Drought in California - my home
The picture shows snow in the mountains of California, 2013 and 2014. Snow usually provides 30% of California's water, so that was bad news. But 2015 was much worse
"We're not only setting a new low; we're completely obliterating the previous record," said the chief of the California Department of Water Resources. There's now only 5% as much snow as the average over the last century!
California has been hit by new weather pattern: the Ridiculously Resilient Ridge
. It's a patch of high atmospheric pressure that sits over the far northeastern Pacific Ocean and stops winter storms from reaching California. It's been sitting there most of the time for the last 3 winters.
We did get 2 big storms this winter. But the water fell mainly as rain
rather than snow
, because of record-breaking heat. It was enough to half fill Shasta Lake and Lake Oroville. But it didn't help the snow pack, which holds more water.
For the first time, the governor has imposed mandatory water restrictions: a 25% cut in water use in every city and town. This will save about 1.8 cubic kilometers of water over the next 9 months - nearly as much as Lake Oroville now holds.
He said:People should realize we're in a new era. The idea of your nice little green grass getting lots of water every day - that's going to be a thing of the past.
But what about agriculture? In California, about 50% of water is used by "the environment": rivers, wetlands, parks and the like. 40% is used by agriculture. 10% is left for businesses and residents.
Brown didn't impose any cuts on agriculture! That sounds unfair, and people are complaining. More water is used to grow walnuts
than to keep Los Angeles going!
We definitely need to improve agriculture. But don't forget: for the second year in a row, farmers in California's big Central Valley are getting hit with big water cutbacks. The ones who get water from the State Water Project will receive only 20% of their usual amount.
Is all this due to climate change? I heard a wise answer to that question: instead of a definite yes or no, just: this is what climate change looks like
. This is the kind of thing we can expect.
And on the Road to Paris
, this week the US submitted a plan to cut carbon emissions by 25% by 2030... but that's another story. Or another part of the same big story.
What California is doing about the drought:http://www.latimes.com/local/california/la-me-ag-water-20150403-story.html
Water used by agriculture in California:http://www.motherjones.com/environment/2015/01/almonds-nuts-crazy-stats-charts
Make your own graphs of the California snowpack:http://cdec.water.ca.gov/cdecapp/snowapp/swcchart.action
There's lots more water data here, too - click items on the menu above.
More on the Ridiculously Resilient Ridge or Triple R
by Daniel Swain, the guy who coined the term:http://www.weatherwest.com/archives/tag/ridiculously-resilient-ridge
In February he wrote:In this sense, the Triple R of 2014-2015 is notably different from 2013-2014. California has certainly received more precipitation this year on a liquid equivalent basis, though we’re once again falling rapidly behind average as February turns out to be mostly dry. The extreme warmth and low snowpack, however, are very reminiscent of recent winters–as is the occurrence of infrequent but intense warm storms. It’s interesting to note that nearly the entire western United States has been exceptionally warm in recent months, while the eastern part of the country remains locked in a recurring nightmare of extreme Arctic outbreaks and almost inconceivable snow accumulations in parts of New England. This overall setup–with a big Western ridge and a deep Eastern trough–has become known as the “Warm West/Cool East” dipole pattern, and it has been a common feature of recent winters in North America. There are a number of hypotheses currently being investigated regarding the causes of an apparent recent increase in the occurrence of this pattern, though there’s not yet compelling evidence pointing to a singular cause (that’s a topic for a future blog post!).What is more certain, at least as far as California is concerned, is that our severe long-term drought is unlikely to improve substantially until this newly-invigorated pattern of persistent West Coast high pressure is no longer dominant.