Vanderbilt paleoclimatologists using pioneering research have uncovered evidence of ancient climate “whiplash” in California that exceeded even the extremes the state has weathered in the past decade. Their findings present a long-term picture of what regional climate change may look like in the state that supplies the U.S. with more than a third of its vegetables and two-thirds of its fruits and nuts.  

“We hope this is useful to planners who are seeking more information on recurrence intervals of climate events like droughts, storms and floods,” said Dr. Jessica Oster, associate professor of Earth and environmental sciences.  

Working with a stalagmite that grew from 8,600 to 6,900 years ago, Oster and a team of researchers set out to identify climate patterns beyond the scope of human records. Their article, “Semiquantitative Estimates of Rainfall Variability During the 8.2kyr Event in California Using Speleothem Calcium Isotope Ratios,” was published in the journal Geophysical Research Letters on Dec. 28. The researchers included graduate student Cameron de Wet and undergraduate Yiruo Xu.  

The records the team measured bookend an abrupt cold snap noted in global climate records 8,200 years ago. The event may have been triggered by the final phases of a melting ice sheet in Canada that dumped cold, fresh water into the Atlantic Ocean. With the Greenland ice sheet melting in a similar way today, Oster said that their research period could have functional relevance to what’s happening with our current climate system.  

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