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Global warming and the El Niño Southern Oscillation

Posted on 29 July 2009 by John Cook

An old chestnut is climbing up the skeptic leaderboard: the El Niño Southern Oscillation. This is due to a new paper published in the Journal of Geophysical Research: Influence of the Southern Oscillation on tropospheric temperature (McLean 2009). What does the paper find? According to co-author Bob Carter, “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." In other words, they claim that any global warming over the past few decades can be explained by El Niño activity.

How do they arrive at this conclusion? They begin by comparing satellite measurements of tropospheric temperature to El Niño activity. Figure 1 plots a 12 month running average of Global Tropospheric Temperature Anomaly (GTTA, the light grey line) and the Southern Oscillation Index (SOI, the black line).


Figure 1: Twelve-month running means of SOI (dark line) and MSU GTTA (light line) for the period 1980 to 2006 with major periods of volcanic activity indicated (McLean 2009).

The Southern Oscillation Index shows no long term trend (hence the term Oscillation) while the temperature record shows a long term warming trend. Consequently, they find only a weak correlation between temperature and SOI. Next, they compare derivative values of SOI and GTTA. This is done by subtracting the 12 month running average from the same average 1 year later. They do this to "remove the noise" from the data. They fail to mention it also removes any linear trend, which is obvious from just a few steps of basic arithmetic. It is also visually apparent when comparing the SOI derivative to the GTTA derivative in Figure 2:


Figure 2: Derivatives of SOI (dark line) and MSU GTTA (light line) for the period 1981–2007 after removing periods of volcanic influence (McLean 2009).

The linear warming trend has been removed from the temperature record, resulting in a close correlation between the filtered temperature and SOI. The implications from this analysis should be readily apparent. El Niño has a strong short term effect on global temperature but cannot explain the long term trend. In fact, this is a point made repeatedly on this website (eg - here and here).

This view is confirmed in other analyses. Hoerling 2008 examines the temperature record from 1880 to 2007 and finds internal variability such as El Nino has relatively small impact on the long term trend. Instead, they find long term trends in sea surface temperatures are driven predominantly by the planet's energy imbalance.

There have been various attempts to filter out the ENSO signal from the temperature record. We've examined one such paper by Fawcett 2007 when addressing the global warming stopped in 1998 argument. Similarly, Thompson 2008 filters out the ENSO signal from the temperature record. What remains is a warming trend with less variability:


Figure 3: Surface air temperature records with ENSO signal removed. HadCRUT corrections by Thompson 2008, GISTEMP corrections by Real Climate.

Ultimately, all the data analysis shouldn't distract us from the physical reality of what is happening to our climate. Over the past 4 decades, oceans all over the globe have been accumulating heat (Levitus 2008). The El Niño Southern Oscillation is an internal phenomenon where heat is exchanged between the atmosphere and ocean and cannot explain an overall buildup of global ocean heat. This points to an energy imbalance responsible for the long term trend (Wong 2005).


Figure 4: Global ocean heat from 1970 to 2008. Dark blue line is yearly ocean heat content for the 0–700 m layer. Light blue line is linear trend (Levitus 2008).

Data analysis, physical observations and basic arithmetic all show ENSO cannot explain the long term warming trend over the past few decades. Hence the irony in Bob Carter's conclusion "The close relationship between ENSO and global temperature leaves little room for any warming driven by human carbon dioxide emissions". What his paper actually proves is once you remove any long term warming trend from the temperature record, it leaves little room for any warming.


UPDATE 7 August 2009: A comment has been submitted to the Journal of Geophysical Research: Comment on “Influence of the Southern Oscillation on tropospheric temperature” by J. D. McLean, C. R. de Freitas, and R. M. Carter (Foster et al 2009). An excerpt from the abstract:

This comment first briefly reviews what is understood about the influence of ENSO on global temperatures, then goes on to show that the analysis of MFC09 severely overestimates the correlation between temperature anomalies and the SOI by inflating the power in the 2–6 year time window while filtering out variability on longer and shorter time scales. It is only because of this faulty analysis that they are able to claim such extremely high correlations. The suggestion in their conclusions that ENSO may be a major contributor to recent trends in global temperature is not supported by their analysis or any physical theory presented in that paper, especially as the analysis method itself eliminates the influence of trends on the purported correlations.

They talk about the 24 hour news cycle. Considering the speediness of the response, I wonder if we're heading towards a 24 hour science cycle.

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Comments 1 to 50 out of 71:

  1. Thanks. As usual you have presented the material with both clarity and brevity.
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  2. Am I correct in saying that if there really is a close relationship between ENSO and earth T since the 1950s/1980s, you are saying it doesn't say anything about the longer term temperature rise, along with the build up of ocean heat over the longer term?
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  3. Actually, Thingadonta, I think what John is saying is that McLean et al are incorrectly concluding that short term relationships between SOI and T mean there is no other cause for the long term warming trend. He's also saying that the relationship between ENSO and Temperature is NOT close unless you remove the long term trend in T.
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  4. Eyeballing the SOI graph some things appear to me:
    1. There is an apparent(slight - maybe my eyes!) downward trend and
    2. The bandwidth of the oscillation has declined, particularly since 1998.
    3. One would expect the lag between the graphs to be reasonably consistent, ( volcanic activity excepted)yet GTTI begins to decline in 2003 before SOI has peaked.

    Also that GHC trend is a bit misleading. It's a big figure but in context equates to around 0.05C/annum if we assume it is restricted to the top 1000m of the oceans.
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  5. The link to the Wong 2005 paper does not work, can it be fixed, or the complete reference shown?
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    Response: Fixed, thanks for the tip.
  6. The ENSO component of warming between 1976 and 1998 has 2 components. The climate shifts (e.g. Swanson and Tsonis) in 1976/1977 and 2001/2002.

    The other contribution atmospheric heat is ENSO decadal variation. Cool La Nina to the mid 1970's, warm El Nino to 1998, cool La Nina since.

    http://www.cdc.noaa .gov/people/klaus.wolter/MEI/
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  7. As an aside:

    Here is a link to the idea that warming produces less low level clouds, thereby further enhancing any warming (like any sunny day once the low clouds are 'burned' off).

    It's just common sense, especially over surface temperate zones, where most 20th century warming has occured. It will magnify any warming trend, regardless of cause (solar or greenhouse gas).

    http://www.guardian.co.uk/environment/2009/jul/23/cloud-cover-oceans-global-warming.

    Unfortunately, the article doesn't link the actual paper.

    Its interesting though how they get it wrong, the article concludes less low level clouds means that clouds won't reduce greenhouse gas warming, when its warming that is reducing low level cloud cover.

    Love those 17th century cloudy, Little Ice Age, European paintings!

    (I seem to rememer that El Nino 1998 was a low loud year?).
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  8. "I seem to rememer that El Nino 1998 was a low loud year" unlike 2009 which seems to be a high loud year for denialists.

    Pearls before swine, John Cook, pearls before swine.
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  9. A better link on changes in low cloud cover.

    http://www.sciencedaily.com/releases/2009/07/090723141812.htm
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  10. How did this paper get published, if it is clearly distorting the truth, or is it a case of the actual paper being factual, and then the authors subsequent comments jumping to unjustified conclusions?
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  11. It's the latter canbanjo. The paper is a run of the mill restatement of the well understood fact that the year on year variability in the global surface temperature is dominated by ENSO (warmer in/shortly after El Nino years; coooler in/after La Nina's)....volcanoes also have a strong effect on variability without having much effect on the long term trend.

    Incidentally, the same applies to the year on year variability in atmospheric CO2 levels which is also dominated by El Nino/La Nina, despite the latter having essentially no effect on the long term trend .

    So the paper very clearly has nothing whatsoever to say about the long term warming trend since 1958. In fact (as John Cook describes very cogently) the method of analysis eliminates this trend.

    The problem is that at least one of the authors has chosen to misrepresent their own paper, for reasons which are all too apparent. It's the latter that is appalling rubbish. One can see how easy it might be to give the impression that a dominant contribution of ENSO to temperature variability is misconstrued to imply a dominant contribution to the long term change in temperature. Normally scientists are extremely careful to ensure that they are clear about what their work actually means. Something is clearly awry in the scientific integrity of at least one of the authors of that paper....the only other interpretation is that this author is simply ignorant of the methodologies, consequences and interpretions of a paper to which he has put his name...

    Incidentally, one might argue that the overall atmospheric/ocean circulation/interactions, of which ENSO is a part, do influence the rate at which heat accumulates in the oceans as a result of radiative imbalance, since presumably ENSO phenomena are part of the "mechanisms" by which excess heat is distributed through the oceans. Thus the more effective the mixing of surface and deeper waters the more quickly the oceans as a whole, will come towards eqilibrium with any radiative imbalance. Thus all circulation processes per se might be expected to slow the rate of warming as experienced at the surface (our land/ocean surface temperature anomalies as compiled by NASA Giss/Hadley/NOAA), since heat that accumulates in the upper ocean layers is more efficiently moved from the surface to the deeper layers, and thus makes less of a contribution to the temperature that we "surface dwellers" experience. The overall equilibrium temperature under the influence of a particular radiative imbalance will, however, be independent of this. That's how I think of this anyway!

    However this latter issue is not a part of the paper under discussion; these phenomena (ocean mixing and ocean/surface/atmosphere heat transfer) are included in Global Circulation Models....
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  12. It is also a case of whether or not one uses unadjusted satellite trophosphere data, or 'flawed' surface data.?
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    Response: The UAH temperature record is adjusted for diurnal drift as is the RSS satellite record. In fact, the main reason for the difference between the two records is how they adjust the data - UAH imposes a cooling effect while RSS imposes a warming effect.
  13. We have discussed this already in a surface temp related post quite some time ago. Considering the stratospheric influence on satellite measurements, unadjusted data is of little usefulness.

    These papers probably had some subsequent research but they are a good way to start.

    http://www.ncdc.noaa.gov/oa/climate/research/rss-msu.pdf
    http://climate.envsci.rutgers.edu/pdf/VinnikovGrody2003.pdf
    Revised 2005 version:
    http://climate.envsci.rutgers.edu/pdf/TrendsJGRrevised3InPress.pdf

    Vinnikov and Grody disagree that trying to remove the stratospheric influence, which is what Fu did, is a better idea than their treatment.
    http://www.ncdc.noaa.gov/oa/climate/research/nature02524-UW-MSU.pdf

    Overall the surface temperature records for both GISS and HadCRUT agree very well with the satellites. Tamino has shown that already:
    http://tamino.files.wordpress.com/2007/08/global2.jpg

    In addition, it is not obvious at all that satellite measurement are overall more accurate than surface.

    There was some disagreement with some balloon data, which was then examined more closely and shown to be defective due to similar diurnal problems as the satellite data:
    http://www.sciencemag.org/cgi/content/short/309/5740/1556

    Watts has now "surveyed" enough surface stations to do a good preliminary analysis. Strangely enough, no data analysis has yet been done on his web site but NCDC did one, which confirms what John V had already shown at the beginning.

    http://www.ncdc.noaa.gov/oa/about/response-v2.pdf

    Data analysis does not show microsite effect to introduce any significant bias.

    UHI has been closely examined before:
    http://www.ncdc.noaa.gov/oa/climate/research/population/article2abstract.pdf
    http://www.ncdc.noaa.gov/oa/climate/research/population/article3abstract.pdf

    Nonetheless, GISS corrects for UHI.

    Sorry for the OT John.
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  14. Thanks Chris, I sent an e-mail to Bob Carter to get his side of the story, he responded as follows (the websites he refers to are this one and realclimate):

    Dear canbanjo,

    Thank you for your interest in our paper.

    There is little point in my responding to ridicule when that ridicule is based upon wilful misunderstanding of the science in question.

    Unfortunately neither of the web sites that you mention provide dispassionate scientific analysis of the AGW issue, and they are therefore not sites that I spend time reading. For their authors are primarily committed to defending against all comers the IPCC's hypothesis of dangerous human-caused warming, rather than testing it independently.

    The McLean et al. paper supports earlier understanding of the effects of ENSO and volcanic eruptions on the climate system, and shows that much of the variance in the global temperature record can be explained by changes in ENSO 7 months prior. That fact leaves no room for a major influence from human carbon dioxide emissions, and cannot simply be shrugged of.

    The paper does not address trends as such (which Real Climate and similar websites often appear to be obsessed by).

    I attach a leaflet which contains some recommended websites and other sources of information on AGW that are of higher quality, and exhibit better scientific balance, than the two that you are currently relying upon.

    Thanks again for writing.

    With kind regards.


    Bob Carter

    Professor R.M. Carter
    Marine Geophysical Laboratory
    James Cook University
    Townsville, Qld. 4811
    AUSTRALIA

    Phone: +61-7-4781-4397
    Fax: +61-7-4781-4334
    Home: +61-7-4775-1268
    Mobile: 0419-701-139
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    Response: Thanks for posting the response from Bob Carter. I'd read some comments from Phil deFreitas which seemed to be backpedalling somewhat - saying that the paper proved El Nino caused short term variations but not the long term trend. So I worried I may be misrepresenting their position, setting up a strawman argument. But Bob Carter is definitely still sticking to the story that El Nino causes long term trends.
  15. I love "The paper does not address trends as such (which Real Climate and similar websites often appear to be obsessed by)." Who would have thought?
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  16. All 8 pages instead of the Abtract in John's Link:

    Influence of the Southern Oscillation on tropospheric temperature
    J. D. McLean,1 C. R. de Freitas,2 and R. M. Carter3
    Received 16 December 2008; revised 23 March 2009; accepted 14 May 2009; published 23 July 2009.

    http://climatedebatedaily.com/southern_oscillation.pdf
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  17. John,
    Bob does say his paper 'does not address trends as such'. So his statements seem rather contradictory. I have asked him to clarify, no response yet.
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  18. Small point: Phil de Freitas = English cricketer of yesteryear. Chris de Freitas = Auckland University academic with a penchant for climate denial...
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    Response: Damn, this is what happens when I stay up late watching the Ashes.
  19. The SOI does show 20 to 30 year cycles. A shift from a negative bias to the 1970's to a positive bias to the late 1990's - in a decadal timescale this is a trend.

    It must have this pattern as a result of the "Great Pacific Climate Shift of 1976/1977". More and bigger El Nino since the mid 1970's than before as a consequence of 'chaotic dynamical climate shifts'.
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  20. Robbo
    I think the AGW skeptics suggest that the shift in the PDO to a warm cycle from the late 1970s enhances the 'warming trend' from the 1980s-1990s and the associated El Ninos in this period, although if there is little/no influence from greenhouse gases during these decades one would also expect a similar drop in T and stronger El Ninas once the PDO shifts back to negative, from ~the early 2000s.

    In other words, the main problem with the Mclean (2009) paper remains, the longer term warming (recently flattening) trend, regardless of what the PDO or El Ninos are doing in the short term.

    At any rate, if the 'PDO shift' idea is anyway influential on earth T, the warming from C02 since the 1970s may have been over-estimated from the AGW camp, as one would expect both 1) stronger El Ninos in the 1980s-1990s(as you mention) and 2)the warm PDO cycle, BOTH to be superimposed on the longer term warming trend, to together produce a more strongly enhanced warming from the late 1970s-1990s. The flat T trend since the early 2000s supports this angle (with the shift back to a cooler PDO), although T should really be dropping further-back to 1970s temperatures-if greenhouse gases aren't really doing anything, and the question remains as to why the longer term warming trend appears to continue. (Notwithstanding a possible heat lag from peak solar activity in the mid-late 20th century, and Hansen's 2005 probably miscalculated/ misinterpreted 'disequilibrium'-already being dicredited since T isn't rising since the early 2000s, despite his predictions when he released the 2005 paper), albeit since the early 2000s at a flattened rate than the AGW proponents have argued.

    The AGW are now claiming 'internal variability' for the pause in warming since the early 2000s (eg from PDOs, ocean absorption etc), but they cant have it both ways (internal variability/negative feebdbacks now, but not positive feedback/enhancements in the period 1970s-1990s), therefore it is indeed likely c02/greehouse gas influence has been over-estimated for the period 1970s-1990s, which started the whole AGW thing off in the first place. In 2011 when the IPCC once again reports, they will have to scale back their T forecasts, if they are to be consistent methinks.
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  21. Thinga,

    I was taking issue with the point that John Cook made of the SOI not having a trend. It does. More positive in the mid 1940's to the mid 1970's and more negative to the late 1990's. This is simply a refection of the state of the Pacific Ocean. More frequent La Nina and a negative PDO followed by more frequent El Nino and a positive PDO. The 20 to 30 cycles are real oceanographic and atmospheric phenomenon. The point is how to assess that statistically (or theoretically)- and no simple approach springs to mind. I would suggest that integrating changes in shortwave forcing – see below – in the models is the next cab off the rank.

    McLean et al are explicit in the discussion on decadal climate shifts – particularly the “Great Pacific Climate Shift” of 1976/1977 and it is far from being McLean et al on their lonesome. It is disappointing that this discussion keeps occurring at all – it is not as if there is not a huge literature on this. Indeed the global whiners were quick to claim the climate shift as a symptom of global warming – before it turned around. Now they can’t back flip fast enough.

    The McLean et al paper takes the first derivative of the time series to filter out chaotic noise. While the method can't say how ENSO contributed to trend - the variation is almost all ENSO - 70 to 80% with a seven month lag behind the SOI. A nice little scientific result. It quantitatively shows that ENSO is by far the biggest influence on global surface temps - so you would expect a period of more intense and frequent El Nino (from 1976 to 1998) to boost surface temps. If that is not proven beyond doubt yet - it is a fairly solid hypothesis and made much more so by the quantified McLean et al results.

    It throws another interesting sidelight on the GCM. What the climate modelers do is take the bottom of the 1976 La Nina and the top of the 1998 El Nino and call that the recent trend in warming due to greenhouse gases - totally bogus cherry picking.

    If you exclude 1976 and 1998 - after Swanson and Tsonis- the trend from all other factors is about 0.1 degree C/decade. If you take the long term trend from 1850 – it is about 0.1 degrees per decade. If you take the 1946 to 1998 period the trend is about 0.08 degrees C/decade. Any of these is a reasonable estimate of background warming from all other factors. The current IPCC expectation of 0.2 degree C/decade in the next few decades is obviously not presently being met.

    On positive AGW feedback, indeed there is a very recent paper by Clement, Burgman and Norris - Observational and Model Evidence for Positive Low-level Cloud feedback which shows an interesting connection between multidecadal cloud changes and decadal changes in ocean indices. It posits a positive global warming feedback between the mid 1970's and the late 1990's from reduced cloud cover. i.e it wasn't greenhouse gases but feedback involving increased shortwave forcing. Trenberth and Fasula 2009, Palle and Goode 2009 - essentially say that clouds were involved (and I have referenced both of these previously) - and suggest that we need to get on top of the cloud variable. As long as Earth albedo persists at the current level – the planet will have about 2 W/m2 less shortwave at the surface than in the late 1990’s – see Project Earthshine – a cooling influence.

    I believe that the decadal changes in global ocean indices are driven by changes in clouds. The $64 dollar question is what drives decadal changes in clouds?

    On a final note - I was expecting the IPCC to moderate their projections in 2007 – so don't hold your breath Although with people like Swanson and Tsonis and Trenberth and Fasulu reassessing their position – there may be hope yet.


    Cheers
    Robbo
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  22. RE 21: Robbo.
    Yes to most of the above.
    cheers.
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  23. Haven't real climate scientists already hashed this out already?
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  24. One "minor" problem with all this - the correct figure is that ENSO accounts for only 3.6% of the variation, not the 70% claimed by McLean et al.

    See http://tamino.wordpress.com for the correct way to calculate the correlation between the SOI and the tropospheric temp anomaly.
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  25. Real climate scientists have settled this.

    http://www.aoml.noaa.gov/phod/d2m_shift/index.php

    Althugh I don't think it's that recent. Hydrologists and Oceanogaphers have been have been working on this for decades.

    And haven't we got over the comparison of peer reviewed science with an anonymous blogger?

    Cheers
    Robbo
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  26. And as usual, your post doesn't address the issue. Can you do anything other than put a few keywords into google and copy and paste stuff here?
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  27. McLean et al discuss, inter alia, innterannual to multi-decadal ENSO variation - as was I?

    The NOAA web page is a respectable link for the multidecadal ocean SST and pressure cycles - which are globally distributed.
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  28. And yet you still say nothing of consequence. You don't "discuss" anything. You provide a link to something that is only tangentially related to the McLean et al paper. You don't comment on the serious and obvious errors in the paper. You quote numbers from the paper that are wrong ("70-80% of the variation"). You ignore the calculations that show that the true figure is around 3.6%, and you just keep ranting.

    Also, calling the McLean paper "peer reviewed" and "science" is seriously stretching the definition of both terms.

    This is not as complicated as you seem to want it to be. ENSO moves heat around. It doesn't produce or absorb heat. So it cannot be responsible for the increasing heat content of the earth.
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  29. Gareth, over at Hot Topic, has linked to an abstract submitted to JGR as a rebuttal to the paper. It is authored by 9 of the biggest names in climate science.

    http://hot-topic.co.nz/big-guns-brought-to-bear/
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  30. The formal refutation linked by Ian is likely to cover the obvious errors we've seen here and elsewhere, and perhaps a few more. The paper's propaganda value (providing largely faux cover for Bob Carter's public statements) should live on for awhile. I see several now obsolete "skeptical" papers that still float around political circles and the blogosphere.
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  31. Here is the full refutation:

    Comment on “Influence of the Southern Oscillation on tropospheric temperature” by J. D. McLean, C. R. de Freitas, and R. M. Carter (Foster et al 2009)
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    Response: Thanks for the URL, all the references I saw to Foster's refutation included no link so good to finally read it. BTW, surely this puts to rest any question that Tamino is Grant Foster, right? :-)
  32. Ah yes, but is Grant Foster Tamino?
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  33. Yet still you persist in ignoring multi-decadal cycles of ocean temperature and the impact on global T that I have more than adequately referenced.

    Some of these multi-decadal influences are defined in An Additional Physical Mechanism for Global Warming Between 1976 and 1998 at:

    www.earthaondocean.robertellison.com.au

    There is an extensive science of multi-decadal variation - with at least three new papers just last month. Swanson and Tsonis on realclimate on the 12th of July, Clements et al on clouds and 'positive feedback' and McLean et al.

    This is a site that trumpets peer reviewed science - let's see the money and not just smart arse comment.
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  34. Robbo is clearly simply going to keep on quoting McLean et al as the last word in climate science, in spite of all the analyses of it, and comments by McLean himself and Carter, showing that it means nothing like what Carter originally claimed. Robbo is clearly able to forget nothing and learn nothing.

    There is a great deal of discussion on the Swanson paper on RC, did Robbo read none of it, understand none of it? The clouds issue is a dead end, everybody, except Robbo, knows that, and yet he persists. Variation in climate is a dead end. Everybody knows there is variation, and cycling, of various kinds. It creates the variation around the mean RISING world temperature levels. So what?

    The phrase flogging a dead horse comes to mind. Except in the case of Robbo and Thingadonta on this thread it is more like flogging a dead horse skeleton most of the bones of which have long since decayed and returned to the soil.
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  35. I'm starting to think Robbo and thingadonta are actually perl scripts implementing Markov chain models of English. The scripts produce plausible seeming sentences with the right keywords, but the actual information content is, well, pretty small.

    Another analogy would be that I could teach my dog to bark whenever I say "stochastic dynamic programming" but I don't really think she's got a lot of useful stuff to say about optimisation techniques.

    She's more of an abstract algebra sort of dog really :)
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  36. The expectation as a result of 50 year climate cycles is for a cooling influence for 20 to 30 years from 1998. This is happening in the real world with no increase in surface temp. for a decade and no increase in ocean heat content since 2003.

    The reason why clouds are increasingly relevant is that actual real world evience shows a decrease in shortwave flux at the surface since 1998 of 2W/m2.

    More science...from IPCC contributors...

    'Global warming due to increasing absorbed solar radiation

    Kevin E. Trenberth

    National Center for Atmospheric Research, Boulder, Colorado, USA

    John T. Fasullo

    National Center for Atmospheric Research, Boulder, Colorado, USA

    Global climate models used in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) are examined for the top‐of‐atmosphere radiation changes as carbon dioxide and other greenhouse gases build up from 1950 to 2100. There is an increase in net radiation absorbed, but not in ways commonly assumed. While there is a large increase in the greenhouse effect from increasing greenhouse gases and water vapor (as a feedback), this is offset to a large degree by a decreasing greenhouse effect from reducing cloud cover and increasing radiative emissions from higher temperatures. Instead the main warming from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts. These findings underscore the need to ascertain the credibility of the model changes, especially insofar as changes in clouds are concerned.'

    As for not understansing Swanson and Tsonis. Well - ‘the nature of these past shifts in climate state suggests the possibility of near constant temperature lasting a decade or more into the future must at least be entertained. The apparent lack of a proximate cause behind the halt in warming post 2001/02 challenges our understanding of the climate system, specifically the physical reasoning and causal links between longer time-scale modes of internal climate variability and the impact of such modes upon global temperature.’
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  37. re: 36
    You're still displaying no understanding. Just quoting a couple of passages is not contributing anything to a discussion. Swanson and Tsonis's comments are speculation, not evidence - but you don't seem to understand the difference.

    The first line in post 36 is "The expectation as a result of 50 year climate cycles is for a cooling influence for 20 to 30 years from 1998". This is stated as if it were a fact. It is not. It is speculation based on poor understanding.

    Do you even realise that, for example, the Pacific Decadal oscillation is *just* the 3rd EOF of SST Anomalies in the pacific? It is not *known* to relate to any physical (atmosphere/ocean) phenomenon - it could just be an artifact of the short period of statistics available. It's at best a minor influence. Especially since it shows no trend.

    You posts are just a version of the Gish Gallop... ignore the evidence, repeat the same demonstrably wrong statements over and over, and toss in largely irrelevant references to make it sound as if you have a clue. Boring.
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  38. Swanson and Tsonis are talking about globally synchonous ocean states that precipitated climate shifts early around 1910, the mid 1940's, the mid 1970's and post 1998. These climate shifts are not speculative but appear in the climate record in both surface temperature and SST records.

    They identify a climate shift post 1998 – and speculate that the current lack of global warming could last for another decade or more. The future is always speculative – but my expectation is based on ‘the nature of these past shifts in climate.’ There has been no warming for 10 years without an explanation other than vague notions of internal climate variability. What is the next reality test? The West Australian Department of Agriculture and Food as of July 2009 expect:

    ‘A HIGH CHANCE THAT A WEAK EL NINO WILL CONTINUE TO FORM, BUT A LAGGING SOUTHERN OSCILLATION LEAVES THE DOOR OPEN FOR POSITIVE NEUTRAL .’

    http://www.agric.wa.gov.au/objtwr/imported_assets/content/lwe/cli/enso_20090710.pdf

    It seems unlikely that the 1998 (monthly) surface temp record will be challenged this year.

    Not sure where the PDO comes in - but it has a physical meaning. The cool mode is associated with upwelling of cold deep ocean currents. Upwelling is suppressed in a warm mode. It makes a huge difference in biological productivity in the north eastern Pacific.

    “The PDO was named by Mantua et al (1997), who demonstrated a connection between salmon abundance and sea surface temperatures in the northern Pacific. Sea surface temperature varied over 20 to 30 year cycles in phase with changes in salmon abundance. Sea surface temperatures were cooler than average for 20 to 30 years – a cool mode of the PDO, and then warmer than average over 20 to 30 years, a warm mode. A warm mode PDO is associated with reduced abundance of coho and chinook salmon in the Pacific Northwest, while a cool mode PDO is linked to above average abundance of these fish. The biology responds to cold but nutrient rich sub surface water upwelling in the north eastern Pacific. The abundance of salmon was greatest in the period between the mid 1940’s and mid 1970’s, least in the period 1976 to 1998 and has, in recent years, rebounded to values not seen since the 1970s (Joint Institute for the Study of the Atmosphere and Ocean (JISAO) - Climate Impacts Group).”

    There is also a connection to ENSO. Verdon and Franks (2006) used ‘proxy climate records derived from paleoclimate data’ to investigate the long-term behaviour of the PDO and ENSO. They found that ‘during the past 400 years, climate shifts associated with changes in the PDO are shown to have occurred with a similar frequency to those documented in the 20th Century. Importantly, phase changes in the PDO have a propensity to coincide with changes in the relative frequency of ENSO events, where the positive phase of the PDO is associated with an enhanced frequency of El Niño events, while the negative phase is shown to be more favourable for the development of La Niña events.’

    Verdon, D. and Franks, S. (2006), Long-term behaviour of ENSO: Interactions with the PDO over the past 400 years inferred from paleoclimate records, Geophysical Research Letters 33: 10.1029/2005GL025052.

    It is this latter propensity that McLean et al discuss – the shift in the Pacific from more frequent and intense La Niña to more frequent and intense El Niño in the 1976/1977 climate shift with an obvious potential to impact on surface temperature.

    The globally linked ocean processes – which include the PDO and ENSO - are the primary manifestation of the climate shifts that Swanson and Tsonis discuss.
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  39. You do understand that even if S&T are right about the "shifts", they are talking about shifts ever upwards- that is a series f transitions to ever higher temperatures, don't you? These are not "oscillations", these are just jumps rather than a relatively smooth rising temperature line. So no consolation in your denialism to be found there. Nor in McLean and all, who are just talking about variation around a rising mean as well. I'm guessing you have neither read, nor thought about, any of his stuff.
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  40. The climate shifts are from one ocean state to another over a year or three and back again over 50 years. The states amplify global warming in the warm state and mask global warming in the cool state. It is a cyclic state of sea surface temperature in the world's oceans that influences global surface temp rather than an oscillation in atmospheric temp. The states seem to be associated with changes in cloud cover.

    Let's accept for the time being that Swanson and Tsonis are correct in assuming that this is 'warming interupted'- 2 or 3 decades of no warming from 1998 - rather than planetary cooling. Swanson and Tsonsis in the graph at realclimate exclude the years of climate shift (1977 and 1998) from the recent trend to get a trend due to greenhouse gases and other factors. You get the same answer if the residual trend is considered for a full cycle between 1946 and 1998 - or even a longer time frame back to 1850.

    The residual trend for all other factors is 1/2 of that commonly quoted. Seen in the context of prudent foresight - the issue is merely less urgent and more amenable to technological solutions. I have no particular urge to continue the ocean and atmosphere experiment past the middle of the century at most. 100% decarbonisation by 2050 is, I feel, achievable. My 'ideological bias' is in not believing that government intervention will achieve any sigificant gains and do so at great cost in human life and to the legitimate aspirations of the world's poor. This is, I believe, a measured and reasonable bias.

    Not sure what the McLean et al reference is about. Bob Carter sent me a copy of their latest paper. I have discussed the paper with John McLean by email (who has pedantically corrected my interpretation)and used their Figure 4 in an upcoming non-peer reviewed article for the dreaded Energy and Environment.

    All that is being claimed is that ENSO has a huge impact on global temperature variation. Fairly obvious but nice to be able to put a number to it. They are not saying anything about a rising trend other than in comment that 'perhaps' ENSO conditons post the 1976/1977 climate shift contributed to recent warming.

    I suspect you might mean Lean et al from the British Met Office? Who expect that that solar irradiance will reassert itself at the peak in the next 11 year solar cycle and record surface temps will again occur by 2014? This assumes that solar irradiance is not trending rapidly down from a thousand year high - to a Dalton or perhaps even Maunder Minimum. And I wonder what implications there are for temps later in the 11 year cycle?
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  41. The main thing about the PDO, if it exists, is that the global warming from 1978-1998 appears to have been enhanced by the shift to a warm PDO, (but yes, the longer term T trend is still up). The shift back to flat T from 1998 would support this.

    But it also means, and this is the point, that the effects of greenhouse gases on T were super-imposed on the warm PDO from 1978-1998, which would mean they have been over-estimated in models, and it is therefore likely if the PDO is significant, and barring other factors (which are also by no means clear) to be at the lower end of model predictions-say 1 degree C by 2100 (and this is without taking into account any effects from solar changes).

    The complete failure of the IPCC models to predict the flat T since early 2000s, and also the ocean flat T/cooling, shows that the c02 models have not taken into account these probably true PDO shifts, and have over-estimated the effects of c02 in the period 1978-1998.
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  42. We should not get carried away with the PDO as a cause of everything. It exists and is stongly evident in the instrumental, proxy and biological record.

    However, a link to changes in cloud cover is suspected - see Amy Clement et al below. The reconstruction of cloud and SLP parameters show the usual decadal pattern. And although the modeling exercise suggests the decline in clouds between 1976 and 1998 is a greenhouse gas feedback - only one model passed the cloud test and the turn around in clouds since 1998 suggests something else. The real question is whether clouds are a cause or an effect. I find it difficult to believe that it is not driven by ionising radiation in the Hale cycle - especially because of the sudden shifts between ocean states - but we shall see.

    There is a balance between turbulent subsurface currents (driven by planetary rotation and thermohaline circulation)and suppression of these currents under a warm surface layer. A little more cloud with a little less shortwave heating of the ocean and the currents upwell strongly in the north east Pacific. A little less cloud and the currents are suppressed. Thus the PDO may be a local manifestation of a global phenomenon - and not terribly important in itself. It is important biologically and as an indication of the persistance of global ocean states.


    Science 24 July 2009:
    Vol. 325. no. 5939, pp. 460 - 464
    DOI: 10.1126/science.1171255

    Observational and Model Evidence for Positive Low-Level Cloud Feedback
    Amy C. Clement,1,* Robert Burgman,1 Joel R. Norris2

    Feedbacks involving low-level clouds remain a primary cause of uncertainty in global climate model projections. This issue was addressed by examining changes in low-level clouds over the Northeast Pacific in observations and climate models. Decadal fluctuations were identified in multiple, independent cloud data sets, and changes in cloud cover appeared to be linked to changes in both local temperature structure and large-scale circulation. This observational analysis further indicated that clouds act as a positive feedback in this region on decadal time scales. The observed relationships between cloud cover and regional meteorological conditions provide a more complete way of testing the realism of the cloud simulation in current-generation climate models. The only model that passed this test simulated a reduction in cloud cover over much of the Pacific when greenhouse gases were increased, providing modeling evidence for a positive low-level cloud feedback.
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  43. "All that is being claimed is that ENSO has a huge impact on global temperature variation. Fairly obvious but nice to be able to put a number to it. They are not saying anything about a rising trend other than in comment that 'perhaps' ENSO conditons post the 1976/1977 climate shift contributed to recent warming."

    Except that the number they put to it is wrong. And for them to make *any* statement about the trend is also wrong as their analysis removed any possible connection with trend.

    Your statement "The climate shifts are from one ocean state to another over a year or three and back again over 50 years" is also provably wrong. You really do just make stuff up don't you?

    Also, no trend in the PDO means it can't have contributed to the trend in observed temps. Still not getting it, are you...
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  44. "The apparent lack of a proximate cause behind the halt in warming post 2001/02 challenges our understanding of the climate system..."

    "There has been no warming for 10 years without an explanation other than vague notions of internal climate variability."

    Maybe my previous speculations on this have been dismissed by you because, as I'm not a scientist, you're simply ignoring what strikes me as a self-evident cause of post 1998 cooling; that surrounding a peak year such as 1998 there was a tremendous amount (how many cubic miles again?) of land ice melting and running off into the oceans.

    Again, as a non-scientist I don't have the detailed numbers and formulas at my disposal to sound like anything but a layman, but still, physics 101 tells me that that much stored cold being released in the form of ice water runoff into the oceans would have to qualify as a "proximate cause behind the halt in warming post 2001/02" and/or an "explanation other than vague notions of internal climate variability."

    How could that many cubic miles of ice water entering the oceans not have a cooling effect on post 1998 climate? It strikes this non-scientist as a particularly obvious cause of post peak temperature drops every time the temperature has peaked this century.
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  45. The first statement above is a quote from Swanson and Tsonis. The second statement is mine - and it echoes a widely expressed sentiment expressed by reasonably non partisan observers.

    Your point seems an entirely reasonable proposition but it is not something that I would claim any depth of knowledge in.

    There is another line of evidence - if you have a look at the Project Earthshine site you will find a graph showing Earth albedo increased by about 1% since 1998 - or about 2 W/m2 of decreased radiative flux at the surface. This is enough in itself to explain the a current lack of warming.
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  46. With a net radiative imbalance of 2 W/m2 - the Earh energy content should have increased by 16 x 10e22 J for 2003 to 2008.

    The heat isn't in land surfaces as these are in short term radiative equilibrium with the atmosphere - and atmospheric temp. has declined since January 1998 in any monthly record. Note that we are looking for total energy content - so let's include El Nino.

    It isn't in the ocean - ARGO data shows cooling for 2003 to 2008.

    If an ocean mass increase of 1mm/year is used (after AR4 and incorporating meltwater volumes from ice, snow and permafrost) - I get 6x10e20 J of energy that is contained in meltwater as internal kinetic energy - some three orders of magnitude less than needed to explain the current lack of warming.
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    Response: This issue is examined in detail at Does ocean cooling prove global warming has ended?
  47. "It isn't in the ocean - ARGO data shows cooling for 2003 to 2008."

    And warming for 2002-2008. Nice cherry picking.

    Also, the ARGO data is very ambiguous - depending on how you analyse it, you can get warming, cooling, or no change over the same period. So your statement "It isn't in the ocean" simply isn't supported by the evidence.
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  48. One thing the ocean isn't doing is:
    -warming the atmosphere to "breaking the 1998 record within a few years after 2005" as predicted by self-perpetuating idea guru Hansen in his 2005 paper press release, made through his inference about 'climate disequilirium', which in turn was made from his inference about a 'heat imbalance', which in turn was made from his inference that the sun had nothing to do with it, and the data was accurate, not ambiguous.
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  49. What a load of gibberish. Hansen has never said "the sun had nothing to do with it". Where do you get this nonsense?

    Another case of the Gish Gallop - ignore the evidence, change the topic a bit, and just keep ranting. Just bizarre.
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  50. Alliecat - the ARGO project came on line in mid 2003.

    You should stop your annoying and pointless ad hominem arguments - not me this time but it is not appropriate for a polite discourse.

    'Since mid-2003, the Argo array of profiling floats and the Gravity Recovery and Climate Experiment (GRACE) satellite gravity mission have made independent observations of the steric and mass components of sea level rise for the first time. Using these data, we investigate recent variability in the components of MSL on seasonal to interannual timescales and their agreement with the independent observation of total sea level rise from satellite altimetry.'

    Willis et al 2008 - link below

    Any previous analysis is based on very scarce data points. For instance - an estimate of Gulf Stream transport changes was based on 5 observations over 40 years.

    Levitus et al used 5 year aggregates because of lack of pre ARGO ocean temp data points. See Harrison and Carson 2007 for a discussion of pre ARGO data density, geographical coverage and trends.

    There are simply not enough data points with insufficient geographical coverage and an insufficient length of record to be accurate or definitive. The identification of multi-decadal variation with a multi-decadal time series is especially problematic.

    See: Harrison, D.E., and M. Carson. 2007. Is the World Ocean Warming? Upper-Ocean Temperature Trends: 1950–2000. Journal of Physical Oceanography, 37, 174-187.

    The ARGO (and Grace) analysis by Willis et al 2008 show that despite:

    ‘the short period of the present analysis, these results have important implications for climate. First, from 2004 to the present, steric contributions to sea level rise appear to have been negligible. This is consistent with observations of ocean surface temperature, which show relatively little change in the global average between 2003 and 2006 [Smith and Reynolds, 2005, http://lwf.ncdc.noaa.gov/oa/climate/research/anomalies/anomalies.html]. It is in sharp
    contrast, however, to historical analyses of thermal expansion over the past decade [Willis et al., 2004] and the past half-century [Antonov et al., 2005; Lombard et al., 2005; Ishii et al., 2006]. Although the historical record suggests that multiyear periods of little warming (or even cooling) are not unusual, the present analysis confirms this result with unprecedented accuracy.

    http://ecco.jpl.nasa.gov/~jwillis/willis_sl_budget_final.pdf

    The case of the missing heat was not addressed in the ocean cooling blog. There is heat (equivalent to the enthalpy of fusion) that is internalised in meltwater. That was the question asked by Thumb.

    The conclusion of the ocean cooling blog was that 6 years of data was not sufficient to characterise trends. Indeed - that is patently correct. Harrison and Carson show why 51 years of data is not sufficient to idenitfy trends.

    I was not however talking about trends but about total heat content of the climate system and how it is evidently not increasing. The lack of warming falsifies the idea of a radiative imbalance resulting in a monotonically increasing global heat content over the past 6 years. Simply - the planet is not warming as predicted.
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