Both increased population and increased economic growth tend to lead to increased consumption. This, in turn, can increase the use of scarce natural resources such as water and energy, unless the rate of growth is offset by increases in the efficiency with which these resources are used. There is evidence of recent significant increases in the efficiency of urban use of water, particularly by households, where total water use has fallen even though the population has been growing strongly. However, it is not known how much of this is due to temporary factors, such as the recent prolonged drought across significant parts of Australia and consequent water restrictions, and how much relates to more permanent changes in the efficiency of water use. Energy intensity also appears to be falling, at least in recent times, in terms of both household and manufacturing energy use; however, for households, the decrease in intensity has tended to only just offset the increase in population growth (see Section 2.2.2).
Increased population can also lead to increased waste, as a result of increased consumption associated with greater numbers of people and increased affluence due to higher incomes. Waste generation has typically grown more quickly than the population, and this trend remains evident in the most recent data. Recycling and energy recovery can mitigate the environmental impact of growth in waste generation. It appears that the tendency to recycle over time has been increasing, but the recovery rate has recently stabilised (see Section 2.2.4).