Water, water everywhere?

We've only got one planet, and while we've got really good at making things from other things we still only have a limited supply of materials. When I think of resources I normally think of fossil fuels, wood, solar, wind and tidal energy and the raw metals we have. Eventually I expect I'd get to water, although it might take me a little while, but this essential resource should be right at the top of our list.

Water is vital for life, there's no denying that and fresh water is what we really need, although we can make it from salt-water with effort, energy and time. In the UK, unless it's a very hot, dry summer, we assume that when we turn on a tap water will come out, no problem. It rains a lot (or feels like it) in the UK too, so we wouldn't expect to be importing water from abroad. But are we?

Maybe not in bottles or tanks but as a large importer of food and commodities the UK actually brings in a lot more water from abroad than we'd first expect. The below map shows water exports and imports by country between 1996 and 2005. Other than the UK there are a few surprises, Australia exports more water than it imports and Europe is a lot redder than Africa. But it's important to keep in mind that this isn't a list of where water is needed, just where it's being taken from and where it's going too. So while Australia suffered from droughts throughout the 00s it was still exporting water out of the country and while Germany is a green and leafy land it imports lots of water.

As the effects of climate change take effect water will only become a more precious commodity for life around the globe. There are many ways to save water at source and in our homes but it's also worth thinking about the effect on water that our weekly shopping has.