Tree rings tell stories of historic droughts by Jason Monroe

Dendroclimatic reconstructions, using ancient tree rings to determine the length and severity of historic weather, of precipitation, temperature and other measures of drought, will be used to show the length and severity of prior droughts dating back nearly 2000 years at a presentation to the Chipeta Chapter of the Colorado Archaeological Society on Sunday titled “How bad can it get? A Paleoclimatic perspective on the current Southwestern drought.”

”It’s pretty hard to tell how bad a drought is until it’s over,” said Jeffrey Dean, a professor at the Laboratory of Tree-Ring Research at the University of Arizona in Tucson via telephone. ”This one could end tomorrow. We just don’t know. Compared to some of the droughts that have been recorded in previous years, this one is not nearly as long — but it has had some severe years.” …

There have been several droughts recorded through the centuries in the West that dwarf the current drought in both severity and duration, Dean said. A drought in the mid-1100s lasted for 50 years, and a second drought, lasting 25 years in the late 1200s, may have been the cause for driving the Anasazi from their cliff dwellings at Mesa Verde.