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
Urban stocks and processes (continued)
Transport supply (continued)
Per capita transport-related greenhouse emissions in Australia are among the highest in the world. In 1998 the transport sector accounted for 16% of Australia's greenhouse emissions and was one of the fastest growing sources of emissions, increasing by 18% between 1990 and 1998 (NGGI 2000):
... unless there is a miraculous turnaround on the science, the greenhouse density of transport will have to plummet if we are to maintain the growth in transport services (Beale 1999).
Figure 41: Energy consumption by transport mode, 1986-1987 to 1997-1998, with projections to 2014-15.
Source: IEAust (1999) based on Bush et al. (1999)
Based on a 'business as usual' scenario, emissions are forecast to increase by 42% on 1994 levels by 2015 (NGGI 2000), whereas our national target under the Kyoto Protocol requires our total greenhouse levels to be reduced to 8% above 1990 levels by 2008 to 2012, this will increase pressure on other greenhouse gas producing sectors to lower their emissions even further to meet the overall target. Road transport accounts for a growing share of transport emissions: 89% in 1998 (NGGI 2000). While cars currently account for more than half of the emission load, the BTE estimates that future growth in road traffic will come predominantly from trucks, in particular light commercial vehicles. Increased air transport emissions will also contribute to an increasing proportion of this problem.
Improved energy efficiency of the fleet due to improved technology is hindered by both the slow scrapping rate, which keeps older vehicles in the fleet, and the increasing preference for large-engined four-wheel-drive vehicles by drivers in cities. A more energy-efficient fleet is needed, since travel demand management measures to reduce traffic and traffic congestion cannot be expected to reduce greenhouse emissions sufficiently in the short term. Initiatives to increase the uptake of new low-energy vehicles would be helpful. The major automobile manufacturers are beginning to market low-energy options, from dedicated LPG vehicles in 2000 to hybrid electric and petrol vehicles in 2001.
Information presented to date plus stocks and flows forecasting for Australia to 2050 undertaken by Foran and Poldy (2000) for the Department of Immigration and Multicultural Affairs, suggest the implications below.
A likely long-term prognosis is that the stock of domestic population in Australia will rise to approximately 25 million by 2050. The most significant feature of this population nearly two human generations away is that its age composition will be skewed towards older age categories, with implications for the areas of health, employment and retirement income. The other feature is that the additional population will be predominantly urban, with a larger urban metabolism (see Figure 3) requirement that would equate to two extra cities the size of metropolitan Melbourne. The stocks of human capital could progress along two main routes. The demographic changes currently underway could give a population of 25 million by 2050, where relatively full employment levels are maintained because of the diversity and scale of the economic structure as it might then be. This might require that people work into their 70s and that they pass through several careers and skill sets during their working life. Alternatively, Australia might make a transition during the next human generation to a high-value, high-skills economy where the global returns on the national skill set are sufficient to allow an equitable existence and rewarding lifestyle without the requirement for a 50-year working lifetime.
A domestic population of 25 million will generate an increased requirement for leisure activities, including domestic travel and tourism services, with the additional factor of people taking more frequent and shorter trips. In addition, even if moderate expectations of growth are met for international inbound travellers, they could number 32 million visitors by 2050 compared to the approximately 5 million visitors today. If current patterns of visitation are maintained, tourism in cities such as Sydney, Melbourne, Brisbane and the Gold Coast will increase markedly and be dominated by overseas visitors. In order to service this requirement, the stocks of visitor accommodation, planes and buses will need to increase proportionally greater than the increase in domestic population. There is also a trend to increasing unit size of tourism stock from backpacker accommodation to five-star hotels, as lifestyle and marketing opportunities become tied to space and opulence. These stock characteristics of greater size and opulence will most probably lead to greater flows of resource requirement, particularly in the area of energy. This trend is not pre-ordained but most studies suggest that it is difficult to decouple the linkage between tourism experience and the stimulation of material and energy flows. An increased emphasis on eco-tourism is unlikely to change the resource implications of tourism growth rates, since eco-tourism is generally high in transport requirements and therefore has fossil energy and greenhouse implications.
By 2050 it is likely that Australia will have 8 million single houses and nearly 4 million other dwellings. Commercial and institutional building space could almost double over the next 50 years. The important factors are that the number of dwellings per unit population is increasing for a wide variety of social reasons. The floor area per unit dwelling is also increasing as affluence increases and lifestyle is tied to space and luxury in a relative sense. The same is also true for commercial and institutional buildings where market position in the case of both five-star hotels and backpacker accommodation is linked to space per occupant. If energy and environmental services (water, waste, heat and lighting) are tied to measures of space, then both the energy and materials used to construct each unit of building will continue to rise, and so too will the yearly operational requirements. Thus, under the most likely scenarios of population and affluence growth, the total stock in terms of area of domestic dwelling space will continue to expand until about 2060, and it will probably attract increasing energy and environmental services on a per unit area basis. In order to plateau the total demand for energy in building stock, building codes and standards would need a requirement that all new buildings meet five-star energy design performance.
The car fleet will probably number 14 million vehicles by 2050, with an additional 5 million urban delivery vehicles. The technology attached to each of these vehicles is critical to important urban function issues such as airshed pollution in our major cities (mostly from vehicles in the future), and for transportation fuel security in relation to future availability and price of oil and natural gas. Possible constraints loom for the longevity of domestic oil and gas stocks over the 25-year and 50-year timeframes respectively. Many changes, both planned and unplanned, could alter this prognosis. Major investment in urban transport systems might reverse the current emphasis on personal vehicles and allow equitable transportation systems for most of our major city inhabitants. Alternatively, new transportation technologies such as hypercars could herald pollution-free airsheds, but congestion will not disappear if high levels of personal mobility and car use are maintained.
By 2050 Australia could be facing the loss of 10 million hectares of productive arable land mainly from the wheat-sheep zones in both eastern and western Australia. The off-site effects of this could be substantial as the influence of dryland salinity and soil acidification, which affects the structural integrity of roads and buildings in rural Australia. Long-distance effects relate to water quality issues, and water treatment costs for cities such as Adelaide could increase substantially as water flow becomes increasingly more saline and more acid. Response mechanisms back at the source of the problem, such as reforesting substantial parts of Australian cleared landscapes, could reduce river flows and non-intuitively actually increase the concentrations of salt and acid because the dilution effect is less. A number of social and political abrasions may continue as resource allocations between rural and irrigation-based populations and urban water populations compete for a limited amount of high quality resource. Long-term land use planning issues will become paramount as urban areas seek to increase and maintain the quality and integrity of their water catchments in an attempt to maximise the value of natural ecosystem services (purity, amount and continuity of urban water supply) by limiting the amount of residential, industrial and recreational development in water catchments near to urban concentrations.
With the exception of oil and gas, Australia's rich endowment of minerals is likely to be adequate for domestic consumption as well as a growing export market well into the future. However, the prognosis for stocks of high-grade iron ore, gold, diamonds, copper, lead and zinc will depend on continuing location of ore bodies of adequate richness. Depending on the construction intensity in Sydney, Melbourne, Brisbane and Perth mega-metro regions, the local availability of key building supplies such as sand and gravel may become constrained. Rather than an absolute limit this would mean higher energy and monetary costs as bulk materials are transported in from further afield. Domestic stocks of easily available oil may become constrained by 2020, but the relatively large stocks of natural gas may last beyond 2050, depending on the volumes of liquefied natural gas that are exported. This generation of citizens. Depending on the dynamics of export markets, the rate of population growth and future requirements for personal mobility, by the year 2050 Australia could face a yearly trade deficit of 2000-3000 petajoules of transport fuels (40-60 million tonnes of oil equivalent). Politically the issue of nuclear energy remains off limits in Australia.
Australia's riverine system has been highly modified by the massive program of river regulation undertaken since 1950 in an attempt to `drought-proof' Australia (Crabb 1997). Major dam construction has been significantly reduced over the past decade, largely due to the economic and environmental costs of such structures. An appreciation of the costs associated with schemes for urban water supply is now very much greater.
The construction of a dam has the primary benefit of increasing the security of water supply. It can also have the secondary benefits of creating a recreation facility for swimming, boating and fishing, as well as providing a landscape feature. But, it also results in reduced and/or regulated flow, the drowning of land and vegetation, and the potential loss of mineral deposits and historic and cultural sites. The altered flow regime of the river has significant impacts on the riverine and aquatic environment, on stream uses such as recreation, and water quality (Crabb 1997). For example, Sydney's major water storages have had a major impact on the Hawkesbury-Nepean system where, in periods of low flow, effluent from the wastewater treatment plants makes a significant contribution to total flows. In future stormwater and wastewater will be required to be harnessed to satisfy the demands of an increasing urban population.