World Resources Institute: We know less about one of world's most pressing challenges today than we did 10 years ago. It's no secret that water - or the lack thereof - will be one of the defining issues of the 21st century. And yet, the United Nations World Water Report, in 2009, stated that when it comes to water, "less is known with each passing decade."
The World Economic Forum recently named the water supply crises as one of the top risks facing the planet - edging out issues like terrorism and systemic financial failure....