ABSTRACT
Urbanisation is proceeding at a rate unprecedented in human history, with a projected growth of two billion city-dwellers over the next 20 years (UN Habitat, 2004). Throughout history, proto-sustainability has been negotiated at the scale of the city-region. Buffeted by complex competing factors, city-regions underwent many iterations of design over time. The great majority of modern urban development is, by contrast, informal and ecologically disconnected. Local balance-seeking processes have given way to the rapid growth of globalisation. Where contemporary policy conventions of city planning are in effect, they have not kept pace with nascent ecological standards in building and infrastructure design. Though recognition of the importance of cities to ecological economics continues to grow, the discipline has found it very difficult to wrest an operationally urban meaning of sustainability from within its boundaries. Current approaches do not provide instructions or a path forward for measurement, accounting or otherwise operationalising that knowledge (Boyd and Banzhaf, 2007; Wallace, 2007). In other words, no system has yet succeeded in analytically inverting familiar metrics and indicators to provide a means to operationalise a coherent sustainable whole at the city scale.
