I am very late coming to this thread, probably because the article's title did not immediately appeal. (And other interests beckoned.) However, after wading through the article's convolutions and the 42 subsequent comments, I have a tuppence which some may think worth considering.

Firstly though, I must compliment Pelican on her posts (I think it's her, rather than his, and please forgive me if I am remiss), and particularly on the posting of Wednesday, 23 November 2011 6:51:55 PM.

It surprises me that the discussion has focused almost entirely on the situation in Oz, rather than looking globally, and I am also surprised by the apparent depth of disconnect of city dwellers from ours, and others', rural realities.

Rurally, I would offer that worldwide food producing resources are finite and rapidly becoming tired - due to production intensity, fertiliser input costs and limits, and soil and topography degradation (erosion, salinity, acidity, loss of soil microbes/ecology, and deforestation). The vagaries of climate and water supply add further uncertainty. Mass hydroponics may be the future, but relevant energy, infrastructure and inputs are massive and also finite.

Human waste recycling will be essential; though the recycling of cadavas (as someone suggested) would contribute little - relative to the protein and energy consumed in a single lifetime.

Environment Is important, as the sea-change diaspora confirms - most wouldn't willingly retire to a highrise. Environment relates directly to quality of life, societal success, custodial integrity, and future-vision. Maintenance of land, forest, aquatic and oceanic environments is foundational to life, atmosphere and sustenance (and much more).

Baby bonuses, family allowances and welfare I see as living standard equity processes, and childcare allowances as productivity enhancing. Immigration control I see as a necessary component in achieving supply/demand balance; and birth control, higher education and better living standards I see as essential for enabling developing nations to achieve similar sustainability, and hence global sustainability.

Overpopulation will destroy our world as we know it, leaving future generations short-changed, disillusioned, and probably miserable.