Thats one estimate of what Australia's population could be by the end of the century. The question then becomes were will everyone live? Demographer Bernard Salt has been looking into this issue:
Does this mean Sydney and Melbourne will account for 24 million if Australia reaches 62 million then? Is this possible?
There is always the argument that new cities will emerge during the 21st century, but in the 20th century only two big cities were created: Canberra and the Gold Coast. Both of these combined accounted for barely one-seventh of the population of Sydney and Melbourne by 2000.
New large cities might be developed in the 21st century, and I hope they are, especially in the north and northwest, but the main focus of population growth will remain the job centres of Sydney and Melbourne.
What is likely to develop during the 21st century is a loose fusing of the cities and towns of southeast Queensland and the NSW Northern Rivers region into a population mass that is never quite equal to that of Melbourne or Sydney....
Its an article well worth reading in its entirety.