The ongoing California drought is the driest period in the state’s history since before Charlemagne ruled the Holy Roman Empire, a new study concludes.
Despite this week’s rainstorm, more than half of California remains in “exceptional” drought conditions, the most severe drought designation. The three-year period since 2011 is the driest in 120 years of recorded history, and a new survey of tree rings in blue oaks now provides a larger historical context. The current drought is the most extreme since the year 800, researchers report in a paper in press in Geophysical Research Letters.