I was wondering how long it would take someone to raise this line of debate, because it is what most people think when you talk about increasing Australia's population.
However I was a little surprised it came from you Trump, being a deep thinker.
Okay, let's roll back to after the second world war.
The Jews and survivors of the Holocaust, a race without a homeland.
Nobody wanted them, even the ships were turned around if you recall.
Eventually a portion of Palestine was provided and in 1948 the State of Israel became a nation.
100,000 displaced Jews walked into this new homeland, of which half was desert.
Today the population of Israel is over 8,000,000, and have become a great nation. Using desalination plants, drip irrigation and aquifers they have managed to grow vegetables and fruit (Remember Jaffa oranges) and their innovations are helping to fill hungry bellies everywhere, but particularly in the developing world.
Now imagine if Australia had given them some of our harsh uninhabitable land to settle in instead.... I think you get my drift here.
Now you say that "
there isn't enough fertile arable land to feed so many without resorting to bulk importing".
Do you realise that if you take all the food and produce Australia currently exports to the rest of the world, it would be enough to feed at least 56,000,000 people without even increasing current crops and production!
We currently have enough food to support far more than our current population that's for sure.
Even if we forget about the vast uninhabitable desert that much of Australia is.... Let's take the state of Victoria (size = 237,000km2) and a population of approx. 6,000,000 million which is not desert or uninhabitable by any means.
Now take the United Kingdom (size = 242,000Km2, so for argument's sake the same approximate size of Victoria)... The UK has a population of 65,000,000 by comparison.
We could easily fit 100,000,000 people in the existing habitable, non-desert areas of Australia.
Manufacturing in this country failed because of lack of population / scale of economy. We are taxed to death because to build infrastructure, provide healthcare, education, etc, etc, relies on only 24 million of us to pay for it.
The only way this country of ours will survive in generations to come is to increase our population and not to keep it small, as most Australians would prefer to see for selfish reasons.
If we don't then one day, maybe not in our lifetime but in our great grand children's time... We will be absorbed by America, lose our identity and become the 51st state of the USA to survive! ... (Or maybe plans are already in place if you believe in the New World Order)