Just briefly the major issue in Australia would be water. But not only do we need it for drinking we also need it for agriculture in order to ensure our food supply can be maintained. I would say the next major resource issues are food, due to the lack of water,followed by energy. We use a lot of energy with the majority being produced from our coal resources but these resource have reached/reaching their peak and hence are dwindling and will not last for much longer. We thus need to find alternative sources of energy (i.e green energy) in order to maintain our population sustainably. Evidently land/space is not a restriction in Australia but it could be soon with the changing climate much of our land is becoming drier and of less use. This could be an issue in the future.