Human settlements: theme commentary prepared for the 2006 Australian State of the Environment Committee

Human settlements need to be considered from two perspectives in state of the environment reporting. Firstly, they constitute an environment in their own right—the built environment—delivering amenity and liveability to resident and visitor populations. Australia's built environment was assessed as contributing 40 per cent of the nation's total asset base of $3500 billion in 2001; by way of contrast, Australia's natural environment (land, minerals, oil and gas, timber) constitute one third (ABS 2003a, p. 875). Furthermore, Australia's human capital has been assessed as being three times that of its physical, or built capital (Wei 2004) and it is increasing its contribution to the national asset base, in absolute and relative terms. Secondly, human settlements are a source of pressure on the rest of the (natural) environment. Settlement-based activities draw down resources such as energy, water, and materials; they convert land into production and consumption landscapes; and they generate wastes and emissions to air, land and water. Understanding how human and built capital interacts with natural capital is fundamental to the planning and management of sustainable human settlements. An extended urban metabolism model was developed for state of the environment reporting on human settlements in Australia as a means of capturing this dual feature of human settlement (Figure 1). Its key elements are described in Newton (2003) and they contribute significantly to the structuring of this commentary. [Introduction]