This article acts as a timely warning for Australia to not overpopulate, particularly as we head into a global era of (probably unprecedented) food, water and energy scarcity. There are serious demographic consequences. Exhibit A and B: Japan and China. If they had their time again I'm confident they would act sooner to ensure a stable population.

The article seems to be saying two contradictory things:

1) The average age of people living in many developed countries will go on increasing.

2) Many people from less-developed countries will move to developed countries.

While both of these may be true to some extent, clearly the average population age of Australia, say, could easily be brought down to whatever figure we regard as desirable simply by allowing preferential immigration by young people from countries where these are still in the majority. To mope and moan about the 'problem' of an ageing population without considering the simple means by which it could be avoided or reversed seems futile.

Let's not forget too that the ageing population is largely due to people enjoying better health for longer. There's no reason why a healthy 70-year-old today can't fulfil the roles that were carried out by a 55-year-old thirty years ago -- and of course many of them are doing just that.

Interesting article. However, if fertility rates continue to DECLINE why are the authors concerned about resources shortages? People may live longer but with an older population there will be an eventual plummeting of numbers due to increased mortality associated with advanced age. As Africa's prosperity increases their fertility rate will drop. The future of the planet is surely one of low population?

Atman, I think the issue is more before there is (possibly) less.

Coincidentally had this open in another window

http://www.fool.com.au/2012/08/investing/global-food-prices-jump-10/

"And just three days ago, leading water scientists predicted that there will not be enough water available on current croplands, to feed the expected 9 billion people on the planet in 2050, unless we change the current trends towards diets common in Western Nations."

Dr Ian Frazer was commenting in an ABC Radio National debate last year about the unsustainability of the health budget if it keeps rising and consuming larger portions of the GDP, much of this is due to the costs of looking after the elderly. Perhaps we should bring back smoking :) It actually costs less having people die earlier, rather than aging.

http://www.nytimes.com/2008/02/05/health/05iht-obese.1.9748884.html?_r=2&scp=1&sq=smokers%20and%20the%20obese%20cheaper%20to%20care%20for&st=cse&gwh=D3EA757B12F86C83B4D97FE3866A29A1

Valley Guy:

...Yours is a flawed argument: The cost of healthcare is paid for by the productivity side of the economy. Obviously, healthy people do live longer, but at the same time they are more productive and more contributive than the long term chronically-ill.

Vally Guy - Fair point about there being more people before the population declines, however I wonder what the graph of population over time actually shows? I think it will be very temporary population spike followed by a sudden decline. Someone must have done the figures?