...again @Manorina, following on from my last post...

Finally, I ask what is the link between "the likely effects of climate change" and overshooting our sustainable population. Our greenhouse gas foibles as a nation are a result of, yet again, a system in need of reform. We emit, CO2 into the atmosphere due to reliance on coal power and other non-renewable sources of energy, which yes, I will give you, is due to our population's hunger for power. However putting a cap on population isn't going to decrease this; the answer is in seeking smarter, greener and more renewable ways in which to supply energy.
As a closing point for you to ponder, the current density of the Australian population is 2.8 inhabitants per sq km, i.e. 34 hectares of land per capita. That is equal to about 30 sports ovals per person. Compare that to the case in India, where a single oval would be shared by 4 people.

@Lucy Montgomery: Australia actually exports around 60% of its agricultural produce.

Yes. And Rudd recently said he expected the population to grow to 40M in 2050. Once it hits 60M, which I guess would be in 2070 or so there will be no exports.

@Lucy Montgomery: It has no hinterland so obviously it doesn't produce most of its own food. But with large agricultural producers in Asia it doesn't need to.

We would be one of those large agricultural producers you are talking about. All of those producers are currently in the same situation as us: they have growing populations. In about 50 years or so, they will have no surpluses. What do you suggest Singapore does then? Apart from starve to death, that is.

You probably don't believe that could possibly happen. If you are typical of the pro growth lobby, you instead believe scientists will wave some magic wand and a solution will just pop into existence.

While I'm impressed with aspects of Jane O'Sullivan's article, I'm worried that by reverting to neo-Malthusianism we don't really address the process that has seen average real wages decline in the US and Australia ever since 1972. This sets the status quo (less than 1% of the population getting richer at the expense of the other 99%+) in concrete rather than remedying it.

The current tax system channels wealth to the wealthy and away from the poor and middle class. The wealthy who own more properties and the more valuable properties are able to claw back all the taxes they've paid by enormous increments in their value of their properties. Renters, or people owning only their home don't enjoy this particular privilege.

To a lesser extent land values are also driven by population growth,of course, so if we directed greater attention to capturing our publicly-generated annual land values instead of penalising labour and capital, we'd have a far superior source of funding public works, health, education, etc. There's natural growth in this revenue base which actually encourages government infrastrucure because it is able to claw back some of its costs as land values are increased by public works.

Singapore uses this base to better advantage than Australia, and, as Lucy Montgomery notes they are actually trying to increase their birth rate. It has been found that birth rates always tend to decline when wealth is better distributed.

Re-formulating a tax system that encourages property bubbles is the best way to delimit population growth, but the pressure the Rudd government is reportedly applying to Ken Henry's suggestion for a federal land tax will probably see this positive option frustrated.

I believe the 60% export is grain only, as we are a net importer of fruit and vegetables and we import most of our fish.

We will need that wheat for the population increase and what if the suppliers of our food stops exporting, as it needs it for itself.
We now even import apples from China.

We also see the worlds fish stocks declining the latest being tuna.

One of the biggest impacts on food production is resources that are, or will be, in decline for example oil and fertilisers.

We will have problems in feeding/sustaining our present population.

It is interesting how the Singapore situation is reported or maybe mis-reported..

The Singaporean Prime Minister's New Year's speech
http://www.pmo.gov.sg/News/Messages/PM+Lee+New+Year+Message+2010.htm
sets it out a different way.

Singaporeans are called upon to increase their birth rate SO that Singapore can reduce the number of immigrants.

The argument is to increase GDP per person, not to to just increase the GDP.

In fact the PM speaks about limiting the number of people in Singapore.

Nobody seems to have thought through the likely consequences of an immigration freeze:

2011: we freeze immigration. China, India and Indonesia immediately apply severe trade sanctions. New Zealand does its best to follow suit and to raise protests about Australia in the Commonwealth, ANZUS and UN forums.

2012: we either back down, run out of electronics and whitegoods, or go to war.

Immigration policy is not made unilaterally.