NBC: Say drought and Americans are likely to think California, but the Golden State is hardly alone when looking across the Western Hemisphere: A dry spell has killed cattle and wiped out crops in Central America, parts of Colombia have seen rioting over scarce water, and southern Brazil is facing its worst dry spell in 50 years. In the U.S., the few who have taken notice of this wider water scarcity include a former director of the U.S. Geological Survey. Now editor-in-chief of the journal Science,...