one that now touches every part of society.

However, sustainability is one of the most diversely used concepts among academics and professionals discussing the future. It has cut across all disciplines and professions and has developed many complexities[1].

In whatever way sustainability is defined and analysed, it is important to see that its roots did not come so much from academic discussion as from a global political process.

Sustainability and Global Politics

The first elements of sustainability emerged on the global arena at the 1972 UN Conference on the Human Environment. At this conference 113 nations pledged to begin cleaning up the environment and most importantly to begin the process of tackling environmental issues on a global scale. The problems of air pollution, water pollution and chemical contamination do not recognize borders. It was acknowledged that it is not possible to allow DDT or PCBs or radioactive materials to be released anywhere without it affecting everyone. Natural resource depletion was also discussed as awareness had grown that depletion of forests, groundwater, soils, and fishstocks had impacted across national boundaries.

Concern about the global environment was very high. Evidence was presented at Stockholm that the scale of the human economy was now significant relative to the natural environment. For examples, the flow of human energy (mostly in settlements) was now roughly equal to the flow of solar energy through ecosystems, with inevitable impacts from the wastes (see Newman, 1974).

This sense of limits was not new for many nations. In the 19th century a similar sense of limits drove Americans to set aside the first national parks as they realised their apparently limitless new frontier had reached the west coast. George Marsh's book 'Man and Nature: Or Physical Geography as Modified by Human Action' first published in 1864 analysed the environmental impacts of US urban and rural development. One hundred years later this sense of limits had become a global phenomenon as the last frontier lands are developed.

PHOTO 1. The sight of the earth from space was one of the first ways that inspired people to see that the global environment had "limits" . It inspired many people to begin the global movement towards sustainability.

The effects of human activity on this biosphere were also beginning to negatively impact human welfare. The spectre of Malthus was raised as a global phenomenon but focussed on the rapidly growing areas of the third world where it was thought that much of the world's future growth and impact would occur (eg Ehrlich and Ehrlich, 1977).

However, this environmental sensitivity is only one side of sustainability. The third world was not so impressed by this new environmental globalism. The new agenda was rapidly turning to one of anti-growth as environmentalists saw the rapacious consumption of natural resources as inevitably linked to economic development. The third world saw it as just another way to prevent them from attaining their goals for development. The 1 billion people living in abject poverty with not even enough food to eat, did seem to have some legitimate claim on a little more of the world's resources. Thus the UN established the World Commission on Environment and Development in 1983 to try and resolve this fundamental conflict. In 1987 they published "Our Common Future" or the Brundtland report, which launched into common parlance the phrase 'sustainable development'. This was then given form, as shown below, at the 1992 Earth Summit in Rio.

Sustainability was presented as an agenda to simultaneously solve the global environmental problem and to facilitate the economic development of the poor, particularly those in the third world. Whereas in 1972 the environment was placed on the global political agenda, in 1992 the environment was placed on the global economic agenda. Thus the characteristics of sustainability can be distilled into four broad policies which have since become the basis of much global action.

Characteristics of Global Sustainability

PRINCIPLES OF SUSTAINABILITY

(1) The elimination of poverty, especially in poor nations, is necessary not just on human grounds but as an environmental issue.

(2) The rich nations must reduce their consumption of resources and production of wastes.

  • Global co-operation on environmental issues is no longer a soft option.

(4) Change towards sustainability can only occur with community-based approaches that take local cultures seriously.

The following four characteristics are derived from the Brundtland Report and are the fundamental approaches to global sustainability that need to apply simultaneously to any approach to the future.

(1) The elimination of poverty, especially in poor nations, is necessary not just on human grounds but as an environmental issue.

Evidence was presented by the Brundtland report from across the globe that poverty is one of the factors degrading the environment because populations grow rapidly when they are based on subsistence agriculture or fishing or plant collection. In the past, the population of subsistence communities was controlled by high death rates but the globalisation of health care has meant that there is no way forward to a new equilibrium but to reduce birth rates. This seems only to occur sustainably when families want fewer children not more and in subsistence economies children are a source of wealth and security (United Nations, 1987).

Where economic and social development do not occur and populations continue growing, the environment inevitably suffers. This feeds back in a poverty cycle, for example much of the Rwanda tragedy has been traced to this process (UN Centre for Human Settlements, 1997). Grass roots economic and social development (particularly women's rights) are necessary to break this cycle (UN, 1987). The alternative is a constant degradation of the 'commons' as more forest is cleared, more soil is overgrazed, more fisheries are destocked (Hardin, 1968). Thus poor nation economic and social development is a precursor to global sustainability.

(2) The rich nations must reduce their consumption of resources and production of wastes.

The average American (or Australian) consumes natural resources 50 times that of the average Indian, and the poorest groups in abject poverty across the world consume 500 times less. By raising the standard of living of the global poor from 1/500th to 1/50th would not be a huge extra strain on resources. The primary responsibility for reducing impact on global resources lies in the rich part of the world.

 

PHOTO 2. The rich world must learn to reduce its resource consumption.

Such a goal cannot be achieved without economic and social change. For example, industry cannot be frozen with 80's machinery, it needs to develop new technology for replacing CFC's, for using less energy, for switching to new renewable fuels and more efficient materials; such change requires economic and social development. Cities will not be less energy intensive if they are frozen in their sprawling 80's structures and they can only rebuild in more compact, transit-oriented forms if they are growing economically and socially. Thus the rich world economic and social development are precursors to global sustainability but in the future they must be much less resource-intensive.

(3) Global co-operation on environmental issues is no longer a soft option.

Hazardous wastes, greenhouse gases, CFC's, and the loss of biological diversity are examples of environmental problems that will not be possible to solve if some nations decide to hide from the necessary changes.

PHOTO 3. Globalalisation of sustainability is essential.

The spread of international best practice on these issues is not some management fad, nor is it a conspiracy for world domination from certain industries or advanced nations, it is essential for the future of the world. Thus a global orientation is a precursor to understanding sustainability.

(4) Change towards sustainability can only occur with community-based approaches that take local cultures seriously.

Most of the debate on sustainability has been through UN conferences and high level international events. However, it is recognised that this can only create the right signals for change, it cannot force the kind of changes which are discussed above. These will only come when local communities find how to resolve their economic and environmental conflicts in a way that creates simultaneous improvement of both. Thus an orientation to local cultures and community development is a precursor to implementing sustainability.

Academic discussions on the meaning of sustainability need to build from this base of four principles. The definition most people have picked up on from Brundtland is that "Susustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs" (WCED, 1989, p.43). Undoubtedly the sustainability agenda is about future generations but it is not trying to create some infinitely durable means of managing society so it can be sustained indefinitely. This is particularly important when it comes to discussing sustainable cities which can become a diversion into ideal city forms or on the impossibility of creating eternal cities.

Sustainability has come from a global political process that has tried to bring together, simultaneously, the most powerful needs of our time:

  • the need for economic development to overcome poverty,
  • the need for environmental protection of air, water, soil and biodiversity upon which we all ultimately depend, and
  • the need for social justice and cultural diversity to enable local communities to express their values in solving these issues.

Thus when we refer to sustainability, it will be the simple idea that means the simultaneous achievement of global environmental gains in any economic or social development. This concept is pictured in Figure 1.

 

Figure 1. The overlapping areas of Economic Development, Community Development and
Ecological Development which are simultaneously required for sustainable development.
Source: Newman and Kenworthy (1999).

The sustainability movement is first and foremost a global movement that in particular is forcing economists and environmentalists to find mutually beneficial solutions.

The sustainable development process has been proceeding at many different levels:

  • In academic discussions (eg how ecological economics can be defined and formulated, Daly and Cobb, 1989, Jeroen et al, 1994).
  • In laboratories, in industry and in management systems as they try to be innovative within the new parameters of reduced resource use and less waste (eg 'the clean production' agenda), and
  • Within governments at all levels and in community processes.

These approaches are usually called 'green economics', 'green technology', 'green planning' etc. When they are no longer called 'green' perhaps we can begin to say that we are becoming more sustainable. However, sustainability is never likely to be a state that we reach but one towards which we need to constantly strive. Sustainability is a vision and a process, not an end product.

Global government responses to sustainability

Most countries, particularly European nations, began to respond to the Brundtland report in the late 80's. One of the first responses was when Canada established their Round Table on the Environment and the Economy which began mapping out what the new agenda meant. In Australia, the Ecologically Sustainable Development process was begun in 1990 involving government, industry, conservation groups, unions, social justice groups and scientists. And in New Zealand the Resource Management Law Reform process began its re-examination of all aspects of government from an environmental perspective. In the US a private sector organisation, the National Commission on the Environment published a report in 1993 entitled 'Choosing a Sustainable Future' which states:

"The economy and the environment can no longer be seen as separate systems, independent of and even competing with each other. To the contrary, economic and environmental policies are symbiotic and must be molded to strengthen and reinforce each other." (p.21)

The US Clinton administration set up the President's Council on Sustainable Development in 1996 as the first US government response to sustainability.

At a global level, after 3 years of preparatory meetings involving thousands of the world's scientists and administrators, the UN Conference on Environment and Development was convened in Rio in 1992. The 'Earth Summit' drew together more heads of government than any other meeting in history and its final resolutions were signed by 179 nations representing 98% of the world. This is about as global as is ever likely to be possible.

The documents agreed to were: a statement on sustainability called the Rio Declaration, a 700 page action plan for sustainability called Agenda 21, a Convention on Climate Change, a Convention on Biological Diversity, and a Statement on Forests (Keating, 1993).

Such plans are still working their way through governments, industries and communities. International treaties are being developed each year to put some substance into the global sustainability agenda including the CFC agreement and the late 90's climate change agreements. In 1997 the 'Rio plus five' Earth Summit occurred in order to report on how well nations were doing on the sustainability agenda.[2]

At the local level the sustainability agenda began to be taken seriously in over 2000 local governments who have implemented Local Agenda 21 Plans or Sustainability Plans since the Rio conference. The stories of hope are rich and diverse when examined at the grass roots level (eg Pathways to Sustainability Conference, 1997). The reason for this is that at the local level it is possible for government to more easily make the huge steps in integrating the economic, environmental and social professions, in order to make policy developments that are sustainable. They are also closer to concerned people and more distant from the single issue powerful lobbies like the fossil fuel and road lobbies, who are so obvious in shaping national priorities.

The local sustainability agenda and the global sustainability agenda are beginning to make more sense when the focus is shifted away from nation-states to settlements. This is the theme of our case studies and it is partly a plea to do more, partly an attempt to help define how we can be more sustainable in our settlements and partly a celebration of those cities and towns who are showing us what can be done.

Application of sustainability to cities

The principles of sustainability outlined above can be applied to cities though the guidance on how this can be done was not very clear in Agenda 21 or the other UN documents. It is probably true to say that the major environmental battles of the past were fought outside cities but that awareness of the need to come back to cities is now universally recognised by environmentalists, government and industry. The OECD, the European Community and even the World Bank now have sustainable cities programs. In 1994 the Global Forum on Cities and Sustainable Development heard from 50 cities (Mitlin and Satterthwaite, 1994) and in 1996 the UN held Habitat II, the Second United Nations Conference on Human Settlements in Istanbul. At the 'City Summit' the nations of the world reported on progress in achieving sustainability in their cities (UN Centre for Human Settlements, 1996).

Anders (1991), in a global review of the sustainable cities movement, pointed out:

"The sustainable cities movement seems united in its perception that the state of the environment demands action and that cities are an appropriate forum in which to act." (p17)

In fact others such as Yanarella and Levine (1992) suggest that all sustainability initiatives should be centred around strategies for designing, redesigning and building sustainable cities. In this global view they suggest that cities shape the world and that we will never begin the sustainability process unless we can relate it to cities.

AN EMERGING FRAMEWORK - THE CITY AS AN ECOSYSTEM

Throughout this century the city has been conceived by sociologists, planners and engineers as a "bazaar, a seat of political chaos, an infernal machine, a circuit, and more hopefully, as a community, the human creation par excellence" (Brugmann and Hersh 1991, cited in Roseland 1992).

One of the strongest themes running through the literature on urban sustainability is that if we are to solve our problems we need to view the city as an ecosystem. As Tjallingii (1993) puts it:

"The city is (now) conceived as a dynamic and complex ecosystem. This is not a metaphor, but a concept of a real city. The social, economic and cultural systems cannot escape the rules of abiotic and biotic nature. Guidelines for action will have to be geared to these rules." (p7)

Like all ecosystems, the city is an open system, having inputs of energy and materials. The main environmental problems (and economic costs) are related to sustaining the growth of these inputs and managing the increased outputs. By looking at the city as a whole and by analysing the pathways along which energy and materials (and pollution) move, it is possible to begin to conceive of management systems and technologies which allow for the reintegration of natural processes, increasing the efficiency of resource use, the recycling of wastes as valuable materials and the conservation of (and even production of) energy .

There may be on-going academic debate about what constitutes sustainability or an ecosystem approach (Slocombe, 1993), but what is clear is that many strategies and programs around the world have begun to apply such notions both for new development and redevelopment of existing areas.

Sustainability goals for cities

How does a city define its goals in a way that is more sustainable? How do you make a systematic approach that begins to fulfil the global and local sustainability agenda? The approach adopted here is based on the experience of the Human Settlements Panel in the Australian State of the Environment Reporting process (see Newman et al, 1996) and on the experience of doing a Sustainability Plan for Philadelphia with the graduate students at the University of Pennsylvania in 1995 and 1997, as well as awareness of the World Bank/UN Habitat project on developing sustainability indicators for cities (World Bank, 1994).

It is possible to define the goal of sustainability in a city as the reduction of the city's use of natural resources and production of wastes while simultaneously improving its livability, so that it can better fit within the capacities of the local, regional and global ecosystems.

This is set out in Figure 1.2 in a model that is called the 'Extended Metabolism Model of the City'. Metabolism is a biological systems way of looking at the resource inputs and waste outputs of settlements. The approach has been undertaken by a few academics over the past 30 years, though it has rarely if ever been used in policy development for city planning (Wolman, 1965, Boyden et al, 1981, Girardet, 1992). Figure 1.2 sets out how this basic metabolism concept has been extended by us to include the dynamics of settlements and livability in these settlements.

 
Fig 1.2 Extended Metabolism Model of Human Settlements
In this model it is possible to specify the physical and biological basis of the city, as well as its human basis. The physical and biological processes of converting resources into useful products and wastes is like the human body's metabolic processes or that of an ecosystem. They are based on the laws of thermodynamics which show that anything which comes into a biological system must pass through and that the amount of waste is therefore dependent on the amount of resources required. A balance sheet of inputs and outputs can be created. It also means that we can manage the wastes produced, but they require energy in order to turn them into anything useful and ultimately all materials will eventually end up as waste. For example, all carbon products will eventually end up as CO2 and this is not possible to recycle any further without enormous energy inputs that in themselves have associated wastes. This is the entropy factor in metabolism.
What this means, is that the best way to ensure there are reductions in impact, is to reduce the resource inputs. This approach to resource management is implicitly understood by scientists but is not inherent to an economist's approach which sees only 'open cycles' whenever human ingenuity and technology are applied to natural resources. However, a city is a physical and biological system. Figure 1.3 and Table 1.1 apply the metabolism concept to Sydney.

Figure 1.3: Resource inputs consumed and waste outputs discharged from Sydney, 1990.
Source: Newman et al (1996)

Table 1.1 Trends in certain per capita material flows in Sydney, 1970 and 1990.
Source: Newman et al (1996)
SYDNEY 1970
SYDNEY 1990
Population
2,790,000
3,656,500

RESOURCE INPUTS

ENERGY/Capita
88 589 MJ/capita
114 236 MJ/capita
Domestic
10%
9%
Commercial
11%
6%
Industrial
44%
47%
Transport
35%
38%
FOOD/Capita (intake)
0.23 tonnes/capita
0.22 tonnes/capita
WATER/Capita
144 tonnes/capita
180 tonnes/capita
Domestic
36%
44%
Commercial
5%
9%
Industrial
20%
13%
Agricultural/Gardens
24%
16%
Miscellaneous
15%
18%

WASTE OUTPUTS
SOLID WASTE/Capita
0.59 tonnes/capita
0.77 tonnes/capita
SEWAGE/Capita
108 tonnes/capita
128 tonnes/capita
HAZARDOUS WASTE
0.04 tonnes/capita 
AIR WASTE/Capita
7.6 tonnes/capita
9.3 tonnes/capita
CO2
7 1 tonnes/ capita
9.1 tonnes/capita
CO
204.9 kg/capita
177.8 kg/capita
SOx
20.5 kg/capita
4.5 kg/capita
NOx
19.8 kg/capita
18.1 kg/capita
HCx
63.1 kg/capita
42.3 kg/capita
Particulates
30.6 kg/capita
4.7 kg/capita
TOTAL WASTE OUTPUT
324 million tonnes
505 million tonnes
The metabolic flows for Sydney in 1970 and 1990 are summarised in Table 1.1; they show that apart from a few air quality parameters there has been an increase in per capita resource inputs and waste outputs. The reduction in hydrocarbons is because they are more completely burnt in modern automobile engines - but this just means that there's more CO2 produced. If CO2 is to be reduced, there needs to be more fundamental change.

The Metabolism approach to cities is a purely biological view, but cities are much more than a mechanism for processing resources and producing wastes, they are about creating human opportunity. Thus Figure 1.2 sets out how this basic metabolism concept has been extended to include livability in these settlements so that the economic and social aspects of sustainability are integrated with the environmental. This approach now becomes more of a human ecosystem approach, as suggested by Tjallingii and others above.

Livability is about the human requirement for social amenity, health and well being and includes both individual and community well-being. Livability is about the human environment though it can never be separated from the natural environment. Sustainability for a city is thus not only the reduction in metabolic flows (resource inputs and waste outputs), it must also be about increasing human livability (social amenity and health).

Livability indicators were produced for Sydney and other Australian settlements for the State of the Environment Report (Newman et al 1996), but were only for the one year. Further studies can determine if aspects of sustainability are improving or not.

How a city goes about achieving an integrated approach to all aspects of sustainability is the theme of our book. It will be essential to understand the dynamics of settlements as shown in Figure 1.2.

Applications of the Extended Metabolism model

The Extended Metabolism model can be applied at a range of levels and to a range of different human activities, for example:

  • Industrial Areas can examine their inputs of resources and outputs of waste while measuring their usual economic parameters and other matters such as worker health and safety. This can then be used to see how mutually useful solutions can be found such as the recycling of one industry's waste as an important resource substitute for an adjacent industry. The Kalundborg area of Denmark has made an assessment of this kind (Tibbs, 1992). Gunther Pauli has a similar proposal for industrial areas when he proposes 'zero-emissions eco-industrial parks' (Pauli, 1997).
  • Households or Neighbourhoods can make an assessment of their metabolic flows and livability and together make attempts to do better with both. Examples of this approach will be examined in later case studies as there are now many examples of this approach in single developments which are being labelled 'urban ecology'.
  • Urban Demonstration Projects can be assessed for their sustainability using the Extended Metabolism model. For example, we were asked to evaluate the Australian Better Cities program which consists of 45 demonstrations of urban innovations. The approach adopted was to try to see the extent to which each project was reducing resource inputs, lowering waste outputs and simultaneously improving the livability of the urban area (Diver, Newman and Kenworthy, 1996).

      An urban demonstration project in Jakarta was evaluated in terms of sustainability using the Extended Metabolism Model. In a study of squatters living along the Ciliwung River in Jakarta, Arief (1998) surveyed the residents and compared them to residents of a nearby high-rise apartment block who had previously been squatters. The question was whether the shifting of squatters was "sustainable" in terms of the Extended Metabolism Model. The apartment dwellers were found to use a little less energy and water (as they had to pay for it), and their waste management was considerably better since the squatters put all waste directly into the river. In human terms, the apartment dwellers had improved incomes and employment (they were able to enter the formal economy) and maintained their accessibility and health; but in terms of all community parameters, the squatter development was far superior because the layout of the housing encouraged people to know and trust their neighbours. The lack of community orientation in the high-rise design questions the fundamentals of its development ethos and points to alternatives like the Kampung Improvement Scheme (Silas 1993).

       

       

      PHOTOS 4 to 7. The squatter settlements in Jakarta need development but the replacement apartments
      are more sustainable in resource use/waste management and in economic terms but are not strong on community indicators.

      Cities can even extend this to events like the Olympic Games and all the facilities and infrastructure they require (see Box 1.3).

      Box 1.3
      Sustainability and Construction
      The Sydney 2000 Olympics are described as the 'Green Olympics' due to the Greenpeace winning design for the Olympic Village. In this Olympic Village there will be 100% renewable electricity (from roof top PV and wind power), energy efficient buildings, solar hot water, no PVC or rain forest timber, a rail service connection, bicycle/pedestrian oriented layout and water and waste recycling systems (Bell et al, 1995). Karla Bell and Associates who were closely involved in the design have also designed a Swedish new town, Hammarby Sjostad, which was part of the failed 2004 Stockholm Olympics bid but which will still be built as a 'spearhead for ecological and environmentally friendly construction' (City of Stockholm, 1997).
      The goals of the new town area model of reduced metabolic flows:
      Energy
      • 100% renewable-based electricity and heating.
      • Energy use to not exceed 60 kwh/m2 in 2005 and reducing to 50 kwh/m2 by 2015.
      Transport
      • 80% commuting by non automobile means.
      • 20% less traffic by 2005 and 40% less by 2015.
      • 15% vehicles using biofuels by 2005 and 25% by 2015.
      • 100% freight vehicles electric or low emission vehicles.
      Material Flows
      • 100% solid waste recycled.
      • 20% reduction in waste by 2005, 40% by 2015.
      • Water consumption reduced by 50% in 2005 and 60% by 2015.
      • Sewage used for energy extraction and nutrients for farm soil.
      • Stormwater used locally.
      Building Materials
      • No PVC or non-recyclable materials to be used.
      • No rain forest timbers to be used.
      • New building materials only 50% of construction by 2005 and only 10% by 2015.
      • No 'sick-building' chemicals in carpets and furniture glues.
      Individual Businesses can apply the Extended Metabolism Model and create a Sustainability Plan. The first business to do a 'Sustainability Report' is Interface (Anderson, 1998) which is a large US company making flooring. They began a process in 1994 after the CEO had read Paul Hawken's "The Ecology of Commerce" and chose to follow a Swedish set of principles called Natural Step (Greyson, 1995)[3]. Their process was similar to the metabolism model in that it examined resources ('what we take'), dynamics ('what we make') and wastes ('what we waste'). It did not specify livability outcomes, though their report stressed that economic productivity improved as much from staff morale as from new technology. 400 separate sustainability initiatives were specified in the firm based on the work of 18 different teams.
      City comparisons By comparing indicators for resource use, wastes and livability in different cities, it is possible to locate those cities (or parts of cities) that have something to contribute to policy debates on sustainability. Much of this book is based on this approach though few cities have done full assessments of their resources, wastes and livability.
      Australian cities were studied using this approach and showed the broad trends set out in Box 1.4. The next case study pursues urban comparison data on a global set of cities and others look at case studies on cities which are overcoming unsustainable trends.
      Cities can operate this model on many such levels, but most of all they need to be able to measure how they are doing overall as a city in reducing their metabolic flows whilst improving their human livability. Most cities will be able to point to a few innovations they are making in sustainability but until they can bring a full assessment of these matters together they will not be addressing the fundamentals of urban sustainability.
      Box 1.4
      Australian Settlements and Sustainability - based on "State of The Environment, Australia 1996".
      1. The larger the cities the more sustainable they are in terms of per capita use of resources (land, energy, water) and production of wastes (solid, liquid and gaseous) and in terms of livability indicators (income, education, housing, accessibility). The reason for this is explored in the next section on city size and sustainability.
      2. Larger cities are however more likely to reach capacity limits in terms of air sheds, water sheds etc. For large cities to continue to grow they will need to be even more innovative if they are to be sustainable.
      3. In geographic cross section across Australian cities there is an increase in metabolic flows and declines in livability indicators from core to inner to middle to outer to fringe suburbs. This pattern is related to the different urban development periods and most recently is related to re-urbanisation by more wealthy residents and firms. This rapid re-urbanisation of more central areas appears to be related to processes of economic change related to the new Information Age.


      PHOTO 8. The redevelopment of inner city areas is a strong step towards more sustainability on all parameters; eg East Perth.

      4. Ex-urban and coastal settlements are the least sustainable of all Australian development. They have large environmental impacts, high metabolic flows and low livability on all indicators.


      PHOTO 9. Scattered development along coasts is one of the least sustainable kind of settlement patterns I ecological, economic and social terms.

      5. Remote Aboriginal settlements leave low metabolic flows and low livability (especially in employment and health) but are the settlements where new small scale eco-technologies are being trialed.

      City Size and Sustainability

      The evidence from Australian settlements in Box 1.4 shows that as cities get larger they become more efficient. This is not new in terms of quantitative studies, nor should it surprise us in theoretical terms. But it does. There are thus some important issues that need to be discussed about city size and sustainability; these will be started here but will be pursued at various points throughout this book. The issue will be looked at from the perspective of economics and ecology.

      The data on city size were clear in our original global cities study (Newman and Kenworthy, 1989). This 32 city survey showed the same pattern: transport energy use per capita generally reduces with city size. Peter Naess from the Norwegian Building Research Institute wanted to try and investigate this phenomenon by eliminating the major variable of cultural difference that so clearly interferes with a global survey of cities. He chose 22 Scandinavian cities and found a very clear relationship between the size of the city and its per capita transport energy use as well as with density.[4] The cities of Copenhagen, Oslo and Stockholm were significantly lower in transport energy use per capita than in smaller provincial town (Naess, 1994).

      PHOTO 10. Stockholm has much lower per capita use of resources
      (and hence waste generation) than smaller Scandinavian towns,
      due to economies of scale and density such as its good public transport.
      It also is well planned to enable corridors of forest into the city.

      Urban economists have been pointing to the efficiency advantages of scale for decades and also the efficiency advantages of density (the two are generally linked). There have been many studies of cities which have found significant economic benefits from scale and density (Hoch 1976, 1979, Sternlieb 1973, Richardson 1973). The benefits in terms of sustainability come from the same kind of economic efficiencies which are applied to environmental technologies, e.g. public transport systems become more efficient as cities grow, waste treatment and recycling systems become more efficient as cities grow (all other factors being equal).

      There are economists like Neutze (1981, 1995) who point to the diseconomies associated with size due to the growth in externalities. Others point to growth in social problems that are said to increase with city size and density (Troy, 1996). However, the data on this question are usually very sparse and the issue seems to be more dominated by ideological stances (see Newman and Hogan, 1982 and subsequent discussion in chapter 5 and 6). Fischer (1976) summarises the elusive search for optimal city size in the following way: "Most urban scholars seem convinced, to quote a British economist, that '...the search for an optimal city size is almost as idle as the quest for the philosophers' stone' (Richardson, 1973: 131). The entire area of speculation is misconceived on several grounds. First, there are no substantial empirical findings pointing to city size at which any "good" - income or innovation or governmental efficiency - is maximized, or any "bad" - crime or pollution - is minimized. In fact, some data suggest that for economic purposes an optimal city size would be larger than any we now have. We have certainly not identified an optimum size for any social-psychological variable. Even if such ideals could be found, they would probably not be the same for a wide variety of social products. The size that maximizes personal incomes would differ from that which maximizes artistic creativity, or that which minimizes pollution, and so on. And it would surely be a vain task to try to sum up all these various "goods" and "bads" into a single measure. (Fisher, 1976, p250)

      In ecological terms, it should come as no revelation that as cities grow and become more complex and diverse, they begin to create more efficiencies. Ecosystems grow from being simple systems with a few pioneering species to more mature ecosystems with diversity and interconnection. Thus after a fire or a flood or some other disturbance, a cleared piece of land will begin developing the structure of its ecosystem with an emphasis on rapid and simple growth. After a period it becomes more diverse and more efficient as it establishes a more complex network of interactions. As Table 1.3 shows, this succession process involves a series of changes which can be paralleled with the processes of urban development.

      Table 1.3 Characteristics of young and mature ecosystems and their application to sustainable development in cities. See: Newman (1975).

      Note: young ecosystems pioneer newly cleared or burned sites and progressively develop into mature ecosystems.

      ECOSYSTEM
      SUCCESSION
      SUSTAINABLE CITY
      DEVELOPMENT
      YOUNG ECOSYSTEM
      MATURE ECOSYSTEM
      YOUNG CITY
      MATURE CITY
      ENERGY and
      MATERIALS
      • High gross photosynthetic activity, low efficiency.
      • Wastage of nutrients.
      • Reduced gross photosynthetic activity, high efficiency.
      • Recycling of nutrients.
      • High energy, low efficiency.
      • Wastage of nutrients and materials.
      • Reduced energy, high efficiency.
      • Recycling of nutrients and materials.
      • ECONOMIC
      • DIVERSITY
      • Producers mainly.
      • Few functional niches - generalists.
      • Balance of producers, consumers, decomposers and integrative species.
      • Many functional niches - specialists.
      • Emphasis on producers, less on manufacturers, little on services.
      • Low functional diversity.
      • Balance of producers, manufacturers, and services.
      • High functional diversity.
      • SPATIAL
      • EFFICIENCY
      • Low spatial efficiency - dispersed.
      • Low structural diversity - small, lateral, little variety.
      • High spatial efficiency - compact.
      • High structural diversity - small and large, lateral and vertical, large variety.
      • Low spatial efficiency - dispersed.
      • Low structural diversity - small, lateral, little variety.
      • High spatial efficiency - compact.
      • High structural diversity - small and large, lateral and vertical, large variety.
      • INFORMATION and
      • ORGANISATION
      • Low species & community diversity.
      • Low community organisation - little interconnection.
      • High species/community diversity.
      • High community organisation - much interconnection
      • Low community diversity.
      • Low community organisation - few networks.
      • High community diversity.
      • High community organisation - many networks.
      • ENVIRONMENTAL
      • CONTROL
      • Low environmental control - resource availability external to biotic system, climate unbuffered.
      • System instability
      • High environmental control - resource availability controlled within biotic system, climate buffered.
      • System stability.
      • Weak protection from environmental perturbations - resources poorly managed, vulnerable to changes in the physical environment.
      • System instability.
      • Strong protection from environmental perturbations - resources tightly managed, more able to buffer and cope with changes.
      • System stability

      Critical to the process of succession becoming more efficient in its use of the natural environment is its increase in information. This is both the raw genetic information of its individual components and the complex interactions and networks that hold it together as a system.

      All analogies from nature need to be carefully considered before they are taken as principles for human society--social Darwinism caused wars and the rise of such socially disastrous theories as the 'master race'. But the analogy of the ecosystem and its obvious application to the urban system at least shows us that it is quite understandable when human activity in cities seems to parallel natural activity.

      Ecological patterns thus help us to see that big cities can be moving, like a maturing ecosystem, towards a more efficient use of resources and a higher level of information, organisation and environmental control.

      Cities can of course choose not to become more efficient as they grow. Cultural forces can always be used to deny the opportunities created by scale and density of activity. However, the evidence suggests that smaller cities find the process of achieving efficiency in economic and resource terms harder than larger cities.

      The strong emotional appeal of 'smallness' to our age is not, however, without its basis. EF Schumacher's book 'Small is Beautiful' is discussed in later case studies with its attack on modern gigantism. The message Schumacher created was that all technology needs to be at the appropriate scale of the community that it is meant to be serving. Community scale technology is emerging as communities begin to assert their role--whether it be in villages in the third world or modern large cities.

       

      PHOTO 12 and 13. Rebuilding villages in cities is a necessary task for sustainability.
      Villages in modern cities require quality public transport at their core.
      Singapore has built transit-based sub centres to ease its traffic problems
      and now Bangkok is trying to do something similar as its traffic is not sustainable.

      The thrust of the New Urbanism and the 'urban village' movement is that communities need to be physically designed for and given infrastructure at the scale of the community. Vast endless suburbs can be given new coherence when focussed around a sub-centre. This is expanded in later cases.

      The recognition of the need for a community scale does not deny the realities associated with a big city. It tries to bring the social dimension into the city in a meaningful way. To try and suggest that all big cities should be dispersed into small ones is to deny some very major forces--both economic and ecological. And the evidence is that this would be counter-productive in terms of sustainability. However to ensure that communities work within big cities is a major policy for achieving sustainability.

      This is also the approach we have taken to growth management, of trying to bring order and focus into the megalopolis around community goals. This is not anti-city but it is a part of asserting the importance of community and the need for environmental and economic responsibility within the city.

      In the US there has been a long term belief in the value of small communities and small towns. The December 15, 1997 issue of Time magazine talked about the Rise of Small Towns, based on the move of some (generally wealthy) people to small towns after finding that even the move to suburbs from the city was not meeting their expectations. This is not statistically a significant movement. Nor can it be separated from the continuing problem of US inner cities. But even the US city is growing larger and is now becoming denser, along with most other cities around the world.

      The driving force behind the growth of cities is human opportunity. The diversity of opportunity in cities continues around the world to be their main magnetism. We can try to deny these opportunities by attempting to artificially constrain city size, as the former USSR tried to do (unsuccessfully) with Moscow. Or we can even have experiments in de-urbanisation like those conducted by Pol Pot and Mao. Indeed some environmental philosophy becomes very anti-urban and verges on suggesting this as a policy framework (see Trainer, 1996, 1995, 1985). The human quest, the process of civilisation, the development of human society, is all about the growth of cities.

      There is no question that cities are now heading in many wrong directions. They are not sustainable. But to suggest that sustainability means the systematic dismantling of cities is neither realistic nor does it have an historical or theoretically sensible basis to it. The urban adventure needs to be grasped and pursued, not denied.

      Cities need to change, but the historic quest for human achievement through urban civilisation, will go on. The great challenge for our cities is that they must now take seriously the quest for sustainability: that cities can be more livable, more human, more healthy places, but that they must learn how to do this by simultaneously using fewer natural resources, creating less waste and thus impacting less on the natural world.

      Indicators of Sustainability in Cities

      Cities around the world are now recognising the need to pursue the sustainability agenda. To do so they are seeking to define indicators of sustainability.

      With the Extended Metabolism model as the fundamental basis, it is possible to derive a set of practical goals or indicators for a sustainable city. Some possible indicators are therefore proposed as being feasible and measurable each year to guide a city as it attempts to create livable communities. Examples of these indicators are set out in Box 1.1. Each one requires further explanation and detail but the basic idea can be seen. Much can no doubt be done to improve on this list which is a scaled-down version of the 150 indicators suggested by the World Bank and UN Center for Human Settlements (World Bank, 1994).

      Box 1.1
      ANNUAL GOALS and INDICATORS for a SUSTAINABLE CITY
      1. Energy and Air Quality
      • Reduce total energy use per capita
      • Decrease energy used per dollar of output from industry
      • Increase proportion of bridging fuels (natural gas) and renewable fuels (wind, solar, biofuels)
      • Reduce total quantity of air pollutants per capita
      • Reduce total greenhouse gases (eg Kyoto goals of 'demonstrable progress' by 2005 and 5% reductions by 2008-12 from 1990 levels and then further reductions annually)
      • Achieve zero days not meeting air quality health standard levels
      • Reduce fleet average and new vehicle average fuel consumption
      • Reduce number of vehicles failing emission standards
      • Reduce number of households complaining of noise reducing.
      2. Water, Materials and Waste.
      • Reduce total water use per capita
      • Achieve zero days not meeting drinking water quality standards
      • Increase proportion of sewage and industrial waste treated to reusable quality
      • Decrease amount of sewage and industrial waste discharged to streams or ocean decreasing
      • Reduce consumption of building materials per capita (including declining proportion of old growth timber to plantation timber)
      • Reduce consumption of paper and packaging per capita
      • Decrease amount of solid waste (including increasing recycle rates for all components)
      • Increase amount of organic waste returning to soil and food production
      3. Land, Green Spaces and Biodiversity
      • Preserve agricultural land and bushland at the urban fringe
      • Increase amount of green space in local or regional parks per capita, particularly in 'green belt' around city
      • Increase amount of urban redevelopment to new development
      • Increase number of specially zoned transit-oriented locations
      • Increase density of population and employment in transit-oriented locations
      4. Transportation
      • Reduce car use (VKT or VMT) per capita
      • Increase transit, walk/bike and car pool and decrease sole car use.
      • Reduce average commute to and from work
      • Increase relative average speed of transit to cars
      • Increase service kms of transit relative to road provision
      • Increase cost recovery on transit from fares
      • Decrease parking spaces per 1000 workers in central business district.
      • Increase length of separated cycleway
      5. Livability Human Amenity and Health
      • Decrease infant mortality per 1000 births
      • Increase educational attainment (average years per adult)
      • Increase local leisure opportunities
      • Decrease transport fatalities per 1000 population
      • Decrease reported crimes per 1000 population
      • Decrease deaths from urban violence
      • Decrease proportion of substandard housing
      • Increase length of pedestrian-friendly streets (based on specific indicators) in city and sub-centres
      • Increase proportion of city/suburbs with urban design guidelines to assist communities in redevelopment
      • Increase proportion of city allowing mixed use, higher density urban villages

      The problem with indicators (whether they be for sustainability in cities or for managing a business), is that they are not always linked to a process that can lead to improvement in the indicator. If they are just for public relations or individual motivation they are not going to work very well. They need to be tied into policies and programs that can create some potential for improvement for the whole city. This book will emphasise the role of policies and programs for overcoming automobile dependence as the basis for creating more sustainable cities. It will examine how this relates to many of the above indicators and the kind of policies and programs that can simultaneously improve all the indicators.

      Each city will of course be best able to define the indicators that matter most to it. For example, Seattle has defined twenty different indicators including the diversity of the local economy, the number of pedestrian-friendly streets, the percentage of youth participants in community services and the quantity of wild salmon returning to urban streams (City of Seattle, 1993). Copenhagen has an indicator of the number of seats available for public use in its streets, squares and parks as this seems to correlate to both enhanced economic vitality and reduced traffic (Gehl and Gemsoe, 1996). Adelaide has an indicator of the amount of rainwater reuse occurring in this water sensitive urban region (City of Adelaide, 1997). The Hague has indicators on the number of storks breeding successfully, the installed wind energy capacity and number of 30 km/h residential zones in their city. They also have combined their environmental indices for water, noise, air, waste, soil, energy, nature, business and mobility into one 'environmental thermometer' that can give a visual representation of whether they are improving or not (The Hague Municipality, 1995).

      One of the indicators that has attracted significant interest as an overview of a city's environmental impact is the Ecological Footprint developed by Wackernagel and Rees (1996). They developed a technique for measuring the impact of a city on the global ecosystem based on the metabolic flows of resources into wastes. They try to estimate the amount of land required to sustain the activities of a city. This includes the land to produce the food and fibre, to mine the resources and to actually build the city, and it also includes the land needed to absorb the wastes. Energy is accounted for by considering the land required to absorb the CO2 produced into biomass.

      The calculations show that a typical North American requires 4 to 5 ha of ecological footprint. If everyone on the globe required this we would need three planets the size of the earth to live on.

      This approach to sustainability graphically shows the extent of our problem in cities - we must reduce our ecological footprint. However it is difficult to use this technique to bring all the impacts back into one land-based parameter. Also, energy does dominate the calculation. It is therefore a little artificial to use as a planning tool but it can be a sustainability indicator guiding cities as they face up to the agenda of reducing metabolic inputs while improving livability.

      Sustainability Plans

      The implementation of sustainability tools is the exciting and frightening prospect for all cities. It is exciting as it gives us a clear task, a whole paradigm for organising our cities, and yet it is rooted in local environments and responses which means everyone can make a unique contribution. It is frightening as it is up to the present generation to reverse the trends of increasing natural resource usage which have been set in place for at least this century and probably more.

      Critical to implementation is the development of Sustainability Plans or Local Agenda 21 Plans as set out in Agenda 21:

      "Each local authority should enter a dialogue with its citizens, local organisations and private enterprises and adopt a 'local' Agenda 21. Local authorities should learn from citizens and local, civic, community, business, and industrial organisations the information needed for formulating the best strategies. This process will also increase household awareness of sustainable development issues." (Sitarz, 1994, p177)

      The process can enable a city to both define its indicators and to assist in the process of change towards achieving them.

      Although most nations have signed Agenda 21 this process of developing Sustainability Plans has been slow in some countries, particularly the US and Australia (though cities like Seattle were quick to develop a plan and the state of New South Wales now require LA21 plans by all local authorities). In most of Scandinavia annual Agenda 21 Plans or Sustainability Plans are required by law and it is even common amongst Indian local authorities.

      Techniques for doing such plans have been outlined (ICLEI, 1996, Selman, 1996) and literature evaluating them is beginning to appear (Parenteau, 1994; Birch, 1994; Brugmann, 1994). Sustainability Plans require two central approaches: integrated planning and community participation. Both of these are quite familiar concepts, but the critical nature of the task means that we must do them with renewed commitment and creativity and in particular, we must now be serious about the natural resource/environmental aspects of these approaches. They can no longer fall off the end of the pile.

      Conclusion

      Sustainability has mostly been defined at the global and national level and only recently has begun to be applied to cities (Mitlan and Satterthwaite, 1994). The Extended Metabolism model provides a way of integrating environmental considerations with the social and economic aspects of cities. The task of applying sustainability can seem to be rather overwhelming at the global level but at the level of cities it becomes meaningful. With 50% of the world's population predicted to be in cities by 2000, cities are an obvious focus for the sustainability agenda, with enormous potential to generate change in how we use natural resources.

      The Extended Metabolism model is an effective way for cities to try to create a holistic picture of their sustainability agenda. It enables urban managers to create a series of sustainability indicators which together can give a sense of whether they are reducing or growing in their resource inputs and waste outputs and at the same time reducing or growing in livability. These indicators can be used to show cities how much they are contributing to global issues such as greenhouse and oil depletion, and to show their local citizens how well they are managing sustainability issues that impact on them directly. However, if a city concentrates only on the local issues it is likely to miss major components of the sustainability agenda as outlined above.

      The sustainability agenda is a major global and local issue. Communities across the world are trying to see how they can simultaneously reduce their impact on the earth while improving their quality of life. This is happening to a greater or lesser extent in all cities. However, it will always be obvious that the global and local must be married much more in this new agenda of sustainability, in all cities.

      References

      Anders, R. (1991) The sustainable cities movement. Working Paper No 2, Institute for Resource and Security Studies, Massachusetts, USA.

      Birch, R. D. (1994) Municipal reporting on sustainable development: A status review. National Round Table on the Environment and Economy Working Paper 24, NRTEE, Ottawa.

      Boyden, S., Millar, S., Newcombe, K., and O'Neill, B. (1981) The ecology of a city and its people. ANU Press, Canberra.

      Brugmann, J. (1994) Sustainability Indicators: Do We Need Them? Initiatives, ICLEI, Toronto, October 8, 1-12.

      Brugmann, J. and Hersh, R. (1991) Cities as ecosystems: Opportunities for local government. ICLEI, Toronto.

      Daly, H. E. and Cobb, J. B. Jnr. (1989) For the common good: Redirecting the economy toward community, the environment and a sustainable future. Beacon Press, Boston.

      Diver, G., Newman, P. and Kenworthy, J. (1996) An evaluation of Better Cities: Environmental component. Department of Environment, Sport and Territories, Canberra.

      Ehrlich, P. R. and Ehrlich, A. H. (1977) Population, Resources and Environment. W. H. Freeman, San Francisco.

      Engwicht, D. (1992) Canberra - Towards a healthy city. Australian Urban Studies, 19(4), 1-4 & 13-15.

      Girardet, H. (1992) The Gaia atlas of cities. Gaia Books, London.

      Hall, P. (1994) The Innovative City. Proceedings of OECD Conference, Melbourne.

      Hardin, G. (1968) The Tragedy of the Commons. Science, 162(3), 1243-1248.

      Jacobs, J. (1961) The death and life of great American cities. Vintage Press, New York.

      Jacobs, J. (1984) Cities and the wealth of nations. Penguin, Harmondsworth.

      Keating, M. (1993) The Earth Summit's Agenda for Change: A Plain Language version of Agenda 21 and the other Rio Agreements, Center for Our Common Future, Geneva .

      Kunstler, J. H. (1993) The geography of nowhere. Touchstone, New York.

      MacNeill, J., Cox, J. E. & Jackson, I. (1991) Sustainable Development - The Urban Challenge. Ekistics, 348, 195-198.

      Ohmae, K. (1990) The borderless world. Fontana, London.

      Parenteau, R. (1994) Local action plans for sustainable communities. Environment and Urbanisation. 6(2), 183-199.

      Pezzoli, K. (1996) Sustainable development: a trans disciplinary overview of the literature. Paper at joint international congress of Collegiate Schools of Planning and the Association of the European Schools of Planning, Toronto, July.

      Roberts, J. (1989a) User-friendly cities: What Britain can learn from mainland Europe, TEST, London.

      Roberts, J. (1989b) Quality streets: How traditional urban centres benefit from traffic calming. TEST, London.

      Sarkissian, W. and Walsh, K. (1996) Community participation in practice series, 3 books and a video, ISTP, Murdoch University, Perth, Western Australia.

      Sitarz, D. (ed) (1994) Agenda 21. Earthpress, Boulder.

      Slocombe, D. S. (1993) Environmental planning, ecosystem science and ecosytem approaches for integrating environment and development. Environmental Management, 17(3), 289-303.

      Tibbs, H. B. C. (1992) Industial ecology: An agenda for environmental management. Pollution Prevention Review, Spring.

      Tjallingii, S. P. (1991) The responsible city. International Federation for Housing and Planning. International Conference, Berlin.

      UN Centre for Human Settlements (1997) Changing consumption patterns in human settlements. A Dicussion Paper, UN Centre for Human Settlements, Nairobi.

      Wolman, A. (1965) The metabolism of the city. Scientific American, 213, 179

      World Bank (1994) World development report 1994. Oxford University Press, New York.

      Yanarella, E. J. and Levine, R. S. (1992) Does sustainable development lead to sustainability? Futures, 24(8), 759-774.

      Discussion questions

      1. Can sustainability be a guiding principle for how we need to approach the future of cities?
      2. What are the key factors working to prevent sustainability in cities?

      [1] Pezzoli (1996) in an overview on sustainability found ten categories of literature using the term and four principal spheres of concern:

      • Environmental context - holistic world views that integrate sociological imagination and biogeographical thinking.
      • Legal and institutional - empowerment and community building which brings localised knowledge and diversity into management and politics.
      • Culture and civil society - incorporating ethics and moral philosophy into the technical and organisational aspects of society.
      • Economy and technology - drawing production and consumption into concert with the capacity of the local and global ecosystem to perform in the long term.

      This book uses all of these categories in applying sustainability to cities. The emphasis is on the last category about resources and ecosystem capacity, but there is always an awareness of the need for a more 'holistic, environmental context' and chapter 6 is devoted directly to the 'empowerment/community building' processes of cities, whilst chapter 7 focuses on the 'ethical/moral philosophy' base for city sustainability.

      [2] For many environmentalists the 'Rio plus five' summit was a dismal performance as so many issues seemed to be no closer to a solution. Nations seemed to be failing to deliver on so many fronts. However, a more perceptive look would see that significant progress had occurred at the global or international level and at the level of the local community, between Rio and New York which give hope for a continuing global process.

      At the global level the following landmarks were achieved:

      " The Biodiversity Treaty, which emerged from the Rio Summit, took effect in 1993 and now requires all nations to keep better inventories of their biodiversity and to ensure protection and sharing in profits from the world's life forms. This is now part of international law.

      " The Law of the Sea, which took 40 years for agreement, is also now part of international law since the required number of nations finally agreed in 1993. It now means for example that fishing of migratory ocean species is regulated.

      " The Ozone Layer treaty took the world's governments a mere 10 years to develop and implement, so that 1996 saw the end of most global production of ozone-depleting chemicals.

      " 1997 saw the start of a new global treaty which prevents the transport of hazardous waste to developing countries, and

      " 1997 also saw the first serious attempts at setting targets on greenhouse gases begin to be negotiated.

      The global agenda in terms of international environmental treaties and laws is quietly and slowly changing how the world does business. There are now over 200 such international agreements.

      [3] The Natural Step is based on 4 principles which question whether any action will:

      a) Reduce use of finite mineral resources;

      b) Reduce use of long-lived synthetic products or molecules;

      c) Preserve or increase natural diversity and the capacity of ecocycles, and

      d) Reduce consumption of energy and other resources.

      The founder of Natural Step is Karl-Hewik Robert, a Swedish scientist and it provides a way of approaching the physical and biological metabolism of any system. However, it does not bring out the livability aspects which seem to be necessary for a full approach to sustainability.

      [4] Density reduces transport energy through several mechanisms: it shortens distances for all modes and it makes transit and bicycling and walking more viable as alternatives to the car; it also makes many journeys redundant as when transit is used many journeys are combined eg going to shops on the way to or from the train. Data from a 1996 study by Dunphy and Fisher show a 21% decrease in daily driving between central Manhattan and outer suburbs in New York but transport energy is 500% less in Manhattan on a per capita basis (see Figure 3.4).


      Disclaimer & Copyright Notice © Murdoch University 2000.
      • © 2008 Murdoch University | Copyright & Disclaimer | CRICOS Code: 00125J | Page Information