That is interesting because he was adamant 10 or so years ago that 10-12m was tops.
Just for a bit of useless information,and for a bit of proportion, the entire Oz population could fit on a parade ground less than 5km square at 1m centres.
The worlds population could fit on a similar parade ground 80 km square.
I know that it's more complicated than that regarding food supplies etc but that's how much space we take up physically.
