ClimateWire: When Daniel Griffin first heard media reports earlier in the fall that California's drought was the worst in the past few centuries, he didn't quite buy it.
Griffin, an assistant professor in the Department of Geography, Environment and Society at the University of Minnesota, had a decade of experience studying paleoclimate and environmental science using tree-ring data. From his research on blue oak trees, he knew that periods without a lot of precipitation weren't that uncommon in the state's...