Urban environmental efficiency

2011

Urban environmental efficiency relates to how well the built environment encourages the efficient use of natural resources—in particular, land, energy and water—and the implications of the built environment for waste production and minimisation.

Land use

Only limited data exist on the extent of land used by the built environment. The available data show that the built environment occupies only a small proportion of Australia. According to the Australian Collaborative Land Use Mapping Program, 14 031 square kilometres (0.18% of Australia's total area) were devoted to 'urban intensive uses'.31 There are currently no formal methods to detect and report land-use change nationally in Australia. However, it is clear that urban areas in Australia are continuing to grow in size. Land that is taken over for urban development is land that cannot be used for other purposes, and often this land has high environmental value.

Energy efficiency

In 2008-09, Australian households used 998 petajoules of energy—about 12% of Australia's total national energy use.32 About three-quarters (74%) of household energy is obtained from secondary sources such as electricity and refined products, with the remaining quarter obtained from primary sources such as natural gas and LPG (liquefied petroleum gas). There has been a trend towards increasing use of primary sources, mainly reflecting growth in household use of natural gas and LPG. Use of solar energy as a primary energy source by households is rather small, at 3.1% in 2008-09 (up from 1.6% in 2001-02).

Household energy use per person increased in the first part of the decade, peaking at 48.0 gigajoules per person in 2005-06. Since then, household energy use per person has fallen by about 5% to 45.5 gigajoules, reflecting more efficient use of energy (Figure 10.13).

One likely factor contributing to this fall is an increase in the use of insulation. In 2002, 57.5% of Australian dwellings had insulation. By 2008, this had risen to 61.5%. During the same period, the proportion of dwellings with solar hot water rose from 4.3% to 7.1%. The proportion of dwellings with heaters fell from 80.5% to 77.4%. Offsetting these factors was an increase in the proportion of dwellings with coolers, from 48.6% to 66.4%.

Households are tending to give greater consideration to energy efficiency when replacing appliances; in 2008, energy efficiency was the major factor considered when replacing refrigerators, freezers, dishwashers and clothes dryers.7 (For washing machines, the predominant factor was water efficiency, and for heaters it was cost.)

For other uses of energy (e.g. industry and transport), it is not easy to determine usage in the built environment separately from usage in other areas. However, energy use in manufacturing may provide some information about energy use in the built environment, as manufacturing predominantly occurs within the built environment. In 2008-09, manufacturing was responsible for a little over one-third (35%) of Australian national energy use, and almost 80% of this was obtained from primary energy sources (mainly crude oil). Since 2001-02, the intensity of energy use in manufacturing (measured as energy used per dollar of industry value added) has fluctuated; it was lower in 2008-09 than 10 years earlier (Figure 10.14). However, caution should be used in relating this to changes in energy efficiency, as other factors such as changing industry structures may also affect intensity of manufacturing energy use.

Estimates of energy use — either by households or by industry — on a comparable city-by-city or state-by-state basis are not readily available.

Water efficiency

In 2008-09, households used 1768 gigalitres of water, which is about 13% of the water consumed in Australia. Of this, 90% was obtained from distributed sources — that is, from centralised water utilities, rather than self-extracted. Household use of distributed water declined 15% between 2004-05 and 2008-09. Per person, the decline was even more significant, at around 20% (Figure 10.15).33

Household distributed water use per person in 2008-09 was highest in the Northern Territory (141 kilolitres) and lowest in Victoria (60 kilolitres). However, care should be used in making comparisons, as different parts of Australia have very different climates, which can affect the availability of, and the demand for, water. Between 2004-05 and 2008-09, per person consumption fell in all states and territories except Tasmania and the Northern Territory, with the most significant falls in Queensland (44%) and Victoria (21%). This undoubtedly reflected the drought conditions in these states during the period and the resulting water restrictions.

In 2008-09, the manufacturing industry used 677 gigalitres of water, which is about 5% of the water consumed in Australia. Half of the water used in manufacturing was obtained from distributed sources. Very little change occurred between 2004-05 and 2008-09 in distributed water use in manufacturing, in terms of either total water use or water used per unit of output. In 2008-09, the highest level of distributed water use in manufacturing occurred in Victoria (110 gigalitres or about one-third of Australian distributed water use in manufacturing), and the highest use of distributed water per unit of output was in Queensland. However, care should be taken in comparing water intensity across states due to significantly different industry structures.

Waste generation and recovery

It is difficult to obtain comparable information on waste in Australia, both across time and across different states and territories. Waste collection systems are fragmented, and there is currently no national approach to the collection of information.

To overcome this problem, the Australian Government Department of Sustainability, Environment, Water, Population and Communities engaged a consultant to develop a methodology for consistent interpretation of state and territory datasets and to produce a report, Waste and recycling in Australia 2011, based on this methodology.34 Methods of compiling and standardising data on waste and recycling, including some scope and definitional aspects, have changed from 2006–07 to 2008–09, so comparisons should be made with caution.

The report found that waste generation per person in Australia was 2139 kilograms, ranging from 1057 kilograms per person in Tasmania to 2665 kilograms per person in Western Australia. The waste recovery rate for Australia was 52%; the Northern Territory had the lowest recovery rate (5%) and the Australian Capital Territory had the highest (76%).

Between 2006–07 (the previous period for which data for Australia are available) and 2008–09, there appears to have been a 6% increase in waste generation and a 7% increase in recovery, suggesting that, at least for this period, growth in waste generation and waste recovery is proceeding at almost twice the rate of population growth. Despite the data limitations, the available evidence suggests that, for earlier periods, the growth in waste generation also significantly exceeded growth in population.

The 2011 report provided estimates of waste generation and recovery by source sector (municipal, commercial and industrial, construction and demolition) for all states and territories (Figures 10.16 and 10.17). Municipal waste, which approximates household waste, accounts for about one-third of waste generation. Queensland has the highest municipal waste generated per person (914 kilograms) and Victoria the lowest (441 kilograms).

 Reedy Creek Waste Landfill and Boral Quarry, West Burleigh, Queensland

Reedy Creek Waste Landfill and Boral Quarry, West Burleigh, Queensland

Municipal waste, which approximates household waste, accounts for about one-third of waste generation. Queensland has the highest municipal waste generated per person (914 kilograms) and Victoria the lowest (441 kilograms).

Municipal recovery rates were highest in the Australian Capital Territory (59%) and lowest in the Northern Territory (15%).

In 2009, the Australian Bureau of Statistics Waste Management Survey of households found that 99% of Australian households participated in some form of recycling and/or reuse of waste.16 Of these households, 98% had recycled and 86% had reused waste. All states and territories had a household recycling rate of more than 95%. Paper, cardboard, newspapers, plastic bottles, glass and plastic bags were the most recycled materials in Australia. These materials are often recycled through municipal kerbside recycling services, which were used by 91% of Australian households.

In 2009, Australian households were recycling the majority of surveyed items at a greater rate than in past survey years. The greatest increase was for steel cans, with 80% of households recycling and/or reusing these in 2009, compared with 70% in 2006.

Waste recycling behaviours embraced by the community tend to be those that are:

  • affordable
  • easily accessible
  • easily linked to environmental benefit.

Although there is a lack of statistical information, there is a prevailing view that because of a less sophisticated infrastructure due to their small size, waste management and recycling are relatively of greater concern in smaller communities.

Harper P (2011). Built environment: Urban environmental efficiency. In: Australia state of the environment 2011, Australian Government Department of the Environment and Energy, Canberra, https://soe.environment.gov.au/science/soe/2011-report/10-built-environment/2-state-and-trends/2-2-urban, DOI 10.4226/94/58b65a5037ed8