21st Century City Challenges
Henderson, Hartley, Ecos
Urban sustainability experts believe that formidable challenges and vulnerabilities confront our cities and that there is an urgent need for an Australian sustainability framework capable of being operationalised. Rather than having a dark view of the next decades, however, we could see this as a time of great opportunity and innovation ahead--if we are prepared to embrace it. Hartley Henderson reports.
Is the population growth and rate of resource consumption in our cities sustainable? How real is the greenhouse threat, and what are the possible consequences if we ignore it? Could our cities run out of water, become too polluted, or be stretched for environmentally neutral energy resources? And what action should be taken to address these issues?
These are just some of the questions on urban sustainability that are now receiving serious attention from authorities in relevant bodies both within Australia and overseas.
Professor Peter Newton, at Swinburne University's Centre for Regional Development in Melbourne, and Program Director at the CRC for Construction Innovation (formerly Chief Research Scientist of the Urban Systems Program at CSIRO), is author of the Human Settlements chapter of the recently released Australia State of the Environment 2006, (1) and is currently assembling a book titled Transitions: Pathways towards Sustainable Urban Development in Australia. His internationally recognised research on urban systems has given him a broad perspective on what he calls the 'looming vulnerabilities' facing our cities as populations grow, resource use increases and the climate warms.
But this perspective also affords him a view of what can be done.
'The looming vulnerabilities for cities include a continuing dependence on depleting sources of fossil fuel, which will have a huge future impact on transport and mobility. Our current water supplies, too, are not sustainable in the context of forecast population, urban development and climate change. Waste generation has been increasing in some states as we lack a more comprehensive cradle-to-cradle perspective in relation to waste management. Pollution halos are also increasingly evident off the coasts and in the airsheds of our major metropolitan areas. Beyond that, we have the not inconsiderable threat of sea level rise to our mostly coastal cities to plan for,' Professor Newton summarises.
'The two leading environmental threats are climate change and resource depletion, with oil as the first major casualty. Resource use is simply not sustainable at our current rate of consumption and pattern of urban development, he says.
'Population growth in each of Australia's capital city central business districts continues, but in terms of absolute population growth, this is dwarfed by suburbanisation. Between 1991 and 2001 Australia's five leading capital cities added 76 000 people to their inner cities and 1.24 million to their suburbs (6 per cent versus 94 per cent respectively of total population change).
'One of the main reasons for downtown population growth is the increase in supply of apartments due to the boom in high-rise construction,' Newton highlights.
'Australia now imports half of its population growth each year and governments control part of the equation through immigration policy and tourism programs. The way our cities are planned also tends to encourage more, rather than less, consumption. When coupled with high levels of per capita consumption, Australia's total consumption is world leading.
'A sustainable human environment requires greater attention to urban planning and design and a reduction in consumption and waste. There is an urgent need for an integrated and properly coordinated approach to the various challenges we are facing, as well as strong leadership.'
His concerns are not new. According to the Water Services Association of Australia (WSAA), although the population of Australian capital cities is projected to increase by 35 per cent by the year 2030, the variability of rainfall and potential climate change impacts are decreasing water yields by up to 25 per cent in some of the water supply catchments serving our cities. …