Many of the water systems in major cities around the world, including in developed countries, have losses of 30-40 percent, says Lars H. Thunell of the World Bank's International Finance Corporation (IFC). And that’s not viable, he insists, so we have to make sure we invest. "I think water is a key part of the whole food-energy-water nexus. They all tie together and they are very interdependent. And the fact of the matter is that people have just been using more and more water without really thinking about how we use it. And now we’re getting to a point, where there is more and more water scarcity in the world, and we’ve got an enormous problem in front of us. The other thing with water is that it’s local. It’s hard to move water around very much. You have to find the solution for water in the various water basins around the world. With the population growing from 7-9 billion to maybe 10-11 billion be 2050, we really have a problem," he said.