If global warming is a serious problem making our summers hotter and our water sources drier, we'd certainly have felt it in California in the last 130 years, right?
But a new study that looks at the Sierra Mountains' snowpack and other statewide precipitation in that span concludes that “over time snowfall in California is neither increasing nor decreasing.”
We'll drink to that.
Well, not so fast:
California native John Christy, director of the Earth System Science Center at The University of Alabama in Huntsville, authored the paper, Searching for Information in 133 Years of California Snowfall Observations, to be published in the American Meteorological Society's Journal of Hydrometeorology.
He tells the Weekly that while his study might calm fears of global warming's contemporary effects in the Golden State, it doesn't conclude that we're in the clear as far as droughts go:
There have been colossal droughts in California in the distant past. You don't need human explanation as a cause for such flux. No matter what you think about global warming, these kinds of long period droughts can return.
The Sierra Nevadas provide much of California's water. They feed L.A.'s need via the Owens Valley and the city Department of Water and Power's aqueduct. (As a side note, see Chinatown and/or Inventing L.A.).
Christy doesn't seem worried:
You'll see very large variations from one year to the next, lots of ups and downs. But you look across 133 years, and they're bouncing around all over, with a mean level that doesn't change. I think there are a lot of claims and worries about the Sierra snowpack, given claims about global warming. Is there some long-term change here? You just don't see that effect on the Sierra.
His study concludes, “[R]egional trends ending in the 2010-11 season for the
longest and most robust time series were not significantly different … “
Christy's work on the environment has been called out in the past as “unscientific nonsense.” He's also been name-checked as a global-warming “denier.”
But the facts of his latest work are right here in black-and-white (link).
Droughts will happen. You don't have to conjure any excuse for them. But it appears the source of the water for California remains fairly steady overall.
Do you believe?