Human Settlements Theme Report

Australia State of the Environment Report 2001 (Theme Report)
Lead Author: Professor Peter W. Newton, CSIRO Building, Construction and Engineering, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06747 7

Waste, recycling and reuse (continued)

Air pollution and greenhouse

  • Energy-related greenhouse gas emissions
  • Energy and urban air quality
  • Urban form and air quality
  • Implications
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    Energy-related greenhouse gas emissions

    Over the past quarter of a century, three energy-related issues have emerged which should signal a halt to 'business as usual' thinking about the future path of development of cities: the cost of energy and its use (with consequent implications for industrial and national competitiveness); greenhouse gas emissions (with consequent implications for climate change and variability); and urban air quality (and its implications for human health and productivity).

    Australia's energy-related greenhouse gas emissions have continued to rise, as shown in Figure 87. It shows trends in energy-related greenhouse gas emissions for major sectors, and total energy-related emissions. Emissions associated with electricity generation, oil refining and gas supply have been allocated to end-use sectors in this graph. It can be seen that industrial emissions are dominant, followed by transport, residential emissions and commercial sector emissions. However, commercial sector emissions are growing rapidly, and growth in total emissions seems to have accelerated since the mid-1990s. This is partly a result of our recent rapid economic growth and continued population growth, but the operation of recently introduced energy markets seems to be an important factor. Saddler (2000) estimates that electricity generation was responsible for 55% of the increase in energy combustion emissions between 1990 and 1997. Overall, electricity generation contributes 37% of national emissions, transport 16% and agriculture approximately 20% of the total (NGGI 2000).

    Figure 87: Energy-related greenhouse gas emissions, Australia.

     Energy-related greenhouse gas emissions, Australia.

    Note: Emissions from energy conversion and fugitive emissions have been allocated to end-use sectors.

    Sources: ABARE (1999); Wilkenfeld and Associates (1998); Bush et al. (1999).

    The greenhouse intensity of Australian end-use energy has also been increasing, particularly since the mid-1990s. This results from the increasing share of electricity in total energy, as well as greater use of coal for electricity generation. Switching from, for example, oil to electricity for some activities can increase emissions per unit of useful energy by two or three times-although the use of advanced electrical technologies such as heat pumps could actually reduce emissions. And using coal instead of natural gas to generate electricity produces around 50% more greenhouse gases per unit of electricity. Projections by Wilkenfeld and Associates (1998) suggest that the greenhouse intensity of energy will decline as a result switching from coal to gas for fuel, and through improved efficiency of electricity generation and energy use. However, such a trend will depend upon the outcomes of energy market reform.

    Greenhouse gas emissions per capita have continued to increase. When energy-related emissions are added to emissions from other sectors, Australians can be seen as the largest per capita emitters of greenhouse gas emissions in the world (Australia Institute 1999). Australia emits 26.7 tonnes per capita, which is 25% above the USA and double the average for developed countries. However, most of the growth in emissions per capita is coming from sectors other than household non-transport energy use.

    If Australia is to meet its Kyoto obligation, major changes will be urgently required within the energy sector, as emissions have already exceeded the 108% of 1990 emissions required in the compliance period of 2008-2012. In fact, the National Greenhouse Gas Inventory revealed that Australia's greenhouse gas emissions in 1998 were 16.9% above 1990 levels (NGGI 2000). It seems increasingly likely that Australia will have to rely on reductions in emissions in sectors other than energy, such as greenhouse sinks, if it is to achieve its Kyoto target overall.

    Energy and urban air quality

    Energy supply and use are major contributors to urban air pollution. For example, energy-related activities and infrastructure were responsible for 70-99% of emissions of major air pollutants in Melbourne in 1995 (Table 72).

    Table 72: Pollutants emitted into Melbourne's airshed, 1995 (tonnes).
    Source CO PM10 PM2.5 NOx VOCs SO2 Lead etc.
    Energy-related sources
    Motor vehicles 560 000 3 500 2 800 54 000 63 000 2 200 180
    Other mobile 6 500 460 410 5 900 2 200 3 300 0.52
    Petroleum refining etc. 1 600 770 470 4 400 14 000 6 400 0.81
    Electricity and gas 1 500 30 25 3 000 1 400 18 0.002
    Road dust - 65 000 26 000 - 0 0 0
    Service stations - - - - 4 300    
    Sources other than transport and industrial fuel combustion 95 520 9 106 5 978 6 076 45 668 265.2 0.9165
    Total of energy-related sources 665 120 78 866 35 683 73 376 130 568 12 183.2 182.2485
    Other sources
    Biogenic 18 0 0 30 880 0.78 0
    Rest of domestic, commercial and rural sources 4 480 494 522 224 20 032 4.8 0.1835
    Rest of industry 6 800 6 700 1 205 12 600 17 600 4 582 2.588
    Total of all sources 676 418 86 060 37 410 86 230 169 080 16 770.78 185.02
    Percentage from energy related sources 98.3 91.6   95.4 85.1 77.2 72.6 98.5

    CO carbon monoxide
    PM10 particulate matter less than 10 microns
    PM2.5 particulate matter less than 2.5 microns
    NOx nitrogen oxides
    VOC volatile organic compounds
    SO2 sulfur dioxide

    Source: EPA Victoria (1998).

    Viewed overall, the Inquiry into Urban Air Pollution in Australia (AATSE 1997, p.9) was able to conclude that 'Australian cities have generally managed to maintain air quality over the past decade, especially compared to similar sized cities around the world'. The 'global' assessment was qualified by noting that the continued growth of Australia's cities will place increasing pressure on their urban air quality. This was seen to be especially so for NOx, hydrocarbons and particulates. In summing up, the Inquiry indicated that:

    On a 'business as usual' basis, pollution episodes would be expected to increase in number with increases in vehicle kilometres travelled by private and, increasingly, commercial vehicles. An accompanying feature of city size is traffic congestion. Already, a number of densely trafficked corridors in major cities produce high local levels of congestion and a corresponding increase in pollutants both for travellers and local residents (AATSE 1997, p 10).

    A more detailed assessment of urban air pollution and its change over time in Australian cities is contained in the Atmosphere Theme Report.

    In an international context, Table 73 reveals that Australian transport emissions are among the highest per capita rates in the world. Rates of NOx and VOCs (the photochemical smog precursors) and CO are all similar to or worse than US cities. They are all more than double the levels found in European cities and are even more extreme in comparison to levels in Asian cities, especially the wealthy Asian cities (Singapore, Tokyo, Hong Kong). SO2 emissions are quite small, though the levels are highest in European cities and lowest in Australian cities.

    Table 73: Transport emissions per capita in global cities, 1990.
    Cities CO2 (kg) NOx (kg) SO2 (kg) CO (kg) VOCs (kg) Fine particles (kg)
    Australia
    Average

    2 788.9

    21.9

    0.6

    185.8

    23.0

    1.4
    North America
    Toronto (metro)
    Average

    4 541.0
    2 434.3

    22.3
    27.0

    1.6
    2.3

    204.5
    160.6

    22.3
    21.7

    1.0
    3.9
    Europe
    Average

    1 887.9

    13.0

    2.0

    72.6

    11.6

    0.8
    Asia
    Tokyo
    Hong Kong
    Average

    Kuala Lumpur
    Bangkok
    Manila
    Average

    1 397.4
    760.4
    1 078.9

    1 424.0
    1 304.4
    610.0
    748.4

    4.4
    8.0
    6.2

    11.2
    3.6
    9.2
    8.7

    0.8
    1.7
    1.3

    1.0
    1.8
    1.5
    1.3

    14.3
    25.2
    19.8

    90.0
    84.6
    67.5
    61.8

    2.0
    2.4
    2.2

    22.8
    23.2
    11.2
    13.6

    NA
    1.1
    1.1

    1.0
    9.1
    1.5
    3.4

    CO carbon monoxide
    CO2carbon dioxide
    NOx nitrogen oxides
    VOCs volatile organic compounds
    SO2sulfur dioxide
    Note that air pollution concentrations are determined mainly by the emissions per unit area, not emissions per capita. On this score, because of their relatively low density, Australian cities are low by world standards. This is shown in Table 74, which compares emissions of VOCs per hectare (a surrogate for pollutants generally) for some of the cities in Table 74.

    Source: Kenworthy et al. ( 1997).