Droughts, it could be argued, are the opposite of news. By definition, they represent the absence of something (namely, adequate rain) happening. And they only occur when that something has already been not-happening for a very long time. As a result, droughts tend not to make the front page. When they do – as happened last summer, when headlines trumpeted the worst U.S. drought conditions in 50 years – the public gets concerned. But soon enough, droughts begin to feel like business as usual again, invisible in their very ubiquity. It's time to start paying attention. Why? Well, first off,...