In the 1930s, tremendous dust storms blew across the Great Plains, with some dust reaching all the way to Washington DC. It has been attributed partially to climate variability and partly to land management patterns which plowed up the fields and left them bare, which made them vulnerable to strong winds. A change in the way lands were managed and a switch to a more hospitable climate stopped the storms from occurring after that period. But some new research indicates that the amount of dust in the Great Plains is rising again due to farming, leading to concerns about a new Dust Bowl. You can read more at Geographical here.
