I got your point. Your reply seems to indicate a fixation with space, "average population density on Earth, is only 47 people per square kilometer. Not that much I reckon..."
My point is that 47 people per sq km may be too many considering other issues besides just the physical space they occupy. Farmers in good rainfall areas will run x number of cattle per acre, but out in the arid country they will talk about x acres per head of beef.
How many people per sq km should [or can] live on the earth? The fact that you reckon 47 people per sq km isn't "that much", tells me you have no idea- as indeed, do I. So, let's keep some headroom- it makes sense because not doing so, would be catastrophic.
Going back to Tim Flannery, if you saw the doco "Two men in a Tinnie", which he featured in with John Doyle, it's clear Australia has a water problem. There were places where they simply couldn't use the boat to get down river because the river was a dust bowl.
