A lovely warm wet but mild Pacific storm has passed, leaving us soothed psychologically here in SoCal.
The storm has done little to relieve our parching: millions of gallons flowed into the state's Oroville resevoir, but it only added up to about 1% capacity.
Today comes this news, from a pair of paleoclimatologists:
Griffin and Anchukaitis found that while the current period of low precipitation is not unusual in California’s history, these rainfall deficits combined with sustained record high temperatures created the current multiyear severe water shortages. "While it is precipitation that sets the rhythm of California drought, temperature weighs in on the pitch," says [Kevin] Anchukaitis.
To me this was the lead — that, implicitly, it's the higher temperatures associated with global warming that have made this a terrible drought, not just the lack of rain.
But the scientific institution's press release led with a number:
As California finally experiences the arrival of a rain-bearing Pineapple Express this week, two climate scientists from the University of Minnesota and Woods Hole Oceanographic Institution have shown that the drought of 2012-2014 has been the worst in 1,200 years.
Okay, that makes sense. In case we don't get the point, the scientists lay it out clearly in a quote:
“We were genuinely surprised at the result,” says [Daniel] Griffin, a NOAA Climate & Global Change Fellow and former WHOI postdoctoral scholar. “This is California–drought happens. Time and again, the most common result in tree-ring studies is that drought episodes in the past were more extreme than those of more recent eras. This time, however, the result was different.” While there is good evidence of past sustained, multi-decadal droughts or so-called “megadroughts”' in California, the authors say those past episodes were probably punctuated by occasional wet years, even if the cumulative effect over decades was one of overall drying. The current short-term drought appears to be worse than any previous span of consecutive years of drought without reprieve.
Haven't found good temp records from 1200, but here's a more recent chart, from the National Climactic Data Center via Bloomberg Business.
Sounds like a pair to look for at the upcoming American Geophysical Union's fall meeting.