Carrying capacity and population
Carrying capacity is usually defined as the maximum population of a given species that can be supported indefinitely in a defined habitat without permanently impairing the productivity of that habitat(19). As environmentalists, we understand that we need to allow other species to continue to flourish on this planet. In practical terms, this means the allocation of significant areas of all representative ecosystems as national parks or equivalent reserves (20).
In terms of social justice, we must also ask how we can create the situation where all people have access to the resources needed for a dignified existence. The pivotal question is how can we do this without living beyond the world’s carrying capacity?
There is no doubt that there will be a limit to the number of people that the Australian continent can sustain into the indefinite future. However, it is premature to talk about ‘carrying capacity’ or placing limitations on population growth without first considering the more fundamental issues of resource consumption, equity between and within nations, and the ownership of the infrastructure that drives consumption. Given the integration of local economies into global markets, it is becoming increasingly difficult to determine what the carrying capacity of a single country might be. The concept of carrying capacity must therefore be re-considered, so that it takes into the account resource flows in the global economy.
Clearly, population growth can cause substantial ecological costs. Under the current high consumption, low density models used in Australia, more people does mean more impact. One example commonly used by those seeking a stabilisation of population is that of South East Queensland [SEQ], where low density urban sprawl is destroying remnant vegetation, coastal environments and previously productive agricultural lands. It should be remembered that much of this growth is driven by internal migrations from southern states rather than new arrivals to the country. In addition, a significant cause of ecological destruction is also occurring through the trend towards households with fewer people, rather than population growth itself. This is a common problem throughout Australia (21). But perhaps the most significant issue in SEQ is that we, as a nation, still allow low density, high resource-consuming urban sprawl of this nature to continue. While many see population growth as the key issue in situations like this, a holistic approach would recognise that this influx of people is occurring in an ecologically unsustainable manner – that is, impacts arise largely from the nature of the development, not simply because of the arrival of these people.
This is essentially a political and economic rather than an ecological issue, covering all levels of government, control over capital and the style of development.
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