© www.nature.comThe future of Southwestern farming?
The arid conditions in the southwest of the United States and the Great Plains have been caused by higher temperatures, while ground water supplies are shrinking. Studies by scientists using computer models show that the US could be in for its worst droughts since the 12th and 13th centuries.
© earthobservatory.nasa.govProgressing drought regions of Southwest USA.
Ben Cook, from NASA's Goddard Institute for Space Studies, also helped to write the paper added that Americans may have to get used to droughts as a way of life. "These mega-droughts during the 1100s and 1200s persisted for 20, 30, 40, 50 years at a time, and they were droughts that no one in the history of the United States has ever experienced," he said in a press release. "The droughts that people do know about like the 1930s 'dustbowl' or the 1950s drought, or even the ongoing drought in California, and the southwest today - these are all naturally occurring droughts that are expected to last only a few years or perhaps a decade. Imagine instead the current California drought going on for another 20 years," Cook added.
Comment: These mega-droughts may not have been experienced by "citizens of the U.S.A.," but they were certainly experienced by native North, Central and South American cultures, as drought is a cyclical and natural weather phenomenon dependent on the trade winds, Hadley Cell cycles and ocean currents such as El Niño and La Niña. They are NOT dependent on, nor exclusively caused by higher temperatures. And, mega-droughts are NEVER "quaint walks through the Garden of Eden!!!"
Comment: FACT: Droughts happened in both cool and warm periods. Check this out... During historic drought years: In 608 A.D. the Euphrates froze. In 829 A.D. the Nile froze. In 865 A.D. fjords filled with sea ice in Iceland and Norway.
North America experienced at least four mega-droughts during the Medieval Warm Period. Mono Lake in the Sierra Nevada has identified a epic period of severe, persistent drought lasting from 892 to 1112 A.D. (220 years), as well as one connecting the northern Great Plains of N. America, across the southwestern U.S. and into Mexico from 735 to 765 A.D. (Stahl et al. 2002.) Other neighboring peoples affected by the drought were the Mayans and inhabitants of Central Mexico, Panama, the Yucatan, the pre-Incas in the high Andean Plateau (the Altiplano) of now Peru and Bolivia, the Teotihuacan of highland Mexico, the Moche and eventually the Toltecs from 1100 A.D. onward.
These resource experts ought to turn it in and go home.