Scientists predict that California’s current drought may be just the beginning of a serious 100-year megadrought. Scientist Lynn Ingram has studied the history of drought in the western United States dating back 3,000 years, and records indicate that California is now in one of its driest periods in over 400 years.
Ingram studied sediment cores inside tubes to get an understanding of past drought periods. A 3-to-5 year drought is considered long, but her research shows that they can last a decade and some droughts have even lasted a century or more. These drought patterns repeat themselves over the centuries, according to Ingram, who warns that California may be due for another lengthy drought period.
Ingram studied sediment in the San Francisco Bay and nearby marshes, which revealed a shift in the type of vegetation that occured over the centuries as plants became more salt-tolerant because of diminishing fresh water runoff during drought periods. Nearby tree rings tell a similar story.
Scientists say that we are nearing the end of a wet period. The 20th century was one of the wettest centuries in over 1,300 years. Coinciding with all that moisture is a period when people built massive cities and re-routed waterways in areas that are traditionally deserts. It is a recipe for some serious water issues heading forward, and Ingram believes that California should be prepared for a megadrought sooner rather than later.