In ten years time, scientists warn, the Southwestern and Great Plains states may face the worst droughts since the 12th and 13th centuries. The persistent droughts, dubbed mega-droughts, may become the new normal in the U.S. if humanity fails to alter the speed of the current climate change rate, scientists suggested.
Scientists used the current weather conditions found in several states in the southwest and the Great Plains to build an advanced computer model. The model revealed that the incoming droughts triggered by uncontrolled climate change may make the previous mega-droughts look “like quaint walks through the Garden of Eden.”
The mega-droughts in the 12th and 13th centuries are believed to be so severe that they have caused the extinction of the Ancient Pueblo natives.
“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,”
said Ben Cook, a co-author of the drought study and researcher at NASA’s Goddard Institute for Space Studies.
Mr. Cook also suggested that Americans should get used to droughts as a way of life.
He described the “dustbowl” in the 1930s, the 1950s drought, and the ongoing California drought as naturally occurring droughts that usually last no more than a few years to a decade. However, the incoming mega-droughts may last decades.
“Imagine instead the current California drought going on for another 20 years,”
Mr. Cook added.
To measure past droughts, scientists studied tree rings, which can accurately tell which years were dry as the rings get wider during wetter years.
Researchers said that their findings are consistent with past researches that had suggested that the Southwestern U.S. and the Great Plains states would become arid over the 21st Century due to climate change. Still, the increasing levels of CO2 in the atmosphere are making things worse.
Scientists said that there will be droughts although the precipitations in some areas may remain constant, because high temperatures lead to more evaporation. For instance, although California had massive rainfall in December, the water supplies across the state couldn’t be refilled.
Another study published in the Proceedings of the National Academy of Sciences shows that the average annual temperature is set to increase by up to 5 percent by the end of this century. A 5 percent in temperature rise is equal to an increase in water reduction by 30 percent, the study authors argued.
Image Source: Phys