I've heard it suggested that water could be the next big international commodity, rather like how oil has been for the 20th Century, and there could potentially be pipelines and tankers carrying supplies of fresh water (assuming that this would be cheaper than desalination), and that nations with large supplies of fresh water/high rainfall could potentially export their water to other countries with less. Don't know if that will end up being the case or not - it would be a long way off, surely, but I guess it's possible.
Which in itself is a recent argument for Scottish independence.
