The nature of Australia’s population debate

The "sustainable population" perspective is frequently posed in terms of Australia having a maximum "carrying capacity" which has been, or may soon be, exceeded. The problem is that this takes a concept from ecological sciences - "carrying capacity" - and applies it inappropriately to a human society. The resource needs and ecological impacts of non-human animals are relatively fixed, being determined by the biological characteristics of the species in question. Human resource needs and impacts, by contrast, are immensely variable, and so too is human "carrying capacity", being substantially determined by culture, technology and the mode of production in a given society.

Thus, in a sense it is true that the current Australian population is "unsustainable", as evidenced by the environmental deterioration documented in the 1996 Federal State of the Environment Report (pdf, 910kb). Our collective impact and resource "take" is more than Australia's natural systems can bear. But in the same sense Australia has never had a "sustainable population" since European settlement. Tim Flannery has suggested that Australia's maximum sustainable population is between 6 and 12 million. Australia's population was within this range for much of our post-1788 history, and our low numbers didn't prevent massive vegetation loss, water pollution, soil degradation and species extinction.

Conversely there is great scope to reduce our collective environmental impact through economic restructuring including smarter production methods, deployment of sustainable technologies, better urban planning, sounder farming practices, etc. The trouble is that we're far from achieving this. Whilst rejecting the reductionist equation between population size and ecological sustainability, calls to double Australia's population must also be rejected as premature as long as our current population is living beyond its environmental means. Only after we achieve sustainability with the population we have, or will have when we level out next century, should we be considering how many more people the continent might sustainably accommodate.

Also, the ability of technological and lifestyle change to reduce our environmental take, whilst ample, are not limitless. Socio-cultural factors limit our utilisation of sustainable technologies which already exist (such as bicycles for urban transit), and there are many problems for which science and technology have yet to yield "fixes". Most importantly, in a liberal society there are limits to the extent to which public policy can engineer changes in people's consumption and lifestyles. Australia's land and water could support many more people if nobody ate meat, drank alcohol, went fishing, played golf or showered daily. We must assume that most Australians will continue to want to do at least some of these things for the foreseeable future, and that it will be neither feasible nor desirable for governments to prohibit them.

Another weakness in the position of population boosters and busters alike is that achieving their preferred targets would require implausible rates of inward or outward migration. Population targets of 40 to 50 million by 2050 would require average annual net immigration of 300,000 to over 500,000 per year. This compares with annual net intakes under the successful post-World War II immigration programs which have usually varied between 50,000 and 100,000, and which have only exceeded 100,000 in a few years when economic conditions were favourable. Simply to state such figures, and to enumerate the practical implications of settling the equivalent of a new Gold Coast or Newcastle each year, is to highlight the difficulties. Yet these difficulties pale compared to those of achieving an average annual outward migration of over 100,000 per year - which is what population reduction to a "sustainable" target of 12 million by 2050 would require.

So does Australia need a policy to either substantially increase or reduce our population from DIMA’s baseline? I suspect not. We are on course for a demographic "soft landing" at a national population of 25 million, which may or may not be more than the ecological optimum, but which can be made sustainable if we are prepared to make the necessary changes in our society and economy. If we're not prepared to do this, capping our population will be futile, boosting it will court disaster, and neither course will offer much hope for a more, rather than less, democratic and pluralistic future.