Why do new freeways fill up with cars so quickly and congestion seems to get worse? Why do we run out of water in our cities and have to install desalination plants? Why is more money being outlaid to reduce queues for the dentist or elective surgery? Why do we import 70% of our seafood, or transport fresh food from north Queensland to Melbourne? Why is it that our electricity infrastructure has had to be so extensively renovated while our electricity bills skyrocket? And why are there no new landfill sites within the Sydney Basin?

The key factor in all of these scenarios is inexorable population growth. It is a significant multiplier of all the other reasons that lead to our communities’ problems in areas like transportation, waste disposal, easy access to fresh food, water, air, education, and health and dental services.

So despite other causes such droughts, floods, the GFC and the high Australian dollar, population growth and a warming climate together underpin the extent to which these problems affect our quality of life. Crikey yesterday examined the link between population growth and greenhouse gas emissions.

It is the absolute numbers in population growth that offer part of the explanation. Also important is our rate of consumption of energy, water, air, land, vegetation and “stuff” (a technical term) by each of the people in the population.

Why have our elected governments not been much more alert to, and proactive in, creating policies and programs that deal with the consequences of population growth?

In our 2010 study commissioned by the Immigration Department on the impact of of different levels of Net Overseas Migration on Australia’s physical natural and built environments out to 2050, we found a serious lack of awareness of just where the notion of population growth actually relates to our environments. There was, for example, a flawed economic logic that suggested that a national optimal number for NOM could be produced to account for impacts on our physical environment.

And further, that such a number could be plugged in to a cost-benefit analysis with an economically derived figure of optimum migration to produce a policy that resulted in maximum sustainable, per capita wealth. The reality is that people live in concentrations called cities and towns, and that migrants can choose to live where they want. So they choose where their fellow countrymen live: primarily in western Sydney, north and west Melbourne and parts of Perth.

Put together, 20% of statistical local areas (ABS zones) account for almost 80% of all migrant residences. A national population figure therefore has no relevance to policy unless it is underpinned by specific and explicit reference to locations where people live. Then, and only then, can one begin to understand the causal links between people in our settlements and the physical natural and built environments which frame our existence.

Our study used various approaches to assess where (and therefore how) this population-environment interaction occurs. We used modelling from CSIRO that explored how the “stuff” of agriculture, industry and commerce adds together to produce our livelihoods and lifestyles in Australia. We used case studies of the three main locations for migrant residence to explore water and food security, energy supply, biodiversity loss, land-use competition, and waste disposal.

Three particular findings from our study were clear:

  1. In modelling the state of stocks and flows of real “stuff” in our world, i.e. not through economic proxies, we found that an annual average NOM of 260,000 people would increase our per-capita wealth by 2.3 times in 2050. By using a NOM of 50,000 our per-capita wealth would be about 2.0 times what it is today. But consider the difference in lifestyles if you had to share your favourite roads and hospitals with many more people for a dubious financial benefit.
  2. Even allowing for a substantial improvement in our water-use efficiency and in technology fixes, our drying climate linked to increased population means serious structural shortages of water will occur in Sydney Melbourne and Perth by 2050 if not much earlier.
  3. Sydney is already dysfunctional, not only with transportation, but waste disposal. What happens when an extra 1 million people are added to its population, a significant proportion of which will be migrants — and another 20% by volume of waste is generated annually. Where does it go? There is no place called “away” any more …

There is a clear need for much more work at the regional level to provide governments with the information required to structure meaningful policies and programs in a systemic way that a) cut across the territoriality of departments and philosophies, especially the thrall of economics; and b) produce said policies with time-spans that appreciate the long-term effects of population well beyond the territoriality (again) of political tenure.