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Global warming and the El Niño Southern Oscillation

What the science says...

Select a level... Basic Intermediate

El Nino has no trend and so is not responsible for the trend of global warming.

Climate Myth...

It's El Niño

"Three Australasian researchers have shown that natural forces are the dominant influence on climate, in a study just published in the highly-regarded Journal of Geophysical Research. According to this study little or none of the late 20th century global warming and cooling can be attributed to human activity. The close relationship between ENSO and global temperature, as described in the paper, leaves little room for any warming driven by human carbon dioxide emissions. The available data indicate that future global temperatures will continue to change primarily in response to ENSO cycling, volcanic activity and solar changes." (Climate Depot)

At a glance

This particular myth is distinguished by the online storm that it stirred up back in 2009. So what happened?

Three people got a paper published in the Journal of Geophysical Research. It was all about ENSO - the El Nino Southern Oscillation in the Pacific Ocean. ENSO has three modes, El Nino, neutral and La Nina. In El Nino, heat is transferred from the ocean to the atmosphere. In La Nina, the opposite happens. So within ENSO's different modes, energy is variously moved around through the planet's climate system, but heat is neither added nor subtracted from the whole. As such, in the long term, ENSO is climate-neutral but in the short term it makes a lot of noise.

The paper (link in further details) looked at aspects of ENSO and concluded that the oscillation is a "major contributor to variability and perhaps recent trends in global temperature". First point, sure. Second point, nope, if you accept climate trends are multidecadal things, which they are.

That might have been the end of it had the authors not gone full-megaphone on the media circuit, promoting the paper widely in a certain way. "No scientific justification exists for emissions regulation", they loudly crowed. "No global warming", the denizens of the echo-chamber automatically responded, all around the internet. This is how climate science denial works.

Conversely, the way that science itself works is that studies are submitted to journals, peer-reviewed, then some of them get published. Peer review is not infallible - some poor material can get through on occasion - but science is self-correcting. So other scientists active in that field will read the paper. They may either agree with its methods, data presentation and conclusions or they may disagree. If they disagree enough - such as finding a major error, they respond. That response goes to peer-review too and in this case that's exactly what happened. An error so fundamental was found that the response was published by the same journal. The error concerned one of the statistical methods that had been used, called linear detrending. If you apply this method to temperature data for six months of the Austral year from winter to summer (July-December), it cannot tell you that during that period there has been a seasonal warming trend. So what happens if you apply it to any other dataset? No warming! Bingo!

A response to the response, from the original authors, followed but was not accepted for publication, having failed peer-review. At this point, the authors of the rejected response-to-the-response started to screech, "CENSORSHIP" - and the usual blogosphere battles duly erupted.

It was not censorship. Dodgy statistical techniques were picked up by the paper's highly knowledgeable readership, some of whom joined forces to prepare a rebuttal that corrected the errors. The response of the original paper's authors to having their errors pointed out was so badly written that it was rejected. That's not censorship. It's about keeping garbage out of the scientific literature.

Quality control is what it's all about.

Please use this form to provide feedback about this new "At a glance" section. Read a more technical version below or dig deeper via the tabs above!


Further details

ENSO, the El Nino Southern Oscillation, is an irregular but well-understood phenomenon that affects the Eastern and Central Pacific Oceans. It is important both on a local and global basis, since it not only causes changes in sea-surface temperatures. It also affects the thermal profile of the ocean and both coastal and upwelling ocean currents.

Such changes can and do affect the diversity and abundance of important edible seafood species. Cold and warm-water forms are forced to migrate to where they find the conditions more to their liking. El Nino events in particular, where warm waters prevail close to the sea surface, can inflict a temporary loss of commercially important species of fish and squid from where they are traditionally fished. Some coastal communities along the Pacific seaboard of South America have a strong dependency on such fisheries. As such, prolonged El Nino conditions can be seriously problematic.

The warm El Nino mode of ENSO also affects global temperatures, as heat energy is transferred from ocean surface to the atmosphere. A strong El Nino is easily capable of raising temperatures above the upward slope that represents the change in radiative forcing caused by our increasingly vast greenhouse gas emissions - global warming, in other words. Conversely, the opposite to El Nino, La Nina, suppresses global temperatures. When several La Nina years occur in a row, climate science deniers are given the opportunity to insist that the world is cooling. This has happened before, most notably in the post-1998 period.

However, as fig. 1 shows, global temperature is rising independently of the short-term ENSO noise. Fig. 1 also shows that 2022 was the warmest La Nina year in the observational record. In fact, El Nino, La Nina and neutral years are all getting warmer.

Variations in ENSO in a warming world.

Fig. 1: variations in ENSO in a warming world. This plot therefore shows two independent phenomena that affect climate: the noisy ENSO and the underlying relentless upward climb in temperatures caused by our rapidly-increasing emissions of CO2 and other greenhouse gases. Temperature records typically get broken in El Nino years because the temperature is given an extra boost. 2016, a major El Nino year, held the global temperature record for a few years, but 2023 saw that record fall again. 2023 is in grey because that El Nino did not develop until later in the year. Graphic: Reaclimate.

The reader should by now be in no doubt about the difference between the long term global temperature trend caused by increased greenhouse gas forcing and the noise that shorter-term wobbles like ENSO provide. You would have seen something similar during the descents into and climbs out of ice-ages too. That's because ENSO has likely been with us for a very long time indeed. Ever since the Pacific Ocean came close to its present day geography, millions of years ago, it has likely been there.

The reader should by now be in no doubt about the difference between the long term global temperature trend caused by increased greenhouse gas forcing and the noise that shorter-term wobbles like ENSO provide. You would have seen something similar during the descents into and climbs out of ice-ages too. That's because ENSO has likely been with us for a very long time indeed. Ever since the Pacific Ocean came close to its present day geography, millions of years ago, it has likely been there.

Nevertheless, here we have something that warms the planet, even if that's on a temporary basis. As a consequence, some people with ulterior motives might just become interested. Over a decade ago now, that's what happened. A paper, 'Influence of the Southern Oscillation on tropospheric temperature' (Mclean et al. 2009) was published in the Journal of Geophysical Research. One of its co-authors, a well-known climate contrarian, commented:

"The close relationship between ENSO and global temperature, as described in the paper, leaves little room for any warming driven by human carbon dioxide emissions."

If you enter the above quote, complete with its quotation marks, into a search engine, you will get lots of exact matches. Strange? Not really, if you have studied the techniques of climate science denial.

  1. a paper is published that barely mentions global warming.
  2. its authors go on to distribute slogans implying that they have put yet another Final Nail in the global warming coffin.
  3. right-wing media of all sorts from newspapers to blogs ensure wide distribution of the talking-points.
  4. individuals serve to fill in the circulation-gaps.

This is how it works, time and again. However, glaring errors were soon noticed in the paper, leading a group of specialists to offer a rebuttal, published in the same journal a year later (Foster et al. 2010).

Statistics is not everyone's cup of tea, but a very straightforward explanation of the key error was provided by Stephen Lewandowsky, writing at ABC (archived):

"This is best explained by an analogy involving daily temperature readings between, say, July and December anywhere in Australia. Suppose temperature is recorded twice daily, at midday and at midnight, for those 6 months. It is obvious what we would find: Most days would be hotter than nights and temperature would rise from winter to summer. Now suppose we change all monthly readings by subtracting them from those of the following month—we subtract July from August, August from September, and so on. This process is called "linear detrending" and it eliminates all equal increments. Days will still be hotter than nights, but the effects of season have been removed. No matter how hot it gets in summer, this detrended analysis would not and could not detect any linear change in monthly temperature."

Anyone can do this in Excel. First input a series of representative temperatures for the transition from Austral winter into summer:

Series of representative temperatures for the transition from Austral winter into summer.

Reasonable? OK, then let's plot them. Still looks like what we'd expect. It gets warmer in Australia from July to December and nights are usually colder than days, right?

Plot of temperatures

Now, let's do that detrending. This is what you get:

Detrended temperatures

As Lewandowsky pointed out in his ABC article:

"Astonishingly, McLean and colleagues applied precisely this detrending to their temperature data. Their public statements are thus equivalent to denying the existence of summer and winter because days are hotter than nights."

In other words: Fail.

Last updated on 24 March 2024 by John Mason. View Archives

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Argument Feedback

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Further reading

NOAA have a very useful resource ENSO Cycle: Recent Evolution, Current Status and Predictions which features recent ENSO activity as well as model predictions of ENSO activity in the near future.

Denial101x video

Comments

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Comments 101 to 123 out of 123:

  1. BernardJ @ 97: I should gave been more specific, actually, and ask also about global surface temps (including land), as I recall they were mentioned. I have to confess I have not followed the whole exchange in every detail, although I find the sum of the examinations by Tom Curtis and IanC quite interesting.
  2. Call me a data analysis nerd, but I'm actually interested in doing some analysis on Bob's figure 13 here. I can easily test whether the case of a non-linearity between Nino3.4 and SST and whether it is statisyically significant. I suspect a regression to take out the SH component of SATO will be helpful. If these check out, the next step would be to look for a longer time series - it too easy to fool yourself on only two events. I'm rather busy at the moment though, so while the analysis is quick I don't have time to dig for the data. Does anyone have it to hand and can put it on a file drop? (Tom - is that the data you have?) ... In terms of where to go with this, you can always narrow down where to look by having a mechanism in mind. Here's a brain dump for future reference: 1. What is the mechanism linking SST to ENSO? Without one, there is no reason to suggest a linear relation except the empirical observation. So no conclusion to be drawn if it is not linear. 2. Obviously, volcanoes -> forcing -> SST. The SH SATO data looks better than the global. Makes sense, most ocean in the SH. 3. Hypothesis: ENSO -> clouds -> forcing -> SST. Review literature on ENSO and clouds. Look at the MODIS data. 4. Hypothesis: ENSO -> temperature -> lapse rate feedback -> temperature. How to test this? OLR? This is all interesting, but I don't see how any of it relates to climate change though. The stable climate state could follow a jump-recovery cycle. When warming is superimposed this turns into steps, but the steps have no meaning with respect to warming. Basically a restatement of Tom's result.
  3. Composer99 says: “Why should anyone here feel obliged to respond to your nonsense?” Unless you can explain those divergences in the sea surface temperature anomalies of the Atlantic-Indian-West Pacific during the La Niña events of 1988/89 and 1998-2001, you cannot explain why surface temperatures warmed. http://bobtisdale.files.wordpress.com/2012/09/figure-13.png Composer99 says: “As far as I can see your questions are an attempt to side-step sea surface temperature trends as well as increasing ocean heat content.” Are you aware that the global oceans can be divided into logical subsets which show the ocean heat content warmed naturally? Since 1950, there have been three 3-year La Niña events. They occurred in 1954-57, 1973-76, and 1998-2001. During the multidecadal periods between those 3-year La Niñas, Ocean Heat Content cooled in the tropical Pacific (24S-24N, 120E-80W). Are you aware that the same holds true for the tropical oceans as a whole? Do you understand how the tropical Pacific warms during La Niña events? Are you aware the Ocean Heat Content for the extratropical North Pacific (24N-65N, 100E-100W) cooled from the start of the dataset until the late 1980s and then warmed in a 2-year period, and that without that 2-year warming, the Ocean Heat Content for that region would show cooling from 1955 to present? Why would anthropogenic greenhouse gas warming only occur during that 2-year period in the North Pacific and during 3-year La Niña events in the tropics. Are you aware that if you combine the tropical Pacific and Extratropical North Pacific OHC data, the data gives the appearance of a continuous warming, like the Global data, but if you isolate the two they indicate something entirely different? Composer99 says: “I mean, come on. Your graph of ‘Detrended Rest-of-World SST Data Disagrees with The Warming of SST Anomalies As Portrayed By AGW Proponents’ [SST abbreviated by me]? Of course it disagrees - you detrended the SST data.” The trends aren’t the topic of discussion in the graph. It’s the divergences during the 1988/89 and 1998-2001 La Niñas that are being discussed. Composer99 says: “As far as divergence between SST behaviour and ENSO goes, one would only expect complete agreement between SSTs and ENSO if ENSO were the sole driver of SSTs.” What’s causing those divergences? Why do they only appear during those La Niña events? Again, unless you can explain those divergences, you cannot explain why the warming in that dataset occurred. Composer99 says: “So how is one to characterize your claim ‘no one here has replied to that question from comment 40’ except as refusal, whether through inability or unwillingness, to read others' posts on this thread?” The “that question” in my statement ‘no one here has replied to that question from comment 40’ had to do with the divergences in the Rest-of-the-World data, but you quoted a statement by Tom Curtis about the East Pacific. Two different datasets, Composer99. doug_bostrom says: “Bob, please just show us how a mass (global ocean+air) can increase in temperature without energy being added to it.” I’ve never said the mass of the global oceans plus air in their entirety can increase in temperature without energy being added to it. The key word in that sentence is entirety. Where have I stated that, doug? As I noted in my reply to Composer99 above: Are you aware that the global oceans can be divided into logical subsets which show the ocean heat content warmed naturally? Since 1950, there have been three 3-year La Niña events. They occurred in 1954-57, 1973-76, and 1998-2001. During the multidecadal periods between those 3-year La Niñas, Ocean Heat Content cooled in the tropical Pacific (24S-24N, 120E-80W). Are you aware that the same holds true for the tropical oceans as a whole? Do you understand how the tropical Pacific warms during La Niña events? Are you aware the Ocean Heat Content for the extratropical North Pacific (24N-65N, 100E-100W) cooled from the start of the dataset until the late 1980s and then warmed in a 2-year period, and that without that 2-year warming, the Ocean Heat Content for that region would show cooling from 1955 to present? Why would anthropogenic greenhouse gas warming only occur during that 2-year period in the North Pacific and during 3-year La Niña events in the tropics. Are you aware that if you combine the tropical Pacific and Extratropical North Pacific OHC data, the data gives the appearance of a continuous warming, like the Global data, but if you isolate the two they indicate something entirely different? On the other hand, are you aware of teleconnections? Are you aware that there’s no heat transfer with teleconnections? Example: Why do the tropical North Atlantic sea surface temperature anomalies warm during an El Nino, doug? Do you know? There’s no direct exchange of heat yet the tropical North Atlantic warms during an El Niño. Why, doug? Could it have something to do with the slowing of the trade winds in the tropical North Atlantic in response to the El Niño? That would result in less evaporation, which is the primary way the oceans release heat. If there’s less evaporation, sea surface temperatures warm, do they not? Also, when the trade winds slow in the tropical North Atlantic in response to an El Niño, there’s less upwelling of cool waters from below the surface and less entrainment of that cool subsurface water. That would cause the seas surface temperatures to warm too. IanC says: “Whether PDO index is abstract is irrelevant, and frankly your complaints about the index are just red-herrings.” It’s not irrelevant. As I noted earlier, the PDO does not represent the sea surface temperature of the North Pacific, the Pacific basin as a whole, or the East Pacific. Here’s a graph that compares the decadal variability of the PDO and the detrended and standardized sea surface temperature anomalies of the East Pacific, North Pacific (north of 20N, same as the PDO), and the Pacific as a whole: http://i49.tinypic.com/slhb8y.jpg I was trying to save you some time. So why not move onto the Rest-of-the-World data and explain why those divergences exist during the La Niña events of 1988/89 and 1998-2001? http://bobtisdale.files.wordpress.com/2012/09/figure-13.png Obviously, the ENSO index, all ENSO indices, fail to account for a portion of ENSO. What is it, IanC? With respect to the other questions and comments: for almost 4 years, I’ve been answering the same questions and responding to the same comments you’ve presented here. There’s nothing new about your questions and comments. Somewhere along the line, I’ve answered them, and for most of them, I can simply cut and paste a paragraph from my book. But you have to be able to answer the last question I asked you. Why do the sea surface temperature anomalies of the detrended Atlantic-Indian-West Pacific (Rest of the World, with the coordinate of 90S-90N, 80W-180) diverge from the scaled ENSO index during the 1988/89 and 1998-2001 La Niña events? If you all can’t answer that question, there’s no reason for us to proceed. Also, when you’ve determined the answer to that question, you’ll likely have determined the answers for many of your other questions. Regards PS: Tom Curtis, thanks for your statistical analyses in comment 80. But you seemed have overlooked something. If you’re so concerned about the statistical significance of the East Pacific and the large standard deviation of that dataset, then why not simply remove the ENSO and volcano signals from the East Pacific data? The primary assumption behind Foster and Rahmstorf and Rahmstorf et al 2012 is that you can remove those signals to provide a better CO2-driven global warming signal. In fact, the East Pacific is the only sea surface temperature subset where you could hope to remove the ENSO signal without leaving significant ENSO residuals. You can’t remove the ENSO signal from the Rest-of-the-World data (90S-90N, 80W-180) without something very obvious occurring? Try it for both datasets, the East Pacific and the Rest-of-the-World. See how it changes your results and opinions.
  4. Kevin C, I have just published the weekly Reynolds SST data I have been using on google docs. The original data can be found for monthly values here; for weekly values here (1980s) and here (1990s and 2000s); and for a gridded data set, here.
  5. Tom: Thanks. Bob: I don't follow your last point. From a (too quick) look at the data, it seems you are saying that the ENSO signal is localised in the SST data, and therefore that removing it globally is invalid? But I presume that is not what you are saying because that would be obviously wrong. The global SST is a linear combination (a weighted sum) of all the regional contributions. If any of the local terms contains an ENSO signal, then the global SST will also contain an ENSO signal, comprising the total of the contributions to the regional SSTs weighted by the fractional contribution of those regions to the global SST. Given that the F&R analysis determined the scale of the ENSO contribution to best fit the global temperature data, it will automatically take that into account.
  6. OK, I did a fit of the rest of the world data against global SST, Nino34, trend and intercept. Best lag was 5 weeks. Then I tried adding a quadratic term in Nino34 to the result. The best fit does indeed show non-linearity, although it's not huge. Here's the linear Nino34 (black), the quadratic term (green), and the total (blue). Stats as follows:
    Coefficients:
                   Estimate Std. Error t value Pr(>|t|)    
    (Intercept)  -5.4532649  0.3452066  -15.80  < 2e-16 ***
    sst$Year      0.0027364  0.0001733   15.79  < 2e-16 ***
    sst$Global    1.0384505  0.0133676   77.68  < 2e-16 ***
    sst$Nino34   -0.0590088  0.0013182  -44.76  < 2e-16 ***
    sst$Nino34sq  0.0052784  0.0008300    6.36 2.62e-10 ***
    However, the autocorrelation in the sst data is substantial. Using an AR(1) model on the model residuals, the number of data per degree of freedom is ~16. (The actual acf suggests it needs an AR(3) model though, so it's worse than that.) That means the std errors are underestimated by at least factor of 4. so the quadratic coefficient falls short of statistical significance. Also, I think the non-linearity is in the opposite direction to Bob's suggestion. It is making the index more positive (i.e. temperature projection more negative) during 1989 and 2000. I may have that backwards though. We can reduce the error bounds by improving the fit of the model - the obvious next step will be to throw in the SH SATO data - or by using a longer time series. However improving the error model would also be desirable.
  7. Bob Tisdale:
    Unless you can explain those divergences in the sea surface temperature anomalies of the Atlantic-Indian-West Pacific during the La Niña events of 1988/89 and 1998-2001, you cannot explain why surface temperatures warmed.
    Shifting burden of proof. You think the divergences matter, you support it with evidence. Re-stating your claim and re-linking to your graphs won't cut it.
    Are you aware that the global oceans can be divided into logical subsets which show the ocean heat content warmed naturally?
    No, they can't. Ocean heat has to come from somewhere. In order for the oceans to have warmed naturally, one would have to show that (a) the current physics of atmospheric greenhouse gases is wrong, and (b) some other, hitherto unknown, source of energy must be inputting enormous amounts of heat into the oceans. It just won't happen on its own, however many (or few) "logical subsets" you divide the global ocean into. It seems to me, Bob, that you are engaged in a fallacy of composition, a rather typical one observed among climate pseudoskeptics. The aggregate of global SST/OHC data will show different behaviour than any given single subset, with increased variance (noise) as you look at increasingly finer resolutions. That's why you need to look at global data to work out the global signal.
    What’s causing those divergences? Why do they only appear during those La Niña events? Again, unless you can explain those divergences, you cannot explain why the warming in that dataset occurred.
    Personally speaking, I don't know. I also don't care since these divergences do not appear to affect long-term global trends in SSTs or OHC. And, as I said (and you have no answer for, apparently), the divergences are only important if ENSO was the sole driver of SSTs. Bottom line is, it seems to me that your participation on this thread can be summed up as a series of logical fallacies: (1) Shifting burden of proof. You are the one who has identified what you suppose to be important divergences in SST behaviour from ENSO index. IMO it is up to you to show they are significant, and not up to others to show they aren't. (2) Fallacy of composition as described above. (3) Red herring (since all this talk of divergences & logical subsets appears to be an attempt to distract from the ongoing rise in SSTs and OHC). (4) Special pleading - "gatekeeping of science"?
  8. @ Bob Tisdale: Once again... Do you agree, or disagree with the following statement? “Naturally occurring climate variability due to phenomena such as El Niño and La Niña impact on temperatures and precipitation on a seasonal to annual scale. But they do not alter the underlying long-term trend of rising temperatures due to climate change as a result of human activities,” said WMO Secretary-General Michel Jarraud. Source:2012: Record Arctic Sea Ice Melt, Multiple Extremes and High Temperatures, WMO Press Release No 966, Nov 28, 2012
  9. Until now I've refrained from commenting on Bob Tisdale's stuff, because I assumed the reason I could see no relevance at all to global warming was my inadequate knowledge. But Bob's subsequent explanations still leave me baffled as to the relevance to global warming. Bob Tisdale, please respond simply and briefly to John Hartz's pointed question.
  10. I don't want to distract from John and Tom's question above, but I now have a full answer to the Figure 13 question. The bulk of the discrepancy between Nino34 arises from the use of a simple lag to shift the Nino34 index relative to the time series. If an exponential lag function (period=0.14y) is used rather than a simple time shift a much better fit is obtained. Adding in the SH SATO with an exponential lag (period=0.8y) mops up most of the rest of the difference between the two curves. Will post graphs and code tomorrow.
  11. Bob, I already said the issues you raised on the PDO index is a red herring, why are you repeating it again? If you really want to save me time, just quit stalling and repeating the same wrong argument the forth time (actually fifth when you post again). Is there an inter-decadal basin wide variability in the Pacific that can explain the lack of warming in the east? "for almost 4 years, I’ve been answering the same questions and responding to the same comments you’ve presented here. There’s nothing new about your questions and comments. Somewhere along the line, I’ve answered them, and for most of them, I can simply cut and paste a paragraph from my book." Then it shouldn't take you long to give satisfactory answers (i.e. with references to journal articles) to my questions? There is actually another question that is crucial to us answering your first question. As Tom noticed, the warming rate depends on the starting date. To make that more precise, I've taken the SSTA of the E Pacific (as you defined it) HADISST, and applied a 10 year low pass filter (this gives the same result as a 121 month running filter). Here's the plot. So here's the second question. Where is the evidence of a lack of warming in the east pacific ? It appears that your question is invalid in the first place. As soon as you give a satisfactory answer to these two, I'll be happy to move the discussion to your the second question.
  12. Progress. With ~407 words Bob answered "no" to the simple question "Is global warming real or not?"
  13. Bob Tisdale@103: Bob, one very simple question; Why haven't you had these revelations published in any reputable journal (ISI)? Really, if indeed this is all true--and I am NOT saying it is--then to pusblish this and quash this climate change "hoax" would make you one very rich and one very well-known person. I may have missed it but what is your CV, vis-a-vis climate scicnce?
    Response: [Sph] SkS regulars on this thread are skirting very close to the dog-piling restriction. Actually, IMO, it's been surpassed. There are now multiple cross-conversations going on. Will everyone please restrain from commenting unless you are already involved in a detailed discussion of the issues? You can hardly expect to get serious answers to questions and to keep the conversation focused when ten people are shouting a dozen questions apiece.
  14. Agreed, Sph: my apologies. I'll back down and listen!
  15. Moderator: What happened to page 3 of this thread? It existed this morning, my time. I only get pages 1 and 2 now. I left a comment at 21:56pm on 29 Nov 2012. How do I access comments higher than 100? Regards
  16. Bob @115, sometimes on SkS when you post on one page of the comments, and your post goes onto the next page, the pagination will not update. Simply click on "comments" in the blue bar at the top, and select the most recent comment in the topic you are interested in and the pagination will refresh.
  17. A recent Realclimate blog post discusses expected regional climate change. Deser finds that regional change over a 50 year period is larger than was expected. They show graphs of extreme temperatures over North America that are very striking. The hottest model run is much hotter than the coldest model run over 50 years. The global temperatures only vary slightly over the 50 year period, while regional temperatures vary a lot. This relates to Tisdale's claim that a small section (smaller than North America) of the Pacific basin is not warming as much as expected. It may just be due to chance. Comparing to the model average is incorrect. Tisdale must compare to the model extremes if he wants to claim that warming is anomalous. If he compares to the model range he will find the models predict the observed temperatures well. Or it may just be that the start date is cherry picked.
  18. Let me start at the bottom and work my way up: michael sweet says at 115: “This relates to Tisdale's claim that a small section (smaller than North America) of the Pacific basin is not warming as much as expected.” North America covers an area of about 24.7 million square kilometers. On the other hand, the East Pacific Ocean (90S-90N, 180-80W) covers about 119.2 million square kilometers. How is the East Pacific “smaller than North America”, michael? michael sweet says at 115: “Or it may just be that the start date is cherry picked.” The Reynolds OI.v2 sea surface temperature data starts at November 1981. There’s no cherry-picking involved on my part. Tom Curtis at 114: Thanks for your assistance. IanC says at 111: “I already said the issues you raised on the PDO index is a red herring, why are you repeating it again?” And I illustrated for you in the graph at comment 103 that there was no relationship between the PDO and the sea surface temperature anomalies of the East Pacific: http://i49.tinypic.com/slhb8y.jpg The PDO is the red herring. IanC says at 111: “There is actually another question that is crucial to us answering your first question. As Tom noticed, the warming rate depends on the starting date. To make that more precise, I've taken the SSTA of the E Pacific (as you defined it) HADISST, and applied a 10 year low pass filter (this gives the same result as a 121 month running filter). Here's the plot…” And here’s a comparison graph of the Reynolds OI.v2 data and the HADISST data for the East Pacific. They have the same linear trend: http://i47.tinypic.com/5b75dz.jpg IanC says at 111: “So here's the second question. Where is the evidence of a lack of warming in the east pacific ? It appears that your question is invalid in the first place.” The HADISST dataset, as illustrated above, has the same lack of warming over the past 30 years. The discussion is satellite-era sea surface temperatures. Why aren’t we looking at the sea surface temperature data prior to the satellite era? Because there’s little source data south of 30-45S. Here’s a map that illustrates the ICOADS sampling locations six months before the start of the Reynolds OI.v2 dataset: http://i47.tinypic.com/k2g6bs.jpg Same map for June 1975: http://i49.tinypic.com/73040z.jpg And it doesn’t get better as you go back in time. Here’s June 1943: http://i49.tinypic.com/2eb8sb8.jpg As I noted in my earlier reply to Tom Curtis… …why not simply remove the ENSO and volcano signals from the East Pacific data? The primary assumption behind Foster and Rahmstorf and Rahmstorf et al 2012 is that you can remove those signals to provide a better CO2-driven global warming signal. In fact, the East Pacific is the only sea surface temperature subset where you could hope to remove the ENSO signal without leaving significant ENSO residuals. You can’t remove the ENSO signal from the Rest-of-the-World data (90S-90N, 80W-180) without something very obvious occurring? Try it for both datasets, the East Pacific and the Rest-of-the-World. See how it changes your results and opinions. Kevin C says at 110: “Will post graphs and code tomorrow” Looking forward to it. Please provide lags for the AOD and NINO3.4 data in months and the scaling factors you determine. Thanks. Tom Dayton at 109 refers to Kevin C at 108. Kevin C says: “Do you agree, or disagree with the following statement?” Disagree. Composer99 at 107 says: “Shifting burden of proof.” I didn’t shift the burden of proof. That was one of my opening questions to you all. Well, that’s it for now. I’ll await Kevin C’s analysis on the Rest-of-the-World data.
    Response: [Sph] FYI, the reason the third page of comments temporarily disappeared, and the reason that your comment numbers no longer match the comments to which they refer, is that three comments were, for various reasons, deleted from the thread, so that for a short while there were less than 100 comments (3 pages worth) when there previously had been more. This will happen from time to time.
  19. Further to Sphaerica's inline moderator comment I shall end my contribution to this thread; I suspect it's played out.
  20. Bob, Seriously, do you see yourself being wrong on the issue? do you see a possibility that your analyses are wrong?
  21. @Bob Tisdale: Do you believe the following graph to be a valid representation of Jan-Oct global land & and surface temperature anomalies with respect to the 1961-1990 base period for calendar years 1950 through 2012? Image and video hosting by TinyPic Source: 2012: Record Arctic Sea Ice Melt, Multiple Extremes and High Temperatures, WMO Press Release No 966, Nov 28, 2012
  22. Bob, I was confused by your constant referring to the Nino3.4 and not the entire East Pacific. It is not clear to me what exactly you are claiming. My point is still valid, you must compare to the range of estimates, not the average. There is a lot of noise that you have to account for. A superficial examination indicates that random variation over the time period you specify could explain the entire difference. You must show that noise cannot account for your claims. Many other data sets exist that expand the time period of your analysis. It has been shown by others in this thread that you cherry picked the data set you used. You are responsible for finding the appropriate data. Limiting your choice to a short data set is cherry picking.
    Response: [Sph] Please back off of accusations of dishonesty (a violation of the comments policy) and stick to the science-based arguments. Future violations will be snipped as necessary.
  23. @Bob Tisdale: You have stated that you disagree with the following statement. “Naturally occurring climate variability due to phenomena such as El Niño and La Niña impact on temperatures and precipitation on a seasonal to annual scale. But they do not alter the underlying long-term trend of rising temperatures due to climate change as a result of human activities,” said WMO Secretary-General Michel Jarraud.* Please explain in one or two succinct paragraphs why you do not agree with the above statement. *Source: 2012: Record Arctic Sea Ice Melt, Multiple Extremes and High Temperatures, WMO Press Release No 966, Nov 28, 2012
  24. A note for clarity regarding ENSO measures: * The oft-referenced NINA3.4 is from the temperature of the central tropical Pacific, and is used (with a 3-month running average anomaly calculation) to define the Oceanic Niño Index (ONI). * The ONI closely tracks the Multivariate ENSO Index (MEI), computed from sea-level pressure, zonal and meridional components of the surface wind, sea surface temperature, surface air temperature, and total cloudiness fraction of the sky. This is a very comprehensive measure in terms of variables tracked. * The Southern Oscillation Index (SOI) is computed from air pressure differences between the NINO3.4 and Tahiti regions. It is rather noisier than and defined as reversed in sense (upside down graphically) from the MEI and ONI measures. All of these measures correspond well to one another - they are all measures of wind-driven heat distribution and resulting cloudiness effects. These are the defined and accepted indexes of ENSO variations. They also, with several month lags dependent on the dataset, have been shown to correspond extremely well with variations in global temperature anomalies, as in Foster & Rahmstorf 2011. [Lag time differences in that analysis are likely due to the differing spatial coverages of GISS, NCDC, HadCRU, and the satellite sets] --- Bob Tisdale - You have asserted (as far as I can see) that recent global warming is due to asymmetric effects between La Nina and El Nino. Several questions have been asked on this thread, which I don't believe have been addressed yet. I'll try here to pose them more clearly: * If as you say La Nina's absorb more heat (due perhaps to changes in cloudiness or other effects) than El Nino releases, how can this have driven warming since the 1970's? There has been a preponderance of El Nino events over that period (fewer than average La Nina events to raise total climate energy, esp. late 1970's-1998), and El Nino events release heat to the atmosphere (and hence to space). By your argument ocean heat content (OHC) should have dropped over that period as atmospheric temperatures rose - instead OHC has steadily risen over that time (down to 2000 meters). * Why now? What has changed? The ENSO has been an existent pattern for perhaps hundreds of thousands of years. Why would it suddenly change behavior in recent years, when it hasn't in the past? I will note that any hypothetic asymmetry between the two phases of the ENSO would simply be a forcing - if an ENSO asymmetry has existed for any significant period of time the climate would have long since come to equilibrium with that forcing. Only a recent change in ENSO behavior could force a change in temperature now. * Finally, what about the greenhouse effect? All atmospheric evidence, including top of atmosphere (TOA) changes such as those measured by Harries 2001 show greenhouse gas changes more than sufficient to account for observed warming without any ENSO influence other than short term variations. Without that GHG influence, any ENSO warming would soon vanish due to increased outgoing infrared radiation. The question here is given the observed and sufficient GHG forcing for warming, what place is there for additional ENSO warming?
  25. To the mods: The links below, "Atmoz compares SOI to temperature, comparing correlations" ...brings up a 404 error: is it me, or is the link broken? In addition the next one: "Debunking of McLean/Carter paper by Tamino" ...brings me a "not found" error on Tamino's blog. Thanks!

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