Guardian: A new paper published in the journal Geophysical Research Letters by Griffin & Anchukaitis concludes that the 20122014 drought in California was its most intense in at least 1,200 years.
The study used drought reconstructions from tree-ring cores, from the North American Drought Atlas (NADA) and from cores Griffin & Anchukaitis collected from blue oak trees in southern and central California. Blue oak tree ring widths are particularly sensitive to moisture changes. According to Griffin,
The...