A new study of the western United States' continuing drought published in Science concludes that it is the driest in 1200 years. Prolonged drought is made worse by man-made global warming the scientists state. Using tree ring and soil moisture data, they compared the current drought that started in 2000 to four previous mega-droughts since 800 AD. Only one other was bigger and drier, which started and in 1575, ten years after the founding of St. Augustine, and ended before the Pilgrims arrived in 1620. Other megadroughts have averaged 28 years in length; the current one is just in its second decade. Some scientists think it has not lasted long enough to be classified as a "megadrought" event.
Last year was relatively wet, but not enough precipitation fell to make up for moisture deficits. What could have been a moderately prolonged drought is made worse by 2.9℉ higher temperatures than before climate change, which sucks moisture from the ground through evaporation. Comparing several computer model scenarios of a world with and without global warming, researchers think 47% of the current severe drought in the West can be attributed to global warming. The U.S. drought monitor
[map] puts much of Oregon, California, Colorado, Utah and Nevada and good
chunks of New Mexico, Arizona and Idaho in abnormally dry, moderate or
severe drought conditions. Wyoming is the only state studied
that does not have large areas of drought.