From October of 2010 through this September 2011, Texas saw its driest year on record, according to the National Oceanic and Atmospheric Administration.
But these historic dry conditions stretch back even further than that.
After examining tree-ring data going back to 1550, researchers at Columbia University found that this year’s drought was only rivaled once in the last 461 years. According to the Palmer Drought Severity Index, a system for measuring wet and dry conditions, the last time Texas experienced a drought this bad was in 1789.
Climatologist, John Nielsen-Gammon, explained the historical significance of the ongoing drought. “This is basically off the charts. Based on past history, you wouldn’t expect to see this happening in maybe 500 or 1,000 years. One more year and we’re already talking about a drought more severe than anything we’ve ever had. And this will become for them, the drought of record.”
The drought, which Nielsen-Gammon says could stretch over a number of years, has devastated cotton crops, livestock, pumpkin crops, and, as the below CBS story points out, Christmas trees. The dry conditions have been exacerbated by a combination of human-caused global warming and La Niña, which pushes unusually cold air from the Pacific Ocean and causes drier-than-average conditions in the Southern U.S.
– from thinkprogress.org