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California Drought Update -- Not Even Close to Worst Drought Ever

January 13, 2015, 1:40 pm

There is little trend evidence anywhere that climate is getting -- pick the world -- weirder, more extreme, out of whack, whatever.  In particular, name any severe weather category you can imagine, and actual data in trend charts likely will not show any recent trend.

The reasons the average person on the street will swear you are a crazy denier for pointing such a thing out to them is that the media bombards them with news of nearly every 2+ sigma weather event, calling most of these relatively normal episodes as "the worst ever".

A great example is the California drought.  Here is the rolling average 5-year precipitation chart for California.  Find the worst drought "ever".

multigraph3

I know no one trusts anyone else's data in public debates, but you can make these charts yourself at the NOAA site, just go here:  http://www.ncdc.noaa.gov/cag/.  The one record set was that 2013 had the lowest measured CA precipitation in the last century plus, so that was indeed a record bad year, but droughts are typically made up of multiple years of below average precipitation and by that measure the recent CA drought is the fourth or fifth worst.

By the way, Paul Homewood points out something that even surprised me and I try not to be susceptible to the mindless media bad news stampeded:  California rainfall this year was close to normal.  And, as you can see, there is pretty much no trend over the last century plus in California rainfall:

multigraph1

 

As discussed previously, let's add the proviso that rainfall is not necessarily the best metric of drought.  The Palmer drought index looks at moisture in soil and takes into account other factors like temperature and evaporation, and by that metric this CA drought is closer to the worst of the century, though certainly not what one would call unprecedented.  Also, there is a worsening trend in the Palmer data.

multigraph_palmer

 

Update:  By the way, the fact that two measures of drought give us two different answers on the relative severity of the drought and on the trend in droughts is typical.   It makes a mockery of the pretense to certainty on these topics in the media.  Fortunately, I am not so invested in the whole thing that I can't include data that doesn't support my thesis.

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Category: Climate

10 Comments

  1. jdgalt:

    California officials announce a "drought" whenever they want an excuse to restrict the use of water (no watering certain days, etc.)

    Of course a level of rainfall that happens all the time (as your graphs show) isn't really a drought at all. The problem is simply that the state won't build enough dams (because each potential site has its NIMBYs who wail that it will encourage more people to move there).

    Not to worry, though. The way the state is overregulating and overtaxing us, everyone who can is moving the heck out. I would if I could.

    January 13, 2015, 2:10 pm

  2. TruthisaPeskyThing:

    I know that it might sound like I do not trust the government, but I find the Palmer drought index to be questionable. My area has been labeled as being in a severe drought when ponds, swamps and marshes are as full as I have ever seen them, and my backyard is so soggy that a riding lawn mower gets stuck. Meanwhile, in the 1930s, many of the lakes were bone dry -- and now they have abundant fish and the beaches are getting even smaller as the water line advances. Maybe in some sense the Palmer drought index is reliable, but it seems to consistently say that things are worse than my experience.

    January 13, 2015, 2:11 pm

  3. mogden:

    60 months is a long window of time to do rainfall averages. The current drought had some exceptionally long dry periods followed by heavy rainfall for brief periods. Even the terrible drought in the mid 70s doesn't register much on that graph, but it definitely was pretty bad in terms of tree death, etc. I think that the window size should be reduced.

    January 13, 2015, 2:30 pm

  4. Matthew Slyfield:

    Who the {BLEEP} cares if a desert that is overpopulated to the point that local water supplies are inadequate even in extraordinarily wet years is experiencing a drought or not? It doesn't matter.

    January 13, 2015, 3:19 pm

  5. STW:

    The American Southwest is a desert. We can move water from here to there and back again but that doesn't change that simple fact. As I recall, the rate of evaporation for much of it is on the order of 10 feet a year. This means, for example, that if we could cover Las Vegas or Phoenix with 10 feet of water they'd still be bone dry after one year. This is not a smart place to have a large population. When the pumps stop it will turn ugly very fast. I lived there for a number of years and recognize that water projects take so long that, while every drought brings forth cries for new projects, the rains return soon enough to prevent those "unneeded" projects from being built. Idiots.

    January 13, 2015, 4:29 pm

  6. HenryBowman419:

    I think the problem is simple: there are simply too darn many people living in Kalifornia.

    January 13, 2015, 5:34 pm

  7. Harry:

    Coyote, thanks for a great series of blog essays.

    Often, you have mentioned that critics have referred to you as a Denier, an attempt to smear you as if you are an Argentinian Nazi. This is a tactic used by other modern-day totalitarians who ironically themselves deny the Holocaust, as in the Supreme Leader of Iran, Ayatollah Ali Khameni, who will say anything to protect his authority. So, death to the heretics, revenge for the Spanish Inquisition and Charlamagne's expulsion of the Moors, and vindication of the wisdom Ali Khameni got when studying at Moscow University.

    Similarly, United Nations bureaucrats, with an eye on a big payoff, try to end the discussion by declaring that the science is settled, fearing scrutiny of their, well, unscientific approach, and comparing critics to Hitler, hoping nobody will notice and ignoring that the burden of proof is on them.

    And similarly, for at least thirty five years speech codes have grown and flourished, in a deliberate effort to stifle academic freedom and promote the careers of people who attack their intellectual competitors, who are the heretics. Along this horror, our government showers these professors with money.

    So when Muslims in the name of Allah behead non-believers, the purpose is to motivate the living to behave, and let them to take their property and rape their non compliant wives and daughters, and to avoid having to work for a living, just like the Barbary Pirates.

    January 13, 2015, 9:54 pm

  9. 4TimesAYear:

    They do know that southern CA has always been desert - hopefully....?

    July 10, 2015, 11:29 pm