In recent days and weeks, we’ve been seeing similar-sounding headlines out of California, such as this:
Sacramento breaks 130-year old for low rainfall
LA is on track to set dry-weather record
Indeed, as my fellow Discover blogger Tom Yulsman noted last month:
We’ll have to wait a couple of weeks for the official year-end precipitation numbers, but there is no question that 2013 will rank as the driest year in the state since recording-keeping began in 1894.
Most of the state’s rainfall comes in the winter—roughly a third of the water used in California is drawn from the Sierra Nevada’s vast snowpack—so it’s the fall-through-spring totals that make or break things in the dry heat of summer.
Meanwhile, California Governor Jerry Brown has recently declared a “drought state of emergency.” During a press conference he said:
We’re facing perhaps the worst drought that California has ever seen since records began being kept about a hundred years ago.
It’s unfortunate that much of the discussion of this drought–reinforced by Governor Brown–is framed around such a short-term perspective. As UCLA geographer Glen MacDonald writes in this 2007 paper:
Instrumental records of climate and hydrology in western North America only span the last 100 years or so. They are too short to capture the full range of natural climate variability, drought behavior and drought impact. The instrumental records are also too short to provide evidence on the full range of potential forcing factors that could produce severe and prolonged droughts.
More illuminating are the tree ring records that MacDonald discusses in his paper, which reveal a series of mega-droughts periodically hammering California over the past millennium. This is not breaking news. Researchers have amply chronicled such mega-droughts (lasting decades and even hundreds of years) for California and the American Southwest. Geographer Scott Stine published a seminal paper on California’s prehistoric drought history in Nature two decades ago. Here’s the 1994 New York Times headline of the story covering that research:
Severe Ancient Droughts: A Warning to California
Earlier this month, after announcing California’s drought state of emergency, Governor Brown told reporters:
It’s important to wake all Californians to the serious matter of the drought and lack of rain. We are in an unprecedented, very serious situation that people should pause and reflect on how dependent we are on the rain, nature and one other.
The residents of California may be facing an unprecedented situation in their lifetimes, but by no means is the drought they are experiencing unprecedented for California. Fortunately, this larger context is being reported by some, such as Bryan Walsh at Time, and Paul Rogers at the San Jose Mercury News.
Governor Brown missed an opportunity to educate California residents about the full history of the landscape they inhabit–an important, cautionary history that today’s Californians may eventually be forced to wake up to.
Below is the U.S. Drought Monitor for California last week.