Watch CBS News

Tree Rings Reveal Most Severe California Drought In 1,200 Years

SAN FRANCISCO (KCBS)— A new study that counted tree rings shows California's drought is the worst in 1,200 years. The scientific study published by the Journal of the American Geophysical union looked at tree rings from 278 blue oaks in central and southern California.

Assistant Professor in the University of Minnesota's Department of Geography Dan Griffin analyzed tree rings that date back to 800 A.D.

Counting Tree Rings Offers Historic Perspective Of California's Drought

"We actually measure the width of the tree rings; wet years produce wide rings and dry years produce narrow rings," Griffin said.

The tree rings show the last three years of drought were the most severe California has experienced in the last 1,200 years.

Our recent wet spell is a good beginning, but much more is needed according to Griffin.

"If we think about the drought as a bank account, there's definitely a great deficit to make up and it could easily take more than just one year to get back up to balance."

The blue oak data was compared to a database of other tree ring records from longer living trees like giant sequoias and bristlecone pines.

View CBS News In
CBS News App Open
Chrome Safari Continue
Be the first to know
Get browser notifications for breaking news, live events, and exclusive reporting.