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Climate Hustle

The temperature evolution after 2016 suggests hotter future

Posted on 11 March 2019 by Ari Jokimäki

Heat has been accumulating to the Earth's climate system quite steadily for decades. This has not prevented the apparent slowdown of warming seen in global mean surface temperature (GMST) since 1998 to become one of the pet claims for climate misinformers. Recently, we discussed this issue in our two papers (paper 1, paper 2).

There are many factors that affect the GMST at any time, which causes the GMST to show quite a lot of variability especially in short term. This variability means that even in the presence of overall long-term warming, almost at any time it is possible to claim that it hasn't warmed since the year X (like the escalator graph so neatly demonstrates). As time goes by, you have to update the X, because with long-term warming you get a new high peak every now and then making it impossible to keep the same X all the time.

Currently there is a transition period going on. While some of the misinformers are still desperately clinging to the expired X = 1998, some of them have switched to X = 2016 (and some of them have curiously taken a kind of a middle ground by claiming that after 2016, we are back at the "hiatus level", but this usually requires some creative, Y-axis inflating graph trickery).

The cherry pick of 2016 is the same as the cherry pick of 1998 - a strong El Niño which is known to elevate the GMST temporarily. With this in mind, I decided to compare the temperature evolution after 2016 to what happened after 1998. I also went a step further and included the temperature evolution relating to another strong El Niño of 1982-1983 that happened during the modern global warming era.

First, let's see how these compare to each other when time window is comparable to the 2016 event. Below I have plotted the temperature evolution of all these three events in the same graph so that they have been offset by their means over the time period equivalent to 2015-2018 (Starting slightly before the 2016 El Niño and extending it to end of 2018 which is the last full year that GISS monthly data currently contains). For the 1998 event this time window is 1997-2000 and for the 1983 event it is 1982-1985. The Y- and X-axis of the graph show the values corresponding to the 1998 event.

(Link to a bigger version of the graph.)

We see that close to a strong El Niño event, the GMST tends to behave similarly regardless of time period. This is not very surprising with such a short time window. Now, let's use the time window that shows the temperature evolution after 1998. Our time window is now 1997-2018, which is 21 years long. Obviously we don't have that much data for 2016, but we have that for the other two El Niños (as a sidenote, one can even add the temperature evolution relating to 1972-1973 El Niño with practically same end result). So let's plot the two events that have enough data, but let's also plot the data we have for 2016 over that, and let's label the X-axis starting from 2015. The X-axis then extends well into the future and we can call the resulting graph a "prediction". Can you see where the temperature is most likely to go in the future?

(Link to a bigger version of the graph.)

To me the graph suggests that, if the past temperature evolution can tell us anything here at all, it is most likely that there will be further warming. That was the end result after the 1997-1998 El Niño event and that was the end result after the 1982-1983 El Niño event. There's no reason to expect anything else after the 2015-2016 El Niño event either. If the past can tell us anything here, it's the hotter future that most likely lies ahead.

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Comments

Comments 1 to 40:

  1. Great post Ari.

    I've posted the following graph below, but in light of Ari's work, I feel it is worth repeating. If we plot temperature anomaly and fit a line to it, and then take the highest temperature anomaly in each decade and fit a line to it, the two lines are parallel. The implication is that as Ari and others suggest, there are years of peak warming because of the El Nino cycle, but the trend of these peak temperatures appears to be the same as the trend for the entire data set.

    No surprise, but just another way to look at the data, and another way to counter the argument that we are cooling.

    Temperature Anomaly

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  2. Yeah good article. However the link to the bigger graph is not much of a bigger graph, and is hard to read (unless my browser is playing up).

    The denialists are wrong to argue we are back to alleged pause temperatures as can be seen in the global temeprature record here.

    I wouldn't worry too much about the denialists. I would suggest most people looking at that NASA graph (or Hadcrut) can see the pause was inconsequential and about 6 - 8 years long in terms of surface warming, and the trend in the latest graph is towards continued warming especially when you look at the lowess smoothing line. People do basic graphs in maths at school and would understand things can be bumpy but its the longer term trend we look at. The only people who won't get this are extremely poorly educated people, and those determined not to grasp it, because of  ideological or other reasons that make them sceptical of the science. Of course they should still be refuted.

    There was a problem when warming did look flat after 1998 that required complicated but correct explanations about natural variability, but that period is obviously over looking at the NASA graph. It also has to be said the so called pause was never long enough or strong enough to suggest the underlying greenhouse gas warming process had somehow stopped, or that some unexpected natural process had taken over the climate. It's just that because of el nino / la nina we end up with a bumpy graph that looks like an escalator.

    The point I'm making is while the article is excellent and of interest to enquiring minds, things have to also be kept simple from the general publics perspective, and a simple graph says a lot to me. I think most educated people looking at the latest NASA graph would see an obvious continuing warming trend.

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  3. Yes, well-done Ari.

       As for the "no warming since..." gambit, I mentioned this previous SkS comment a couple of weeks ago over at Tamino's, but it is worth pointing to it again. From July 2016:

    https://skepticalscience.com/news.php?n=3441#117799

    ...and here is the image it contained:

    1998 to 2016

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  4. BOb, the trouble is, that pseudo-skeptics and misinformers are doing exactly the same thing.

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  5. Thanks all! Nigelj, to me the graphs open up clearly larger, and for example the texts on them are easy to read, so I suggest it might have to do something with your browser. If others have problems with graphs, let me know.

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  6. => Global warming will happen faster than we think

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  7. SirCharles@6 Interesting graph. It would require 0.5C of warming in the 2020's, vs the 0.2C/decade of warming that we've typically experienced. Anything is possible, but I've struggled with this kind of messaging. I decided to base my projections on the Keeling Curve, because if you fit 60 years of CO2 data you get a quadratic function that fits the data with a fitting parameter of 0.99 (1.0 represents a perfect fit). We are trying to motivate action based on the most solid evidence we have, and I think the Keeling curve comes about as close as we can to solid data that we can use to confidently project what will happen if we don't take drastic action.

    I'm not suggesting your curve is wrong. I am simply suggesting that the Keeling curve on its own is scary enough to motivate action, and it is based on 60 years of solid evidence of how the entire system (humans + nature) has been responding.

    The gray data points that are mushed together to form a thick, gray line from 1958 to 2018 is the data for the Keeling curve. The thin curve on the left shows rising CO2 projected into the future based on a fit of the 60-year Keeling curve and indicates when we are projected to lock in particular temperature anomalies based on a climate sensitivity of 3C/doubling CO2. The curve on the right projects when we will realize that temperature anomaly, based on a 30-year time lag between commitment and realization.

    Keeling Curve

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  8. Great post and comments. Looking at Evan’s plot @1, one could say “ok denialists, let’s ignore El Ninõ years”. What do we have left, a plot of annual temperatures, complete with annual variations, that have warmed about 1°C since 1970. 

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  9. Recommended supplementl reading:

    Global Warming ‘Hiatus’ Is the Climate Change Myth That Refuses to Die by Kevin Cowtan & Stephan Lewandowski, DeSmog, Mar 9, 2019

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  10. nigelj and Ari,

    A bit of playing with the 'zoom' level of my browser indicates that a 'zoom' of 200% results in the image in the OP being the same size on screen as the image size produced by clicking the link to a bigger version (the linked screen image appears at 100% zoom).

    Basically, the link goes to an image that is 200% of the OP scale if the OP is being viewed at 100% zoom (no zoom).

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  11. OPOF, good advice.  When I originally clicked on the link to the graph it opened as a rather small image and the print was fuzzy.  But the graph opens at a good size in my other computer and phone (both also using google oddly enough and the same version) so its an issue with one of my computers and it's google browser. Strange things computers.

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  12. scaddenp@4

    I disagree. THe problem is that the pseudo-skeptics and misinformers have nothing new to say, short of re-hashing zombie myths that are easily debunked by a simple search-and-replace, and that their "arguments" are easily foreseen several years in advance.

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  13. Making a claim that takes 'time to be proven to be incorrect' is a common tactic of the climate science deniers. They are not being skeptical of the science. They are politically trying to delay the improvement of awareness and understanding among the general population regarding how incorrect and harmful the people they are voting to support actually are.

    A similar tactic will be used when the most recent decade of data is added to the global surface temperature escalator. The claim will be made that the economic harm of the correction is now so big (because the economy was incorrectly increased in the wrong direction and the needed correction is more significant and needed in a shorter time frame). Surely it would be prudent and pragmatic to wait until one more decade of temperature data is actually gathered. We really need to be very sure about this - don't we?

    The people who have developed undeserved perceptions of superiority (wealth or power) by benefiting from the burning of fossil fuels, particularly through the past 30 years when it was undeniable that the activity needed to be globally curtailed, fear the coming correction will actually negatively affect them and their 'status relative to others' (as it should - they should particularly lose any increased perceptions of status obtained through the past 30 years).

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  14. It seems to me claims its cooling again (insert 1998, 2018, whatever) are a form of stalling for time, just like the claim I have often heard "climate is so complicated so we need more research before cutting emissions". Stalling for time is a common denialist rhetorical tactic, and could be included in courses on denial 101x (if it isn't already).

    Realcimate.org have a new page called the crank shaft, on some of the whackiest, craziest pseudo science theories. I thought at first the examples were satire, but no they are apparently real.

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  15. Rather than debate again & again the hiatus or slower warming issue, I respectfully suggest researching & discussing a related issue.  Has anthropogenic warming offset natural cooling forces since 2000 or so?

    The annual average global temperature has NOT trended downwards since 2000, 2015 or some year in between.  EVERYONE concedes this point.  One might reasonably expect a downwards trend since then because of a routine, recurring, widely acknowledged 60-80 temperature cycle.  The cycle's most recent warming phase started 1970-1975, or so.  The cooling phase should have started 30-40 years later, which would place the start date between 2000 & 2015.

    So, why has the cooling phase NOT made an appearance?  The answer should profoundly influence expectations for climate.

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    Moderator Response:

    [PS] I am not aware of any scientific basis for a 60-80 cycle though I aware of pseudo-skeptic pundits pushing the idea. Can you please provide references to support this "widely acknowledged" cycle? (especially interested to know where in the natural world, this extra energy is supposed to come from).

  16. The 60-80 year cycle refers to AMO/AMV, I think. One of the first papers discussing it was Schlesinger & Ramankutty (1994): An oscillation in the global climate system of period 65-70 years. See also my paperlist on the subject.

    At least one of the hiatus papers (in the paper sample of our paper 1 linked in the post above) mentions that there was a switch to cooling in Atlantic at around 1995. There aree some other papers also that discuss the role of Atlantic relating to the global warming hiatus. I think the answer to ThinkingMan is that the cooling phase might already have made an appearance but in the presence of long term warming, it doesn't show so clearly in the global mean surface temperature. While AMO's effect is strong around Atlantic, it's effect to GMST might not be so strong.

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  17. To the moderator:  Your request for documentation encourages confidence in  "skepticalscience".

    To Ari:  Thank you for providing relevant docs and related comments.

    To all:  A hypothesis consistant with my 18 Mar. post is:  Anthropogenic warming countered the cooling phase of the current 60-80 year temperature cycle.  The answer may be there is no such cycle, as the moderator suggests.

    If, however, such a cycle does exist, the fact a downward temperature trend has not started since 2000 may give credence to the concept human caused releases of greenhouses are affecting temperatures.  Man's influence may have offset natural forces driving the cooling phase.  This possibility should be welcome by AGW advocates.  The proposal should not be viewed suspiciously as a Trojan Horse deployed by deniers.

     

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  18. The 80-year period for climate cycles was riniging bells, and I managed to find a bit of support to the idea:

    "On the basis of 200 years of data, Willett (1964) notes that sunspot activity, as indicated by the Zurich relative sunspot number (Fig. 48), has cyclic variations of 80 and 11 years, with the latter being composed of alternating maxima of high and moderate intensities (the double sunspot cycle).

    (Sellers, W.D., 1965, Physical Climatology, U Chicago Press, p221)

    The reference to Willett is H.C. Willett, 1964 "Evidence of Solar-Climatic Relationships", pp123-51, in Weather and our Food Supply, Iowa State University, Ames.

    Mind you, I first read that when Sellers' book was not much more than a dozen years old. It is, shall we say, a bit dated now.

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  19. ThinkingMan @17,

    The concept of a natural unforced climate cycle is part of the denialist armoury and is usually presented as a 60-year cycle. I think it gets lengthened to allow more abiguity when fitting it to data.

    The sole basis of it is the global temperature record which can been seem as having peaks in 1880, 1940 & 2000 and dips in 1910 & 1970. Thus a 60-year cycle is proposed as causing these peaks and dips.

    Hadley global temperature

    Those proposing the existence of such a 60-year natural cycle have failed to take the idea forward. Further the peaks and dips can be understood without the existence of some grand natural wobble.

    Thus the so-called 'hiatus' of recent years can be explained by the impact of ENSO which is a natural wobble-maker. Yet such a natural wobble does not explain the slight cooling post-1940. This has more to do with a slowing of AGW positive forcings through those years and a massive increase in the rate of anthropogenic SO2 emissions. The 1940 peak is more of a challenge but over half of it results from forcing, most of this anthropogenic. And back to the 1880 dip, the volcanism during the latter part of the 19th century easily privide the dip without any 60-year wobble.

    Another approach to finding a 60-year wobble is to seek evidence for the wobble within the known natural oscillation. As set out above, ENSO (& thus PDO) are not powerful enough to be a source of the size of wobble being talked about. One other candidate is AMO mentioned @16. AMO is an interesting phenomenon. It was fisrt identified within a proxy reconstruction of North Atlantic temperatures. This were part of the work that resulted in the famous 'hockeystick' reconstruction of Northern Hemisphere temperatures. And here's a thing - the AMO is not seen in the 'hockeystick',  suggesting it too has not the power to provide a significant 60-year global wobble (IPCC AR5 also demonstrate the lack of power) although there is much work now showing the AMO is a true oscillation of roughly 60-year pitch.

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  20. "Climate oscillation" on wikipedia lists various relevant cycles. The AMO is around 60 years. The Gleissberg cycle is a weak solar cycle of about 88 years.

    Of interest is the statement "a 60-year climate cycle recorded in many ancient calendars[1]" This in turn is linked to a paper by Scarfetta . "Empirical evidence for a celestial origin of the climate oscillations", but the link to this paper wouldn't open when I tried it. The title of the paper does not inspire me with confidence.

    However I think its a good point that given the so called pause was definitely not a period of cooling any such cycle (if it exists) is fairly weak and is being dominated by AGW.

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  21. nigelj @20,

    The title? It is that the author is away with the fairies that "does not inspire me with confidence." The PDF below should work. Enjoy!!

    And that mention of "many ancient calendars" referenced in Wikithing appears as the un-referenced quote:-

    "A quasi-60 year cycle has been found in numerous multi-secular climatic records, and it is even present in the traditional Chinese, Tibetan and Tamil calendars, which are arranged in major 60-year cycles."

    Scarfetta N. (2010) 'Empirical evidence for a celestial origin of the climate oscillations and its implications.'

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  22. Scarfetta has tried to relate climate to who knows now how many unphysical cycles. However, the methodology used to detecting them is, well somewhat suspect. This paper does a take-down of the methodology and reanalysis with proper method. Scarfetta replied but another take-down here.

    While the statistical/mathematical analysis is pretty confusing, the real issue is the lack of any credible physical mechanism.

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  23. MA Rodger @21, thanks. The Scarfetta paper (2010)  claims there exists a 60 yr climate cycle related to motions and gravity of the planets Jupiter and Saturn, and he makes the claim it will cause global cooling from 2000 - 2030. This idea has all been dealt a rather lethal body blow by the last 4 years temperatures, right in the wrong place in his cycle! So yeah fairyland stuff, and spurious correlations perhaps, or just some very weak insignificant relationship.

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  24. To all: TY for the informative feedback.

    The point some APPARENT cycles are NOT genuine cycles is valid.

    It is also the case that genuine cycles with differing periodicities can cancel, mute or accentuate their expression.

    The above combined with the many natural forces influencing temperature, climate ... makes validating and explaining cycles a brain busting challenge.

    "Proving" AGW offset natural cooling forces from 1998 to the present will be at least as challenging.   Timing (reasonable start dates for a possible natural cooling phase) is only one feature that prompted me to raise the possibility.  A second is:  The approx. 0.2C/decade rate for AGW is similar to the rates at which temperature trended downwards from 1880 to 1910 and the early 1940s to the mid 1970s.  The dates are approximate.  A third is:  The AGW concept may be valid despite the fact climate models as a group overstated the amount the amount of warming over the past 20 yrs or so.

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  25. Invoking unspecified "natural cycles" does not further understanding. There are certainly natural "cycles" or more likely quasi-periodic variations at work. It is important to distinquish between internal variability (energy moving around in an unevenly heated water-covered planet) and variability in climate forcing (eg milankovich cycles, solar output variation, volcanic aerosols). Internal variability is things like the ENSO cycle which is dominate cause of intra-decadal variability. These are unpredictable, (chaotic) and affect climate largely by heat exchange between ocean and atmosphere. Climate models have no skill in predicting these variations. When you see a graph like:

    then the grey area is the space defined by multiple individual model runs. Any observational line within the grey area is compatiable with the model output. If you look at individual runs of the climate models, then you see the many possible outcomes. This post covers what the models are actually telling you. There is no skill expected at decadal predictions, but the model mean does a pretty good job at prediction the 30-year (climate) trends.

    While small amounts of heat transfer from oceans affect temperature, blaming warming on heat coming from the ocean while ocean heat content is increasing is "voodoo economics". If some unknown ocean "cycle" is providing the heat, then how come the ocean is getting hotter?

     

    Variation in external forcings is another story. The milankovich forcing is readily calculated and we are warming despite a very slow negative orbital forcing. Solar has quasi-periodic cycles but we can directly measure solar input at top of atmosphere. You cannot claim a solar cause when solar input is flat or declining. Volcanoes of cource are unpredictable but models must put in a "average" changes to aerosol forcings or the models would run too hot. You can always re-run models with actual forcings for solar, volcanic etc and this is done.

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  26. Scaddenp:  Will reply at another time.

    All:  Parts of this article are relevant to the concept.  https://judithcurry.com/2015/11/03/natural-climate-variability-during-1880-1950-a-response-to-shaun-lovejoy/

    Yes, I know Judith Curry's name will cause some followers of this blog to recoil.  Pls read the paper, nevertheless.

    The 2nd & 4th graphs are pointed out because a picture is worth1000 words.  The 4th graph shows that since 1950, rising atmospheric CO2 levels explain well a long term temperature trend.  The 2nd graph shows the difference between recorded temperatures and temperatures consistent with contemporaneous CO2 levels.  The difference is attributed to "natural variability".  Pls note the downward trend in natural variability from 2000-2012.  Whether the downward trend is caused by a cycle or natural events with unpredictable timing is a side issue.  The important outcome is:  Rising CO2 levels apparently (and may have indeed) offset natural cooling forces since 1998-2000.  This possible outcome supports the AGW case.

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  27. "The important outcome is: Rising CO2 levels apparently (and may have indeed) offset natural cooling forces since 1998-2000. This possible outcome supports the AGW case."

    Yes it does.

    The pdo ocean cycle here correlates rather well (by eye) with the bumps and dips in the surface temperature record since 1900, including the so called recent pause. 

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  28. The blog post happily assumes variation from the trendline is "natural variability". Huh?

    Above the climate forcing used by models. Volcanoes are of course natural variability but it would be a mistake to regard the variability as unforced change. Furthermore, the effect of man-made aerosols (ie pollution) 1940-1960 remain hard to tie down.

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  29. scaddenp:  Do you accept or reject the possibility AGW offset natural cooling forces from 1998 to the present?  And, are those specific cooling forces adequately reflected in the CMIP5 ensemble mean?   Your position is not clear in your two recent posts.

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  30. ThinkingMan @26,

    You point not to a "paper" but to a 2015 blog and its author is somebody called Vaughan Pratt. It is only posted by Judy Curry on her blog-site.

    Even so, it is full of enough nonsense to match that of Curry. The initial assertion (from Curry) that:-

    "About 40% of the warming since 1880 occurred prior to 1950, and is not attributed to human greenhouse gas emissions."

    and (from Pratt) that:-

    "The importance of this period (ie late 19th century to 1950) is that it contains by far the best data we have about natural variability in the absence of significant variation in CO2."

    This is pure nonsense. Examine IPCC AR5 Table AII.1.2 and you find that a third of the CO2 forcing to 2011 and almost the same proportion of 'GHG Other*' to 2011 were present by 1950. Curry's grand climate wobble is based solely on a dip and a peak in the global average temperature record. This is not insignificant & Curry is plainly wrong to suggest it is. Her grand wobble theory has no basis other than that. It is no more than curve-fitting and has no serious evidential support.

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  31. thinkingman - I appreciate your question. It is always good to clarify so we dont talk past each other. It is also worth clarifying "cooling".

    By "natural cooling forces" I understand you to mean things that would affect the temperature trend as opposed to year by year or even decadal average variation. On scale of 3-10 years, then the natural, chaotic, ENSO cycle is dominant. The upper ocean exchanges heat with atmosphere. A series of La Nina can look like cooling; a series of El Nino can look like warming. However on climatic scales (or even scales of decade), these do not affect the temperature trend. I mention this because you asked "since 1998" which immediately rings alarm bells. A lot of pseudo-skeptic arguments are based on cherry picking a big El nino event and then comparing trend after that. You can expect "since 2016" to become popular on certain websites.

    Assuming you mean temperature trend and actual forcing, I can be more definitive. You could say that AGW is countering some external forcings. The Milankovich cycle has been slowly cooling for some time, though the effect is so slow that its impact on climate even over a century would be hard to determine. You could also argue that total solar irradience trends since 1990s has been slightly negative. The change in forcing again is incredibly minor comparied to measured AGW-driven changes in surface radiation. I dont see volcanic aerosols having any particular trend.

    I do not see any convincing evidence for some magical 60 year/80 year cycles, especially when proponents struggle to identify a physical source.

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  32. ThinkingMan , it's always worthwhile to step back occasionally and look at the bigger context.

    Global surface temperature had been at a fairly flat plateau for (roughly) 5,000 years of the Holocene Maximum ~ which has been followed by (roughly) 5 or 6,000 years of gradual decline (related to the Milankovitch cycle of insolation).   Owing to the present relatively-low ellipticity of the Earth's orbit, the next glacial phase is due in 20-30,000 years ~ and may be skipped altogether since the oceans are being unusually warmed by AGW.

    The Little Ice Age, the Medieval Warm Period, the Roman Warm Period etcetera are only tiny wiggles in comparison to the multi-millennial decline in temperature.

    Against this long-term decline, you can see the last (roughly) 100 years demonstrates a temperature rise which is shooting upwards like a rocket.   And is now surpassing the Holocene Maximum.   IMO it is beyond ridiculous for denialists to assert that our modern-day global warming is the result of a 60-year oscillation in oceanic currents.

    Yet that is what some of the (more intelligent) denialists assert.   No need to waste your time reading Professor Curry's blog ~ she is still suggesting that "up to" 60% of modern warming could be caused by confluence of oceanic current cycles.   Quite marvellous it is, how a giant dose of "Motivated Reasoning" can so completely distort the rational thinking of an educated intelligent person.

    You see rather similar bizarre thinking coming from Lindzen & Spencer & others.   (And much of the remainder of denialists are still loudly proclaiming that CO2 has zero or negligible Greenhouse effect.)

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  33. Eclectic @32,

    When pointing out that the next glacial phase is due in about 20,000 to 30,000 years it could be helpful to add "Easy to get fossil fuels that have been discovered and left in the ground could be burned nearer that time to help human civilization get through that event".

    By then climate science may have developed understanding leading to better ways of dealing with that event. But it would still be 'helpful to future generations' if lots of easy to get fossil fuels were found and left in the ground for a future 'true emergency (energy warming, or other helpful puprose)' rather than harming the future generations by rapidly burning them up now.

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  34. I was looking for something completely unrelated in the list of sceptical myths, and I came across this skepticalscience.com myth buster on Scarfettas 60 year cycle. Hiding in plain sight!

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  35. scaddenp, TY for clarifying.  Your commitment to basing explanations on identifiable natural and man made factors is respected.

    Let me clarify my frame of reference.  30+ year temperature trends are my focus.

    1998-2000 were not cherry picked. They may begin a break in the temperature trend that began 1970-1975.  1998-2000 is also commonly cited as a starting point for reality departing, by a wider & wider margin, from climate model temperature forecasts.  Finally, the bottom half of the 1st graph in the previously mentioned Shaun Lovejoy critique draws attention to 1998-2000.

    The bottom half is also consistent with a possible 60-80 yr temperature cycle. Pls note the three cooling trends in the "residues".  One ends 1910-1915.  The next ends 1975 or so.  The third spans the charts final dozen or so years, and it starts "on schedule".

    FYI, the 60-80 yr cycle is mentioned because it may explain in part or fully why actual temperatures are so far below climate model projections / estimates.  Solar cycles, ocean cycles and other natural forces not adequately simulated by models may also explain the departure.  Finding and describing the force or forces is important to the AGW concept.

    nigelj, will read the myth buster pointed out above when time allows.

    TY to all others who have commented.  Very informative & thought provoking.

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  36. Thinkingman, you are falling for a number of deniers tricks here.

    1998-2000 "commonly cited" by pseudo-skeptics trying to claim the science has got it wrong and it is a cherry-pick because it only considers part of the record, and to make it work, you have to start the period with an exemptional El nino. Do the the arguments still make sense if you start with 1996?

    This post here goes in a proper statistical analysis of what is going on. You also seem to bought the idea that something has gone wrong with model predictions. This is nonsense. No scientist expects the actual temperature time series to evolve along the model mean. The science (everything we know about ENSO) says that is impossible.  Please read again my earlier reply. A good expectation is that the 30-year trend in temperature series will be close to the 30-year trend in the model mean. However, there is still a wide uncertainty in climate sensitivity.

    Finally, I do not accept that you can take two cooling periods (1910-) and (1940-) caused by two different changes in climate forcing and propose a natural cycle for them.  This is not evidence, it is misinformation.

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  37. ThinkingMan , the other "denier trick" is to completely ignore ocean warming.

    Global surface temperature is easy to measure on an annual, or indeed monthly, basis.   The ocean, less easy to measure at fine scale over short periods ~ but the ocean trend is upwards, because the basic physical process of Greenhouse warming is continuing unabated.   That is the crux of the matter.

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  38. Good point Eclectic. Surface temperatures have wide natural variation but ocean heat (where most of the warming ends up after all) have far less. Some wiggles are oceans exchanges heat with atmosphere but on far less scale than surface temperatures.

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  39. ThinkingMan,

    Since you claim to be interested in 30+ year data trends please evaluate any of the surface temperature data sets (the 1880 to present day monthly NASA-GISS data is easy to get here) as folows: Look at the value of the 30 year rolling averages. Each new monthly average creates a new 30 year average with the 359 months before it (or every new yearly average creates a new one with the 29 years before it).

    I know it can be done because I have done it. It is not complicated. And the 30 year averages do indeed 'not just go consistently upward' when you look at all the data this way starting from 1880.

    What I found is that the 30 year averages ending in 1994 (the set from 1965 through 1994) were increasing or decreasing (yes there is a period when the 30 year averages notably decline).

    The extremes of the 'rates of change per decade' in that range of the data set are from -0.03 C/decade to +0.10C/decade.

    All of the 30 year averages since 1994 have been at rates of change greater than +0.10 C/decade. And the rate rapidly increased to 0.17 C/decade by the 30 years ending in 2004. And all the more recent values have rates that exceed 0.17 C/decade.

    So the 30+ year evaluation does not show what you are hoping to see.

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  40. Thinkingman, Foster and Rhamstorf did an exercise depicted here removing el nino / la nina, the solar cycle and volcanic activity from the temperature record and the so called 'pause' after 1998 completely disappears. So why would you need to consider some new and questionable 60 year cycle?

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