Rahmstorf et al (2012) Insist on Prolonging a Myth about El Niño and La Niña
Guest post by Bob Tisdale
Anthony Watts of WattsUpWithThat forwarded a link to a newly published peer-reviewed paper by Stefan Rahmstorf, Grant Foster (aka Tamino of the blog OpenMind) and Anny Cazenave. Thanks, Anthony. The title of the paper is Comparing climate projections to observations up to 2011. My Figure 1 is Figure 1 from Rahmostorf et al (2012).
The authors of the paper have elected to prolong on the often-portrayed myth about El Niño-Southern Oscillation (ENSO):
Global temperature data can be adjusted for solar variations, volcanic aerosols and ENSO using multivariate correlation analysis…
With respect to ENSO, that, of course, is nonsense.
Figure 1
The Rahmstorf et al (2012) text for Figure 1 reads:
Figure 1. Observed annual global temperature, unadjusted (pink) and adjusted for short-term variations due to solar variability, volcanoes and ENSO (red) as in Foster and Rahmstorf (2011). 12-months running averages are shown as well as linear trend lines, and compared to the scenarios of the IPCC (blue range and lines from the third assessment, green from the fourth assessment report). Projections are aligned in the graph so that they start (in 1990 and 2000, respectively) on the linear trend line of the (adjusted) observational data.
INITIAL NOTE
Under the heading of “2. Global temperature evolution”, in the first paragraph, Rahmstorf et al (2012) write:
To compare global temperature data to projections, we need to consider that IPCC projections do not attempt to predict the effect of solar variability, or specific sequences of either volcanic eruptions or El Niño events. Solar and volcanic forcing are routinely included only in ‘historic’ simulations for the past climate evolution but not for the future, while El Niño–Southern Oscillation (ENSO) is included as a stochastic process where the timing of specific warm or cool phases is random and averages out over the ensemble of projection models. Therefore, model-data comparisons either need to account for the short-term variability due to these natural factors as an added quasi-random uncertainty, or the specific short-term variability needs to be removed from the observational data before comparison. Since the latter approach allows a more stringent comparison it is adopted here.
In the first sentence in the above quote, Rahmstorf et al (2012) forgot to mention that the climate models used in the IPCC projections simulate ENSO so poorly that the authors of Guilyardi et al (2009) Understanding El Niño in Ocean-Atmosphere General Circulation Models: progress and challenges noted:
Because ENSO is the dominant mode of climate variability at interannual time scales, the lack of consistency in the model predictions of the response of ENSO to global warming currently limits our confidence in using these predictions to address adaptive societal concerns, such as regional impacts or extremes (Joseph and Nigam 2006; Power et al. 2006).
Refer to my post Guilyardi et al (2009) “Understanding El Niño in Ocean-Atmosphere General Circulation Models: progress and challenges”, which introduces that paper. That paper was discussed in much more detail in Chapter 5.8 Scientific Studies of the IPCC’s Climate Models Reveal How Poorly the Models Simulate ENSO Processes of my book Who Turned on the Heat?
THE MYTH CONTINUED
The second paragraph of Rahmstorf et al (2012) under that heading of “2. Global temperature evolution” reads:
Global temperature data can be adjusted for solar variations, volcanic aerosols and ENSO using multivariate correlation analysis (Foster and Rahmstorf 2011, Lean and Rind 2008, 2009, Schönwiese et al2010), since independent data series for these factors exist. We here use the data adjusted with the method exactly as described in Foster and Rahmstorf, but using data until the end of 2011. The contributions of all three factors to global temperature were estimated by linear correlation with the multivariate El Niño index for ENSO, aerosol optical thickness data for volcanic activity and total solar irradiance data for solar variability (optical thickness data for the year 2011 were not yet available, but since no major volcanic eruption occurred in 2011 we assumed zero volcanic forcing). These contributions were computed separately for each of the five available global (land and ocean) temperature data series (including both satellite and surface measurements) and subtracted. The five thus adjusted data sets were averaged in order to avoid any discussion of what is ‘the best’ data set; in any case the differences between the individual series are small (Foster and Rahmstorf 2011). We show this average as a 12-months running mean in figure 1, together with the unadjusted data (likewise as average over the five available data series). Comparing adjusted with unadjusted data shows how the adjustment largely removes e.g. the cold phase in 1992/1993 following the Pinatubo eruption, the exceptionally high 1998 temperature maximum related to the preceding extreme El Niño event, and La Niña-related cold in 2008 and 2011.
IT IS IMPOSSIBLE TO REMOVE THE EFFECTS OF ENSO IN THAT FASHION
Rahmstorf et al (2012) assume the effects of La Niñas on global surface temperatures are the proportional to the effects of El Niño events. They are not. Anyone who is capable of reading a graph can see and understand this.
But first: For 33% of the surface area of the global oceans, the East Pacific Ocean (90S-90N, 180-80W), it may be possible to remove much of the linear effects of ENSO from the sea surface temperature record, because the East Pacific Ocean mimics the ENSO index (NINO3.4 sea surface temperature anomalies). See Figure 2. But note how the East Pacific Ocean has not warmed significantly in 30+ years. A linear trend of 0.007 deg C/decade is basically flat.
Figure 2
However, for the other 67% of the surface area of the global oceans, the Atlantic, Indian and West Pacific Oceans (90S-90N, 80W-180), which we’ll call the Rest of the World, the sea surface temperature anomalies do not mimic the ENSO index. We can see this by detrending the Rest-of-the-World data. Refer to Figure 3. Note how the Rest-of-the-World sea surface temperature anomalies diverge from the ENSO index during four periods. The two divergences highlighted in green are caused by the volcanic eruptions of El Chichon in 1982 and Mount Pinatubo in 1991. Rahmstorf et al (2012) are likely successful at removing most of the effects of those volcanic eruptions, using an aerosol optical depth dataset. But they have not accounted for and cannot account for the divergences highlighted in brown.
Figure 3
Those two divergences are referred to in Trenberth et al (2002) Evolution of El Nino–Southern Oscillation and global atmospheric surface temperatures” as ENSO residuals. Trenberth et al write:
Although it is possible to use regression to eliminate the linear portion of the global mean temperature signal associated with ENSO, the processes that contribute regionally to the global mean differ considerably, and the linear approach likely leaves an ENSO residual.
Again, the divergences in Figure 3 shown in brown are those ENSO residuals. They result because the naturally created warm water released from below the surface of the West Pacific Warm Pool by the El Niño events of 1986/87/88 and 1997/98 are not “consumed” by those El Niño events. In other words, there’s warm water left over from those El Niño events and that leftover warm water directly impacts the sea surface temperatures of the East Indian and West Pacific Oceans, preventing them from cooling during the trailing La Niñas. The leftover warm water, tending to initially accumulate in the South Pacific Convergence Zone (SPCZ) and in the Kuroshio-Oyashio Extension (KOE), also counteracts the indirect (teleconnection) impacts of the La Niña events on remote areas, like land surface temperatures and the sea surface temperatures of the North Atlantic. See the detrended sea surface temperature anomalies for the North Atlantic, Figure 4, which show the same ENSO-related divergences even though the North Atlantic data is isolated from the tropical Pacific Ocean and, therefore, not directly impacted by the ENSO events.
Figure 4
There’s something blatantly obvious in the graph of the detrended Rest-of-the-World sea surface temperature anomalies (Figure 3): If the Rest-of-the-World data responded proportionally during the 1988/89 and 1998-2001 La Niña events, the Rest-of-the-World data would appear similar to the East Pacific data (Figure 2) and would have no warming trend.
Because those divergences exist—that is, because the Rest-of-the-World data does not cool proportionally during those La Niña events—the Rest-of-the-World data acquires a warming trend, as shown in Figure 5. In other words, the warming trend, the appearance of upward shifts, is caused by the failure of the Rest-of-the-World sea surface temperature anomalies to cool proportionally during those La Niña events.
Figure 5
I find it difficult to believe that something so obvious is simply overlooked by climate scientists and those who peer review papers such as Rahmstorf (2012). Some readers might think the authors are intentionally being misleading.
FURTHER INFORMATION
The natural processes that cause the global oceans to warm were described in the Part 1 of YouTube video series “The Natural Warming of the Global Oceans”. It also describes and illustrates the impacts of ENSO on Ocean Heat Content for the tropical Pacific and the tropics as a whole.
Part 2 provides further explanation of the natural warming of the Ocean Heat Content and details the problems associated with Ocean Heat Content data in general. Part 2 should be viewed after Part 1.
And, of course, the natural processes that cause the oceans to warm were detailed with numerous datasets in my recently published ebook. It’s titled Who Turned on the Heat? with the subtitle The Unsuspected Global Warming Culprit, El Niño Southern Oscillation. It is intended for persons (with or without technical backgrounds) interested in learning about El Niño and La Niña events and in understanding the natural causes of the warming of our global oceans for the past 30 years. Because land surface air temperatures simply exaggerate the natural warming of the global oceans over annual and multidecadal time periods, the vast majority of the warming taking place on land is natural as well. The book is the product of years of research of the satellite-era sea surface temperature data that’s available to the public via the internet. It presents how the data accounts for its warming—and there are no indications the warming was caused by manmade greenhouse gases. None at all.
Who Turned on the Heat? was introduced in the blog post Everything You Every Wanted to Know about El Niño and La Niña… …Well Just about Everything. The Updated Free Preview includes the Table of Contents; the Introduction; the beginning of Section 1, with the cartoon-like illustrations; the discussion About the Cover; and the Closing. The book was updated recently to correct a few typos.
Please buy a copy. (Credit/Debit Card through PayPal. You do NOT need to open a PayPal account.). It’s only US$8.00.
CLOSING
Rahmstorf et al (2012) begin their Conclusions with:
In conclusion, the rise in CO2 concentration and global temperature has continued to closely match the projections over the past five years…
As discussed and illustrated above, ENSO is a process that cannot be removed simply from the global surface temperature record as Rahmstorf et al (2012) have attempted to do. The sea surface temperature records contradict the findings of Rahmstorf et al (2012). There is no evidence of a CO2-driven anthropogenic global warming component in the satellite-era sea surface temperature records. Each time climate scientists (and statisticians) attempt to continue this myth, they lose more and more…and more…credibility. Of course, that’s a choice they’ve clearly made.
And as long as papers such as Rahmstorf et al (2012) continue to pass through peer review and find publication, I will be more than happy to repeat my message about their blatantly obvious failings.
SOURCE
The Sea Surface Temperature anomaly data used in this post is available through the NOAA NOMADS website:
http://nomad1.ncep.noaa.gov/cgi-bin/pdisp_sst.sh
or:
http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?lite=
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Richard Tol is not impressed:
#Doha: Sea levels to rise by more than 1m by 2100 http://t.co/h2cNEMo7 Rahmstorff strikes again with his subpar statistics
http://twitter.com/RichardTol/status/273691430101323776
To Bob Tisdale: I have been planning to buy you new book, but thought I should first clean out my hard drive climate library to ensure I comfortably have enough space for it. Now I see (as you and RobertInAz point out) it is 561 pp. with lots of graphics. Could you give me a rough ballpark as to the total megabytes invoved in the download upon purchase?
richardscourtney says:
December 1, 2012 at 1:54 am
Phil.:
At November 30, 2012 at 5:59 pm you provide your usual inaccurate knit-picking and assert I am “not very accurate on facts” (which is laughable coming from you).
Well you raised the subject of the reviewing of Einstein’s papers and got almost everything about it wrong so as everyone can see you were completely inaccurate on the facts I guess we should be thankful that you spelled his name right? Getting the name of the journal wrong is a rather basic error! You also sought to imply that Einstein was a complete unknown whereas in fact he had already published in Annalen (5 papers before 1905). Also you said “For example, knowing there was such a prejudice of all potential reviewers, the then Editor of Nature published two papers by an incompetent patents clerk without putting the papers to peer review.” This is a complete fabrication, peer review was not the rule then and since Einstein submitted his papers via Planck no such thoughts would be entertained by Drude (the editor). Also Einstein had a Doctorate, indeed, one of the 1905 papers was his thesis and was the work for which he was later awarded the Nobel prize
It seems you have picked up the baton of irrelevant distraction from trafamadore. My advice is that you don’t bother because your track record shows you are even less competent at it than he is.
For example, in your post I am answering, you say Einstein had his work “peer reviewed” because he asked Plank to comment on it. Well, according to that criterion, Tisdale has had much more peer review of his work because he has put it on the internet for everybody to comment on it.
I agree with Matthew if anyone is guilty of ‘irrelevant distraction’ it is you and comparing Max Planck to the readership of WUWT is ridiculous. Quality beats quantity in this case. In your usual style you didn’t answer my post, you rarely do in fact, you just pout.
The subject of this thread is a review of the ridiculous paper by Rahmstorf&Foster.
Address the criticisms of the Rahmstorf&Foster paper or go away.
Now you’ve corrected your typo so that I can now see the context of your previous quote I might do so. If it were your blog you could issue orders, but since it isn’t consider yourself ignored.
Matthew R Marler:
At December 1, 2012 at 8:31 am you write to me saying
I was clearly, unambiguously and entirely right, not wrong.
The issue was ‘peer review’ for publication; i.e. the selection by a journal Editor of reviewers who provide him/her with advice on whether or not to publish a paper submitted for publication.
The issue was NOT the provision of a paper by its author for comment by other scientists.
At December 1, 2012 at 1:54 am I wrote
That is true.
You have asserted, “When you are wrong on the details that you have introduced into the discussion, you ought to admit it and apologize”.
I await your apology.
Richard
Phil.:
Your content-free diatribe at December 1, 2012 at 2:36 pm (which attempts to divert from thew subject of this thread) concludes by saying to me
O dear! That puts me on a par with you! I never thought I could sink that low.
Richard
ridhardscourtney: I await your apology.
lol!
You were just plain wrong.
Matthew R Marler:
I was just plain RIGHT and you have not stated any way in which there was any error in what I said.
Onlookers can see that for themselves so I fail to understand why you try to pretend otherwise.
Richard
Leigh B. Kelley: Sorry for the delay getting back to you. Who Turned on the Heat? is about 23MB in pdf form.
To Bob Tisdale: Thanks Bob! With a bit of pruning, my old machine can handle that. I wish that more people would read your account (or read it with more care). I have not found the basic outline at all hard to understand. If correct, your account is devastating to the basic IPCC metric for AGW, global mean near surface air temperature, but that was their choice. And of course, if the new metric were to change to OHC with all or a substantial part of the GHG heat mixing into the deep ocean, that has its own severe problems (and not just in terms of uncertainties in the measurements!).
Leigh B. Kelley says: “With a bit of pruning, my old machine can handle that.”
I’m glad I didn’t publish it only in Kindle form. The file size is then 55MB. One of these days I may publish it that way, maybe next year.
richardscourtney says:
December 2, 2012 at 6:00 am
Matthew R Marler:
At December 1, 2012 at 8:31 am you write to me saying
When you are wrong on the details that you have introduced into the discussion, you ought to admit it and apologize. If someone with the stature of Planck recommends publication of Bob Tisdale’s work in the peer-reviewed literature, I am sure it will be published. Since you claimed that Einstein’s paper had not been peer-reviewed, you ought to admit that you were wrong.
I was clearly, unambiguously and entirely right, not wrong.
No you weren’t, first of all you got the journal wrong, a basic error particularly for two of the most famous papers in modern physics!
The issue was ‘peer review’ for publication; i.e. the selection by a journal Editor of reviewers who provide him/her with advice on whether or not to publish a paper submitted for publication.
The issue was NOT the provision of a paper by its author for comment by other scientists.
Again you were wrong, ‘peer review’ is the review of papers prior to publication by knowledgable peers in the field. The model you described is not the only one and was certainly not the only one used in the past. You said that the editor of Annalen der Physik, Drude, himself a professor of physics, “knowing there was such a prejudice of all potential reviewers, the then Editor of Nature (sic) published two papers by an incompetent patents clerk without putting the papers to peer review”, this is untrue, their usual reviewing procedure was followed as it had been for Einstein’s previous publications in that journal. It was commonplace for authors to submit their papers via a peer, in this case Planck, for review prior to submission to the journal, certainly Drude receiving a paper from Planck with a recommendation to publish would not seek out further reviews! This procedure was followed as recently as the 1970s by the Proceedings of the Royal Society, you would submit your paper to a FRS asking him to review it for Proc Roy Soc, this was a stronger form of review than the anonymous reviews since when the paper was published the Fellow’s name was added below the title line, so his reputation was on the line too!
As usual when caught out in an error you refuse to address the error and instead resort to ad hominem attack and bluster and in this case even state that you made no errors, do you still think that these papers were published in Nature?
herefore, I write to spell-out the issues which you raise when you write, “all times were less than 15 years”.
And I’m writing to point out the mistake you have made.
Firstly, in 2009 the US National Oceanographic and Atmospheric Administration (NOAA) reported at
http://www1.ncdc.noaa.gov/pub/data/cmb/bams-sotc/climate-assessment-2008-lo-rez.pdf
on page 123: actually 23
“The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate.”
NOAA said that in 2009 and, Werner, you show that there has now been “zero trends for intervals of 15 yr or more” so there is a “discrepancy” between what the models predict and “the expected present-day warming rate”.
Yes they said that but the context is important, which why I asked for the correct reference.
There I found out what Richard had omitted which completely changed the meaning. The full quote is as follows:
“ENSO-adjusted warming in the three surface temperature datasets over the last 2–25 yr continu-
ally lies within the 90% range of all similar-length ENSO-adjusted temperature changes in these simulations (Fig. 2.8b). Near-zero and even negative trends are common for intervals of a decade or less in the simulations, due to the model’s internal climate variability. The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate.”
The statement only applies to temperature histories from which the ENSO effect has been removed (i.e. ENSO-adjusted), it does not apply to to unadjusted histories unlike Richard is trying to claim! The R & L paper shows that we are not in a zero trend period of 15yrs+, if you don’t trust this paper’s analysis you need to find a different ENSO-adjusted history (perhaps the method of Thompson et al.) if you wish to apply the NOAA statement.
Phil. says:
I agree with you; the entire discussion there seems to involve the ENSO-adjusted data. However, I think there is also an additional problem with Richard’s claim: I read the statement from Santer et al as saying that a trend of zero lies outside the 95% confidence cone on the trend for the climate model simulations for 15 year periods. [From where they have put the parenthetical remark “(at the 95% level)” this seems to me like the correct way to read it.]
What Richard has done is changed the goalposts from what Santer et al. set out as the criterion: Yes, it may be true that the actual trend in the data may itself have a 95% confidence cone that includes the possibility of zero trend. But, that is not the same thing as saying that the actual computed value of the trend is zero. It is in fact positive.
Well at least Bob Tisdale has a mechanism to explain warming. But it almost certainly wrong.
As for the 15 years for global warming, lets just forget that and use 1995 as a start date for all future “no warming since…” claims. Anyway, since Bob has a mechanism to explain warming, why would you guys want to say there wasn’t any?
BTW, have there been any statistically significant periods of global cooling in the past 60 years?