About a dozen megadroughts struck the American Southwest during the 9th through the 15th centuries, but then they mysteriously ceased around the year 1600.
About a dozen megadroughts struck the American Southwest during the 9th through the 15th centuries, but then they mysteriously ceased around the year 1600. What caused this clustering of megadroughts — that is, severe droughts that last for decades — and why do they happen at all?
If scientists can understand why megadroughts happened in the past, it can help us better predict whether, how, and where they might happen in the future. A study published today in Science Advances provides the first comprehensive theory for why there were megadroughts in the American Southwest. The authors found that ocean temperature conditions plus high radiative forcing — when Earth absorbs more sunlight than it radiates back into space — play important roles in triggering megadroughts. The study suggests an increasing risk of future megadroughts in the American Southwest due to climate change.
Previously, scientists have studied the individual factors that contribute to megadroughts. In the new study, a team of scientists at Columbia University’s Lamont-Doherty Earth Observatory has looked at how multiple factors from the global climate system work together, and projected that warming climate may bring a new round of megadroughts.
Read more at The Earth Institute - Columbia University
Photo: A drought-damaged ranch in California. CREDIT: Cynthia Mendoza/USDA
