| Water is everywhere, but only a litle piece of it is directly usable. Only a small fraction of water is fresh and most of that is locked up in icecaps. Of the tiny fraction that is usable only three percent occurs in the atmosphere, rivers, lakes and the rest is held underground. Even so, the "usable hydrosphere" contains more water than we will likely need for years. The problem is that water is so unevenly distributed. Many people are Fighting floods while other people are going thirsty. |
