Age: GLOBALLY, it’s hardly surprising that the emphasis on water supply these days is on how to get more. Water consumption is doubling every 20 years as the world’s population balloons towards 10 billion and growth in China drives a switch to higher-protein, more water-intensive diets. In Europe, climate change and affluence are proving an equally menacing combination: 200 million sun-lovers are flocking into coastal areas of the Mediterranean every year. As resort tourists they use four …