Summary: The severe drought across the Western U.S. is already causing long term problems, exacerbated by the warming atmosphere driven by climate change. As William Brangham reports from California's San Joaquin Valley, the demand for water has threatened the drinking supply for hundreds of thousands of rural residents -- including the farmers who grow a significant part of the country's food supply. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders
