"A worst-case scenario devised by US researchers shows that the American southwest could experience a 60-year stretch of heat and drought unseen since the 12th century.

Researchers at the University of Arizona examined studies of temperature changes and droughts in the region over the past 1,200 years and used them to project future climate models in the hope that water resource managers could use the information to plan ahead.

An examination of the past, through human-kept records but also via rings in the cores of trees that can show periods of wetness or drought, showed that dry spells of earlier centuries were much worse than any we have seen in modern times."

AFP had the story December 14, 2010. [2]