USGS models ‘Climate-change-induced aridity’ in California

More climate modeling from a  non-climate organization, I hope they still track Earthquakes.

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News Release

Climate Change and Water Supply in California’s Central Valley: A Model Approach

SAN DIEGO, Calif. — Scientists have developed a new method to help resource managers plan for possible changes in water supplies due to climate change, and have applied the technology to forecasting water supplies in California’s Central Valley. Although it is not possible to provide exact forecasts of future climatic conditions, the new computer model projects that declines in precipitation, increases in temperatures, more frequent and longer droughts, and increased urban water demand, could result in significant reductions in streamflows. This would reduce the water available for animal and plant habitats, and for agricultural irrigation, and could result in a fundamental shift to dependence on groundwater.

“Climate-change-induced aridity will prompt countless seemingly independent decisions in California’s fields, factories, and homes to adjust sources of water supply that summed together can have a major impact on the state’s environment, economy, and infrastructure,” said USGS Director Marcia McNutt. “The value of this new model is that it provides far-sighted managers and alert stakeholders with a view to that future such that negative impacts can be anticipated and mitigated before they become problems.” 

“This transition to using more groundwater may cause additional land subsidence that could be hazardous to agriculture, environmental habitat, and canal systems, as well as transportation and urban infrastructure, and could ultimately require water use limitations,” said U.S. Geological Survey hydrologist and lead author, Randall Hanson. 

The Central Valley is one of the world’s most productive agricultural regions, providing the U.S. with one quarter of the nation’s food, including 40 percent of the nation’s fruits, nuts, and other table foods. 

From 1961 to 2003, surface water supplied 53% of total water delivered to the Central Valley except during droughts. The Central Valley study demonstrates that the new method, coupling computer models of supply-and-demand-driven groundwater and surface-water systems, with global climate models, can show potential vulnerabilities in hydrologic systems and potential trends due to changes in climate. 

The unique model connects many environmental and human factors, such as water runoff from surrounding mountains, the demands, uses and movements of water for irrigation and natural vegetation, and the changes of groundwater and stream-flow supply under a climate change scenario. The model gives scientists and resource managers the ability to analyze the impacts of combined surface and groundwater use throughout the entire Central Valley hydrologic system.  

The USGS and the National Oceanic & Atmospheric Administration conducted the study using the existing Central Valley regional hydrologic model to develop the new tool. The tool could eventually be used as a blueprint for climate adaptation efforts for major aquifers across the United States and internationally, where there are complex agricultural, ecological and urban water demands. The article detailing this study, “A method for physically based model analysis of conjunctive use in response to potential climate changes,” published in the journal Water Resources Research, and more information about USGS studies on climate change and water use can be found online.

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June 7, 2012 12:25 pm

Should be simple to test: there’s been some warming, what’s the observed precipitation trend? If it’s not signficantly negative, there is pretty much no way the model can be right.

June 7, 2012 12:25 pm

1. Anyone who who believes in consistent precipitation in California hasn’t lived there very long.
2. Sec. Chu claims that AGW will make agriculture non-viable in the Golden State by the end of the century.
3. I am a native Californian and I have noticed that a lot of skeptics are too, for whatever reason.
4. Don’t Sell Your Coat

Gary Pate
June 7, 2012 12:31 pm

While there is absolutely no evidence to suggest that “declines in precipitation, increases in temperatures, more frequent and longer droughts” is occurring, let’s be alarmist & act like it is really happening. BTW, the cure is more money for govt.
Yeah, that makes sense…

D. W. Schnare
June 7, 2012 12:36 pm

FWIW, regional climate models show California getting more rain under increased CO2 scenarios, nor less, at least according to the last time I spoke with Dr. Michaels.

June 7, 2012 12:37 pm

Central Valley water planners are far more worried about anticipating future Endangered Species listings than anticipating minor changes in climate. Changes in climate have very little effect on water availability, but one dead beetle in the wrong place can shut down all dams, canals and farms forever.

June 7, 2012 12:59 pm

Andrew says: “Should be simple to test: there’s been some warming, what’s the observed precipitation trend? If it’s not signficantly negative, there is pretty much no way the model can be right.”
Tested, and failed. Precipitation in central California is positively correlated (albeit weakly so) with an increasing trend variable since 1895-in fact, there are weak positive correlations all over the state except a climate division in the North. This indicates a positive trend in precipitation while the Earth warmed. How large, I can’t say.
Well maybe they mean that even though there might be a little more precipitation, the heat will evaporate it away? Well, let’s look at a drought index, then, the Palmer Drought Severity Index. In this case, it’s worth noting that negative values indicate drought, so a positve correlation indicates increasing index values, or a wettening (less dryening?) trend:
Guess what? For that same climate division that makes up central California, the correlation is positive with the trend variable! Again, the model used by USGS is predicting changes in California in response to warming in the future that are opposite to how it is responding so far. The model fails a simple test.
You can generate the correlation maps with climate divisions here:

F. Ross
June 7, 2012 1:11 pm

” …the new computer model projects that declines in precipitation, increases in temperatures, more frequent and longer droughts, and increased urban water demand, could result in significant reductions in streamflows. …”

Well, huzzah, huzzah!
If they re-programmed the “new computer model” to project decreases in temperatures, less frequent and shorter droughts,etc. it [the model output] COULD result in more [projected] streamflow. BFD
If I write a program to “project” a group of random numbers subject to the Lotto rules, it COULD provide me with winning ticket. Not holding my breath, though.

Luther Wu
June 7, 2012 1:13 pm

“Could”- 5X
What ever happened to the meme that increased winter precipitation (heavy snow) was due to increased temperatures (warmer air holds more moisture) which are all humanity’s fault?

F. Ross
June 7, 2012 1:14 pm

” …the new computer model projects that declines in precipitation, increases in temperatures, more frequent and longer droughts, and increased urban water demand, could result in significant reductions in streamflows. …”

Well, huzzah, huzzah!
If they re-programmed the “new computer model” to project decreases in temperatures, less frequent and shorter droughts,etc. it COULD result in more streamflow.
Sorry for the double post

June 7, 2012 1:30 pm

Models made in Californee freshly cooked from real baloney,
All adjusted to alarm you with numbers absolutely phony,
And concocted on your dollar, highly priced enough to gall ya,
All designed to shrink your wallets while enriching rich alarmists…
And the silent scream from science is a crime to every one of us…

June 7, 2012 1:46 pm

Andrew says:”You can generate the correlation maps with climate divisions here:”
I must apologize, I fear my early conclusion seems to be erroneous. It appears there is something funny going on with the correlation map generator, in that it is not matching the climate division data at the same site. precipitation trend and the palmer drought trend are, in fact, slightly negative for California Division 5, at least according to the data at that site. Why the correlation map indicates otherwise is not clear.
The precipitation trend, again from the division data itself, is about -0.123 inches per decade. The mean is about 20.066 inches per year, the standard deviation is about 6.170 inches, the r is about -0.0677. Pretty obvious, I think, that it’s not distinguishable from zero.
The Palmer Drought (annual averages) trend is about -0.009 units per decade, the standard deviation is is about 1.995 units, the r is about -0.155. Again, this is probably not distinguishable from zero.
So it might be the case that central California gets drier when the climate warms, but the trend is so small and insignificant that it fails to provide evidence that supports the model being used by USGS that there will be significant drying. It also fails to provide sufficient evidence to reject the hypothesis that central California drought has zero tendency to increase with warming.

June 7, 2012 1:57 pm

Looks to me like someone asked the USGS to look into whether land subsidance would be an issue if climate change made California more arid. That is the report is projecting changes in surface water flow, changes to ground water pumpage rates due to reductions in surface water flow and land subsidance due to increased ground water pumpage. Since the primary question seems to center on land subsidance, this is properly within the purview of the USGS.

Charles Gerard Nelson
June 7, 2012 1:58 pm

Just a few short years ago the Australian CSIRO and attendant media scaremongers had projected/predicted a drying/warming scenario for the Continent.
And we all know how accurate that turned out to be!

June 7, 2012 2:06 pm

Average annual rainfall total is listed on the weather page of the Sacramento Bee.
Pre global warming hype it was listed as 17.89 inches. After GW hype the paper switched to using a running 30 year average, which was made popular by the warmers and political operatives.
See they never bothered to read the caveat that 30 years is the minimum threshold for significant climatology.
Today the Bee lists average annual rainfall in Sacramento as 20.27 inches.
Were’s the drought, stupid?

jack morrow
June 7, 2012 2:10 pm

The things people do to get money. The government employees are the best at the game.

June 7, 2012 2:12 pm

Don’t get me wrong. I like the USGS to make bogus predictions based on the official DNC political positions.
I want them to make total and complete fools of themselves. So let’s not write them letters to correct their errors.

June 7, 2012 2:31 pm

One of the greatest threats to CA agriculture is the Delta Stewardship Council ( Whatever they do, be sure the people will have to pay for it. Does anyone still think the economy is recovering?

June 7, 2012 2:35 pm

if there is a shortage of water here in the Golden State these last 10-20 years its usually due to the increased population, which has been caused by illegal immigration. And the last i heard the state gov’t plans on cutting everyone’s water by 50% in the next 10 years because?
because they can??
because they are planning for greatly increased illegal immigration???
[Moderator’s Query: Joe, you’ve made two interesting assertions here. Can you back them up with citations or links? -REP]

Dave Dodd
June 7, 2012 3:00 pm

As an ex-USGS employee, I can state this: they are under the Department of Interior and they do have a Water Resources division, which , when I was employed, monitored such things as waterflow down the Colorado River, and potentially looked into the levels of water tables, reservoirs and local water supplies for regional/community water consumption. As an electronics technician, maintaining some of the relevant equipment, I was never aware there were any crystal balls to repair. Damn! I’d love to still be there repairing those! 🙂

June 7, 2012 3:31 pm

Obviously I’m a Californian, but I don’t get it. Today 15 counties have been made eligible for drought-loss loans (, and yet (thanks for the link to another WUWT reader) according to CA Water Resources (, we’re at or above above normal at all but one reservoir.
I think someone just has too much money, and they are looking anywhere to give it away. Apparently, it is the U.S. Small Business Admin that is trying to help out the Fed Government in shedding excess funds.
So, again, why do they need more climate axes if they have this fund burning a hole in their pocket? Couldn’t some of this money be returned to the Fed Gov to reduce the Fed debt? Or maybe this is just more stimulus? Hire someone to dig a hole, and hire someone else to fill it up? Kind of like my wife: only happy when she is buying something, even if it is something neither of us will ever want….

June 7, 2012 3:51 pm

Australia more droughts, dams will be empty,more heat waves ,we will be fighting each other in the streets, old people will die, no food production,mental problems, sea level rising, no more snow and anything else you can make up. as of 6/7/12 dams are all overflowing snow on the snowy mountains we are breaking cold and rain records farmers are laughing will be a good snow season

June 7, 2012 4:15 pm

re: state plans for cutting water usage (per household) by 50% in the next 10 years, i’ve heard this on the radio multiple times by at least 2 diff. sources, will try to find proof on the web in next few hours.
re: cause of statewide water shortages being due to increased population, (which in turn is due to illegal immigration). I don’t think many (any?) would dispute this.
What i also hear is that these state regional planning commissions are preparing for a CA population of 50+ million in a few decades, which is the reason they want this “stack and pack” housing. Also, the so-called high-speed rail doesn’t pencil out unless we have much higher population densities.

Charlie A
June 7, 2012 5:09 pm

It must be a slow news day at USGS.
As best i can tell, the subject of the “news'” release is which says “published 4 February 2012”
I tried to figure out where they validated the model at the regional level but couldn’t.
I do see in Figure 4a that the authors expect an immediate, dramatic change in mean streamflow. There is a very obvious change in the statistics of streamflow as the graph moves from “simulated historic” to “simulated future” streamflow. Very strange.

Owen in Ga
June 7, 2012 5:12 pm

Wow, how many levels of fail can we see here. Rainfall not decreased = fail. Plants grow better with less water in CO2 richer atmosphere= no crops fail. Dam flow rates have been determined politically rather than conservationally and they are still above normal=Fail.
They did get it right that IF more groundwater were used (for whatever reason) then ground subsidence would occur, and I would trust their figures on ground water effects because that is what they specialize in – the ground! Any weather prognostication is just pure hokum.

Bill Illis
June 7, 2012 5:13 pm

I hate these studies that say drought and reduced precipitation is going to occur (in any particular location anywhere).
Water vapour, in the theory, is supposed to increase by 7% per 1.0C increase in temperatures. So Water vapour is supposed to increase by about 21% when we hit 3.0C of warming.
Water vapour cycles through the atmosphere (evaporation, clouds, then rain) each 9 days so there is no way a 21% increase in water vapour is not going to mean more rain everywhere on the planet.
The last time it was 1.0C warmer, the Saharra was savanna, forested and full of lakes. The last time it was 3.0C warmer (the Miocene which is the subject of an arcticle below), the entire planet was forested (except for Antarctica) which means there was considerably more rainfall than today, everywhere.
These studies are not even based on what the science is about. It is, frankly, disgusting that all these scientists jump on this drought forecast bandwagon and they should be told this.

Jim Clarke
June 7, 2012 6:08 pm

Hang on a second folks. The model is probably very useful no matter what the future climate is like. While the article only talks about a hotter and drier climate, I am sure the model could help planners when it gets cooler and wetter as well (the likely scenario over the next few decades).
I think this particular model could very useful. If the users can only input a hotter and drier scenario, it is not the models fault.

June 7, 2012 7:20 pm

Lake Tahoe and Donner Lake and the Truckee River are all full to the brim! Just drove by. John Christy’s study of snowfall in the Sierra indicated that there was no change in snow depth in 130 years. How can you have max water in the Sierra but a drought en route to it?

Brian H
June 7, 2012 7:45 pm

Yes, the next report will be about the modelling of heavier precipitation, and the Climate Disruption’s increased flooding.
Or maybe not…

June 7, 2012 8:42 pm

i can’t find the 50% reduction in 10 years anywhere on the web so my guess is its wrong.
I heard it over and over again on the “Master Gardeners + Friends” radio show on
KNCO 830 AM (Grass Valley, CA) and the hosts say they work for the County Extension and
sounded like they knew what they were talking about so i figured they did. (I thought
maybe they got the word from others in gov’t). I’ve also heard similar on other local
gardening shows in the Sacramento area as well as KMJ 580 in Fresno although its possible
i read into what they were saying based on what i’d heard on KNCO.
That said, current population of CA is 37-38 mil according to wiki and i see estimates
to 50+ million as soon as 2025. Where is that water going to come from?

June 7, 2012 8:44 pm

(apologies the formatting, had to copy to notepad, cut + paste, etc.) 🙁

June 7, 2012 9:14 pm

In 2007, federal judge Oliver Wanger imposed limits on the amount of … in California’s Central Valley in order to protect a two-inch endangered fish, then along comes these folks who promptly attribute the reduction in water in the Central Valley to some variant of Global Warming.
In this case Global Warming has a face .. and that face is federal judge Oliver Wanger with a copy of the Endangered Species Act.

June 7, 2012 10:23 pm

joe says:
June 7, 2012 at 8:42 pm
i can’t find the 50% reduction in 10 years anywhere on the web so my guess is its wrong.
I heard it over and over again on the “Master Gardeners + Friends” radio show>>>>
The official goal seems to be 20%, and not an outright reduction, but a “per capita” reduction.×2020/index.shtml
That number could be spun a lot of different ways. For example, once the California economy completely collapses under the weight of ill advised climate policies, 2/3 of the people will leave the state for jobs elsewhere. Coupled with a 20% per capita reduction, that would be a 60% over all reduction 😉

June 7, 2012 10:29 pm

The Central Valley is one of the world’s most productive agricultural regions, providing the U.S. with one quarter of the nation’s food, including 40 percent of the nation’s fruits, nuts….>>>>
Well, there are a ton of nuts in California, but I don’t think they originate in the agricultural area. And a lot of them seem to be imported from outside the state.
Oh, we’re talking about food? OK, never mind.

Harold Pierce Jr
June 7, 2012 10:41 pm

RE: “China Town” all over again.
Who were the really deep pockets that financed the enviros law suite on behalf of the “endangered” delta smelt? The rich city guys who want to buy cheap land for their country estates, boutique wineries, horse farms, private golf courses, etc from the farmers after they all go bust and sell off the land for peanuts.
You can bet your bottom dollar that once these guys get the land they covet, the delta smelt will be found not to be endangered afterall, the pumps will be turned back on, and water will flow into the valley in great abundance.
Where are the Mexican revoutionaries when we need them?

gopal panicker
June 7, 2012 11:12 pm

i was under the impression that the central valley used to be mostly desert and all this agriculture depends on imported water…as does LA….check out ‘the cadillac desert’

June 7, 2012 11:55 pm

davidmhoffer says:
June 7, 2012 at 10:23 pm

The Left in government have figured out how to get whatever they want, they just have to be patient. Of course they would like to replace traditional American institutions with socialist alternatives. But they can’t just say now we are going to change this and do that instead. The usual tactic is to claim there is a problem with whatever they have targeted, and keep “fixing” it until they are “forced” to completely replace it. In this case, what they want to do is overturn water rights based on 1927 and prior law. The State Legislature could legally wipe out existing water rights any time they want, but they are afraid of the fallout with the voters. However, if the pressure goes up on people, i.e. water bills get more and more expensive, then they will demand a solution.
The way it works is the state mandates more and more for water agencies to do for “safety” of water consumers and agency workers. Fairness also increases costs, e.g. prevailing wage requirements. As these mandates are heaped on small agencies and large, rates must go up. Environmental regulations require very expensive studies for even medium sized projects. Systems that could otherwise have lasted another 15 or 20 years may have to be replaced or substantially modified. Wells that had produced healthful water for decades are now deemed too dangerous for domestic supply without expensive new filtration. People blame the agencies, not the regulators. So in the end, the State comes in to “protect” people. They’ve already done that with electricity.
I would not be surprised if we had no water rights within 5 to 10 years, unless we can reverse the trend. Everything will be controlled by technically incompetent bureaucrats in Sacto the same way they control energy. They will be able to dictate water use as well as energy use. That gives them essentially complete control over where people can live and what they do. Marx and Engles must be very proud.

June 8, 2012 12:35 am

I would not be surprised if we had no water rights within 5 to 10 years, unless we can reverse the trend.>>>
There is no such thing as a linear trend in climate, nor in politics. The pendulum swings and swings back. The US is moving toward increased regulation and government control. China is moving toward decreased regulation and government control. Will they pass each other in the middle? Perhaps, but I doubt it. There was a backlash against Jimmy Carter wondering about the world apologising for America’s success. He was replaced by Reagan who wondered about the world bragging about America’s success. He challenged the Soviet leadership to “tear down this wall”. They didn’t, but they stood idly by while the populace did. 10 years earlier the populace would have been machine gunned to death for their efforts. Their pendulum swung too. Now you have Obama, who makes Carter look right wing. Will he be replaced next election? Perhaps. Will the financial crisis in Europe force them to abandon their ill advised climate policies? They have turfed the windmill subsidies in Spain. When the lights don’t come on for days at a time in Germany, France, and the UK and the elderly die in droves because they can’t heat their homes, will the populace demand change? Perhaps, perhaps not, but likely. As the private sector gains power and influence in China, will the government reign them in like the Russians did the oligarchs? Perhaps.
Political trends are not linear.

June 8, 2012 3:57 am

Harold Ambler says:
1. Anyone who who believes in consistent precipitation in California hasn’t lived there very long.
Where on the planet can you find consistent precipitation? Even precipitation which follows a consistent pattern. e.g. somewhere which never experiences unexpected droughts and floods…

Brian H
June 8, 2012 4:54 am

As the private sector gains power and influence in China, will the government reign them in like the Russians did the oligarchs?

Is a reign-in anything like a rain-out? Can you rain in a horse? How long has Queen Elizabeth’s rein been?
Maybe you should use “rane” for all of them. That way your spelling and word selection will be universally incorrect, instead of haphazardly.

Brian H
June 8, 2012 5:02 am

The above was for dmh.
As for political pendulums, the underlying economics seems to be:
Right-wing regime allows buildup of wealth and (over-)confidence; voters are induced to vote in “fix everything” leftists, who degrade and cripple the economy; in desperation, a right-wing regime is voted in, repeat. .

June 8, 2012 5:22 am

Here at the USGS, we decided to stop predicted earthquakes- no good at doing that- pick making any prediction that has a slight chance of being right.

Brian H
June 8, 2012 6:15 am

Mark says:
June 8, 2012 at 3:57 am
Where on the planet can you find consistent precipitation?

I invite you to spend a winter in the Pacific NW. You will doubt no more.

June 8, 2012 10:27 am

Can’t spell, never could, and don’t care.
I cn evn tke almst all the vwls out of ths sntnce cmpltly and mst ppl will knw exctly wht I mnt so cmplng abt my spllng is rlly ptty, dnt u thnk?

June 8, 2012 10:48 am

We’d actually benefit from a warmer world here in CA. Anyone who witnessed the warm 1990s knows this. What is troubling is the obvious impact of the thus far cool 21st century. We’re drying up.

Gary Pearse
June 8, 2012 1:36 pm

Geologists were the last to come to the climate change sweepstakes… but then the USGS no longer does much geology.

V Martin
June 8, 2012 6:54 pm

Well, there might be some truth to this at least on a localized basis. Here’s what I figure… as we know, California has installed lots of industrial wind turbines and one of the unintended consequences of IWTs is that it raises the night time temperature of the air close to the ground…. essentially the boundary layer gets disturbed due to the action and mixing effect of the IWTs. Warmer air means more drying out of the soil. So… how to solve the problem? Obviously, more pumps and irrigation is required. Just thinking here but if it is just windy enough, the IWTs will make enough electricity to run the pumps that are now needed to irrigate the soil which was dried out by the IWTs. Make sense?

June 9, 2012 11:03 am

Neo is right, any current water problaems in California are related to the, unfortunatley successful, antics of the enviro-wackos which includes the EPA and certain leftist judges.
Case in point: Many decades ago, (circa 1920s but I am uncertain), concern for the water supply of the growing population of the San Francisco Bay Area inspired the then current leaders of government to construct the Hetch-Hetchy reservoir in an un-used and remote part of Yosemite National Park. An added side benefit was a guaranteed supply of inexpensive electricity for the same communities.
Fast-forward multiple decades and now the dam, water supply and cheap electricity have ended because “Officially”: a) It was improper to ‘deface’ the National Park in this way to benefit a minority, b) We must remove this impediment to the natural environment and allow native fish species to recover, c) miscellaneous etc to a) and b).
Unofficially we see the fulfillment of ‘skyrocketing energy prices’ and an enhanced control over those pesky Republican leaning agricultural areas which also benefited from the excess water supply created.
My city has had mandatory water rationing since the Hetch-Hetchy decision was made leading to enormous water bills, dead lawns and, yes, higher electricity rates.

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