SOME things are more important even than the fate of the goods and services tax. A question I regard as just a tiny bit more significant to our future is whether we can continue increasing our population and material standard of living without doing irreparable damage to the environment.
Few of us noticed in all the excitement over tax reform, but last week we made a big step forward in answering this question. The CSIRO unveiled the results of a ground-breaking, two-year project - the Australian National Outlook report - in which it integrated a model of the economy with no less than eight models of different aspects of the global and domestic natural environment in which the economy exists.
So, is ecologically sustainable growth possible? Is it possible to "decouple" continuing economic growth from continuing environmental vandalism?
It depends on what you mean by "growth". There's enormous confusion on this point because what economists take the word to mean is not what scientists take it to mean.
What scientists mean by growth is growth in the "throughput" of natural materials and energy - using those resources to generate economic activity and, in the process, turning them into various forms of pollution and waste.
They point out that such growth simply cannot continue indefinitely because the natural world - the global ecosystem - is of fixed size. They're merely stating the first law of thermodynamics.
But that's not what economists mean by growth. They mean an increase in gross domestic product, most of which is caused by increased productivity (efficiency). It may or may not involve an increase in the economy's throughput of natural resources.
So what does the CSIRO's modelling say?
It says GDP can continue growing strongly, but throughput of natural resources can't. So the people who want continued growth in GDP win, but so do those saying ever-increasing use of natural resources must stop.
Since no one knows the future, CSIRO's economists and scientists ran through their super model 18 different scenarios covering different rates of growth in the global population, different degrees of global action to restrain climate change and a range of differing development in Australia.
All 18 scenarios project continuing strong growth in Australia's population and GDP out to 2050. But get this: only three of those scenarios also saw improvement or no further deterioration on the model's three key indicators of environmental health: emissions of greenhouse gases, water stress and loss of native habitat. Two of the three scenarios see no increase in the economy's annual throughput of natural resources, while the third projects a fall in material throughput of 38 per cent.
All this says ecologically sustainable growth and decoupling do seem to be possible, provided the world gets its act together.
The good news is that the model's results don't rely on "technological optimism" but nor do they require that we renounce our materialist ways and become greenie vegan mud-brick makers. We don't need to do anything we don't already know how to do and, in many cases, have already begun doing. We just need to do a mighty lot more of it.
The bad news is that we can't do it on our own. We need effective international action to limit the world's population to 8 billion in 2050 and limit global warming to 2 degrees in 2100. This would require "very strong" efforts to reduce greenhouse emissions.
The two other environmentally not-so-bad scenarios - involving world population growing well beyond 8 billion and global warming limited to 3 degrees - would require "strong" efforts to reduce emissions.
Strong translates as a worldwide price per tonne of carbon dioxide emissions of $US30 ($42); very strong translates as $US50 a tonne.
These world prices would be applied in Australia. But we'd have a comparative advantage over many countries that would reduce the carbon price's adverse effects on our economy: we could achieve up to half our required reduction in net emissions by "carbon sequestration" - reforestation of cleared land, either with one species of eucalypt or a range of eucalypts. At these carbon prices, our farmers could earn up to five times what they make to produce beef.
Our greenhouse emissions per person would fall from five times the global average in 1990 to below average by 2050. Our biggest problem would be avoiding water stress, particularly because reforestation would add to the problem. The price of water for agriculture would be a lot higher and, in the cities, we'd have to do a lot more desalination and recycling for industry.
All modelling is far from infallible. The good thing is that a last we've made a start at reconciling our materialist ambitions with the constraints imposed by the natural environment we hope to continue living in.