No offence, but the details you give about australia are suitable for a primary school talk.
I've considered them.
You talk a bit about carrying capacity etc (I didn't): but how much do you know about agriculture?
Add up all the productive temperate and tropical zones in Australia and you still end up with a huge chunk of good agricultural land. I never said it was like the US and anyone that even goes near that discussion probably has a pretty limited grasp on things, or they want too much. I suspect for most Australians, it is both.
