While the last few weeks have brought some rain to drought-ravaged areas of California, the U.S. Drought Monitor says it’s not nearly enough to recover the massive losses in groundwater reserves that have been used. Though the rainy season is occurring as it usually does, the western half of southern California is still seeing 25-75% of normal rainfall year-to-date and collected data indicates that the state would need to see more precipitation than normal to offset the groundwater levels. Even with up to 4 inches of rain falling in the northern half of the state, the drought is expected to continue.
Additionally, new research suggests that the current drought is the worst in 1,200 years. Climate scientists from the University of Minnesota and the Woods Hole Oceanographic Institution looked at tree-ring samples from blue oak trees in southern and central California to establish that the 2012-2014 season has been historically dry. Though the state is no stranger to droughts, the study’s authors say that it is the consistency of the dry season that gives pause, with dry years usually being punctuated with occasional wet years.
“We are entering a new era where human-wrought changes to the climate system will become important for determining the severity of droughts and their consequences for coupled human and natural systems,” says Kevin Anchukaitis, one of the authors of the study.