CSIRO Division of Wildlife and Ecology, Canberra

(Talk to Australians for an Ecologically Sustainable Population Oct 17 1992)


Earlier generations of Australians imposed massive change on the natural resources of the continent. This includes the Aborigines who practised firestick farming over vast areas and who probably hunted the megafauna to extinction. Much of the change has been the result of settlers' misjudgments as to the nature of the resource base and ignorance of the consequences of their actions.

Some actions like the release of rabbits and foxes would almost certainly never have been made if the consequences could have been foreseen. Other actions, like stocking the rangelands heavily and cropping erodible soils may have gone on irrespective of any awareness of the consequences. Each generation, consciously or unconsciously, chooses the degree to which it sacrifices natural resources for development and commodity production. It is important that the present generation learn from the past but there is little point in dwelling on it.

The present generation continues to exchange natural resources for development and resource-based production in much of Australia, although at a much reduced rate. The focus of community attention on this exchange is shifting from farmlands to forests and the coastal zone and from land degradation issues to pollution issues, particularly water pollution.

The general resource depletion issue which is dividing the community is whether or not we have the right mix of (a) economic benefits flowing from natural resource use and (b) the environmental disbenefits of losing service and amenity functions of natural resources.

The umbrella task in managing Australia's natural resources is to decide how far and fast to travel down this one-way street while developing strategies and technologies which will allow us to improve the tradeoff rate between amenity/service costs and economic benefits.

To get this balance right in coming decades we need a range of well-developed strategies, policies, and social technologies. These include:

. national population and settlement strategies

. price-signalling instruments which ensure that those who deplete the community's natural resources pay the full cost. These include regulations, resource use rights, royalties set by tender and resource rent taxes.

. social technologies which allow the economic benefits and environmental costs of local and regional activities to be considered fully. These crucially include land use planning, project impact assessment and state of environment reporting.


When I was asked a week ago to stand in as a speaker on the theme of an overexploited continent I decided that I did not want to deliver yet another `expose‚' of how Australians have overused their country. I would rather talk about the short and long term benefits and disbenefits of what we are doing with our natural resources today, or about how we could be planning to manage our natural resources in the future.

Catalogues of environmental disasters only breed anger or depression and eventually overwhelm our capacity to act. Certainly we need enough history to know what to avoid but the question of where we go from here is more important than where we have come from. For example, the livestock carrying capacity of our rangelands has declined markedly this century, mainly due to overstocking. The question which matters now is whether we can profitably stabilise production from the rangelands at reduced levels and whether we can prevent further extinctions of pastoral zone mammals and birds. We have learned the lesson from history that an abundant species can disappear with startling rapidity. Localised species occurring over only limited areas are in particular danger, as are species occupying specialised habitats.

Another example of learning. We have learned that exotic plants can sit around doing nothing for decades and then explode across the landscape. Mimosa pigra slumbered in the Darwin botanic gardens for more than eighty years before running wild. And so on.

Some spectacular historical misjudgments

Because European settlers had to learn to understand the Australian environment from scratch, it is inevitable that they should have made misjudgments about the consequences of various land management practices. Four of the more spectacular of these have been what I will call `high regret' misjudgments about

* long-term livestock-carrying capacity and crop yields in inland areas

* the impact of introducing feral animals (particularly rabbits and foxes) on pasture and range productivity

* the effects of introducing exotic plants destined to become weeds of agricultural and natural systems, e.g prickly pear

* the risks and consequences of floods and fires.

I call these `high regret' misjudgments to make the point that, with foresight, earlier generations would have almost certainly acted differently with respect to these matters.

These can be compared with what we might term `don't know' misjudgments such as:

* the unforeseen consequences of excessive clearing of timber, e.g. salinisation, erosion, woody regrowth

* the effects of uncontrolled irrigation, e.g. salinisation of soil and water

* the susceptibility of bare soil to water and wind erosion

* the effects of agricultural and pastoral development on biodiversity

I call these `don't know' misjudgments because even with foresight as to what their actions were setting in train, earlier generations of Australians may still have decided, either as individuals or as a society, to accept the resource degradation, the loss of natural capital accompanying their activities in return for the cash in hand and the chance to exchange natural capital for built capital. We just don't know.

The reason why I suspect that things would not be greatly different even if our ancestors had been clairvoyant is that we continue to do the same sorts of things today even

* when we can see the effects of past practices;

* when the natural capital which is being degraded is in much greater demand/shorter supply than one or two generations ago.

* when we know much more about cause- effect links than our grandparents.

While I might wish that our grandparents had acted differently, they were nonetheless doing what every community does and that is to make tradeoff choices between resource conservation values and resource development values.

It may be correct to be trenchantly pro- or anti-development for political reasons but not when we are trying to think about our options rationally, if I can invoke a much-abused word. Development, meaning here urbanisation and the expansion of output from the resource-based industries, is a one-way street. We can never travel down it without losing something in the way of irreplaceable amenity resources and without permanently decreasing the range of future possibilities for using what's left. There seems to be a widespread unwillingness to accept this blindingly obvious fact. This does not mean we should never travel the development path.

I will put it in parable form. If loss of conservation values is the `fuel' which propels the primary industries `engine', we have to (a) decide how much fuel to put in the tank and (b) see if we can improve fuel consumption.

Developed resources cannot be undeveloped and a conservative or precautionary approach to resource management is therefore appealing. Conservatism in resource management is the philosophy that one needs to think very carefully (and this takes time) about the gains and the losses before embarking on irreversible development, especially of relatively undisturbed areas.

The present

Let me turn more explicitly to the present.

Population growth, a central concern of the present audience, is only one in a long list of societal processes/activities customarily seen as contributing to loss of environmental quality. Others on the list are population re-distribution, increasing consumption of material goods, waste and residue disposal practices, intensification and extensification of primary and secondary industries, urban expansion, income redistribution, resource allocation procedures, etc. etc.

Collectively, these processes, even as they generate benefits for some, (a) consume, (b) ration, (c) degrade and (d) pollute natural resources, normally meaning water, air, biodiversity and earth materials resources. This is what I mean by loss of environmental quality.

More concretely, concern over the impacts of human activity (not just population growth) on water, air, biodiversity and earth materials resources takes three main forms:

(a) decline in the availability and functionality (productivity) of natural resources valued for primary or resource-based industries. These are tourism, mining, farming, forestry and fishing and the natural resources they depend on (industrial natural resources) include, for example, soils, water supplies, landscapes, forests, rangeland and fish stocks.

The concern here is essentially economic - for the viability or sustainability of primary industries which are depleting their natural capital.

(b) decline in the availability and functionality of natural resources valued for their direct contribution to people's physical and spiritual health - amenity resources. Lists of amenity resources include air for breathing, water for drinking, biodiversity for marvelling at and landscapes for playing in.

Let me take one example in the area of biodiversity. Today, threats to wildlife are indirect rather than direct. It is not like 1924 when we exported 2 m koala skins. The basic threat now is destruction of habitat. We know that the geographic range of many species is decreasing as their habitats are developed or destroyed. It is true that the massive land clearing for agriculture of the 1950s and 1960s is over. Nevertheless,

* small-scale clearing of patches of native vegetation continues at a reduced rate in temperate Australia

* woodchipping threatens large areas of forest habitat in New South Wales and Tasmania

* there may yet be a sizeable expansion of cropping in central Queensland

* there are some significant areas which might still be opened up to pastoralism, notably in Western Australia

* chemical thinning of very large areas of Poplar Box woodlands in Queensland and northern New South Wales remains a possibility

* droughts will continue

* predators are still spreading

* most importantly, species conservation efforts are insufficient to significantly throw the odds back in favour of threatened plants and animals.

(c) decline in the availability and functionality of natural resources valued for their capacity to provide environmental services, that is, to improve the functioning of natural resources with productive and/or amenity values. Most environmental services can be viewed as recycling of some sort. Lists of service resources include vegetation for maintaining atmospheric oxygen levels, wetlands for removing pollutants from water supplies, ecosystems for recycling nutrients through the food chain.

The phrase `decline in the availability and functionality of natural resources' is an accurate but cumbersome description for the type of environmental quality loss of interest here. Shorthand alternatives are `environmental impacts', `environmental costs' and `natural resource depletion'.

While most of the processes which historically reduced environmental quality remain with us today in some form, two particularly fast-growing inter-related threats need to be clearly flagged. One is water pollution and the other is coastal development.

The Australian coastal zone provides sites for a wider range of uses and functions than any other part of the continent. These include residential and commercial use, recreational use, commercial fishing, ports (about 120 in all) and sea transport, waste disposal, tourism, conservation of natural environments and industrial uses such as cooling, salt production, pulp production, mining and agriculture. Not only do Australians want to live (and hence work) near the coast, it is a major focus for outdoor recreation and local and international tourism.

For some decades now, about a quarter of the Australian population has chosen to live within three km of the coast (McDonald et al., in press). If this proportion holds as total population grows towards a projected level of 27 million by 2051, there plausibly could be another three million people living in the coastal fringe by then. McDonald et al. (in press) conclude that three urban regions (based on Sydney, Brisbane and Perth) will not be able to accommodate their projected coastal fringe populations without resorting to some combination of (a) high population density (b) building on depositional terrain which has considerable service value (c) urbanising currently unpopulated open space and rare vegetation associations, both of which have high amenity value.

The impacts on environmental quality of future population growth will be concentrated in coastal areas, particularly the twenty per cent of coastal Australia which is urbanised or urbanising.

Water pollution and waste disposal are already widespread, although generally localised, issues in coastal zone management. Examples include runoff of agricultural chemicals, pulp mill effluents, sediment loads, offshore sewage disposal, heavy metal pollution, eutrophication from urban runoff and fertiliser leachates, oil spills, depletion of seagrass fish nursery areas, overdevelopment of biologially important estuaries and coastal waterbodies (Cocks 1992). Unless much greater efforts are made to manage such problems, they can only get worse as population growth leads to the growth of coastal cities.

The future

My own ideas for developing, conserving and managing Australia's natural resources in the 21st century have been built up around a suite of 15 goals identified as needing to be achieved on the way to ensuring that those resources satisfy the most important of our material, spiritual and emotional needs as far as possible; in short, to ensure that Australia remains a good place in which to live. They include conservation goals (soil, air, water, plants, animals, cultural sites), primary production goals (farming, forestry, fishing and mining), other land use goals (settlements, Aboriginal lands, parks, tourist areas) and community management goals (social and physical infrastructure).

Making and implementing resource management strategies to achieve these goals is constrained by the extent and type of knowledge we have of our natural resources and of techniques by which these might be used and conserved; by the dominant values of the Australian socio-political system; and by the sheer technical difficulties and uncertainties of efficiently and effectively identifying and evaluating candidate strategies.

Discussion of how to proceed in the face of these constraints particularly highlights the challenges of developing social technologies for trading off competing interest group demands (what is equity?), making multi-valued choices (how many apples equal one orange?) and accumulating sufficient actionable knowledge (what if..?) to develop creative options.

To get the balance between resource-based economic activity and natural resource depletion right in coming decades we will need a range of well-developed strategies, policies, and social technologies. These include:

(i) national population and settlement strategies. There is a strong prima facie case for the negative impact of population growth on environmental quality but it still has to be convincingly demonstrated and disentangled from factors such as affluence and others mentioned earlier.

(ii) price-signalling instruments which ensure that those who pollute, degrade, and destroy the community's natural resources pay the community full compensation. These include regulations where appropriate, resource use rights, royalties set by tender and resource rent taxes.

(iii) social technologies which allow the economic benefits and environmental costs of local and regional activities to be considered fully. These crucially include land use planning, project impact assessment and state of environment monitoring.

The last of these is very new to Australia and aims to develop indicators of the functionality and availability of water, air, biodiversity and earth materials resources.

Land use planning and project impact assessment have been around for many years, but still lack teeth and suffer strong opposition from business interests.


The availability and functionality of Australia's natural capital (water, air, biodiversity and earth materials resources) has been declining for a very long time and will continue to decline. Whether the increases in consumption and in built capital made possible by this loss justify it remains a matter of personal values, probably with no blanket answer.

Looking to the future however, we need to question just how much consumption and built capital we want and how we can minimise the cost, in environmental terms, of getting what we want. Alernatively, we need to ask what natural resources we want to retain and how we can maximise economic benefits subject to that constraint.