Human settlements: 3.2 Population pressures

Independent report to the Australian Government Minister for the Environment and Heritage
Beeton RJS (Bob), Buckley Kristal I, Jones Gary J, Morgan Denise, Reichelt Russell E, Trewin Dennis
(2006 Australian State of the Environment Committee), 2006

3.2 Population pressures (more information on this topic) 

From an environmental perspective, the key issue arising from human settlements is the pressure they impose on the environment in terms of the demand for land, water, energy and other resources. As this section demonstrates, a long-term but immediate change in materials and energy balances is needed to give more efficient urban systems, and this requires a decoupling of resource use from economic progress.

Australians are consuming more resources. The trends of the past five to ten years indicate that during a period of relatively high employment and sustained high consumer confidence, per capita household consumption expenditure  has increased in real terms by 25 per cent from 1995–96 to 2003–04. This puts more pressure on the environment and on cultural heritage.

Realising a sustainable human environment requires a reduction in net consumption and waste. This will involve greater population densities than currently is the case, significant increases in building and material recycling, the capture and use of stormwater, the recycling of wastewater and biological waste, and improved urban form and urban structures. It also requires changes in behaviour by individuals, so education and awareness-raising are important factors. The challenge is to implement this insight.

Water presents particular issues for human settlements. A huge contribution to resolving Australia’s ‘water crisis’ could be made by using existing technologies to improve the yield of water supply catchments; better utilise runoff from urban stormwater; and greatly increase water reuse and recycling.

Urban development

Urbanisation is an increasing pressure on some areas of Australia’s land resource. At most risk is the coastal strip  , which is experiencing an increasing demand for housing by a growing population (Table 2). Most Australians live within 50 kilometres of the coast, and most tourism occurs there. At greatest risk are areas close to capital cities where high-quality arable land and many coastal low-key holiday settlements near the capital cities are being replaced by low-density suburban forms. The result of these trends is that many coastal cities are merging to form ‘mega-metropolitan’ regions—systems of interlinked cities. The regions of greatest development are:

  • south-eastern Queensland and northern New South Wales (Hervey Bay to Byron Bay)
  • Sydney mega-metropolitan region (Newcastle to Wollongong)
  • the Port Phillip region (Queenscliffe to Portsea)
  • north of Perth in the City of Wanneroo to south of Perth in the City of Mandurah (Figure 3).

The risk for the eastern seaboard is that, if left unchecked, this coastal development will soon give rise to a largely contiguous urbanised east coast seaboard stretching from Hervey Bay to the Surf Coast in Victoria. Only protected areas along the coast such as national parks and other reserves will not be urbanised. At risk are highly productive agricultural lands, areas of heritage significance and unprotected ecologically significant remnant habitats. In other areas, coastal development is encroaching into fire-prone areas of coastal heath, forest and shrubland.

Table 2: Size and density changes in estimated resident population of coastal areas in Australia, 1996–2004
Coastal areas (as defined by Statistical Local Areas)a Areab
(’000 km²)
Estimated resident population
(’000s)
Average annual population change (%c)
1996 2001 2004 1996–2001 2001–04
All coastal areas 2 163.1 7 482.0 7 971.7 8 283.5 1.3 1.3
Coastal areas excluding capital cities 2 149.2 2 977.7 3 193.4 3 339.6 1.4 1.5
Coastal areas within capital cities 13.8 4 504.4 4 778.3 4 943.9 6.1 3.5
Australia 7 705.3 18 310.7 19 413.2 20 111.3 1.2 1.2

Notes:
a Coastal areas are all Statistical Local Areas (SLAs) with a boundary adjoining the sea, including those with boundaries adjoining harbours and rivers, such as Leichhardt (A) in Sydney harbour and South Perth (C) on the Swan River in Perth. Note that many SLAs extend inland for large distances (for example, East Pilbara Shire in Western Australia has a coastline of roughly 80 kilometres and an area of over 350,000 square kilometres)
b based on 2004 Australian Standard Geographic Classification (ASGC) boundaries.
c average annual growth rate

Source: ABS (2005a)

In New South Wales, coastal urban expansion has been limited because the state government has bought strategic areas of land, and continues to do so. Between March 1995 and May 2006, approximately 37 000 hectares of coastal national parks were created. In total, some 140 000 hectares of land in New South Wales is protected and managed in coastal national parks. Combined with Queensland’s efforts, this protects more than 600 kilometres in the Nowra to Noosa coastline from urbanisation.

The challenges the mega-metropolitan regions create for planning and governance are complex. The public costs associated with these lifestyle choices and the demand for infrastructure are significant. For example, agricultural production from peri-urban regions is estimated to be a quarter of Australia’s total gross value of agricultural production (Houston 2005), yet there is no national mechanism in Australia for monitoring the loss and its impacts. National monitoring of biodiversity loss through urban expansion has been similarly neglected. It is encouraging that emerging long-term development strategies are starting to define limits to urban expansion and protect and conserve rural land and conservation areas (for example, Melbourne 2030, Sydney Metropolitan Strategy, Southeast Queensland Regional Plan, Planning Strategy for Adelaide).

In several major urban areas of Australia where urban growth pressures are high, progress has been made in recognising the importance of urban form. The pace and scale of redevelopment and outward expansion in many Australian cities provides opportunities for changing urban form to increase urban efficiency.

Energy use

Across Australia, total energy use  has continued to increase (Table 3). This is a result of Australia’s increasing population as well as more industries and more people using more energy, despite a small offset as a result of improved energy efficiency. Growth in use of renewable energy sources  is slow, amounting to less than 6 per cent of energy used in Australia (Table 4). Use of liquid gas is increasing in some areas, such as Brisbane and Canberra public buses (Table 5), but the full potential is not being realised.

Table 3: Energy use per capita and per unit GDP in Australia, 1997–98 to 2003–04 (more information on this topic) 
Year Energy consumptiona (PJ) Estimated resident populationb (’000) GDP*c
$m
Energy use per capita
(GJ per capita)
Energy use per unit GDP
(GJ per $m)
1997–98 4777.6 18 711.3 633 353 255.3 7 543.3
1998–99 4884.7 18 925.9 666 921 258.1 7 324.3
1999–2000 4971.0 19 153.4 692 264 259.5 7 180.8
2000–01 5034.1 19 413.2 706 109 259.3 7 129.4
2001–02 5110.8 19 641.0 733 647 260.2 6 966.3
2002–03 5215.1 19 872.6 756 170 262.4 6 896.7
2003–04 5345.7 20 111.3 783 593 265.8 6 822.0

Note: PJ – petajoule; GJ – gigajoules
* Reference year 2002-03

Sources: column a Donaldson (2004),column bABS (2005b), column cABS (2004b)

Table 4: Energy end-use by source and by sector Australia, 2001–02 (more information on this topic) 
  Petroleum products Electricity Natural gas Bio-fuels Solar Total
Total final energy consumption (PJ) 1 530.0 689.9 649.3 1.5 4.4 3307.5

Note: PJ – petajoules

Source: Donaldson (2004)

Table 5: Energy consumption by Canberra’s public bus fleet, 2002–03 to 2004–05
Fuel type Energy use (GJ)
2002–03 2003–04 2004–05
Automotive diesel 315 674 321 869 302 183
Electricity 7 871 8 379 8995
Greenpower 2 332 2 602 2749
Liquid petroleum gas - 12 17
Natural gas 9 561 19 764 43 281
Petrol 2 466 2 570 2581
Totals 337 904 355 196 359 807

Note: GJ – gigajoules

Source: ACTION Authority (2005)

Road transport  is the single biggest user of energy, consuming almost 40 per cent of the energy used in Australia (Figure 4). On roads, private passenger vehicle travel represents three-quarters of total road travel, and although total petrol consumption continues to increase, there are signs of household consumption stabilising. This would be influenced by higher petrol prices and more fuel-efficient cars (Figure 5).

Figure 4: Energy end-use by source and by sector Australia, 2001–02

 Energy end-use by source and by sector Australia, 2001–02

Note: Industry and construction includes iron and steel, chemical, other industry and construction.
a excludes wood and bagasse and includes recyclables.
Source: Donaldson (2004:43)

Figure 5: Quarterly average retail price of petrol in Australia’s eight capital cities, 1982–2006

 Quarterly average retail price of petrol in Australia's eight capital cities, 1982-2006

Note: from 1994, figures are for unleaded petrol. Leaded petrol is approximately 2 cents per litre more expensive.
Source: after various ABS catalogues 6403.0

The rate of growth in share of road travel is greatest in the category of light commercial vehicles servicing intra-urban freight needs. Growth in volume of freight transported by road, both within and between cities, has also continued at rates more closely aligned to rates of economic growth than population growth.

Electricity consumption has been steadily increasing, and this is a direct result of economic growth. The rate of growth in electricity consumption is also expanding, from an increase of 1.9 per cent in 2001–02, to 3.4 per cent in 2002–03 and 5.0 per cent in 2003–04 (ESAA 2005). The main users of electricity are the industry and construction, residential and commercial sectors. The changing patterns of electricity consumption are partly linked to the growth in commercial and residential air conditioning load of 20 per cent a year for the last five years (Figure 6). Improved thermal design of Australia’s buildings is needed to reduce the need for air conditioning, particularly given the increases in temperatures in the last 30 years, and thereby mitigate this pressure on the environment.

Figure 6: Australian electricity consumption

 Australian electricity consumption

Note: PJ - petajoules
Source: ABARE (2005a)

Increasing energy use is of concern because it directly affects environmental quality. Much of Australia’s energy use is based on non-renewable fossil fuels such as coal and oil and, aside from the direct environmental impacts of extraction, the emissions from burning these products impact on air quality and on climate change through greenhouse gas emissions. For example, the use of petroleum products in the road transport sector is directly associated with high levels of particulates, carbon monoxide and other pollutants (see ‘Ambient air quality’).

Water use

Water use  continues to increase across Australia. In 2000–01, just over two-thirds of water consumed in Australia was used by irrigated agriculture, with only about 5 per cent of water used by other rural sectors . Domestic use accounted for only 9 per cent of water use. Industrial and commercial use accounted for the rest. The impacts of Australia’s water use on inland waters is discussed elsewhere (see ‘Inland waters’).

Water reuse  has increased, albeit slowly. In 2001–02, 516.5 gigalitres of water was reused, which is a substantial increase from the 134.4 gigalitres reused in 1996–97. Some 82 per cent (423.3 gigalitres) of that was reused by irrigated agriculture, and 23.1 gigalitres was reused in other rural sectors.

Only 9 per cent of Australia’s sewage effluent was being recycled in 2001–02, which is an improvement from the estimated 7 per cent during 1996–99. The extent of wastewater reuse increased in all Australian states, except Queensland, from the late 1990s to early 2000s (Table 6); however, the rate of recycling varies greatly between states, with South Australia being the leader and the Northern Territory being well behind.

Table 6: Water discharge and reuse from water utility sewage treatment plants in Australia, 1996–99 and 2001–02
State or territory 1996–99 2001–02
Effluent (GL/yr) Recycled (GL/yr) % Effluent (GL/yr) Recycled (GL/yr) %
Qld 328 38 11.6 339 38 11.2
NSW 548 40.1 7.3 694 61.5 8.9
ACT 31 0.25 0.8 30 1.7 5.6
Vic. 367 16.9 4.6 448 30.1 6.7
Tas. 43 1 2.3 65 6.2 9.5
SA 91 9 9.9 101 15.2 15.1
WA 109 5.5 6.1 126 12.7 10
NT 21 1 4.8 21 1.1 5.2
Aust. 1538 112.9 7.3 1824 166.5 9.1

Note: GL – gigalitre

Source: Radcliffe (2003)

Strategies for the capture, treatment and use of stormwater—the realisation of ‘city as catchment’—are poorly developed. Urban stormwater from the many hard surfaces in cities is essentially not used, even though the area of the combined ‘catchment’ is equivalent to that of most urban water supply catchments. The exception is the increasing use of rainwater tanks ; some 17 per cent of Australia’s households had rainwater tanks (1 340 700 tanks) in 2004; an increase from 15 per cent of households since 1994. This reflects better government and community acceptance of the need to reduce water use. Even though more Australians are now reporting that they use water conservation measures, it is too early to assess whether the change in attitude is reflected in the water use data. As much as 44 per cent of household water is still used outside the house, although water restrictions in the major metropolitan areas have had some effect on use of water on gardens.

Water Futures Project—Toowoomba

Toowoomba’s water supply dams were at about 25 per cent capacity in April 2006, and the city was on severe water restrictions. The Council proposed a Water Futures programme to look at ways to better use the available water. The most significant aspect of the programme was to treat wastewater to a high degree and to mix it with water in the supply dams. The mixed water would then be further treated before being used for drinking water, and would have supplied about a quarter of Toowoomba’s total water needs in 2025. There would also have been more water available for coal washing, irrigation, power generation and industrial use. Irrespective of the science, these issues will always be controversial. A Toowoomba Water Futures Poll was held on Saturday 29 July 2006 to determine whether the proposal to use recycled and treated wastewater as a water supply option for the city and surrounding industry would be accepted. The residents rejected the proposal in July 2006.

Source: Toowoomba City Council (2006)

Waste

The amount of waste generated in Australia  has increased with population. Around one tonne per person per year is disposed into landfill (Table 7), but the amount is decreasing in some states (ABS 2003b).

Table 7: Solid landfill waste quantities in Australian states and territoriesa, 2002–03
Sector Amount of waste to landfillb(’000 tonnes)
NSW Vic. Qld SA WA Tas. NT ACT
Domestic and municipal 1 657 2 133 1 108 na 741 na na 82
Commercial and industrial 2 358 2 790c 522 na 420 na na 98
Construction and demolition 1 193 200 na 1 525 na na 27
Other 545 986 na na na
Total b 5 208 5 467 2 815 1 252 2 696 na na 207

Note: na – not available
a data as reported by state and territory government departments and Environment Protection Authorities across all industries
b caution should be exercised when making state comparisons due to scope differences across states and territories.
c Victoria reports commercial, industrial, construction and demolition waste as a combined amount

Source: ABS (2004c:15)

Most households in Australia’s cities recycle some waste, especially newspapers and green waste, and waste recycling and reuse . Amounts of solid wastes recycled] rates in general have increased to an average of 36 per cent across Australia (WCS Market Intelligence 2001). In areas outside the capital cities, the recycling rate is lower because of the logistics and costs associated with collection and transport from rural areas to processing plants. Reuse of waste, in contrast, is higher among rural and regional households.

Most states and territories have implemented waste reduction policies with a view to reducing the amount of waste to municipal landfills. These have been broadly successful. For example, of the waste generated from building activity on an annual basis in the Sydney region approximately 10 million tonnes are now recycled or reused, 2.5 million tonnes are reprocessed into building materials off-site, and 1 million tonnes are disposed of annually to landfill (DEC NSW 2003).

In Australia, product stewardship schemes are being used by industry and governments to bring the key players together to understand and correct market failures in the life cycle of products and materials, such as packaging, newsprint, plastic bags, refrigerants, farm chemicals, motor oil and polyvinyl chloride. Schemes are also being developed for tyres, televisions and computers. The schemes are implemented largely through voluntary and co-regulatory arrangements involving the Australian Government, state governments and industry.

Despite these efforts, it is clear that almost all (96 per cent of Australia’s waste ends up in landfill. This compares with 70 per cent in the United States (approximately 16 per cent is incinerated) and 50 per cent in Sweden (where 45 per cent is incinerated) (Batten 2002). Although the potential is far from being realised, a small amount of the methane generated from landfill sites is recovered, mainly for electricity generation, increasing from a negligible amount in 1990, to 24 per cent in 2003 (DEH 2005a). Many of Australia’s landfill waste disposal sites do not incorporate measures for the collection and treatment of landfill gas. An estimated 80 per cent of Australia’s municipal solid waste is available for this purpose, representing a source of approximately 50 gigajoules annually excluding the total potential from existing landfill sites (ABS 2003b, Aquatech 1997).

The Productivity Commission (2006a) released its draft report on Waste Generation and Resource Efficiency on 23 May 2006. The report focuses solely on the downstream environmental impacts of waste disposal and does not investigate outcomes from implementation of more resource efficient practices or cleaner technologies. In summary, the Commission found that waste management policy in Australia needs to be refocused, and the attitudes of both policy makers and the community need to be guided by rigorous analysis of costs, benefits and risks in order to secure the best returns for the community. While recycling can be good up to a point, returns diminish when it is pushed too far.

The amount of used oil being recycled under the Product Stewardship for Oil programme has increased dramatically. Of an estimated 280–300 million litres of potentially recoverable used oil, more than 220 million litres were recycled and reused in 2004–05, a large increase from the estimated 160 million litres of used oil recycled before the introduction of the programme in 2000 (Figure 7).

Figure 7: Volume of used oil recycled under the Product Stewardship for Oil Programme, 2000–01 to 2004–05

 Volume of used oil recycled under the Product Stewardship for Oil Programme, 2000-01 to 2004-05

Note: 2000–01 data are for six months, from the start of benefits from the Product Stewardship for Oil Programme in January 2001.
Source: DEH (2006a)