National Public Radio: The U.S. had its hottest year on record last year. That heat, combined with the relatively dry winter that came before, has brought a historic drought.
From forest fires and low crop yields, to infrastructure and recreation, the drought has been costly, with early estimates putting the cost at between $50 billion and $80 billion.
The U.S. Department of Agriculture has declared a disaster area in more than 1,000 counties, and now the drought is hitting America's most important waterway - the...