Although we have not specified what we mean by sustainability and therefore what we mean by sustainable cities we have accumulated enough scientific evidence to suggest that the effect of human agency on local and global ecosystems resulting from the way we live is unsustainable.
This paper argues that the form and structure of the city contributes to the present generation of environmental stress and that we can significantly reduce that stress without sacrificing living standards by changing the form and structure of our cities.
Australia's urban areas are the locations where the greater proportion of the nation's wealth is created and held and where the culture of the nation finds expression. In this most urbanised of nations, the cities and urban areas are also the locations where the great proportion of the population engage in a wide variety of economic, social and political pursuits.
Our cities are our most intensively shaped landscapes. They are the most heavily overlaid and inscribed by the pipes, wires, roads, tracks and cultures that reflect and represent our aspirations for the present and our images of the future. They are the locations of much pollution, are the generators of much of the greenhouse gas emission, the greater part of the waste stream and the demands for water, which have such a devastating effect on many of our catchments.
Over the past century we have witnessed increasing concern over a range of environmental issues. We have expressed that concern in a variety of ways and taken a series of initiatives to minimise what we used to call 'externalities'.
The development of water supply, sewerage and drainage systems, the regulations to control water pollution, the introduction of clean air regulations, the separation of residential development from industrial activities, the introduction of town planning all had a concern over environmental issues at their heart.
We now see that concern over the viability of the biosphere itself is rising and that rather than be seen as 'externalities' environmental issues are of central importance.