Well, Dick, that's a neat comeback; but the problem is that you raise a 'problem,' but don't offer a solution. If we can't handle increased immigration, to support an increasingly aging Australian one, what's the alternative? Compulsory euthanasia for those over 65 who aren't self-sufficient?
In response to what I regard as scaremongering, I suggest you get hold of a book by a well known American journalist. He's no bleeding heart, is conservative and Republican, and is a champion of minimal government interference in the free economy. Some of those traits may be familiar to you.
I am sure you have heard of P.J. O'Rourke. Have a read of his 1994 book - it's called All the Trouble in the World, and is sub-titled The Lighter Side of Famine, Pestilence, Destruction and Death. It might cheer you up a little.
At the very least, read the chapters on Overpopulation and Famine. They blow holes in what I regard as your simplistic, Chicken Little approach to this issue.
Mods: Apologies; but DirtyPierre and Dick started it Mum.