The drought that began in 2000 is now the driest two decades since 800 A.D.
According to a new study published today in Nature Climate Change, the Western U.S. and northern Mexico are experiencing their driest period in at least 1,200 years.
One-fifth of the current megadrought is attributed to human-caused climate change. Emissions of greenhouse gases warm the planet, accelerate evaporation, and disrupt weather patterns.
Generally, a megadrought is considered to be both severe and long, lasting several decades. However, even a megadrought can have periods of wet weather. There are just not enough consecutive wet years to end the drought.
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