Study: Warming makes US West megadrought worst in modern age

SETH BORENSTEIN

AP Science Writer

KENSINGTON, Maryland (AP) - A two-decade-long dry spell that has parched much of the western United States is turning into one of the deepest megadroughts in the region in more than 1,200 years, a new study found.

And about half of this historic drought can be blamed on man-made global warming, according to a study in Thursday's journal Science.

Scientists looked at a nine-state area from Oregon and Wyoming down through California and New Mexico, plus a sliver of southwestern Montana and parts of northern Mexico. They used thousands of tree rings to compare a...