Water: Although most of Earth is covered by water, less than 1 percent of it is accessible freshwater. And the demand for that water is constantly increasing. The increase is a corollary of the rising demand for food—almost three-quarters of global water use goes to agriculture. Many water researchers believe that as many as 4.5 billion people could be short of water by as early as 2025. As with food, the disciples of Borlaug tend to react in one way to this worry; those of Vogt, in another.
