I keep reading about these future "water wars" and can't help but wonder how much of the prediction is realistic and how much is coloured by Silicon Valley types extrapolating globally from what they see locally.

I live in northern Britain and, even at the height of summer, it's rare for a week to go by, without at least one day of heavy rainfall.

Maybe it's me who's extrapolating globally from what I'm seeing locally. But I don't get any sense at all that the world is getting drier.

Still, if the 'water wars' predictions do turn out to be true, maybe we'll have an interesting reversal of fortunes in the future, where damp, wet, soggy countries become fabulously wealthy, like the OPEC nations today --through exporting tankers full of their spare rainwater.

Let's see how the Arabs like queuing up at the pumps to fill their drinking vessels at £2/litre!