Abrupt changes in GHCN station-level temperature records contradict the anthropogenic global warming (AGW) claims.

Guest post by Jens Raunsø Jensen

Preamble
Inspired by a statement by Dr. Kevin Trenberth in the e-mails referred to as Climategate 2.0 (#3946 discussed here), it is hoped that climate scientists will have “an open enough mind to even consider” that the global warming of the 20th century could have occurred mainly as abrupt changes in mean temperature linked with natural events. Observational data supports that claim, at variance with the AGW “consensus view”.

Summary
Abrupt or step changes in temperature regime has been the subject of many discussions on this and other blogs and in the peer reviewed literature. The issue is not only statistical. More importantly, any presence of major step changes in mean temperature regime may contradict the claims of the AGW theory and models, i.e. the claims of increasing and accelerating temperature and of human emissions of GHGs being the major cause for the relatively high temperatures in the second half of the 20th century.

In this post, 232 complete and unadjusted GHCN station records are analysed for step changes in the period 1960-2010, and it is argued that:

  • Abrupt changes in temperature linked with natural climate events may be widely responsible for the “global warming” during the second half of the 20th century.
  • 50% of sample stations have not experienced increased mean temperature (”warming”) for more than 18 years.
  • 70% of Europe stations have not experienced warming for more than 20 years.
  • The relative role of natural processes in global warming is very likely underestimated by IPCC.
  • The global average temperature curve is ”apples and oranges” and is widely misinterpreted using linear trend and smoothing techniques as indicating a pattern of widespread uniformly increasing temperature.

Objective and methodology.
The post is in continuation to my earlier post on the subject (http://wattsupwiththat.com/2011/08/11/global-warming-%e2%80%93-step-changes-driven-by-enso/ ), now including a near-global station level analysis. The post is based on a ppt presentation including additional details given at a researcher’s workshop at University of Copenhagen, 15th November 2011 (http://www.danishwaterforum.dk/activities/Researchers_Day_Climate_Change_Impact_2011.html ).
The objective with this analysis has been (i) to examine the land-based temperature records at station and higher levels for the presence of step changes during the period 1960-2010, and (ii) to assess the implications for our assessment of global warming during that period. Please note that the objective has not been to dismiss a (likely) presence of an anthropogenic warming signal, or to establish a climate model, or to make projections for the future. The issue is step changes in observational data during 1960-2010.

I have used the documented Regime Shift Detection tool of Rodionov (2004, 2006; www.beringclimate.noaa.gov/ ). The results are considered to be statistically robust (ref. the ppt presentation for details on parameter settings and a verification of the assumptions of constant variance and a likely negligible influence of autocorrelation).
The station level data is from GHCN (“after combine”, http://data.giss.nasa.gov/gistemp/station_data/ ) and include ALL stations with a complete record in the period 1960-2010 in broadly defined sampling regions (ref. Fig. 1).

A total of 232 stations were identified, with 54% located in Europe and Russia. The sampling criteria result in wide differences between the “regions” in terms of station number, density and distribution. Also, the “regions” are more or less homogeneous climatologically. However, this is not of material importance for the following discussion and conclusions.


Fig. 1. Distribution of sample stations according to sampling criteria.

Results
Significant step changes are widely found in the T-records and representative examples for 3 “regions” are shown in Fig. 2a-c. The temperature increase in the steps is typically of a size which is comparable to the often quoted global warming during the 20th century.

Fig. 2a. Alaska T-anomaly (n=9). Step, 1977; T-change = 1.5 oC; significance 0.000001


Fig. 2b. Fichtelberg, Europe. Step, 1988; T-change = 1.0 oC; significance 0.00009

Fig. 2c. Malacca, South-East Asia. Steps: 1978, 1990 and 1998; T-change = 0.4+0.3+0.4 = 1.1 oC; significance, 0.0004, 0.0007 and 0.003.

Warming during 1960-2010 was clearly a non-linear process at station level, with the step pattern differing among the “regions”. The global average T-anomaly curve, constructed by averaging across station-level T-anomaly curves, is therefore highly deceptive in propagating a message of near-linearly increasing temperatures, contrary to the actual processes at station level. Thus, the global T-anomaly curve is inherently “apples and oranges” and can not be used to identify a meaningful global AGW trend if the step changes are neglected. Then, the apparent AGW trend will in reality mainly capture the aggregated effect of the sudden step changes (as e.g. in Foster and Rahmstorf, 2011).

The steps are concentrated in few short periods. Disregarding 39 steps after 2005 (considered highly uncertain and “in progress”; 2/3 ups and 1/3 downs), it is found that:

  • The steps occur predominantly (58%) in three 3-year periods: 1977/79, 1987/89 and 1997/99 (Fig. 3).
  • 72% of all stations, and more than 50% of stations in each “region” (except Arctic), have one or more steps during these periods (e.g. 89%, 56% and 93% of Europe, Russia and South-East Asia stations, respectively; Fig. 4).
  • 78% of Europe stations have a step change in 1987/89, during which the major part of the entire warming of the 2nd half of the 20th century apparently took place.
  • 2 or 3 steps are common in South-East Asia (especially 1987/89 and 1997/99), but one step only is common in records from Alaska (1977/79), Europe (1987/89) and Russia (1987/89).


Fig. 3. Distribution of step changes by year of change.

Fig. 4. Percent of stations with one or more steps in indicated 3 periods.

Similar step changes are identified in national average records (ref. link to presentation above): US contiguous 48 states (GISS): 1986 and 1998; Australia (BOM): 1979 and 2002; and Denmark (DMI): 1988. The steps in the Global T-records are: Crutem3gl: 1977, 1987 and 1998; GISS L/O: 1977, 1987 and 1998; and Hadcrut3: 1977, 1990 and 1997.

The steps are statistically highly significant. But are they supported by a probable physical cause? The answer must be yes for the majority of steps. The steps occur in a temporal and spatial pattern coinciding with well-documented events and regime changes in the ocean-atmosphere system:

  • 1976/77: the great pacific shift from a “cold” to a “warm” mode (e.g. Trenberth, 1990; Hartmann and Wendler, 2005).
  • 1987/89 and 1997/99: the two clearly most intense El Niños of the period, 1986/88 and 1997/98, with the intensity here defined as event-accumulated nino3.4 anomalies (NOAA’s ONI index); there were two less intense events in 1982 and 1991, the impact of which was probably occluded by the major volcanoes El Chichon and Mt. Pinatubo.
  • A regime shift in NH SST in 1988/89 (Yasunaka and Hanawa, 2005).
  • A new regime of constant temperature after the 1997/98 El Niño, i.e. the now widely accepted “hiatus” in global warming.
  • Documented step changes and regime shifts in marine ecosystems, e.g. the late 1980s in Europe and in the Japan/East Sea.
  • The short-term regionally diverse global impact of ENSO events is generally well-known.

The empirical evidence, from this station level analysis and other sources, is unequivocal: the step changes in mean temperature are likely real and associated with natural events. The physical mechanisms remain to be understood, and this is certainly not to claim, that ENSO events are the only elements of the natural cause-effect chain.

It is therefore concluded, that the major part of the temperature change (global warming) in the 2nd half of the 20th century occurred as abrupt changes in mean temperature associated with natural events in the ocean-atmosphere system. Still, a warming/cooling trend – albeit relatively small compared with the step changes – could of course be hidden by the regime change model. But it seems inconceivable, that steadily increasing CO2 levels could be responsible for the major sudden changes observed as e.g. in Alaska in 1977, Europe in 1988 and South-East Asia in 1998. In principle, the natural events and step changes could have been amplified by human caused warming, but this is currently pure speculation.

Implications when accepting the presence of steps
“Increasing temperature and accelerated warming” : this study does not support general statements like that. The bulk of the “global warming” has likely taken place in abrupt steps, and 50% of the stations analysed has not experienced any significant warming for more than 18 years (Fig. 5). In Europe, 70% of the stations have not experienced significant change in mean temperature for more than 20 years.

In South-East Asia, the median value is 13 years as many stations here also experienced a step change in 1997/98 (Fig. 4).


Fig. 5. Years of constant T-mean prior to 2010. Box-Whisker plot, 1st and 3rd quartiles. (note: uncertain up and down step changes during 2006-2010 are disregarded).
Challenging the IPCC consensus view, i.e.: “Most of the observed increase in global average temperature since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse-gas concentrations”. However, the finding above, that abrupt changes linked with natural processes likely account for most of the increase in temperature during 1960-2010, contradicts the IPCC claim regarding the relative importance of natural and human causes. Thus, when IPCC (AR4) can only reproduce the T-curve by including GHG effects, then logically

  • either the IPCC GCM models do not adequately model the natural processes of high significance for the temperature variations (there is still low confidence in the projection of changes in the ENSO variability and frequency of El Niños, ref. the recent SREX-SPM IPCC report),
  • or/and the IPCC has overestimated the climate sensitivity to CO2 changes by eg. attributing natural temperature increases to CO2-induced feed-back processes.
    In either case, the relative importance of natural processes for the T-changes has likely been underestimated by IPCC.

Conclusion
This study has established that step changes in land-based temperature records during 1960-2010 are common and very likely real and linked with natural climate events. The step changes are statistically highly significant and with a systematic yet regionally diverse pattern of occurrence coinciding with major climate events and regime shifts. This finding has far reaching consequences for our analysis of climate records and for our assessment of global warming.

Thus, although many different statistical models can be applied to explore the pattern of T-change, the presence of step changes invalidates the widely used statistical techniques of linear trend and smoothing as means of identifying the pattern of temperature variation during 1960-2010.

Furthermore, the step changes account for the main part of the temperature changes during the 2nd half of the 20th century. The logical consequence is that natural processes have been the major cause for the temperature change during this period, leaving a secondary role to other causes such as the anthropogenic greenhouse effect.

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205 thoughts on “Abrupt changes in GHCN station-level temperature records contradict the anthropogenic global warming (AGW) claims.

  1. Jens Raunsø Jensen
    Great work and very interesting thinking on climate with respect to temperature. The obvious question is why. At least the question has now been postulated.

  2. I trust that, should this research hold up, that a CONDITION of IPCC report 5 being ALLOWED TO BE WRITTEN will be a requirement to:
    1. Acknowledge the implications of this research.
    2. State that the IPCC has denigrated those who suggested such research for 20 years.
    3. Ensure that there is a political price to pay for those who did that denigration.
    4. That henceforth, the only criterion for research being included in IPCC reports will be its scientific validity.

    Any chance of that do you think?

  3. “However, the finding above, that abrupt changes linked with natural processes likely account for most of the increase in temperature during 1960-2010, contradicts the IPCC claim regarding the relative importance of natural and human causes.”

    Lets not forget that a complex, chaotic, non-linear system like the climate system might respond to a steady anthropogenic forcing with discrete (stepwise) state changes. Thus the contention that

    “The logical consequence is that natural processes have been the major cause for the temperature change during this period, leaving a secondary role to other causes such as the anthropogenic greenhouse effect.”

    is not necessarily correct as it could be that the observed “natural processes” are themselves the natural effects of the anthropogenic greenhouse cause.

    However, I do agree that

    “the presence of step changes invalidates the widely used statistical techniques of linear trend and smoothing as means of identifying the pattern of temperature variation during 1960-2010″

    is quite likely to be correct.

  4. This is laughable. Your starting premise – “any presence of major step changes in mean temperature regime may contradict the claims of the AGW theory and models” – is wrong. You’ve used an arbitrary subset of the available data. Your methodology consists of drawing arbitrary lines on that data. Your conclusions, as a result, are wildly erroneous. Watts of course lacks the critical thinking skills necessary to discriminate between science and nonsense.

  5. The regime change analyzer is a nice tool. Would you explain how it works in layman’s terms, how you applied it to these time series, and the reason it’s an appropriate statistical method? The PPT link is a little too brief to get a good understanding of it.

  6. This study highlights why, from time to time, farmers lose their shirts. Only the well-seasoned shirt losers change to another crop fairly quickly. Currently I know of one or two who have planted the same field of spring wheat, year after year, only to have it frozen out by June. Back in the 70’s it was crop after crop of peas that wilted under a hot Sun and warm nights by June.

  7. what is the % of C02 in the atmosphere? .004%? What part of that is natural and what part is “anthropogenic”? Does anyone know? Even if we stipulate that there is some greenhouse effect caused by man how significant is it compared to natural green house effect? How significant are land based temp records when most of the planet is water or ice? I don’t think the science is settled.

  8. This is something that Bob Tisdale has shown on numerous occasions and yes it appears to be real.

  9. Sorry if I am being stupid but I can’t see Trenberth’s comment in the link to email 3046?

    Regards

    S

    REPLY: Yes, I don’t see it either, perhaps the number for the email he gave is a typo (I added the link) – So I’ve removed the reference to Dr. Trenberth for now until Jens can clear up the discrepancy – Anthony

  10. Reasonable thoughts JT, except there are well documented natural mechanisms, with all the necessary energy and teleconnections, for such temperature shifts. There is no documented CO2 driven mechanism with enough energy to cause such things to occur in the oceanic-atmospheric regimes highlighted in the study. Until you can overrule a known cause, you cannot propose another driver unless you can clearly delineate a reasonable CO2 mechanism. In addition, recent studies of oceanic-atmospheric events (IE tornadoes, hurricanes, blocking highs, etc) show no correlation whatsoever with increasing CO2.

  11. This is brilliant work!

    It seems similar to ‘punctuated equilibrium’ (popularly called ‘evolution by jerks’) which was vociferously denigrated when first proposed, but now seems generally accepted. Things change slowly for long periods, and then a specific environmental change triggers a sudden major revolution. Staircases, not gradual slopes.

    Perhaps this is the start of bringing Climate Science up-to-date with other sciences?

  12. @JT

    “Lets not forget that a complex, chaotic, non-linear system like the climate system might respond to a steady anthropogenic forcing with discrete (stepwise) state changes.”

    +++++++++

    I agree that the possibility should be considered. What is needed is for the IPCC, in its documents, not just by mouth, to entrench the idea that the steps are real, important, and traceable. The implications will follow. At the moment either due to ignorance or attitude, the IPCC does not consider that most temperature change is natural. There are a group of scientists, some of whom do very good work, supporting the view that CO2 from anthropogenic sources is not just a cause, but the major cause of temperature rises. I do not understand how Trenberth, for example, who is obviously brilliant and a dedicated researcher, can support so publicly the CAGW view when his own works are used by investigators to demonstrate the paucity of that same theory.

    If the IPCC were to entrench in its works the view that the climate is indeed complex, chaotic, non-linear and poorly understood, keeping an open mind would be a pre-requisite for working on its reports. This has not been the case to date because, apparently, of the premature conclusions about human influence on the climate (which might be between almost none and approximately zero).

    That the statistical techniques used to estimate the past and future climate are inadequate and hiding the meaning within the records does not surprise me at all. Re-smoothing smoothed data sets, including trends in data sets as independent variables (!) and misapplication of sophisticated statistical tools (hockey stick generators) seem to have blinded otherwise competent scientists to what is going on.

    The fact that Enron (etc) worked out how to capitalise on the difference in CO2 emissions between oil, coal and natural gas is no surprise either. Big business with imaginative employees seeking private profit at public cost is hardly news, is it? The PR campaign to promote “Scary Movie 6, the Climate Catastrophe” is, like its prequels, a parody of the scientific method and academic discourse. The whole ‘green job’ thing is just another set of opportunists seeking private profit at public cost. The green politics movement is just another power grab rooted in selling guilt and accountability to a populace that is naturally considerate of others and respectful of their own acts and attitudes.

    From http://en.wikipedia.org/wiki/Carpetbagger

    “In the United Kingdom, the term was adopted to refer informally to those who join a mutual organization, such as a building society, in order to force it to demutualize, that is, to convert into a joint stock company, solely for personal financial gain.”

    “…they are said to have politically manipulated and controlled former Confederate states for varying periods for their own financial and power gains…”

    We are surrounded by climate carpetbaggers.

  13. How is the selection of sites arbitrary Alan? Are you saying his selection criteria was bad and was purposely done to prove his bias? And are you saying that after discovering these step changes, he “eyeballed” the step change lines and free handed them in some sort of arbitrary way? What you are accusing this researcher of boarders on unethical research practices. Is that your accusation? If it is, please show your evidence of such biased unethical research practices.

  14. Jim murphy says:
    January 5, 2012 at 6:36 am
    “what is the % of C02 in the atmosphere? .004%? What part of that is natural and what part is “anthropogenic”? Does anyone know? Even if we stipulate that there is some greenhouse effect caused by man how significant is it compared to natural green house effect? How significant are land based temp records when most of the planet is water or ice? I don’t think the science is settled.”

    According to Jan Veizer the anthropognic contribution to the annual CO2 budget is 5%.

    SEE HIS CANADIAN TESTIMONY POSTED EARLIER AT THIS BLOG

    He also said: “to claim that CO2 drives the climate is similar to claim that the Economy of Puerto Rico is driving the World Economy.

    http://wattsupwiththat.com/2012/01/01/canadian-senate-testimony-skeptic-side-now-being-heard-in-canadian-politics/

  15. I think Joseph D’Aleo and or Joe Basrardi had a similar article about the step changes in the temperature record triggered by El Nino’s.

  16. Crispin in Waterloo says:
    January 5, 2012 at 6:51 am
    The fact that Enron (etc) worked out how to capitalise on the difference in CO2 emissions between oil, coal and natural gas is no surprise either. .. We are surrounded by climate carpetbaggers.

    climate carpetbagger: Noun – one who exploits or manipulates fears over climate change to gain financial or political advantage..

  17. @Alan Statham says:
    January 5, 2012 at 6:17 am

    Sorry my debating team gives you an F, just blowing hot air does not advance the discussion, it just shows your an angry little man.

  18. It should be relatively easy to show whether Mr. Jensen’s step-change temperature measurement numbers are correct or incorrect. If the measurements are reasonably accurate, IPCC warming theory clearly must be revised. A few more days of WUWT commentary should assist the review process.

  19. Re Alan Statham:
    Your aspersion regarding Anthony Watts tells us more about you than it does about him. Anyone who has read this blog, even those who now and then disagree with WUWT, realize Anthony Watts is a man of integrity and smarts. If you have an argument to make about this particular entry, then make it. Don’t just snidely squeak from your hole in the ground. Put another way, you think you’re so smart, how about showing us? Make the case.

  20. Of course the “natural” fluctuations would be seen as step-changes, as that is exactly what ocean (ENSO & AMO) and solar will look like when superimposed on top the anthropogenic signal. It is true that the anthropogenic signal is not accelerating, and is a nice slow but steady linear rise in temperatures, which is exactly what the Foster & Rahmstorf found when factoring out these “natural variability” factors:

    http://iopscience.iop.org/1748-9326/6/4/044022

    While skeptics are keen to criticize the Foster and Rahmstorf study, or at least significantly question certain areas of it, in fact, your analysis of the “step wise” increases only reinforces the validity of this study, and the ultimate finding that when factoring out the natural variability such as ocean, ENSO, and volcanic activity, a steady linear (i.e. non accelerating) rise in temperatures can be seen in the record. The “step wise” increases only occur when natural variations (i.e. ocean & solar & volcanic) line up with the underlying forcing coming from greenhouse gases. Thus, you’d expect a step-wise increase when and El Nino and warm PDO aligned, and even more so, when aligned with a solar maximum and minimal volcanic activity. Global temps will “step up” during these alignments of natural and anthropogenic forcings, and while they may fall back from the peaks of these “step up” periods, they never fall back to lower levels that break the underlying the long-term anthropogenic warming. This is exactly what Foster & Rahmstorf found and exactly what other “step wise” increase studies found– the steps are related to the alignment of all forcings during certain periods, but the underlying forcing from additional greenhouse gases can still be seen as a linear trend underneath all these “steps”.

    If Foster & Rahmstorf are correct, (and related notion of “step wise” increases), then in the next few years we should get the opportunity to put these notions to a test, as it is very possible that we’ll get one of those alignment periods where the natural variations (i.e. solar & ocean) will once more align to the positive side with the underlying anthropogenic forcing. Such that for example, should we get an El Nino around the time of Solar Cycle 24 Max, we could see another step up in temperatures, with modern temperature records being set. These temps will of course subside once Solar Max has passed and the El Nino wanes, but the new underlying higher step will have been established. Time will tell…

  21. Alan Statham: your:

    Your starting premise – “any presence of major step changes in mean temperature regime may contradict the claims of the AGW theory and models” – is wrong.

    Nope. AGW theory rests on temperatures rising more or less in lockstep with CO2 levels. A step change would imply natural variation, or an unknown anthro component. NO AGW model shows step changes.

    You’ve used an arbitrary subset of the available data.

    Nope. As Jens states, he used ALL stations in the GHCN network, from the defined geographical areas, as long they have a continous record from 1960. The continuity is the only arbritary function. Granted, I would like to see North American data, too, south of 60.

    Your methodology consists of drawing arbitrary lines on that data.

    Nope. As Jens also explains in his Methodology, he uses a Regime Shift Detection Tool, and gives the reference and methods.

    Your conclusions, as a result, are wildly erroneous.

    Nope. You are shown to wildly erroneous, by not actually reading the posting by Jens.

    Watts of course lacks the critical thinking skills necessary to discriminate between science and nonsense

    Nope. That would be seem to you, actually, and your inability to read comprehensively.

  22. Alan Statham said @ January 5, 2012 at 6:17 am

    “This is laughable. Your starting premise – “any presence of major step changes in mean temperature regime may contradict the claims of the AGW theory and models” – is wrong. You’ve used an arbitrary subset of the available data. Your methodology consists of drawing arbitrary lines on that data. Your conclusions, as a result, are wildly erroneous. Watts of course lacks the critical thinking skills necessary to discriminate between science and nonsense.”

    What an excellent example of warmist argument this is Alan. You offer no evidence for an assertion and make a personal attack on the publisher. And you are no doubt utterly bewildered when we do not immediately say to ourselves: “Gosh! Obviously I have been wrong all this time. Carbon pollution really does cause increased droughts, rainfall, sea level, acne, prostitution, obesity and everything.

    What a dork!

  23. I recall reading one article written by Ross McKitrick where he shows a temperature graph with a big step just when the thermometers in the canadian surface stations were changed from mercury/alcohol to thermocouples. I may be recalling the whole thing wrong though.

    If it is a question of equipment change, it would explain why in some countries there is just one step change and others have two or three. And it would be man-made, not natural. :P

    It would be nice if somebody could find the article I am talking about. :) The only paper I can find is this one: http://www.uoguelph.ca/~rmckitri/research/nvst.html but here the plot is temperature vs. number of stations, and there is a big step right on the year 1990. I wonder if this graph is related in any way with the plots shown here. I cannot find any other article so maybe I am miss-remembering it.

  24. It’s an interesting idea, and it sounds at least plausible, but it raises a whole lot of questions in a laymans mind.
    Why did so many stations not register the step changes. Is it possible that we are seeing a churn of instruments or sites or recording methods. Do we see steps going in both directions

  25. cui bono said @ January 5, 2012 at 6:42 am

    “This is brilliant work!

    It seems similar to ‘punctuated equilibrium’ (popularly called ‘evolution by jerks’) which was vociferously denigrated when first proposed, but now seems generally accepted. Things change slowly for long periods, and then a specific environmental change triggers a sudden major revolution. Staircases, not gradual slopes.

    Perhaps this is the start of bringing Climate Science up-to-date with other sciences?”

    Punk eek is still on the nose for many evolutionary biologists, especially I imagine for Dawkins. Despite the now overwhelming evidence for horizontal gene transfer (HGT), particularly among plants, most evolutionary biologists are sticking to the gradualist Darwinian meme. They believe that admitting that the gradualist meme was incorrect would reinforce the Creationists’ argument. Thus the biological community say certain things among themselves, but the message for the hoi poloi is entirely different. Good science is far less important than fighting the evil Creationists.

    What we see in the climatological community is not much different to several other sciences. It just has more importance given the dire effects of crippling Western economies.

  26. Jens, the folks on SkepticalScience are questioning whether step-change models make any testable predictions. When we strip away the pointlessly tendentious SkepticalScience rhetoric (which I condemn!) we are left with reasonable questions like “If El Niños cause abrupt temperature step changes upward, why wouldn’t La Niñas cause equivalent abrupt temperature step changes downward?”

    More broadly, step-change models have an unbounded number of independently adjustable steps. So why should we embrace arbitrarily-complicated step-change models, when non-step models like Foster & Rahmstorf (2011) — which are mathematically simpler and physically well-motivated — describe the overall climate-change data impressively well?

    One key question is this: Do step-change models predict that simpler non-step models, like Foster & Rahmstorf (2011), will fit the climate-change data less well in coming decades?

    Conversely, if step-change models cannot make even this one basic prediction, why should we embrace them at all?

  27. Alan Statham says:
    January 5, 2012 at 6:17 am

    Alan Statham is a fictional character in the British sitcom Green Wing, played by Mark Heap.

    http://en.wikipedia.org/wiki/Alan_Statham

    Both Alan and his argument appear to be fictional.

    REPLY: Yeah, he uses a Proxyserver also, appears to be one of our former friends (I won’t name him) who has been asked to leave for juvenile behavior but can’t stay away – Anthony

  28. Most interesting approach. The regional look at things is one of the approaches advocated by Roger Pielke, Sr. It has much merit. It is unfortunate that so many got off on this AGW track. Had we spent half the wasted time and effort we would be much further along. It did and we can do little about it now but try and refocus on the real drivers. I have puzzled and will continue for some time I suspect to understand why we humans insist on reducing things, highly complex and poorly understood things, to a single value or catch phrase. That practice ultimately devalues and obfuscates.

  29. Leif: your

    Why are the “steps” always up?

    They aren’t. Fig 2a and 2b shows a negative step change.

  30. I will admit to a bias, but what I see in those three graphs (Figure 2a, 2b and 2c) is not what he sees. Yes, there are steps. The Alaska one I think is a real thing, because it is well documented that there was a step change in 1976-1977. I do have to ask what portion of Alaska he is including, though. The entire state? That is a real hodge-podge of regions. It seems like an odd amalgam to include. The other two I would consider to be artificial. The German one just happens to coincide with the onset of the IPCC, the great dying of the thermometers and the still unknown adjustments being made behind closed doors. The Malacca graph looks at first glance to also be an artifact of periodic adjustments which we have seen evidence of here at WUWT. That is, except for the 1976-1977 step, which, like Alaska’s same step, is supported by history and predates efforts to ‘prove’ global warming exists.

    It would be instructive to see the raw data for all three. I don’t trust GHCN data; GHCN is too close to CRU and the IPCC.

  31. Urederra: Didn’t Anthony’s white wash/latex paint on the Stephenson screens show similar step changes — that local temperature records showed a step up when the screens were changed from white wash to latex paint?

  32. Alan Statham says:

    January 5, 2012 at 6:17 am

    This is laughable. Your starting premise – “any presence of major step changes in mean temperature regime may contradict the claims of the AGW theory and models” – is wrong. You’ve used an arbitrary subset of the available data. Your methodology consists of drawing arbitrary lines on that data. Your conclusions, as a result, are wildly erroneous. Watts of course lacks the critical thinking skills necessary to discriminate between science and nonsense.

    No more stupid than saying that carbon dioxide back radiates when in practice if you look at the spectrum from the surface of the earth there is no back radiation to be seen!

  33. Leif Svalgaard said @ January 5, 2012 at 7:33 am

    “Why are the “steps” always up?”

    Because temperature has been rising until recently? Presumably if the next 30 years is a cooling regime, the steps then will be down. Or is this too obvious?

  34. R. Gates: the Tamino/Rahmstorf paper mostly does not address the step changes in the years shown by Jens. If these were taken out, then the warming 1979-on would be even less than 1.4-1.75 deg/century, as proposed by FR2011.

    Also, Jens makes this point in his post:

    Then, the apparent AGW trend will in reality mainly capture the aggregated effect of the sudden step changes (as e.g. in Foster and Rahmstorf, 2011).

  35. I think Leif asks a good question:

    “Leif Svalgaard says:
    January 5, 2012 at 7:33 am

    Why are the “steps” always up?”

    I would like to know if there are similar station records from the cooling period from 1940-1975 (or whenever it was) that show similar down steps.

    I think this is a good example of the “devil is in the detail” concept – by only looking at averages we are losing the real information in the data. I have a bone to pick with arithmetic means being used in weather predictions in a more general sense, but averaging across very large geographic regions (and using such averages to fill in places where the data is not available) really is losing most of the information.

  36. Leif Svalgaard said @ January 5, 2012 at 7:33 am

    “Why are the steps always up?”

    This is a good question. What I’d also like to know is if these “steps” are seen in the numerical climate model predictions, and, if not, why not?

  37. Leif Svalgaard says:
    January 5, 2012 at 7:33 am
    Why are the “steps” always up?

    What makes you think they were ‘up’ between MWP and LIA ?

    The period 1940 to 1975 or so was only a very slight cooling so there might be no clear downward steps.

  38. Tom_R says:

    January 5, 2012 at 8:23 am

    A lot of the 1987-1989 step change may be attributed to the fall of the Soviet Union.

    Is that the Russian Steppes?

  39. Leif Svalgaard says:
    January 5, 2012 at 7:33 am

    Why are the “steps” always up?
    =======================================
    Because we’re at the bottom……
    ….when you’re at the bottom, you can only go up

    If we went down from here, that would truly be unprecedented ……….

  40. I’m sick and tired of being sick and tired.

    I saw this http://forecast.weather.gov/product.php?site=SHV&product=PNS&issuedby=SHV coming out my local NWS office and couldn’t help myself after being inspired by two articles, one above, the other was “The ‘great dying of thermometers’ – helping GISS find the undead thermometers… and a response by Max Hugoson, June 7, 2010 at 9:49 am discussing the BTU content of air at various temp and humidity.

    Below is my response. Edited for privacy.

    Webmaster, please forward to the appropriate meteorologist.

    Comments on: http://forecast.weather.gov/product.php?site=SHV&product=PNS&issuedby=SHV

    Does the NOAA/NWS have any plans to calculate or report the actual stored energy in the atmosphere when making high temperature measurements? When making a claim such as the year 2011 was one of the hottest years ever the thought that degreed and accredited meteorologists seemingly ignore the fact that “cooler” air with substantially greater humidity contain a significantly greater quantity of heat energy makes the claims ring false.

    You also appear to ignore, or simply not report the fact that the same energy delivered to the earths surface (soil) will heat the soil to a higher temperature when the proportion of water in the soil is at a theoretical minimum as we had through the 2011 summer. Owing to the heat storage capacity of the water molecule vs. the negligible heat storage capacity of air, and the re-radiation of the heat energy from the soil back to the atmosphere, it’s no wonder that 2011 easily ranks as one of the “hottest” years ever. Had we been receiving any significant amount of rainfall and had the same temperatures along with normal humidities then we would have something newsworthy.

    Examples: 105 F and 15% R.H. = 33 BTU/cu.ft. of air vs. 85 F and 70% R.H. = 38 BTU/cu.ft. of air

    As it is, the actual heat energy contained in the atmosphere was not significantly different compared to the normal values of the region surrounding Shreveport. Please make those clarifications in the record report contained on the home page of station shv.

    I send this email from my company email address, but the opinion expressed is my own and does not necessarily reflect that of XXXXXXXXXXX.

    Thank you, and I await a reasoned response disputing my arguments or a clarification of the record report on your webpage.

    Phillip XXXXXXXXXX.
    Senior Plant Chemist
    XXXXXXXXXXXXXXX
    O: XXX.XXX.XXXX
    BB: XXX.XXX.XXXX

  41. @JT
    “Lets not forget that a complex, chaotic, non-linear system like the climate system might respond to a steady anthropogenic forcing with discrete (stepwise) state changes.”

    I’m beginning to doubt whether the earth’s climate can be described as a chaotic system. Looking at the records the earth seems to have a remarkable temperature regulation system. There have not been wild excursions which you would expect from a chaotic, non-linear system. There have been changes over geological time but were these chaotic?.. The temperature over the last 1000 years appears to have been remarkably steady within a relatively narrow band. Just because we don’t understand the mechanisms doest make them chaotic.

  42. Rob Potter says: “averaging across very large geographic regions (and using such averages to fill in places where the data is not available) really is losing most of the information.”

    That is the problem with statistics. Picking start/stop over such a large time period one can demonstrate a reasonable clam. Jens is using raw data rather than the often used adjusted data that is then messaged further. It is an interesting look at temperature change in certain climate areas. Climate to my understanding is wet, dry, continental, tropical, marine, etc. Those are what they are because of continents and oceans local influence. If those climates warm or cool, it does not change the climate. But my profession is not climatology, just a curious George.

  43. I’m not clear on what the black lines in figures 2(x) represent.

    It would appear to show a level period of some variable number of years with a step up (or down) at irregular intervals.

    Is the “flat” region intended to convey that there is no trend in this period? e.g. 1976 – 2005 in figure 2a.

    I think this is very important, because if there truly is NO trend during this interval, this implies that the natural decay after the step precisely matches the AGW signal as proposed by R Gates above – a precise match that is so unlikely that is can be discounted.

    However if the flat line is just there to connect the steps, then the possibility of a saw-tooth that would naturally returns to zero except for AGW remains. Which is it?

  44. Why are the steps always up?

    Easy! To make the past look colder and the present warmer. Ask any team member or any of their apologists.

  45. I can’t wait for the heavyweights :)

    This appears to be a rather large cat amongst the pigeons. Thank you Jens.

    Leif – we emerge from a “little” ice age. If the steps (any of them) were “down” I would increase my fear of the coming cold period (post 2013)

    Alan Statham is a fictional character in the British sitcom Green Wing, played by Mark Heap. Both the actor and the character are studies in mimicry, comic farce and buffoonery. Both are truly brilliant – the creation and the creator.

    “Our” Alan Statham, is a risible ideologue – not comic or funny – maybe farcical. Not critical in their beliefs or their thinking. Thread-jacking, religious true believer maybe, but no longer entertaining to me – if they ever were.

  46. You can’t fully know global surface temperatures by measuring air temperatures. There is too much heat in the oceans to do this. Furthermore, heat moves around too much in the oceans to think of it as a constant, unvarying factor in models of heat at the earth’s surface. The weight of the atmosphere is represented by just 33 feet of water. Roughly speaking you can think of the total heat contained in the atmosphere as amounting to the heat in just the top 33 feet of the ocean. The Argo project in which robotic floats monitor ocean temperatures to a depth of 2000 meters is an important step to take before realistic climate models will be created. Stating a global surface temperature trend based on air temperatures alone is premature. Ask the climatologists attached to the Argo project and I’m sure they will agree. In fact, Kevin Trenberth is quoted in a National Public Radio article about heat in the oceans and the Argo project as saying, “But what this does is highlight some of the issues and send people back to the drawing board.” http://www.npr.org/templates/story/story.php?storyId=88520025
    The truth is that scientists can’t fully account for what’s going on with global heat let alone the global climate. I submit that the contribution of CO2 to a global warming trend is too inconsequential to be significant or worrisome. Pointing at scant evidence such as air temperature records and proxies and sounding an alarm is akin to the barnyard rooster who thinks his crowing makes the sun rise. Climatologists need to attend to the quality of their arguments and refrain from thinking themselves important simply because important matters are at hand.

  47. Les Johnson says:
    January 5, 2012 at 8:22 am
    “Why are the “steps” always up?”
    They aren’t. Fig 2a and 2b shows a negative step change.

    They don’t. That last data point does not qualify as a step change.

    Stephen Wilde says:
    January 5, 2012 at 9:05 am
    “Why are the “steps” always up?”
    What makes you think they were ‘up’ between MWP and LIA ?

    What makes you think there were steps back then?

  48. Leif, it appears to me that the steps have been predominantly up since the 1750s but predominantly down the previous 250 years.

    Don’t ask me why?

  49. PRD says:”I’m sick and tired of being sick and tired.”

    Amen. Agenda driven science of meteorological cherry picking is the new norm that discredits the occupation. It is viral in scope. Not to politicize the blog, but a lot of this is out of control through our lack of competent leadership; who are …. I won’t go there.

    Good luck.

  50. Titan 28 says:

    “Re Alan Statham:
    Your aspersion regarding Anthony Watts tells us more about you than it does about him. Anyone who has read this blog, even those who now and then disagree with WUWT, realize Anthony Watts is a man of integrity and smarts. If you have an argument to make about this particular entry, then make it. Don’t just snidely squeak from your hole in the ground. Put another way, you think you’re so smart, how about showing us? Make the case.”

    Good comment. Repeated for effect.

  51. Leif Svalgaard said @ January 5, 2012 at 7:33 am

    “Why are the steps always up?”

    ______
    Until a study similar to FR2011 were to show a shift down in the underlying long-term linear rise in temperatures, the steps would always have to be up. Since the forcing from the additional greenhouse gases isn’t going away anytime soon, expect the steps to always be up, though of course we could get periods where the natural variations (solar, ocean, volcanic) are working nearly in unison against the anthropogenic greenhouse forcing, such that the “step up” is more a step sideways for a while, but these natural forcings will not work in the same direction for long…i.e. look for another potential “step up” in the next few years if solar and ocean cycles once more work in the same direction for a period of time along with anthropogenic forcing.

  52. A physicist says:
    January 5, 2012 at 8:18 am

    { . . . we are left with reasonable questions like “If El Niños cause abrupt temperature step changes upward, why wouldn’t La Niñas cause equivalent abrupt temperature step changes downward?”}

    By quoting the above, you imply you believe it is a reasonable question. It is not. El Niños are a release of and movement eastward of quite warm water that has accumulated in the western Pacific Ocean. La Niñas are the sloshing of that same warm water in the return direction. There is no reason to expect moving warm water westward to cause average global temperature to decrease. If you or the person quoted think the renewed upwelling of cold water off the coast of SA is the major component of a La Niña – to be looked to for a step change down – show some numbers.

  53. Frank K. says:
    January 5, 2012 at 8:49 am

    What I’d also like to know is if these “steps” are seen in the numerical climate model predictions, and, if not, why not?
    _____
    Only to the extent that “natural variability” can ever be seen in the climate model predictions, which would be very little. Specifically what would have to be seen are times when all the factors of natural variability (ocean, solar, volcanic) align themselves in the same direction as the underlying forcing from greenhouse gas increases, such that a step-up would be indicated. Much more logical is to go back after the fact and remove these forcings to see what the underlying linear rise is…as Foster & Rahmstorf did.

  54. A Physicist said:

    More broadly, step-change models have an unbounded number of independently adjustable steps. So why should we embrace arbitrarily-complicated step-change models, when non-step models like Foster & Rahmstorf (2011) — which are mathematically simpler and physically well-motivated — describe the overall climate-change data impressively well?…

    Conversely, if step-change models cannot make even this one basic prediction, why should we embrace them at all?

    Is this work considered a model? Or is it a thesis based on actual observation. In the comments several AGW advocates have knocked this bit of research because it doesn’t offer predictions… Which, BTW, I though was not the purpose of climate models in the first place. Aren’t they supposed to be “projections”?

    With many of the ocean current phenomena going negative, the next five years are going to be very interesting indeed!

  55. Latitude says: Why are the “steps” always up? Because we’re at the bottom … when you’re at the bottom, you can only go up.

    What concerns many climatologists about the 600-million-year graph that Latitude provided, is that the sun has been growing (linearly) hotter throughout all of it. As the graph shows, the steady increase in our sun’s hotness has been offset by a steady decrease in planetary CO2 levels.

    The common-sense possibility that seriously worries many climatologists is that we carbon-burning humans are irretrievably breaking the CO2 offset mechanism that Latitude’s graph shows so vividly. The simplicity of the Foster & Rahmstorf (2011) analysis (as independently verified by many here on WUWT), and the robustness of the heating trend that analysis shows, indicates that this possibility should be regarded seriously.

  56. John F. Hultquist says:
    January 5, 2012 at 9:51 am
    A physicist says:
    January 5, 2012 at 8:18 am

    { . . . we are left with reasonable questions like “If El Niños cause abrupt temperature step changes upward, why wouldn’t La Niñas cause equivalent abrupt temperature step changes downward?”}

    By quoting the above, you imply you believe it is a reasonable question. It is not. El Niños are a release of and movement eastward of quite warm water that has accumulated in the western Pacific Ocean. La Niñas are the sloshing of that same warm water in the return direction. There is no reason to expect moving warm water westward to cause average global temperature to decrease. If you or the person quoted think the renewed upwelling of cold water off the coast of SA is the major component of a La Niña – to be looked to for a step change down – show some numbers.
    _____
    As has been accurately pointed out is the fact that El Nino’s are not the opposite of La Nina’s, however, in one regard they are– and that’s the net energy gain or loss by the oceans. This is not to say they are exactly opposite in magnitude, but they are in direction, such that, globally speaking, El Nino’s show a net energy loss from the oceans, and La Nina’s see a net energy gain. What has happened over the past 30+ years is that there has been less energy loss during El Ninos than gained during La Ninas or ENSO neutral periods. This in itself adds to the “step up” phenomenon. Some would also posit that this net energy gain by the oceans is at least part of extra energy kept in the system from the additional greenhouse gases.

  57. R Gates says:

    While skeptics are keen to criticize the Foster and Rahmstorf study, or at least significantly question certain areas of it, in fact, your analysis of the “step wise” increases only reinforces the validity of this study, and the ultimate finding that when factoring out the natural variability such as ocean, ENSO, and volcanic activity, a steady linear (i.e. non accelerating) rise in temperatures can be seen in the record. The “step wise” increases only occur when natural variations (i.e. ocean & solar & volcanic) line up with the underlying forcing coming from greenhouse gases.

    If the rise in air temps are cause (more) by the oceans releasing more of its stored heat in steps rather than increases caused by extra GHG emissions , then the F & R assessment is simply incorrect.

  58. This made my day.. no better way to conclude a ridiculous argument, than to make clear .. that your opponent(s) (Alglorites) have jumped, Lemming style, to conclusions founded only in their own ideolgies, not conclusive science. I was amazed .. at the the vitriol of the attack that was issued here. It was pure venomous hatred. But the rebuttal, will likely cost me a keyboard due to spilled tea and a pulled oblique from the outburst of raucous laughter so explosive, I likely increased my carbon footprint thrice over with the needed respiration to set things right that followed. Seriously… whoo need a moment.. This was an amazing piece of Emperical..Science.. Imagine that?

  59. Leif Svalgaard says:
    January 5, 2012 at 9:44 am
    What makes you think there were steps back then?
    =================================
    Why would anyone think different?…..same things that go on now, have not changed…
    ….no one fell off the edge, it’s still roundish…………

  60. R. Gates says: “Until a study similar to FR2011 were to show a shift down in the underlying long-term linear rise in temperatures, the steps would always have to be up. Since the forcing from the additional greenhouse gases isn’t going away anytime soon, expect the steps to always be up, though of course we could get periods where the natural variations (solar, ocean, volcanic) are working nearly in unison against the anthropogenic greenhouse forcing, such that the “step up” is more a step sideways for a while, but these natural forcings will not work in the same direction for long…i.e. look for another potential “step up” in the next few years if solar and ocean cycles once more work in the same direction for a period of time along with anthropogenic forcing.”

    You crack me up with your constant position that it is all about anthropogenic forcing. Mankind is doomed. Also, you NEVER explain any other warming period. Anyway, thanks again for reminding me I am at fault for warming the planet every time I exhale. By the way, do you use paper products?

  61. Les Johnson says:
    January 5, 2012 at 8:22 am
    “Why are the “steps” always up?”

    Actually, global temperature changes, since the beginning of time, follow Lennon, McCartney, et al’s theory of Helter Skelter, published back in 1967. Abstract:

    “When I get to the bottom I go back to the top of the slide
    Where I stop and I turn and I go for a ride
    Till I get to the bottom and I see you again…
    Helter Skelter baby, Helter Skelter….”

  62. Urederra says: January 5, 2012 at 8:07 am

    I recall reading one article written by Ross McKitrick where he shows a temperature graph with a big step just when the thermometers in the canadian surface stations were changed from mercury/alcohol to thermocouples.

    Try this

  63. Les Johnson says:
    January 5, 2012 at 8:22 am
    “Why are the “steps” always up?”

    Actually, global temperatures changes, since the beginning of time, follow Lennon, McCartney, et al’s, significantly recognized and peer-reviewed theory of “Helter Skelter,” written and published, worldwide, in 1968. The following is perhaps the most relevant quote, from the abstract:

    “When I get to the bottom I go back to the top of the slide
    Where I stop and I turn and I go for a ride
    Till I get to the bottom and I see you again….
    Helter Skelter, Helter Skelter, baby….”

  64. My suggestion is that the IPCC adopt this work by Jens Raunsø Jensen as the IPCC AR5.
    And call it quits.

  65. Henry@Jens Jensen, Hultquist &&&

    I am puzzled that all the graphs here at WUWT always only show the anomalies of the average temps.
    It gives you really only half the story.
    If you were to look also at the maxima and minima, as (also) reported by each (weather) station, you get a lot more information.

    http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming

    e.g.
    Looking at the differences between the results from the northern hemisphere(NH) and the southern hemisphere (SH), what we see is happening from my dataset is that more (solar) heat went into the SH oceans and is simply taken away by water currents and/or weather systems to the NH. That is why the NH is warming and that is why the SH does not warm.

  66. R.Gates says:
    Some would also posit that this net energy gain by the oceans is at least part of extra energy kept in the system from the additional greenhouse gases.

    Henry@R.Gates
    Did anyone ever measure the change in humidity over the years?
    After looking at the daily average readings from about 20 weather stations all over the world I am finding a change of about -0.02%RH per annum, global average.

    http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming

    So, if this estimate is not far from being correct, then the average global humidity is now about o.75% RH lower than it was 37 years ago.
    If I am not mistaken (at 15 degrees C) that translates again to a loss of about 0.1% in absolute humidity.
    You see how that compares with the increase in CO2? (0.01% increase over the last 50 years)

  67. ‘a physicist’ says:

    “As the graph shows, the steady increase in our sun’s hotness has been offset by a steady decrease in planetary CO2 levels.”

    Don’t be ridiculous. The sun’s temperature [or "hotness"] has steadily increased, while CO2 levels have fluctuated. Thus your conclusion is bunkum.

  68. >>This study has established that step changes in land-based
    >>temperature records during 1960-2010 are common and very
    >>likely real and linked with natural climate events.

    Let’s rewrite that for you:

    “”This study has established that step changes in land-based temperature records during 1960-2010 are common and very likely to be linked to scientists ‘rebasing’, ‘adjusting’ or ‘fiddling’ the figures.””

    It all seems rather reminiscent of the ‘adjustments’ Anthony Watts’ discovered in station records. Check out this article by Willis Eschenbach on the rebasing of Darwin’s record, which turned a cooling trend into a warming trend.

    http://wattsupwiththat.com/2009/12/08/the-smoking-gun-at-darwin-zero/

    .

  69. Leif says: “Why are the steps always going up?”

    There are no steps. The steps are a statistical manipulation. There is no point in arguing it other than it shows another method to illustrate a change in temperatures that were chosen over a period of time out of context. Leif set you up on a side show.

  70. highflight56433 says:
    January 5, 2012 at 10:27 am
    (to R. Gates)

    You crack me up with your constant position that it is all about anthropogenic forcing. Mankind is doomed. Also, you NEVER explain any other warming period. Anyway, thanks again for reminding me I am at fault for warming the planet every time I exhale. By the way, do you use paper products?
    _____
    Funny, but my very point was that it was not all about the anthropogenic forcing, but rather the “step ups” were precisely the times that natural variability (i.e solar, oceans, volcanic) aligned themselves in the same direction as the underlying upward linear trend from greenhouse gas forcing. Also, as I have not mentioned “catastrophic” effects from the lont-term forcing from anthropogenic greenhouse gases, your “Mankind is doomed” comment seems to be coming from you, as it certainly isn’t from me.

  71. >>The common-sense possibility that seriously worries many
    >>climatologists is that we carbon-burning humans are irretrievably
    >>breaking the CO2 offset mechanism that Latitude’s graph shows so vividly.

    And the common-sense possibility that seriously worries many botanists, is that if the CO2 levels continued southwards below 250 ppm, then all plant life would die. The industrial Revolution happened at an opportune moment, and has prevented botanical asphyxiation.

    .

  72. R. Gates said: “Global temps will “step up” during these alignments of natural and anthropogenic forcings, and while they may fall back from the peaks of these “step up” periods, they never fall back to lower levels that break the underlying the long-term anthropogenic warming.”

    But why is it not a case of “they never fall back to lower levels that break the underlying long-term natural rise that started at the end of the LIA?” Sorry if this seems like a really stupid question.

  73. While we’re on about temp data.

    I see the hopeless NZ Chicken Little AGW/CC Lemmings over at Hot Topic have awarded WUWT a Climate BS Award, re take on the BEST Data.

    Gee it’s Rich coming from them. Considering the Numerous Climate BS Awards that could go for fraud, dishonesty and over exaggerations, etc to AGW/CC!

    Prat Watch #2: the 2011 Climate BS Awards

    http://hot-topic.co.nz/2011-climate-bs-awards/

  74. Michael J Alexander says:
    January 5, 2012 at 10:14 am
    (to R Gates):

    “If the rise in air temps are cause (more) by the oceans releasing more of its stored heat in steps rather than increases caused by extra GHG emissions , then the F & R assessment is simply incorrect.”
    _____
    The rise in atmospheric temperature are is not singularly caused by the oceans releasing more heat than they take up during El Ninos as FR2011 showed quite clearly an underlying linear rise in atmospheric temperatures when factoring out the energy added to the atmosphere from El Ninos. FR2011 showed that the natural variations will sometimes work with, and sometimes work against anthropogenic greenhouse forcing, and it’s also important to remember that other anthropogenic forcings, such as from aerosols, can also work in the opposite direction to greenhouse forcing.

    Here’s the best thing about the FR2011 study– it makes a specific, verifiable prediction going forward, as it gives a specfic linear rise in temperatures that should be seen quite readily in future years once the natural variability is factored out. In some years the natural variability will add to this longer-term linear rise and some years it will work against it, but the underying rise should always be there (because the greenhouse gases are surely going to be). Skeptics are always wanting specific ways that AGW can be disproven…well, here you go.

  75. David, UK says:
    January 5, 2012 at 11:22 am
    R. Gates said: “Global temps will “step up” during these alignments of natural and anthropogenic forcings, and while they may fall back from the peaks of these “step up” periods, they never fall back to lower levels that break the underlying the long-term anthropogenic warming.”

    But why is it not a case of “they never fall back to lower levels that break the underlying long-term natural rise that started at the end of the LIA?” Sorry if this seems like a really stupid question.

    _____
    Simply put, the greenhouse forcings from the 40% additional CO2, and similar increases in NH2 and N2O are always present and collectively they present that linear rising “baseline” trend that FR2011 found, and around which natural variations from solar, oceans, volcanic can only vary up or down for shorter perids, but they can’t and don’t affect the long-term upward forcing.

  76. The common-sense possibility that seriously worries many climatologists is that we carbon-burning humans are irretrievably breaking the CO2 offset mechanism that Latitude’s graph shows so vividly.

    Ralph says: And the common-sense possibility that seriously worries many botanists, is that if the CO2 levels continued southwards below 250 ppm, then all plant life would die. The industrial Revolution happened at an opportune moment, and has prevented botanical asphyxiation.

    Ralph, that claim is truly remarkable, in that (personally) I have never seen it made by any scientist (botanist or otherwise).

    As Willis Eschenbach is fond of requesting (and quite rightly), could you please provide some citations to the effect that declining CO2 levels “seriously worry many botanists”? Thanks!

  77. JT: Lets not forget that a complex, chaotic, non-linear system like the climate system might respond to a steady anthropogenic forcing with discrete (stepwise) state changes. Thus the contention that

    “The logical consequence is that natural processes have been the major cause for the temperature change during this period, leaving a secondary role to other causes such as the anthropogenic greenhouse effect.”

    is not necessarily correct as it could be that the observed “natural processes” are themselves the natural effects of the anthropogenic greenhouse cause.

    However, I do agree that

    “the presence of step changes invalidates the widely used statistical techniques of linear trend and smoothing as means of identifying the pattern of temperature variation during 1960-2010″

    The best measure of the gradually accumulating heat might be the gradually increasing mean temperature, even as the distribution of the heat has the stepwise character presented in the main post. I mention this as a possibility; I don’t disagree with what you wrote.

  78. Ralph says:
    January 5, 2012 at 11:21 am

    And the common-sense possibility that seriously worries many botanists, is that if the CO2 levels continued southwards below 250 ppm, then all plant life would die. The industrial Revolution happened at an opportune moment, and has prevented botanical asphyxiation.

    ____
    We didn’t get “botanical asphyxiation” during the past several million years of cycles of glacial advances when CO2 levels would routinely drop to 180ppm, so the notion that we’d get is when levels dropped below 250 ppm is of course unfounded on any science, or logic for that matter.

  79. R. Gates says: “Funny, but my very point was that it was not all about the anthropogenic forcing, but rather the “step ups” were precisely the times that natural variability (i.e solar, oceans, volcanic) aligned themselves in the same direction as the underlying upward linear trend from greenhouse gas forcing. Also, as I have not mentioned “catastrophic” effects from the lont-term forcing from anthropogenic greenhouse gases, your “Mankind is doomed” comment seems to be coming from you, as it certainly isn’t from me.”

    My case made. You do not go any where but the same mantra.

  80. R Gates cites the work of Foster & Rahmstorf (F&R) which suggested that after removing exogenous factors from the temperature records (El Ninos/Ninas, Volcanoes and TSI) you are left with a more-or-less steady rate of temperature increase. The question is “Is the work of F&R compatible with Jensen’s claim that much of the temperature increase in the last few decades occurs in step changes?”

    In his analysis of the Hockey Stick, Steve McIntyre showed that feeding a stochastic red-noise data set into his approximation of the Mann algorithm inevitably produced a Hockey Stick. It would be interesting to start with an F&R temperature linear series, add in stochastically the ‘noise’ around that series, add in the same three factors and see how often, if at all, the Regime Shift Detection tool of Rodionov found ‘steps’ in the synthetic data sets.

  81. R. Gates says:
    January 5, 2012 at 11:47 am
    We didn’t get “botanical asphyxiation” during the past several million years of cycles of glacial advances when CO2 levels would routinely drop to 180ppm, so the notion that we’d get is when levels dropped below 250 ppm is of course unfounded on any science, or logic for that matter.

    Try this simple experiment, Mr. Gates. Put your ivy, or whatever little plant you might have into a sealed glass container with adequate soil and moisture. Put it near a sunny window so that it continues to receive adequate sunlight. Without ever opening the container or allowing an exchange of the atmosphere sealed within the container, measure the growth. Alongside this container have an identical plant in the same soil and same soil volume that also receives adequate moisture and sunlight. Talk to this uncontained plant whenever practical.

    Measure the growth of these two plants over the course of a month, two months, etc.

    This should suitably display what a lack of CO2 will do for plants that otherwise have little to no other limiting factor to their growth. (Liebigs law)

  82. highflight56433 says:
    January 5, 2012 at 12:09 pm
    R. Gates says: “Funny, but my very point was that it was not all about the anthropogenic forcing, but rather the “step ups” were precisely the times that natural variability (i.e solar, oceans, volcanic) aligned themselves in the same direction as the underlying upward linear trend from greenhouse gas forcing. Also, as I have not mentioned “catastrophic” effects from the lont-term forcing from anthropogenic greenhouse gases, your “Mankind is doomed” comment seems to be coming from you, as it certainly isn’t from me.”

    My case made. You do not go any where but the same mantra.
    ____
    Your case made? I suppose if your “case” is to try to prove that black is white, or visa versa.

    And in respect to my going to the same “mantra”…it is the nice thing about the laws of physics that they are so consistent.

  83. “The station level data is from GHCN (“after combine”, http://data.giss.nasa.gov/gistemp/station_data/ ) and include ALL stations with a complete record in the period 1960-2010 in broadly defined sampling regions (ref. Fig. 1).”

    oh dear.

    there’s your problem sparky.

    1. you are using an old dataset
    2. looks like you’ve found one of the things we already knew about RSM.. you realize
    that “after combine” means after the old RSM method is applied. You are looking
    at stations that have been “combined” by GISS to create artifical “new” stations from a
    collection of pieces. It’s not GHCN data after that step.

    If you want to do regime shift detection ( I used that package back in 2007-2008) I would
    suggest that you

    1. Not get your data from the GISS site, but go directly to the source: Ghcn monthly, or better
    Ghcn daily.
    2.. Not use data where stations have been “combined” . Either use raw or homogenized
    3. Have a look at some of the better struc change packages out there ( see Cran )

    4. look at the US records as well.

  84. @R. Gates said:

    And in respect to my going to the same “mantra”…it is the nice thing about the laws of physics that they are so consistent.

    ——————————–

    Ahhh, but that is not technically accurate as the laws of physics are not consistent as they are applied differently depending on the scale, i.e. large bodied objects’ behavior can be predicted by classical Newtonian physics and small bodied objects’ behavior can be predicted by quantum physics.

  85. So, as any decent geologist will confirm, climate change is normal and natural – at least it has been for at least the last 600 million years.. The only question remains is just how much of the global temperature rise of ~0.7 degrees C over the past 150 years is man made and howmuch is natural climate cycles.

    The alarmists say the rise is all the fault of man, while the sceptics say man could have caused around 20-30% of the warming.

    The alarmists want to try and fix the climate to stay a steady state, which is obviously impossible to all but the most simple minded. The cost of trying to achieve this impossible goal will beggar the western world, while the eastern world just looks on and laughs at the stupidity of our politicians promoting this alarmist nonsense.

  86. Has there been any work done to look at the data being collected from thousands of small weather stations around the world by http://www.wunderground.com/ ? Something like 12,000 in the US alone, over 20,000 world wide.

    REPLY: No, and the problem with those is that many are even more problematic in siting than USHCN and GHCN stations. Plus, many are these cheap Chinese POS weather stations made by Oregon Scientific and LaCrosse – from experience I can tell you they lack out of the box accuracy and have tendency to drift over the long term. Exposure of the thermometer sensors in these is also very problematic. There are some good stations in this network, such as Davis Vantage Pro which have NIST traceable calibrations, but the siting of these is still a big unknown. – Anthony

  87. Changes in a global average is not evidence for a global effect as the cause.

    While I applaud a regional analysis, this study to a degree falls into the same logical fallacy (of underlying global causes).

    Without a plausible mechanism, I’m inclined to think the steps are a statistical artifact (of the method).

    R Gates said,

    it’s also important to remember that other anthropogenic forcings, such as from aerosols, can also work in the opposite direction to greenhouse forcing.

    In recent decades global aerosol levels have declined, which means the aerosol forcing has been in the same direction as GHGs (ie warming).

  88. Step changes in average surface temperature are present in regions that are not highlighted in this post. For instance there was a major upward step change in New Zealand in the mid 1950’s that was followed by 60 years of relatively flat trend, particularly in the South Island.

    I am personally suspicious of arguments that the various step changes can simply be averaged out to give the global AGW signal. If ultimately we start to see numerous (natural) regional step changes in the other direction then how are the alarmists going to rationalise that?

  89. Some of the ‘steps’ will also be splice artifacts from the ‘homogenizing’ process.

    There are assumptions made when segments from different thermometers (some with the same name but slightly different locations or hardware) are merged to make a single “record” of a “place”.

    If demonstrated how this can be happening in the data in:

    http://chiefio.wordpress.com/2010/04/03/mysterious-marble-bar/

    Which takes the individual station data and one step at a time merges them (individual flat) into a longer term rising “trend” (that matches the “trend” found by GIStemp). I then developed a method to look at the data without that splice artifact and found much different results from GISTemp. (The dT/dt method to the right of that link in categories)

    Since then they have eliminated individual station data from GHCN and moved the “splicing” out of GIStemp and “upstream” to inside NOAA / NCDC (where, on presumes, they hope it will not be as visible…)

    IMHO, some of the timing on when particular thermometers come into and leave the system are curiously synchronized with some of those natural cycles and can help facilitate the occurrence of such “spice artifacts” from the homogenizing process.

    So while I’m pretty sure a lot of the step function is from natural causes, I suspect that is then reflected (perhaps with added ‘vigor’) in the temperature record via the way different thermometer segments are spliced to create a fictional record of longer duration.

  90. One reason we might only see step ups has to do with how the planet manages heat. If the method is absorption into the oceans and infrequent releases of that energy, then you would expect the increases to be in steps. If the cooling is just the lack of heat injections then it would be slow/steady and we would not see steps down.

    Not to say there couldn’t be a stepwise cooling mechanism, it just may not be active in our current climate.

  91. Urederra says:
    January 5, 2012 at 8:07 am

    “I recall reading one article written by Ross McKitrick where he shows a temperature graph with a big step just when the thermometers in the canadian surface stations were changed from mercury/alcohol to thermocouples. I may be recalling the whole thing wrong though.”

    Is this the one?

    http://www.uoguelph.ca/~rmckitri/research/nvst.html

  92. Interesting approach and it addresses one of my major problems with the whole process of deriving a “global average temperature” — you lose so much potentially interesting information in creating the average. I believe it was on this blog someone commented ” global average temperature fits the earth’s climate like a burlap sack fits Paris Hilton”, or words to that effect. In point of fact a burlap sack will fit Paris Hilton, but it will also hide all the most interesting regional departures from the average shape.

  93. If this sediment core data is at all accurate then temperature has been trending down and becoming more chaotic for the last several million years. How anyone can say anything about a trace gas having any recent effect is patently ridiculous. (Sorry, the chart was found on wikipedia.) Seems I saw a similar graphic of ice core data in Unscientific American last year or so that showed the opposite, with temperature more stable over the last 3 mm or so years. I argue that climate is chaotic with too many variables to predict particularly over the short (thousands of years) term.

    http://en.wikipedia.org/wiki/File:Five_Myr_Climate_Change.svg

  94. I have a small technical question: your post keeps mentioning “significance”, but how do you define significance here? What probability is your p-value exactly representing? I ask, because the use of “traditional” significance measures does not make sense in this context, and these measures cannot be used to evaluate “model fits”, which I assume is what you are after. Any background information or reference to papers that contain this information are welcome. Thanks in advance.

  95. Have to agree with JT here. The homogeneous solutions to the earth climate system my have discrete structure that is being probed by the forcing caused by CO2. However, If the climate model are worth anything, they should have seen this structure. Question is only how long it takes before they do and how ugly the fix will be to make them do so.

  96. Justin K says:
    January 5, 2012 at 12:45 pm
    @R. Gates said:

    And in respect to my going to the same “mantra”…it is the nice thing about the laws of physics that they are so consistent.

    ——————————–

    Ahhh, but that is not technically accurate as the laws of physics are not consistent as they are applied differently depending on the scale, i.e. large bodied objects’ behavior can be predicted by classical Newtonian physics and small bodied objects’ behavior can be predicted by quantum physics.

    ____
    Though we’ve not yet found the perfect unification in the laws of quantum effects and gravity, we certainly will someday as such a unification certainly does exist, and it will be as consistent as the very existence of stars, galaxies, and all the rest of the wonderful things that make up this universe. It takes both quantum effects and gravitational effects to allow you to even exist here on earth, so feel glad for that very stable consistency.

  97. Alan Statham says:
    January 5, 2012 at 6:17 am
    “This is laughable. Your starting premise – “any presence of major step changes in mean temperature regime may contradict the claims of the AGW theory and models” – is wrong. You’ve used an arbitrary subset of the available data. Your methodology consists of drawing arbitrary lines on that data. Your conclusions, as a result, are wildly erroneous.”

    Apparently, you are nominating the author for a lead author position with the IPCC. Good judgement!

  98. Philip Bradley says:
    January 5, 2012 at 1:15 pm

    In recent decades global aerosol levels have declined, which means the aerosol forcing has been in the same direction as GHGs (ie warming).
    _____

    Actually, this is not true for the period after 2000. Stratospheric Aerosols have shown an increase over the past 10 years or so, at least partially off-setting some of the forcing caused by the increases in greenhouse gases. See:

    http://www.noaanews.noaa.gov/stories2011/20110721_particles.html

  99. JT says:
    January 5, 2012 at 6:17 am

    “Lets not forget that a complex, chaotic, non-linear system like the climate system might respond to a steady anthropogenic forcing with discrete (stepwise) state changes.”

    Warmists bring up this idea of a chaotic system constantly but only in defense of their other theories. They never manage to explicate it or show that it is well confirmed. The modelers do not address a chaotic system. The paleoclimatologists do not address a chaotic system.

    Who among climate scientists addresses a chaotic system? What confirming evidence do they provide?

  100. thepompousgit says:
    January 5, 2012 at 8:17 am

    Thanks for the info. Please give us a reference to get us started on this particular topic.

  101. Jan de Ruiter says: I have a small technical question: your [Jensen's] post keeps mentioning “significance”, but how do you define significance here? What probability is your p-value exactly representing? I ask, because the use of “traditional” significance measures does not make sense in this context, and these measures cannot be used to evaluate “model fits”, which I assume is what you are after. Any background information or reference to papers that contain this information are welcome. Thanks in advance.

    Jan makes a good point. The tool that Jensen (the Regime Shift Detection tool) is using tests the null hypothesis that the data points are: (1) normal, (2) stationary, and (3) independent.

    However, even in the absence of regime shifts (“steps”) we have reason to anticipate that the data-set being analyzed is non-normal, non-stationary, and non-independent, and so we expect that the statistical significance values assigned by the Regime Shift Detection tool will be fragile (not robust).

    As a common-sense example, in Figure 2a the claimed significance is “0.000001”, and yet the unaided eye has great difficulty seeing any step changes in the data at all.

  102. R. Gates said @ January 5, 2012 at 3:18 pm

    “Though we’ve not yet found the perfect unification in the laws of quantum effects and gravity, we certainly will someday as such a unification certainly does exist, and it will be as consistent as the very existence of stars, galaxies, and all the rest of the wonderful things that make up this universe.”

    R Gates, you seems to know more about these things than Stephen Hawking. When did you receive your Nobel prize in Physics?

    Quoting Hawking:

    “But I think that quantum theory and gravity together, introduces a new element into the discussion that wasn’t present with classical Newtonian theory. In the standard positivist approach to the philosophy of science, physical theories live rent free in a Platonic heaven of ideal mathematical models. That is, a model can be arbitrarily detailed and can contain an arbitrary amount of information without affecting the universes they describe. But we are not angels, who view the universe from the outside. Instead, we and our models are both part of the universe we are describing. Thus a physical theory is self referencing, like in Godel’s theorem. One might therefore expect it to be either inconsistent or incomplete. The theories we have so far are both inconsistent and incomplete.

    Quantum gravity is essential to the argument. The information in the model can be represented by an arrangement of particles. According to quantum theory, a particle in a region of a given size has a certain minimum amount of energy. Thus, as I said earlier, models don’t live rent free. They cost energy. By Einstein’s famous equation, E = mc squared, energy is equivalent to mass. And mass causes systems to collapse under gravity. It is like getting too many books together in a library. The floor would give way and create a black hole that would swallow the information. Remarkably enough, Jacob Bekenstein and I found that the amount of information in a black hole is proportional to the area of the boundary of the hole, rather than the volume of the hole, as one might have expected. The black hole limit on the concentration of information is fundamental, but it has not been properly incorporated into any of the formulations of M theory that we have so far. They all assume that one can define the wave function at each point of space. But that would be an infinite density of information which is not allowed. On the other hand, if one can’t define the wave function point wise, one can’t predict the future to arbitrary accuracy, even in the reduced determinism of quantum theory. What we need is a formulation of M theory that takes account of the black hole information limit. But then our experience with supergravity and string theory, and the analogy of Godel’s theorem, suggest that even this formulation will be incomplete.

    Some people will be very disappointed if there is not an ultimate theory that can be formulated as a finite number of principles. I used to belong to that camp, but I have changed my mind. I’m now glad that our search for understanding will never come to an end, and that we will always have the challenge of new discovery. Without it, we would stagnate. Godel’s theorem ensured there would always be a job for mathematicians. I think M theory will do the same for physicists. I’m sure Dirac would have approved.”

    http://www.hawking.org.uk/index.php/lectures/91

  103. >> Rob R says:
    >> January 5, 2012 at 1:24 pm
    >> Step changes in average surface temperature are present in regions
    >> that are not highlighted in this post. For instance there was a major
    >> upward step change in New Zealand in the mid 1950′s that was
    >> followed by 60 years of relatively flat trend, particularly in the
    >> South Island.

    I hope these trends weren’t derived from NIWA’s ridiculous Seven Station
    Series, which they skite about on their website as being “representative of
    New Zealand”. The four in the South Island are all (near-)coastal.

  104. re: Leif Svalgaard says:
    January 5, 2012 at 7:33 am
    Why are the “steps” always up?

    One Viking asked another, in Greenland in the year 1300, “Why are the steps always down?”

    Answer that question and you’ll answer your current one.

  105. I am unconvinced.

    On some of these graphs a step looks like maybe it might be a better fit than a straight line. But others – especially the ones you have kitted out with multiple steps, look more like straight lines than a bunch of steps to me. You can model a straight line with steps if you use enough steps. But why should you? Where is the analysis to show that steps actually do a better job than straight lines at fitting to these curves? The Mk1 eyeball just doesn’t cut the mustard in this situation.

    Anthony sometimes fits a sine wave to his temperature series. But he always includes the disclaimer that this is for amusement only. Your analysis needs a similar disclaimer. Instead however you make wild claims which massively overreach the extent of your analysis.

    So you fitted steps to some generally increasing graphs. It is a very long way from there to the claim that “Abrupt changes … contradict the anthropogenic global warming (AGW) claims”.

    I am … highly sceptical … of your claims.

  106. Theo Goodwin said @ January 5, 2012 at 4:02 pm

    “thepompousgit says:
    January 5, 2012 at 8:17 am

    Thanks for the info. Please give us a reference to get us started on this particular topic.”

    Horizontal gene transfer
    From Wikipedia, the free encyclopedia
    “HGT” redirects here. For other uses, see HGT (disambiguation).

    Horizontal gene transfer (HGT), also lateral gene transfer (LGT), is any process in which an organism incorporates genetic material from another organism without being the offspring of that organism. By contrast, vertical transfer occurs when an organism receives genetic material from its ancestor, e.g., its parent or a species from which it has evolved.
    Horizontal gene transfer is also the primary reason for bacterial antibiotic resistance [1][2][3][4] and this often involves plasmids.[5]. Genes that are responsible for antibiotic resistance in one species of bacteria can be transferred to another species of bacteria through various mechanisms (e.g., via F-pilus), subsequently arming the antibiotic resistant genes’ recipient against antibiotics, which is becoming a medical challenge to deal with. This is the most critical reason that antibiotics must not be consumed and administered to patients without appropriate prescription from a medical physician.[6] Most thinking in genetics has focused upon vertical transfer, but there is a growing awareness that horizontal gene transfer is a highly significant phenomenon and amongst single-celled organisms perhaps the dominant form of genetic transfer.[citation needed] Artificial horizontal gene transfer is a form of genetic engineering.

    http://en.wikipedia.org/wiki/Horizontal_gene_transfer

    —————————————————————————————–

    There’s a bunch of references at the foot of the article. It’s also a rather neater explanation for some 30+ species acquiring the C4 process in a very short space of time, rather than invoking coincidence.

  107. PRD says:
    January 5, 2012 at 9:18 am
    I’m sick and tired of being sick and tired.

    I fully agree with your points on enthalpy. It seems that professional meteorologists and many on these blogs have been drawn into the simplistic thinking disregarding humidity and using ‘average atmospheric temperatures’. The post is a good one but is the incorrect argument. We should be using your argument:

    “Examples: 105 F and 15% R.H. = 33 BTU/cu.ft. of air vs. 85 F and 70% R.H. = 38 BTU/cu.ft. of air”

    And keep repeating the enthalpy argument back to people who can only talk in atmospheric temperatures

    As I posted in the ‘Big Picture’ thread:

    “Let us take a cool humid afternoon in Louisiana after a rainstorm has just stopped and the air temperature is a relatively cool 25C (77F) but the humidity is close to 100% at the same time in the Arizona desert after several weeks of drought the temperature is a really hot 38C (100F) but the air is almost zero humidity. It may come as a surprise to some that the 25C atmosphere in Louisiana holds twice the energy 76.9KJ/Kg, as the dry 38C atmosphere in Arizona 38.3KJ/Kg . If there are actually droplets of water for example a post shower mist in the Bayou then the energy content of the 25C Louisiana atmosphere is considerably greater. This is due to the enthalpy difference between saturated and dry air. (see http://www.engineeringtoolbox.com/enthalpy-moist-air-d_683.html )”

    If meteorologists were to really understand enthalpy they would be pointing out that ‘averaging’ temperatures from the just post dawn minimum with high humidity with the late afternoon maximum in lower humidity is nonsensical and only exhibits ignorance of basic meterorology and atmospheric physics. The accuracy of reading the temperatures, the mathematics of the averaging of temperatures and the statistical analyses of the extracted values may be faultless – but the results are based on a totally invalid assumption: atmospheric temperature is not a metric for atmospheric heat content. It is the heat energy budget that the AGW proponents claim is the problem so they should be measuring atmospheric heat content. We should not join the ignorant climate ‘scientists’ under their lampost – we should be pointing out their ignorance and correcting them every time they say ‘atmospheric temperature’.

  108. A physicist says:

    Jens, the folks on SkepticalScience are questioning whether step-change models make any testable predictions. When we strip away the pointlessly tendentious SkepticalScience rhetoric (which I condemn!) we are left with reasonable questions like “If El Niños cause abrupt temperature step changes upward, why wouldn’t La Niñas cause equivalent abrupt temperature step changes downward?”

    More broadly, step-change models have an unbounded number of independently adjustable steps. So why should we embrace arbitrarily-complicated step-change models, when non-step models like Foster & Rahmstorf (2011) — which are mathematically simpler and physically well-motivated — describe the overall climate-change data impressively well?

    I too have my doubts about step models. Clearly, if you have any trending dataset, there will be a step model that approximates it better than a flat line. A step detector will find that model. However, there is a reason why steps might be expected. In chaos theory, there is the concept of an attractor. Briefly, a chaotic system can ‘orbit’ an attractor (a set of values for variables, such as temperature, etc.) and if the system receives a severe ‘bump’ it can be jogged into a regime where it orbits a completely different attractor. The book “The Death of Economics” by Paul Ormerod contains a very readable discussion in the context of economic variables such as inflation, employment figures, boom/bust cycles etc.

  109. R Gates, the very fact that you keep referring to rather strong solar influences on these ups and downs of temperatures, and that you appear to be able to “see” it in these swings, makes me question your contention that CO2 has an effect as well.

  110. Stacey says:
    January 5, 2012 at 6:41 am
    Sorry if I am being stupid but I can’t see Trenberth’s comment in the link to email 3046?

    Regards

    S

    REPLY: Yes, I don’t see it either, perhaps the number for the email he gave is a typo (I added the link) – So I’ve removed the reference to Dr. Trenberth for now until Jens can clear up the discrepancy – Anthony
    >>>>
    I have already noted a month ago that certain Climategate email databases use a different numbering schemes. That is probably the problem. An email number needs a specific site also.

  111. I don’t really have any doubt that step changes are occurring and if the steps were attributed to natural changes there would be little else left. But I don’t see how steps need only be of natural origin.
    Also I have seen others argue quite plausibly that after each ENSO event there is a residual that takes some time to dissipate.
    Perhaps there would be some profit in considering the hypothesis that the “steps” are instead changes in the rate of change.

  112. So, the dispute comes down to this:
    Is there a continuous trend that artifactually looks like steps,
    or
    Are there steps which have been smoothed statistically into the apparency of a continuous trend?

    Or a small trend with overlaying steps? Or a negative trend which has been overwhelmed by a few upward steps? Or …

  113. The steps occur with an 11-year cycle after solar minima. This is to be expected as the rise to the max reinforces the background warming, while the fall to the min tends to oppose it producing a flat trend as happened in the last decade too. Expect the next step soon unless the solar max is weak.

  114. There may not be a negative step. Just because the system warms with a stepwise process does not in any way mean that it cools with an inverse process.

  115. Pamela Gray says:
    January 5, 2012 at 7:22 pm
    R Gates, the very fact that you keep referring to rather strong solar influences on these ups and downs of temperatures, and that you appear to be able to “see” it in these swings, makes me question your contention that CO2 has an effect as well.
    _______
    The two are hardly mutually exclusive, and certainly sometimes work in the same direction, and sometimes work in opposition. CO2 and all greenhouse gases certainly have an effect on climate. To deny this effect is to deny some very basic physics. The only real issue in my mind is the extent to which the 40% increase in CO2, and similar increases in N2O and methane, will have on the climate, and ultimately what effect a doubling of CO2 will have, as that is apparently where we are heading. Anyone who claims they know for certain what effect this will have, after all fast and slower earth system feedbacks are considered, is lying. No one knows for certain, though better and better estimates with higher degrees of confidence will be coming out in the months and years ahead.

  116. R gates,
    I would remind you of a mathematical fact that I’m sure you know.
    A linear increase of the form T(n) = T(n-1) + C, where “C” is a constant,
    Is a reducing NOT a constant RATE of change.
    In other words, the annual increase is becoming less and less important for each passing year.

    To have a constant RATE of increase would require T(n) = T(n-1)*(1+r)
    Where “r” is a value less that one (for example 0.02 ot 2% p.a.).

    Even if you ignore the cyclical compoent of the global temperature (cycle length abot 60 years) and the fact that the cycle seems to have peaked and is now heading down once again.
    Then the linear component is somwhere in the nature of 0.7 degrees p.a. or about 2% p.a. (expressed in degrees absolute).
    This rate of increase is therefore declining on a compound basis, year by year.

    But, as somebody with a sould grasp of science, I’m sure that you were well aware of that already.

  117. Ops = there I go again.
    Last line should read “sound” rather than “sould”.

    I repeat:
    “But, as somebody with a sound grasp of science, I’m sure that you were well aware of that already”

  118. thepompousgit says:
    January 5, 2012 at 4:28 pm
    R. Gates said @ January 5, 2012 at 3:18 pm

    “Though we’ve not yet found the perfect unification in the laws of quantum effects and gravity, we certainly will someday as such a unification certainly does exist, and it will be as consistent as the very existence of stars, galaxies, and all the rest of the wonderful things that make up this universe.”

    R Gates, you seems to know more about these things than Stephen Hawking. When did you receive your Nobel prize in Physics?
    _________
    My confidence is based on a philosophical perspective more than having a PhD in quantum physics. A ten dimensional model of the universe (with six that are wrapped up) solves many issues and can unite the quantum level and gravity. Hawking, whom I admire very much, is a giant in the field, but younger minds and newer ideas will move this field forward rapidly in the next few years and a truly unified theory is far closer than most might realize. What will blow most peoples mind’s will be the implications, especially regarding the multiverse we live in. Expect evidence of that coming in the next few years…

  119. Leif Svalgaard says:
    January 5, 2012 at 10:31 am

    Henry Galt says:
    January 5, 2012 at 9:38 am
    Leif – we emerge from a “little” ice age.

    Right, it is called Global Warming
    Right, but not ‘anthropogenic global warming’

    We are just near the peak of the curve. It’s generally downhill for the next 500 years. Unless the next 50 take us into the overdue glaciation. Unless we are at the end of the ice age and the earth returns to it’s favoured equilibrium around 8C warmer than now.

    Place your bets.

  120. http://www.apegga.com/members/Publications/peggs/Web11_02/kyoto_pt.htm

    We published this in 2002:

    Although the radiosonde record lacks the dense spatial coverage from satellites, it does extend back to 1957, a period that includes the recent rapid rise in atmospheric CO2 concentration. The radiosonde record shows no linear warming trend in global average temperature prior or subsequent to a dramatic shift in 1976-77. That warming, known as the Great Pacific Climate Shift of 1976-1977, is not attributable to human causes but is a natural shift in the Pacific that occurs every 20 to 30 years.

  121. Suppose there are both step-wise changes and a small linear trend. Since the linear trend is smaller than the step-changes, the trend would be hidden by the steps being just a little bit bigger (or smaller).

    Conclusion is that you can’t rule out a linear trend unless you can quantify the size of the steps from another data source.

  122. R. Gates said: “Simply put, the greenhouse forcings from the 40% additional CO2, and similar increases in NH2 and N2O are always present and collectively they present that linear rising “baseline” trend that FR2011 found, and around which natural variations from solar, oceans, volcanic can only vary up or down for shorter perids, but they can’t and don’t affect the long-term upward forcing.”

    I see. So you’re justifying an assumption with another set of assumptions based on the faulty assumption that H2o feedback must be positive. Brilliant.

  123. “A physicist” wrote:

    “The tool that Jensen (the Regime Shift Detection tool) is using tests the null hypothesis that the data points are: (1) normal, (2) stationary, and (3) independent.”

    If that is the case (and I have no reason to doubt this information), the use of significance measures is not informative at all. The p-value just gives the probability that this data series (or more extremely differing ones) occurs when we assume that the null hypothesis is true, that is, that the data is (1) normal, (2), stationary, and (3) independent. So here, when we see p = .0000001, we know that it is very unlikely that these data occur if the null hypothesis is correct. Interesting, but that tells us *nothing* about how well the step function fits. In fact, it tells us nothing at all about the step function. What would be much more informative here is the likelihood ratio of p(data|step function) / p(data|null hypothesis).

    Cheers, Jan

  124. This seems like a silly post. The temperature is not going up steadily, it has odd unpredictable jumps now and then. Its still going up, and the best candidate to explain it is CO2.

    Its as though the author has looked at the motion of a surfer, and tried to explain it while ignoring the wave the surfer is on.

  125. Rex

    No, its based on evaluation of all of the NZ temperature records over the full period of measurement. Thats several hundred individual stations, scores of which were active during the 1950’s period.

  126. clipe says:
    January 5, 2012 at 1:40 pm
    Urederra says:
    January 5, 2012 at 8:07 am

    “I recall reading one article written by Ross McKitrick where he shows a temperature graph with a big step just when the thermometers in the canadian surface stations were changed from mercury/alcohol to thermocouples. I may be recalling the whole thing wrong though.”

    Is this the one?

    http://www.uoguelph.ca/~rmckitri/research/nvst.html

    Yeah, thanks clipe and Lucy, that is the one I found but I thought It was about temperature versus sensor change.

  127. Crispin in Waterloo says: January 5, 2012 at 6:51 am “we are surrounded by climate change carpetbaggers”.

    Yes, and there is the possibility that carpetbaggers are paying people to ignore step responses like you have shown and to substitute blame-mankind explanations.

    I do not know if that carpetbagger description can be applied to the people connected with this paper. It’s long, but if you ever had doubts about a European-led one world Government, read this:

    http://www.newgrowthpath.eu/wp-content/uploads/2011/06/A_New_Growth_Path_for_Europe__Final_Report.pdf

  128. Henry@tallbloke
    I have been wanting to ask you:
    Do you know if anyone ever measured the change in humidity over the years?
    After looking at the daily average readings from about 20 weather stations all over the world I am finding a change of about -0.02%RH per annum, global average.

    http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming

    So, if this estimate is reasonably correct, (like I found my estimate of average temp. increase of o.014 degrees C per annum also reasonably correct), then the average global humidity is now about o.75% RH lower than it was 37 years ago.
    If I am not mistaken (at 15 degrees C) that translates again to a loss of about 0.1% in absolute humidity.
    Note how that compares with the increase in CO2. (0.01% increase over the last 50 years)

  129. Thanks JRJ for a thought-provoking follow-up to your earlier post on step changes. Judging by the way you’ve brought the trolls out after their Christmas/New Year hibernation, there would seem to be something here worth looking at.

    That ‘Great Pacific Shift’ of 1976/77 continues ti intrigue me. Those of us who were in the UK in the summer of ’76 will remember it as a blisteringly, most un-Britishly hot summer, when we had to learn to complain about the heat rather than the rain [grin]. Do we know what happened around then on the planetary or solar scale, since it seems to have upped Earth’s overall energy level so noticeably? Presumably, what goes up will come down at some point, and it would be nice to have some idea what precursor(s) to look for.

  130. “No more stupid than saying that carbon dioxide back radiates when in practice if you look at the spectrum from the surface of the earth there is no back radiation to be seen!”

    It’s literally insane to deny the existence of something that’s been known for decades. Do a web search for “infrared sky spectrum”.

  131. Amazing that not a single commenter appears to have realised that “abrupt changes in mean temperature” are expected, predicted and observed in response to smooth changes in climate forcings. The temperature history of the Earth does not merely show such changes; it’s dominated by them. Some people call them “tipping points”.

  132. Alan Statham says:
    January 5, 2012 at 6:17 am

    This is laughable. Your starting premise – “any presence of major step changes in mean temperature regime may contradict the claims of the AGW theory and models” – is wrong. You’ve used an arbitrary subset of the available data….

    Like “The last 2000 years” or “the last 30 years” or “the last 150 years”? The whole damn scientific discipline has been predicated on arbitrary data choices.

  133. AusieDan says:
    January 5, 2012 at 9:57 pm
    R gates,
    I would remind you of a mathematical fact that I’m sure you know.
    A linear increase of the form T(n) = T(n-1) + C, where “C” is a constant,
    Is a reducing NOT a constant RATE of change.
    In other words, the annual increase is becoming less and less important for each passing year.

    To have a constant RATE of increase would require T(n) = T(n-1)*(1+r)
    Where “r” is a value less that one (for example 0.02 ot 2% p.a.).

    Even if you ignore the cyclical compoent of the global temperature (cycle length abot 60 years) and the fact that the cycle seems to have peaked and is now heading down once again.
    Then the linear component is somwhere in the nature of 0.7 degrees p.a. or about 2% p.a. (expressed in degrees absolute).
    This rate of increase is therefore declining on a compound basis, year by year.

    But, as somebody with a sould grasp of science, I’m sure that you were well aware of that already.
    ~~~~~~~~~
    You make a good point related to the characterization of the underlying linear rise in temperature found by FR2011. The rate of increase is linear over the period they looked at and was in the range of 0.014 to .018 K per year. So it is not put in percentage terms, but a simple linear rate over this period, which obviously would be a smaller percentage as temperatures increase. More interesting to me is the question as to whether this underlying rise is truly linear, as the period studied is far too short to really know. If it is being caused by increases in greenhouse gases, then this increase over a longer time frame surely is not actually linear, as certainly it didn’t start out at the current rate with the very first increases in anthropogenic greenhouse gases back in the 1750’s.

  134. There is nothing unusual happening to weather or climate in the last 50 or 100 years or 1000 or 100,000 years – it has all happened before, over and over again.
    Attempts to state otherwise have relied on faulty, false and/or fraudulent analyses.

    Here, I think, is the bigger picture.

    The “mainstream argument” of the climate skeptics is:
    There is no real evidence of positive feedback,
    AND
    there is real evidence of negative feedback,
    SO
    the probability is “climate sensitivity” is ~1 degree C or LESS
    which is OK (we said this in 2002*),
    IF
    one accepts the mainstream argument;

    BUT
    there is perhaps a much bigger problem with the mainstream argument:

    Atmospheric CO2 LAGS temperature at all measured time scales**,

    SO
    the hypothesis that CO2 is a significant driver of global temperature apparently assumes that the future is causing the past. This assumption should cause some concern, in my opinion.

    The popular counterarguments are:
    a) This lag of CO2 after temperature is a “feedback effect”,
    OR
    b) The Principle of Uniformity of Nature has recently been rescinded;
    OR
    c) Occam’s Razor can safely be disregarded in this instance;
    OR
    d) This lag is clear evidence that time machines really do exist.
    All four counterarguments a) to d) are supported by equal amounts of compelling evidence. :-)

    Earth has seen no significant global warming for a decade or so. Score one for the skeptics.

    In fact, not one of the IPCC’s scary global warming and extreme weather predictions has materialized – a perfect track record – of false alarms.

    By the way, in 2003 I wrote that global cooling would soon recur. Faites vos jeux!

    _______________________________________________________________

    *

    http://www.apegga.com/members/Publications/peggs/Web11_02/kyoto_pt.htm

    **

    http://icecap.us/images/uploads/CO2vsTMacRae.pdf

  135. John Brookes says
    The temperature is not going up steadily, it has odd unpredictable jumps now and then. Its still going up, and the best candidate to explain it is CO2.

    Henry @ John
    John, my data set (after statistical analysis of 20 weather stations) shows that maxima, means (=average temps) and minima have risen at a ratio of 7:3:1

    http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming

    If more CO2 or more GHG were to be blamed for the warming, should that ratio not be the other way around?

  136. tallbloke says:
    January 5, 2012 at 11:42 pm

    We are just near the peak of the curve. It’s generally downhill for the next 500 years. Unless the next 50 take us into the overdue glaciation. Unless we are at the end of the ice age and the earth returns to it’s favoured equilibrium around 8C warmer than now.

    Place your bets.
    _____
    “Peak of the curve”? No evidence of such.

    “Downhill next 500 years.” No evidence of such.

    “..next 50 take us into overdue glaciation…” Definitely no evidence of such.

    “…end of the Ice Age…” Not by natural variability or Milankovitch cycles or continental configuration, so if we are, it will come through sensitivity to anthropogenic greenhouse gas forcing being much much higher than anyone really can see right now. If this is the case, it will still take quite a while to melt all that continental ice in Greenland and Antarctica.

  137. Thanks for the many comments and suggestions. Being back from work, here is my response:

    JT, Jan05 6:17 am: I do agree that the “natural processes” could have been influenced by an anthropogenic warming, but find that idea currently speculative as I mention in my post. Ref also Pamela Gray at 6:41 am

    Gary, Jan05 6:19 am: pls. consult the reference link I have provided to the statistical tool I have used.

    Leif Svalgaard, Jan05 7:33 am: you ask why the steps are always up? Why not? Pls. note that I am only concerned with the period 1960-2010.

    R Gates, Jan05 7:52 am: I disagree with your assessment that Foster and Rahmstorf have factored out the “natural variability factors”; Bob Tisdale in his recent post on the subject provide insight on this issue.

    A Physicist, Jan 05 8:18 am: I disagree completely with your preamble that models like Foster and Rahmstorf are simpler than the regime step change model. Also, as I tried to make clear in my introduction, this analysis is not an attempt to establish a climate model with predictive capability, but simply an attempt to let the observational data tell us what the pattern of temperature change during 1960-2010 was like. That pattern is adequately described as consisting of abrupt changes in mean temperature regimes.

    Steve Garcia, Jan05 8;23am: the steps around 1987/89 and 1997/99 are also supported by independent published studies, a few of which I mention in the post.

    Rob Potter, Jan05 8:35am: as I have mentioned, I am not concerned with the temperature pattern outside the period of “global warming”, only with the period 1960-2010. This is not an attempt to develop a climate model.

    Steveta_uk, Jan05 9:32am: the significance of the trends during the “flat” periods are dubious due to short time periods and/or the influence of step change processes, and I would discourage that these short term variations be summarised in trends.

    Steven Mosher, Jan05 12:35pm: What problem, “sparky”? the data set I have used is not old or to my knowledge corrupted significantly by the “combine” procedure; pls be more specific if you have evidence to the contrary. Regarding your suggestion to analyse US data: as I mentioned in the post, I have done the analysis also for US contiguous 48 states with a similar result (ref also the presentation I link to), clearly indicating what would happen if I were to analyse station level records in the US (which I am not).
    BTW, what is your view on the subject of the post: are abrupt changes an important feature of the temperature records of the 1960-2010?

    E M Smith, Jan05 1:28pm: I agree with your concern over the true origin of many T-records, but having inspected all the records I have used I do not think that many of the (relatively large) steps in my analysis (complete records only) can be artefacts of splicing. I did delete a few potential records from my analysis on a suspicion of homogeneity problems.

    Jan de Ruiter, Jan05 2:21pm: pls refer to the link in my post for details on the statistical tool; the significance you refer to is the significance (probability level) for accepting the HO hypothesis that there is no regime change at the change point – basically a t-test.

    Ian H, Jan05 4:40pm: you are unconvinced, ok. Try to reconsider the number of station level temperature curves that exhibit the step change pattern and the coincidence with documented physical and biological changes in the ocean-atmosphere system.

    Regards, …. jens

  138. In his posting at 8:35am. Rob Potter brought up a point that deserves further comment. He wrote: “…..averaging across very large geographic regions (and using such averages to fill in places where the data is not available) really is losing most of the information.” (I believe that some data are “averaged” over 1200 km.)
    I live in New Brunswick, on the E coast of Canada. Cradled to our E is Prince Edward Island, and hanging off our SE extremity is the peninsula of Nova Scotia. We get weather forecasts covering all three provinces, and the conditions can be several degrees and several inches/cm of snow different, all within a distance of, say, 200 km or 200 miles. If our readings can be so different over such (relatively) short distances, how much can we trust data from 1200 km away? (We have the complication of large bodies of water near or around us, and that has a pronounced effect.)
    IanM

  139. “The relative role of natural processes in global warming is very likely underestimated [...]” / “This study has established that step changes in land-based temperature records during 1960-2010 are common and very likely real and linked with natural climate events.”

    “very likely” is putting it way too collegially. I would suggest replacing misdirected loyalty to severely misguided colleagues with loyalty to overpowering natural truth. Nature mercilessly crushes the abstract belief systems of misguided colleagues.

    “The empirical evidence, from this station level analysis and other sources, is unequivocal: the step changes in mean temperature are likely real and associated with natural events.”

    Again, “likely” suggests possible willingness to be a voluntary victim of natural correction. Everyone: Please see Judith Curry’s article on error cascades: http://judithcurry.com/2012/01/05/error-cascade/ .

    It will be interesting to see if the mainstream risks “double or nothing” by continuing to push an abstract solar-terrestrial narrative that is MERCILESSLY contradicted by observational data. At some point the brighter leaders in the mainstream community should realize that even if they get wool over eyes temporarily, there’s no avoiding eventual bust. The longer the delay in narrative correction, the more damaging will be the height from which the fall occurs. The damage potential isn’t increasing linearly; it’s increasing EXPONENTIALLY. I soberly hope that the brightest academic leaders have paused to consider this (and the implications, including severe costs to society & civilization).

    Sincerely.

    Moving on (from forest-level-view) to some more technical considerations (i.e. some tree-level-views)…

    “[...] the presence of step changes invalidates the widely used statistical techniques of linear trend and smoothing as means of identifying the pattern of temperature variation during 1960-2010.”

    It doesn’t invalidate the techniques, but I can agree that some parties exercise grossly insufficient interpretive care. I advise those careless parties to diagnostically explore a MUCH wider range of stats, keeping in mind that different stats have different properties. I also sternly caution against the hazards of making unconscious assumptions as a function of bad cultural habit (e.g. as happens notably in the fields of economics, physics, & mathematical statistics).

    Compare the following:
    1. http://wattsupwiththat.files.wordpress.com/2012/01/2d6nxhj1.gif
    2. http://wattsupwiththat.files.wordpress.com/2011/12/image10.png

    Lesson for those who expect global average temperature to follow the solar cycle:
    There’s such a thing as spatiotemporal VARIANCE (and other moments).

    In the field of advanced physical geography there are pockets of awareness of the need to explore the variability of parameter estimates as a function of scale. Those carefully taking advice from the enlightened few can learn something quite interesting about QBO-timescale coherence in the early 1970s.

    I can recommend the following article to stimulate new perspective on old surroundings falsely assumed to be “well-understood”:

    Lilly, J.M.: & Olhede, S.C. (2009). Higher-order properties of analytic wavelets. IEEE Transactions on Signal Processing. 57(1), 146-160.

    http://www.jmlilly.net/papers/lilly09-itsp-cp.pdf

    See particularly Figure 6 on p.12 to foster a generalized view.

    “78% of Europe stations have a step change in 1987/89, during which the major part of the entire warming of the 2nd half of the 20th century apparently took place.”

    Vincent Courtillot has warned about this. It’s encouraging to witness multi-track awareness convergence.

    This graph is also beautiful:

    (I hope readers have noticed that Jens has the geography organized roughly by latitude.)

    Thanks for these important contributions Jens:

    Best Regards.

  140. Leif Svalgaard says:
    January 5, 2012 at 7:33 am

    Why are the “steps” always up?

    Why was the great climate shift of 1976 up.

  141. Now come on Latitude, not fair, you’re not supposed to lift the curtain and show temperature data prior to 1880.
    It’s interesting to note the lack of correlation between CO2 and Temperatures.

  142. @Jens Raunsø Jensen
    “there were two less intense events in 1982 and 1991, the impact of which was probably occluded by the major volcanoes El Chichon and Mt. Pinatubo.”

    More likely that 1982/3 El Nino was so strong due to a response to the cooling from the stratospheric aerosols. The cooling driving the other El Nino`s is due to falling solar wind speeds. What this means is that a major step up such as 1976/7 is actually rooted in the 1973-76 La Nina, when solar wind speeds were continuously high and were warming the oceans more, but is not until the SW speed has started to fall, and the trade winds drop, and the Ekman pumping of the equatorial Pacific ceases to produce an El Nino episode, that we see the full effects of the temperature rise.

  143. Steven Mosher: If you want to do regime shift detection ( I used that package back in 2007-2008) I would
    suggest that you

    1. Not get your data from the GISS site, but go directly to the source: Ghcn monthly, or better
    Ghcn daily.
    2.. Not use data where stations have been “combined” . Either use raw or homogenized
    3. Have a look at some of the better struc change packages out there ( see Cran )

    4. look at the US records as well.

    I for one hope that jens raunsø jensen takes that advice. The analysis that he reported here is informative, and it presents a good possibility about the climate system, namely that gradual accumulations of heat in the system produce step changes in many locations, where the step changes are driven by increased energy flows in the many naturally occurring and identifiable processes. Nonlinear dissipative dynamic systems with fluctuating inputs can behave that way. His analysis is completely independent of any particular hypothesis about mechanisms causing the increase in global spatio-temporally averaged temperature: it neither supports nor undermines the hypothesis that the increased temperature is caused by increased CO2 in the atmosphere. As written, it makes no predictions about the future, except that if mean temperature continues to increase there ought to be more identifiable step changes in temperature records of particular recording sites: in that, it is analogous to statistical modeling of radioactive decay, where the aggregate decay rate is exponential, and where each atom decays discretely but unpredictably; there are other macro stepwise processes, such as animal learning, where each animal learns a task at a particular trial, but the mean performance of the animals is gradually increasing across learning trials.

    jens raunsø jensen says:
    January 6, 2012 at 9:36 am

    Those are good responses to mostly responsible comments. I want to thank you for your work (caveat some problems pointed out by others) and I hope to read a followup. Arguments that you are wrong are generally inadequate; I am skeptical, but my curiosity has been stimulated.

  144. Leif Svalgaard says:
    January 5, 2012 at 7:33 am
    Why are the “steps” always up?

    It would be interesting to see whether any of these steps correlate with the mass extinctions of “cooler” weather stations, and/or “upgrades” in measuring equipment.

  145. @Jens Raunsø Jensen

    With all due respect, I am afraid that very few of your opponents will lose many seconds of sleep over this. If you try to link abrupt shifts to ENSO influence while rejecting a strong underlying linear forcing/trend, then you obviously should expect the overall trend 1960-2010 to be flat(ter) in an analysis like Foster & Rahmstorf´s which removes the ENSO signal – and quite to the contrary, they find a strong and much clearer linear trend. Whether you agree or disagree with the overall conclusions of F & R: How do you reconcile this?

    And besides, your reply to Leif Svalgaards criticism:

    Leif Svalgaard, Jan05 7:33 am: you ask why the steps are always up? Why not? Pls. note that I am only concerned with the period 1960-2010.

    appears to be a complete non-answer. Surely you are aware that there has been quite a few instances of both El Niño and La Niña in your selected period, right? Are you seriously trying to argue that ENSO/El NIño can cause upward abrupts shifts, while ENSO/La NIña are simultaneously unable to cause similar cooling? That would require some serious rewriting of presently acknowledged oceanic physics (not to mention, of course, why this phenomenon apparently failed to exert its influence during e.g. 1860-1910 or other 50-year cycles of overall cooling). And as far as I´m concerned, there has been no trend in ENSO influence at all over your timeframe:

    http://cses.washington.edu/cig/pnwc/aboutenso.shtml

    Overall, your argument suffers from the same problem as has been pointed out at many other occasions where people have tried to find “stepwise abrupt shifts”: There are no physically supported explanations behind your reasoning, just handwaving and appeals to plausibility without too much afterthought. Do you honestly hope to come up with serious challenges to the mainstream climate science, or are you merely happy to provide a little entertainment for gullible and/or not too insightful members of the choir?

    The latter is, in my opinion, a little sad for someone claiming to do science. Surely, it is well below the usual standard at the University of Copenhagen that apparently presently funds both you and me.

  146. I think that both scientists and skeptics agree that the world’s climate is a noisy, variable system. This analysis does not differentiate between a stepwise mechanisms and a consistent linear increase (as expected from increasing GHG) coupled with natural variability. This post shows why peer review is needed to evaluate alternative hypothesies.

  147. Christoffer Bugge Harder, Jan08 4:33pm:

    Your comments seem to rest on the assumption that I am presenting a climate model. As I have emphasised time and again (see also post), this is not a climate model, but an attempt to clarify the pattern of temperature change during the period of global warming 1960-2010 based on an empirical analysis of the station-level observational data using a documented and published statistical method. Next, basic implications of the pattern are discussed. In my world, this is a perfectly valid scientific undertaking.

    The observational data shows beyond any reasonable doubt that abrupt changes may account for the major changes in temperature during that period. Furthermore, these regime changes coincide with major documented events in the ocean-atmosphere system as exemplified by ENSO. Furthermore, the regime changes are widely documented in independent climate and ecosystem studies published in the peer-reviewed literature (see examples in post). Do you disagree with that?

    Pls. note that I make it explicit in the post that I do not see ENSO as the only element in the cause-effect chain. I have no further speculations to offer as to the mechanisms and the relative roles of Nino and Nina, especially not for periods outside 1960-2010 as you ask for. Again and again, I am not discussing a climate model, pls. focus on the objective of the analysis.

    Finally, read the preamble and ask yourself if you have really read the post with a scientist’s open mind. And if you want to continue the dialogue with me, then please refrain from using abusive ad hominem statements.

    Regards ….. jens

  148. Dear BillD

    I would like to ask you to read my report

    http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok

    and let me know what you think of it.

    As far as peer review is concerned:
    I so much liked this post by Craig Goodrich here on WUWT (I am sure he does not mind if I quote him again):

    I am sick to death of their rote yapping about “peer review,” when they have perhaps irremediably corrupted the process, and when the point of science was never “peer review” per se but complete openness as to methods and data — which they have steadfastly, almost neurotically, refused to allow. I am nauseated when I hear their “oil funding” chorus, when Greenpeace and the WWF have each received more than two orders of magnitude more funding from corporations than all the free-market think tanks combined — let alone the skeptical science community.

    But what makes me really sick is the realization that the $100 billion or so wasted on “climate science” — not quite yet an oxymoron, thanks only to Lindzen, Christy, our own Willis, and a small brave band of real scientists — could have bought an insecticide-impregnated mosquito net for every bed in Africa and South Asia, plus enough DDT to control mosquitoes in swamps near populated areas, with enough left over to keep NASA’s Mars program viable.

    But instead of eliminating malaria and keeping mankind’s restless ambition alive, thanks to the warm-mongers we spent the money gazing at our global navel hoping to find the Global Warming Fairy, while at the same time utterly devastating millions of acres of wildlife habitat and peaceful countryside with useless industrial wind turbine phalanxes — which generate no actual power but lots of tax breaks and subsidies — in the quest for some delusional “renewable energy,” clearcutting rainforests for palm oil and fraudulent “carbon sinks,” and doubling world food prices by supporting ethanol production.

    So having worked as hard as ever they can to destroy what natural environment remains in the developed world, and to murder as many as possible through starvation and disease in the undeveloped world, these wonderful people preen themselves and vaunt their moral superiority as “humanitarians” and “environmentalists.”

    Sorry, I had to go get my barf bag.

    I realize that WUWT, CA, and the rest of the climate realist blogosphere attempt to maintain a civilized level of objective scientific discourse, free from the diatribes that pervade warmist rhetoric. But sometimes it is necessary to vent, and my infrared iris opens up…….

  149. If I’m reading this right, you are modeling this as separate step changes in n=232 station records, with (from eyeballingfigure 3) about 2-3 steps per series at the best fit times.

    Doesn’t this methodology ultimately end up fitting about n*5 parameters, or about 1400 unconstrained coefficients in the 232 multiple-step-change models?

  150. @ Andy and Utahn – “Tamino” has an agenda – he’d try to “debunk” a straight line made of two points if it was posted here. Heh. Let’s see what Jens has to say.

    If we paid attention to Tamino’s way of seeing the world, there would never be any discussion allowed but his. WUWT is about open discussion of ideas like this, “Open Mind” is not.

  151. Hi Anthony
    Do you perhaps know if anyone ever measured the change in humidity over the years?
    After looking at the daily average readings from about 20 weather stations all over the world I am finding a change of about -0.02%RH per annum.

    http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming

    So, if this estimate is not far from the truth, like my estimate on the means is not far off from what Spencer & others get, then the average global humidity is now about o.75% RH lower than it was 37 years ago.
    If I am not mistaken (at 15 degrees C) that translates again to a loss of about 0.1% in absolute humidity.
    You see how that compares with the increase in of CO2? (0.01% increase over the last 50 years)

  152. @Jens Raunsø Jensen

    to begin with, my comment was not intended as an ad hominem, so sorry for any careless wording and/or offense you may have felt in that regard. And I am well aware that your analysis is not a GCM model (if that is what you gathered from my comment, I must admit that I fail to see how you got that impression). What you are doing is simply to fit a regime shift model from Rodionovs software upon some selected station data – and then you hint at some suggested ENSO link (and some other even flimsier ones) as putative causes for “regimental” warming. Then you use this a basis for arguing that GHGs cannot be primarily responsible for the observed global warming.

    However, I honestly do think that your analysis is well below normal, reasonable scientific standards (it certainly would not stand much of a chance passing any kind of fair and serious peer review) and your answers to the fair and well-argued comments you receive are either evasive or leaves the reader with the impression that you don´t understand the criticism. Let me elaborate:

    The observational data shows beyond any reasonable doubt that abrupt changes may account for the major changes in temperature during that period. Furthermore, these regime changes coincide with major documented events in the ocean-atmosphere system as exemplified by ENSO. Furthermore, the regime changes are widely documented in independent climate and ecosystem studies published in the peer-reviewed literature (see examples in post). Do you disagree with that?

    If one tries, as you do, to claim that these putatively ENSO-linked “abrupt shifts” are primarily responsible for the temperature being about 0,7C warmer in 2010 compared to 1960, then I (along with all the peer-reviewed literature on the subject) certainly disagree, yes. As has been shown many times, the temperature pattern 1960-2010 fits very well with an overall increasing trend driven by GHGs, with ENSO, PDO/AMO superimposed upon as short-term (10-15 years) noise signal, either weakening or enhancing the GHG forcing. You do not even seem to be aware that the AWG theory does not even project that the temperatures should rise linearly?

    According to the very same peer-reviewed literature you claim to rely upon, which has suggested exactly such models of climate shifts induced by ENSO or PDO – e.g. Keenlyside, Mojib Latif et al. in Science (2008), or Swanson and Tsonis (GRL 2009) – there is zero net positive (or negative) forcing from ENSO/PDO/AMO over time, since the warm and cold phases of PDO/AMO and El Niño/La Niña cancel each other out. Or, to put it simpler, oceans do not “generate” heat, they merely redistribute it. Really, this should be obvious to you just by looking at a simple graph of ENSO oscillations:

    http://chartsgraphs.files.wordpress.com/2009/01/giss_enso_sato2.png?w=500&h=565

    Both Latif and Swanson themselves has made this painstakingly clear when explaining their findings in order to avoid exactly these kind of common misunderstandings that you are repeating here. Here is Latif, who linked short term-changes to PDO (http://www.spiegel.de/wissenschaft/natur/0,1518,551060,00.html):

    Mojib Latif [warnt] ausdrücklich davor, die Simulationen falsch zu interpretieren: “Wir postulieren nicht, dass die vom Menschen verursachte Klimaänderung nicht so schlimm ausfallen wird wie befürchtet.” Der generell nach oben weisende Trend werde nur von einer langperiodischen Schwingung überlagert, die in den kommenden Jahren netto zu einem geringeren Temperaturanstieg führen könnte.

    (Sorry that I could find an Englisch source, but I´m sure that as a fellow Dane, you read German.)

    Thus you do have a major problem in your analysis that the steps are always up (as Leif Svalgard pointed out), since this shows precisely that there must be an underlying external forcing (such as GHGs, solar irradiation etc.) causing the overall warming trend – actually, if you try to link ENSO to data with significant net changes over time, then I fail to understand why analysing e.g. 1860-1900, 1940-75, 1960-2010 or any other comparable interval would matter the slightest to this argument, as you appear to think.
    Whether you want to do climate modelling or not: If you are seriously trying to argue that ENSO (or AMO/PDO) influence is able to cause abrupt and permanent climate change, then you would need to demonstrate how this is physically possible, e.g. by identifying some previously unknown oceanic component – or by explaining how you think that oceans could be able to generate heat. (The latter would surely require some rewriting of major foundational physics as well, not to mention a very convincing demonstration as to why these abrupt one-directional upward shifts you think you have identified has not made the planet warm indefinitely. :) You most definitely cannot link the main T-increase to any of these known natural cycles you mention, as has long been well known and documented. Thus, based on this major problem alone, there is no particular reason to explore your “hypothesis” further.

    You simply don´t seem to realise this? I´m sorry, but this really is very simple physics that certainly should not bother you, if you think a little more carefully about it.

    Furthermore, even just considering the statistics part of your analysis, you surely must be aware that your regime shift tool will be able to find “regime shifts” in just about any kind of data with an increasing trend and some noise? As Grant Foster has shown here (http://tamino.wordpress.com/2012/01/09/steps/#more-4606), dummy data designed artificially to have a perfectly linear trend with red noise is found to have several significant “regime shifts” by Rodionov´s software. Clearly, this is nonsense, and it should not be surprising to anybody having used a “fit model to X” function in a standard statistics package, as I´m sure you have done a number of time. This merely shows that the null hypothesis of no-change is wrong, not that a stepwise model is the best way to describe this change. In fact, he shows that just by using the Akaike criterion for model selection, a two-way linear model subdividing your data for Malacca into a flatlining 1950-75 part and another trending linearly upward from 1975-2010 is superiour to your stepwise model. Thus, even leaving out all the erroneous interpretations of your findings regarding ENSO/PDO links, you fail even to show why your preferred model is superiour.

    So finally, having reread the preamble, I have just this to say: As a humble PhD student, I´m certainly trained to have an open mind. But I have also learned to be sceptical of simple model fits, especially if followed by bold interpretations without any supporting physical documentation or justifications. Furthermore, I know that with an ENSO trend of about zero over 50 years, then an interpretation linking warm shifts to warm phases in this period of time requires implicitly ignoring all the equally cool shifts. I think we both know that just leaving out data that do not fit a hypothesis is at best sloppy scholarschip, typically reflecting either a poor understanding of the subject in question or a confirmation bias often resulting in self-delusion. Honestly, I think Trenberth and all his fellow climate scientists would laugh, were they ever to read this, and I also think that you will realise the obvious problems yourself if you try to owe up to your own preamble.

    Regards,

    Christoffer

  153. Christoffer Bugge Harder says
    “fits very well with an overall increasing trend driven by GHGs”

    Henry@Christopher
    Honestly, looking at the results of maxima, means and minima together, apparent ratio: 7:3:1
    which you can only see in my own tables, of summarised results of 20 weather stations,

    http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming

    I don’t know how you can possibly figure out that that statement you made can possibly be true.
    Come to me with test results that prove that minima are rising, pushing up means, and we will talk again.

  154. Well, Henry,

    I certainly agree that comparing nighttime and daytime temperatures would constitute an excellent test of the GHG fingerprint. But hey, let´s take a look at the global result, rather than just 20 random (or carefully selected?) weather stations, shouldn´t we?

    Obviously, the ratio since 1950 is 2:1 in favour of the nighttime temperatures.

    (Let me hazard a couple of guesses on the response: You don´t trust pre-1975 data for some unspecified reason/you don´t trust post1975 data for another unspecified reason/the nighttime temperatures are subject to significant UHI/daytime temperatures are subject to even larger uh-oh no smaller UHI or whatever/you only trust stations close to Northern Ireland/Hockey stick fraud Michael Mann is bald and so is Gavin Schmidt/all surface data are manipulated and the BEST team is part of the plot/yeah, but…..AL GORE!)

  155. Well, Henry,

    I certainly agree that comparing nighttime and daytime temperatures would constitute an excellent test of the GHG fingerprint. But hey, let´s take a look at the global result, rather than just 20 random (or carefully selected?) weather stations, shouldn´t we?

    Obviously, the ratio since 1950 is 2:1 in favour of the nighttime temperatures.

  156. Hi Christopher
    Interesting challenge.
    But it is not clear from the graphs that you quote from which station(s) they were collected?
    It reminds me vaguely of an interesting controversy I encountered during the collection of my data:

    http://letterdash.com/HenryP/what-hanky-panky-is-going-on-in-the-uk

    Apart from the above, where I wanted to see what is going on with the data coming from Gibraltar,
    I can assure you that I did select my stations randomly.
    Continuous daily data from pre 1975 are indeed difficult to find from randomly selected weather stations.

  157. Christopher says:
    and the BEST team is part of the plot

    Henry@Christoper
    I remember that the BEST results only show the mean average
    I thought at the time when the controversy here raged, that those results were rather useless (to me).

  158. Anthony said:
    “@ Andy and Utahn – ‘Tamino’ has an agenda – he’d try to ‘debunk’ a straight line made of two points if it was posted here. Heh. Let’s see what Jens has to say.”

    Is Jens still reading comments? I hope so and I will await an update/rebuttal of Tamino’s analysis, which looks pretty hard to rebut.

    As far as agenda’s go, does that invalidate an argument? In addition, looking at the last 100 posts or so on this site it looks like there is a pretty clear agenda, since just about every post appears to either : implicate something besides C02 as a cause of warming; minimize or trivialize the impact of global warming, whatever the source; or show some flaw or uncertainty in the scientific literature or scientists studying AGW. Not even 1 post out of 100 that argues could have a problem from AGW?

  159. Well said, Utahn. I don´t care about either Jens Raunsø Jensen´s, Watts´ or Tamino´s respective agendas – whatever Grant Foster (Tamino) may have said or done in the past hardly takes anything from the fact that he offers some pretty hardheaded statistical objections that torpedo every single one of Jens Raunsø Jensen´s core claims here. Surely, for this analysis to stand, Jens will need to show both that a) his regime shift model is superiour to others (providing some AIC support), and if so, b) what kind of underlying forcing that could have caused a net change over the timeframe 1960-2010.

    He´ll need to find something presently unknown or undescribed: Given the undisputed fact that there is no net change in the ENSO contribution over the years 1960-2010, I think everybody can readily agree that ENSO could not possibly be responsible for any of the observed warming in this period, and the authors having published on regime shifts in the peer reviewed literature Jens claims to have read/be relying upon explicitly denounce “analyses” like this as common misunderstandings, so it is indeed quite a task Jens has assigned to himself.

  160. Andy and Utahn, and Anthony Jan10 6:04am:

    You are referring to a post entitled Steps at Open Mind by Tamino.

    First, having tried recently to comment on that site only to be censored out, I do not feel inclined to respond to posts at that site which seems to be driven by a political agenda rather than by a wish to explore the science with an open mind.

    Paraphrasing Willis, quote me correctly and I shall respond. Tamino misrepresents my post in his opening statement. My post does not “contradict man-made global warming” but contradict, as explicitly stated, some of the main specific claims of the AGW hypothesis. I clearly state that in my view an AGW signal – albeit relatively small – is likely to be present and could be hidden by the step analysis. I argue, that unless there is evidence (and not only speculations) that man-made warming is the main cause for the sudden steps, then IPCC has likely got the balance between natural and anthropogenic forcings wrong. It is the balance I am concerned with. A simple analysis of the primary temperature data along with other empirical observations on the physical and biological systems supports my argument, and as far as I know there is no supporting evidence for man-made warming to be the cause of the abrupt changes.

    Tamino claims that my post does not even establish the central claim that station level records goes through step changes rather than linear changes (I assume that Tamino means linearly increasing when he talks about linear changes). The central claim is that abrupt changes are present. How much does it take for Tamino to accept a likely presence of abrupt changes in the T-records? I have demonstrated, not for one station but for the 232 stations with complete records in the broad regions analysed, that station level records widely display very significant abrupt changes in a systematic pattern somehow linked with documented natural extreme climate events in the period considered. Consequently, the observational data and supporting evidence questions the validity of assuming that the T-records are uniformly and linearly increasing during the period of global warming (as eg. assumed in Foster/Tamino and Rahmstorf). At least, Tamino and others now need to consider that possibility, rather than just dismissing the evidence as “silly”.

    Tamino goes on with examples to demonstrate that basically any curve with a true trend may/will be interpreted by the step model as consisting of steps. Of course, this is trivial, and I already in my earlier post on the step changes made that caution. But the fact that such examples can be constructed does not disprove the real presence of many of the step changes. And why does Tamino cherry-pick the Malacca case with the many steps for his criticism? I would recommend Tamino and like-minded to analyse eg. the many European and Russian stations with only one step change occurring around 1988 and compare the performance of the step model with a linear regression model for the period 1960-2010. I have no doubt that in most cases the step change model will prove to be superior from a statistical point of view (also using Akaike’s information criterion, as I have tried early on in a few cases). However, comparing different models statistically is complex and likely to produce ambiguous results. The issue of physical support for the models is more important.

    The crucial point which Tamino conveniently neglects is that there are independent observational and published evidence for the regime changes identified in my analysis. I suggest that Tamino and like-minded start with reading eg. Trenberth (1990) and ask yourself, if the step change in 1976/77 was real or not, and whether there is any evidence or high probability that this step is caused by man-made warming. The zero-hypothesis is a natural cause. Looking forward to see your assessment.

    Regards … jens

  161. @HenryP

    The graph I cited is from Vose in GRL (2005). Here is a simplified draft version of this with open access:

    ftp://ftp.ncdc.noaa.gov/pub/data/papers/200686amsp4.1rvfree.pdf

    The datasets used cover the entire globe, using GHCN as the primary source:

    Data for this study were compiled from 20 source datasets. The primary sources were the Global
    Historical Climatology Network (Peterson and Vose, 1997) monthly and daily databases (which contain most of the data used in Easterling et al.), and two editions of World Weather Records (1981-1990 and 1991-2000). These global datasets were supplemented with acquisitions from Argentina, Australia, Brazil, Chile, Cuba, Greece, Iran, New Zealand, and South Africa. CLIMAT reports were used to update about 20% of thestations after 1994. In addition, high-quality synoptic
    reports were included to fill recent gaps in about 10% of the stations (provided digital and manual checks indicated that the synoptic data closely matched historical monthly time series during periods of overlaps).

    From the conclusion:

    From 1950-2004, the least squares regression trend in annual maximum temperature is 0.141°C dec-1, in minimum temperature is 0.204°C dec-1, and in DTR is -0.066°C dec-1. The trends in maximum and minimum temperature exceed those in Easterling et al. (1997) by 0.050 and 0.018°C dec-1, respectively, whereas the DTR trend is less by 0.018°C dec-1. The larger maximum and minimum trends are generally consistent with the large positive global temperature anomalies observed in most years since 1993 (Levinson et al., 2005) while the smaller DTR trend likely reflects the accelerated rate of warming in the maximum.

    This appears pretty solid to me. At the very least, you´ll certainly need to present some very convincing arguments and thorough analyses showing why your selected 20 stations should perform better than a global assessment like this.

  162. @HenryP

    The graph I cited is from Vose in GRL (2005). Here is a simplified draft version of this with open access:

    ftp://ftp.ncdc.noaa.gov/pub/data/papers/200686amsp4.1rvfree.pdf

    The datasets used cover the entire globe, using GHCN as the primary source:

    Data for this study were compiled from 20 source datasets. The primary sources were the Global Historical Climatology Network (Peterson and Vose, 1997) monthly and daily databases (which contain most of the data used in Easterling et al.), and two editions of World Weather Records (1981-1990 and 1991-2000). These global datasets were supplemented with acquisitions from Argentina, Australia, Brazil, Chile, Cuba, Greece, Iran, New Zealand, and South Africa. CLIMAT reports were used to update about 20% of thestations after 1994. In addition, high-quality synoptic reports were included to fill recent gaps in about 10% of the stations (provided digital and manual checks indicated that the synoptic data closely matched historical monthly time series during periods of overlaps).

    From the conclusion:

    From 1950-2004, the least squares regression trend in annual maximum temperature is 0.141°C dec-1, in minimum temperature is 0.204°C dec-1, and in DTR is -0.066°C dec-1. The trends in maximum and minimum temperature exceed those in Easterling et al. (1997) by 0.050 and 0.018°C dec-1, respectively, whereas the DTR trend is less by 0.018°C dec-1. The larger maximum and minimum trends are generally consistent with the large positive global temperature anomalies observed in most years since 1993 (Levinson et al., 2005) while the smaller DTR trend likely reflects the accelerated rate of warming in the maximum.

    This appears pretty solid to me. At the very least, you´ll certainly need to present some very convincing arguments and thorough analyses showing why your selected 20 stations should perform better than a global assessment like this.

  163. Dear Christopher
    To quote from the first sentence of the report that you quoted:
    Minimum temperature increased about twice as fast
    as maximum temperature over global land areas since
    1950,

    I am sorry to say that this not corroborate my own findings at all,
    in fact, as an example, look at what I got here:

    http://www.letterdash.com/HenryP/de-forestation-causes-cooling

    How would you explain the results I am getting there?

    (I can prove that I am not ” making anything up”)

    http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming

    Try also following the discussion on this

    http://wattsupwiththat.com/2012/01/08/the-moon-is-a-cold-mistress/#comment-860663

  164. I clearly state that in my view an AGW signal – albeit relatively small – is likely to be present and could be hidden by the step analysis. I argue, that unless there is evidence (and not only speculations) that man-made warming is the main cause for the sudden steps, then IPCC has likely got the balance between natural and anthropogenic forcings wrong. It is the balance I am concerned with. A simple analysis of the primary temperature data along with other empirical observations on the physical and biological systems supports my argument, and as far as I know there is no supporting evidence for man-made warming to be the cause of the abrupt changes.

    But dearest Jens,

    you apparently still fail to understand that the empirical observations on the physical systems you are talking about do not support your argument at all – on the contrary, they explicitly contradict it. The net contribution of ENSO over 1960-2010 to the climate system of Earth is zero – once again, this is very well documented from the literature you claim to be familiar with. Do you seriously dispute this, if you take another look at ENSO over time?

    http://cses.washington.edu/cig/pnwc/aboutenso.shtml

    Over shorter timescales of, say, 5 years, ENSO is certainly able to cause abrupt changes in warming, and indeed, I think everybody will agree that the abrupt rises are likely heavily influenced by El Niño – but these will be followed by an equally sized and abrupt cooling influence over a timeframe of 50 years. Thus it is just not physically possible for ENSO to have caused these stepwise changes resulting in a net temperature increase over a timeframe of 50 years – unless it has been superimposed on a steadily increasing positive external forcing like e.g. GHGs or solar irradiance. Your conclusion about balance does not follow from your arguments: The overall net contribution from ENSO 1960-2010 is zero, while in the same time, the CO2 forcing increased by about +1,5 W/m2. The isolated radiative effect because of CO2 is simple radiative physics calculations using Arrhenius´ law, which is acknowledged by even most sceptics – I hope we can agree on that?

    Why, then, is it that you appear to think that this suggests that IPCC (or anyone else, for that matter) has got the balance between natural (here ENSO) and anthropogenic forcing wrong? Considering only CO2 and ENSO, it is obvious that ENSO does have an important role in many or all your “shifts”, where it overwhelms the yearly CO2 signal by an order of magnitude for a short while. However, the balance of their respective contribution to the warming 1960-2010 is a 100% for CO2 and 0% for ENSO. There is no contradiction at all in this, as you appear to think.

    I would very much appreciate if you would at least try to respond to this central point. It really is easy to see for any open mind.

  165. P.S. You also appear to have misunderstood a couple of other things:

    The zero-hypothesis is a natural cause.

    It is perfectly fine to look at natural climate drivers, but one cannot just throw out “natural variability” without a physical mechanism as an explanation – that is not a scientific hypothesis, but mere handwaving. It is well known and undisputed that CO2 has contributed about the aforementioned 1,5 W/m2 over the last 50-60 years. If you think that other sources have contributed more to the the warming in the same period, then you need to suggest a specific natural cause (or several ones) which could have contributed with a forcing larger than this.

    …..the observational data and supporting evidence questions the validity of assuming that the T-records are uniformly and linearly increasing during the period of global warming (as eg. assumed in Foster/Tamino and Rahmstorf).

    I think you have misunderstood F & R quite spectacularly, if it is their ERL 2011 paper you are referring to. They don´t “assume” T-records to be linear (in fact, if you read Foster´s post, he even explicitly states that T-records need not be linear under the AGW hypothesis), and they actually don´t assume anything really – they remove the variation due to ENSO (and solar cycles + volcanic aerosols) – and then they get a linear trend.

    For your hypothesis about ENSO causing shifts leading to an overall 1960-2010 warming stronger than CO2 to be true, the remaining warming trend/signal after this removal should be significantly weakened compared to the “raw” warming in this period. And it is not.

  166. @ Christoffer Bugge Harder

    “Over shorter timescales of, say, 5 years, ENSO is certainly able to cause abrupt changes in warming, and indeed, I think everybody will agree that the abrupt rises are likely heavily influenced by El Niño – but these will be followed by an equally sized and abrupt cooling influence over a timeframe of 50 years.”

    Can this just be assumed ? It seems to me as Jens hints that the idea that there must be a natural zero balance is still rather speculative. The wikipedia article on the ENSO phenomenon does not give the impression that it is as well understood as you claim.

    An example:
    “A joint study by the National Aeronautics and Space Administration and the National Oceanic and Atmospheric Administration concluded that climate change may contribute to stronger El Niños.”

    Note the wording “may”. To a skeptical layman like myself this indeed does sound like much more study is required of the underlying mechanisms of these phenomena to make the kind of certain statements that you do in this area.

  167. @Cubie

    I work on microbiology and DNA sequencing, so in climate science, I´m also nothing but a sceptical layman. But to my mind, scepticism is a two-way thing: Sure, one should demand evidence instead of simply believing, but then one should also accept a claim when supported by overwhelming evidence – and one should not suggest hypotheses that are are odds with basic facts, or which make things more complicated without explaining more observations.

    First of all, I certainly don´t say that there is a “natural zero balance” on all possible climate factors – I simply focus on ENSO because that is what Jens´ post here (and the previous one) hints at as a possible explanation. It is indeed very well documented that oceans do not generate new heat, they only redistribute existing heat back and forth – and to be able to induce a net heating of 0,7C to our climate system, basic physics obviously requires some kind of external heat source, i.e. external climate forcing. (This could, of course, theoretically still be a natural one (e.g. solar irradiance), but this is something that would need to be documented separately.)

    That ENSO has, over time, a net forcing of zero, is not, as you appear to think, an “assumption”, but something that has been measured and well documented for many years. I really recommend this page again:

    http://cses.washington.edu/cig/pnwc/aboutenso.shtml

    I can point you to many other similar research pages like that if you are interested.
    Since ENSO cycles only last for a few years at most, we have had numerous ups and downs in the timeframe since 1950 where we have good documentation, so there is not a shortage of data to evaluate this effect.

    You agree that in the years 1960-2010, the ENSO curves show many equally significant cold shifts, too, right? Why, then, are only warm cycles apparently able to influence the climate system, following Jens´ argumentation? Clearly, every honest person with an intact common sense can readily see that this is absurd on its face. The likely answer is, of course, that ENSO is just short-term noise upon an underlying positive forcing, which enhances it in El Niño years and suppresses it in La Niña years but makes no net contribution to the balance at all over a timeframe of 50 years. Jens simply appears to ignore La Niña.

    I have yet to see anybody, even arch-scepticists, even try to make a physically supported case for ENSO having any kind of trend over 20 years or more, and whatever one thinks of Jens Raunsø Jensen´s analysis here, then he obviously has not tried that either. And to do that would require quite an effort, which would possibly involve rewriting even the basic laws of thermodynamics. At the very least, he would have to provide some very good arguments as to why all measurements of ENSO hitherto have been wrong. And so far, he does not even appear to realise this gaping hole in his argument.

    Let me emphasise that I don´t think he has written this out of dishonesty or stupidity, but I do find it puzzling that he is able to miss something so bleedingly obvious. Ferrgodnesssake, the software Jens is using is developed by people from NOAA where lots of professional researchers have analysed things like ENSO and its climatic importance for decades. Apparently, Jens must have thought that none of these had ever considered looking at their own data. I do know that every now and then, amateurs suddenly find new way none of the professionals had ever thought of, but it is much much more common for amateurs to just having misunderstood or overlooked some basics. If one amateur thinks that he has made a scientific breakthrough in his cellar, then to my mind, healthy scepticism should warn him to make damn sure by independent confirmation that there is not basic mistakes in his analyses or experimental design before making bold public proclamations about having invented a perpetuum mobile, a cure against AIDS or discovered cold fusion.

    To me, this post is just another display of the profound lack of scepticism and Dunning-Krügerish disregard for facts all too often seen by other overconfident amateurs in many fields.

  168. Why, then, is it that you appear to think that this suggests that IPCC (or anyone else, for that matter) has got the balance between natural (here ENSO) and anthropogenic forcing wrong? Considering only CO2 and ENSO, it is obvious that ENSO does have an important role in many or all your “shifts”, where it overwhelms the yearly CO2 signal by an order of magnitude for a short while. However, the balance of their respective contribution to the warming 1960-2010 is a 100% for CO2 and 0% for ENSO. There is no contradiction at all in this, as you appear to think.

    Just to clarify: I certainly don´t mean to say that CO2 alone has caused a 100% of the climate changes since 1960 – only that if you in an isolated CO2 vs. ENSO comparison sum the combined net forcings of just ENSO and CO2 in the last 50 years, then this amount to a total of about 1,5 W/m2 – and of this, CO2 has contributed 100% and ENSO 0%.

  169. @HenryP

    thank you for the answer. I appreciate your politeness despite my somewhat sarcastic response.

    However, the only obvious responses I can think of why the global assessment of Vose does not corroborate your findings of minimum temperatures from 20 random stations is that your sample is likely to be either too small or not representative. One needs to be sceptical towards ones own findings, too, and certainly, Vose´s study is by far the more thorough one, right? ;)

    Furthermore, I have had a look at your link here:

    http://www.letterdash.com/HenryP/de-forestation-causes-cooling

    and I must say that I don´t understand your reasoning about deforestation causing cooling. Leaving aside the fact that you don´t provide any documentation for the correlation with deforestation in Argentina, then exposing soil by cutting down trees might as well decrease the albedo unless trees are replaced with some new vegetation? And if trees are burnt, they produce CO2, too .- actually, tropical deforestation contributed about 20% to the yearly human CO2 output of about 29 metric gt…………..?

  170. Jensen, you say: “Tamino goes on with examples to demonstrate that basically any curve with a true trend may/will be interpreted by the step model as consisting of steps. Of course, this is trivial, and I already in my earlier post on the step changes made that caution.”

    But your conclusion in the post says:
    “…the presence of step changes invalidates the widely used statistical techniques of linear trend and smoothing as means of identifying the pattern of temperature variation during 1960-2010.

    Furthermore, the step changes account for the main part of the temperature changes during the 2nd half of the 20th century. The logical consequence is that natural processes have been the major cause for the temperature change during this period, leaving a secondary role to other causes such as the anthropogenic greenhouse effect.”

    So you admit that statistically significant step changes are commonly seen in known linear trends with noise, yet still believe that finding them invalidates those known linear trends?

    And those noise-related artificial “step changes” explain the known linear trend, rather than the known linear trend itself??

  171. CBH says:

    http://wattsupwiththat.com/2012/01/05/abrupt-changes-in-station-level-temperature-records-contradict-the-anthropogenic-global-warming-agw-claims/#comment-861557

    I quote again since it seems you did not get that, it says
    “over global land areas”

    So what happens over the oceans (71%) is not important?

    I am saying the opposite as what you are saying, namely, I think my sample is more representative:

    I have balanced my tables NH and SH latitude and & 70/30 sea -land as far as possible.

    the reason why you can trust my results is because everyone (BEST, Spencer, etc) gets about the same for the means for past 3-4 decades: i.e. +0.14 degree C/decade warming.

    I did provide a link showing a possible relationship between de-forestation/ greening and cooling/warming, in my blog here,

    http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming

    namely,

    http://wattsupwiththat.com/2011/03/24/the-earths-biosphere-is-booming-data-suggests-that-co2-is-the-cause-part-2/

    admittedly I still have to work on finding the correlation coefficient for which I need to find the actual data of the Leaf Area Index

    I am hoping to get hold of the 3x Liu’s one day…

  172. @ Christoffer Bugge Harder

    Thanks for your interesting reply.

    “That ENSO has, over time, a net forcing of zero, is not, as you appear to think, an “assumption”, but something that has been measured and well documented for many years. I really recommend this page again:
    http://cses.washington.edu/cig/pnwc/aboutenso.shtml

    I honestly cannot see anything in that link that supports a net forcing of zero from the availible evidence. It is certainly true that Multivariate ENSO index shows plenty of La Niña events, however from around 1970 it seems that the recorded El Niño events become much more powerfull than La Niña. Would you agree to that interpretation?

    “You agree that in the years 1960-2010, the ENSO curves show many equally significant cold shifts, too, right? ”

    Same as above. From about 1970 El Niño appear to become much more intensive than La Niña. I am not aware if anyone has given any theoretical explanation of why this is so. The orthodox answer seems to be AWG influence. Which could be true but since the causes of ENSO are not fully understood this could be a premature conclusion.

  173. Dear Cubie,

    I have done a series of simple excel plots/correlation of the values of the yearly MEI (Multivariate Enso Index) with GISS Land-ocean temps over the years 1950-2011:

    Data from these sources:

    MEI:http://www.esrl.noaa.gov/psd/enso/mei/table.html
    GISTEMP:http://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts+dSST.txt
    CO2: ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt
    Forcing calculation formulas: http://www.esrl.noaa.gov/gmd/aggi/

    Depending (very much!) on the beginning and start years, one cand get weak positive or negative trends for ENSO over timeframes of about 40 years, as you appear to suggest. E.g, the 40-year trend from 1972-2011 is negative, while the 1971-2010 is positive. However, none of this is remotely as strongly correlated with temps as CO2 forcing, neither the 1960-2010 record – which, needless to say, would be the very minimal requirement for Jens´ hypothesis to hold true – leaving out the physical fundamental problems………

    …….because these are all much more important, as far as I see it: Whatever the sign of ENSO, even if it were strongly positive over some period (and it is not), this still wouldn´t change anything for the basic physical problem: The oceans by themselves still do not generate any extra heat to the system, which is necessary for the system´s net temperature to increase. You would still need to point to an external heat source to explain a net warming. I have nothing qualified to say about whether AGW has or will enhance the El Niño effects in the future (and in this case, I guess you would be likely to see an upward trend over the years), but this clearly still would not mean that ENSO by itself would be causing this net temperature increase, only that the yearly noise from the redistribution of heat would be more extreme.

    Furthermore, if you check out Lyman et al. on the total upper oceanic heat content (OHC) 1993-2008 (not just the surface or the land temperatures):

    http://www.nature.com/nature/journal/v465/n7296/pdf/nature09043.pdf

    then the ups and downs of ENSO are barely visible on the OHC. This, to my mind, is just another clear illustration that Jens´ hypothesis of abrupt ENSO-driven persistent effect on the climate is nonsense.

    And once again, if you check out this illustrative WMO graph of La Niña years:

    then once again, the overall trend even singling out the La Niña years goes in one direction. Even though 2011 was a La Niña year, it still ranks as one of the tenth warmest ever measured. This is, once again-again, just another big red flag that oceans are not driving any global warming.

    Just to finish off, I´m no climate scientist, so some of the above might be a bit incomplete or overly simplified. There are lots of blogs by professionals out there doing a much better informed and more thorough job in explaining this stuff than I could possibly do, but I guess that unfortunately, most sceptics would tend to just dismiss many of them right away, so I have simply tried to present the best science-educated-climate-layman job I could muster here. And I certainly agree that there is a lot to be discovered out there and lots of AGW-related hypotheses we cannot show to be true with any reasonable certainity.
    But on the other hand, there are also quite lots of hypotheses that, just based on the facts we already have, can indeed be clearly shown to be wrong, poorly thought through, incoherent, internally contradictory and rooted in misunderstandings, and Jens´ post here pretty much meet all these criteria. :)

  174. Looks like discussion has waned. Oh well, on to the next “Anything But Carbon” explanation, I guess…

  175. Utahn says:

    Looks like discussion has waned. Oh well, on to the next “Anything But Carbon” explanation, I guess…

    Hi Utahn,
    Well, actually you are lucky. Here we love everybody, whether they like carbon or not. Not like other sites like Sceptical Science where they ban and censor people like me who dares to sing another tune,

    like saying that more carbon dioxide is better….

    Be blessed by knowing that driving a car (if you can still afford it) is good for the environment as it stimulates growth of more trees and greenery!

    http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok

  176. “Here we love everybody, whether they like carbon or not. ”

    Commenters, perhaps, posters, not so much, if the last 100 or so posts are representative.

  177. I don´t know if this can breath a bit of life into the discussion, but I contacted Kevin Trenberth about Jens Raunsø Jensen´s, shall we say, unorthodox interpretation of Trenberth´s 1990 paper to support his thesis about ENSO being the main factor of the temperature rise in the last 50 years.

    Jens Raunsø: The crucial point which Tamino conveniently neglects is that there are independent observational and published evidence for the regime changes identified in my analysis. I suggest that Tamino and like-minded start with reading eg. Trenberth (1990)………

    Let´s recapitulate: The issue is not whether ENSO is able to trigger sudden increases, or equally dramatic declines, in temperature from one year to another, e.g. like the 0,2C increase from 1995/96 to 1997/98. I think everybody agrees to this – this, per se, tells us nothing about the balance between different forcings over a timeframe as large as 50 years.
    The issue is whether ENSO is likely or even able to generate some sort of new heating to the system in this process in order for the temperature to be able to increase by as much as 0,7C in 50 years – or at the very least, whether ENSO could be responsible for a larger fraction of this 0,7C than GHGs. This is what Jens Raunsø Jensen is implicitly or explicitly trying to make a case for.

    I asked Trenberth:

    Isn´t it true that ENSO does not create any new heat in the system? So if there is an increase of 0,6-0,7C since 1960, then one cannot link this increase to abrupt ENSO-related periodic warm shifts over a period of 50 years (as there is strong La Niña natural cooling cycles as well) and claim that this is much larger than the GHG forcing? That is what the gentleman on WUWT is trying.

    and he replied:

    Basically yes. ENSO sequesters heat and then releases it: mostly. Of course there can be residual effects as entropy is increasing. i.e. there is mixing that is not reversible. So ENSO could be one way that some heat builds up but we have no evidence to show that. So best to think of ENSO as not contributing to any new heat: only contributing surges of heat during latter part of El Nino part of cycle while La Nina is a build up of heat phase.>/b

    So, just like the critics have asked all along: ENSO merely cyclically builds up heat but releases it again, and while ENSO could in theory have a residual heat build-up effect, there is no evidence for that.
    To my mind, this also corresponds fine with the lack of trend – or at best, a weak insignificant one – in MEI over the last 40-50 years. Simply pointing at selected jumps and associate these with El Niño while failing to explain or even mention why the many other equally forceful La Niña apparently have not caused any cooling is deeply unscienfic.

    Just to be absolutely clear, I furthermore asked:

    Do you think that Jens Raunsø Jensen has made a reasonable hypothesis by suggesting that natural ENSO-related variability could have caused most of the warming since 1960 – and that he quotes your paper in context?

    and Trenberth replied:

    No, not at all.

    [Italics mine, CBH]

    Quite unequivocal, indeed. Not only has Jens Raunsø Jensen no physical support for this thesis, but his sources disavows his interpretation of their papers. This, to me, should settle the matter for now.

    If Jens still thinks that he has a case, I think it is fair to say that he´ll need to show some pretty convincing evidence for this net buildup of heat in ENSO for his hypothesis to remain standing. It´s very fine to have an open mind, but to make new discoveries of permanent worth, one obviously needs some facts and some coherent hypotheses rooted in physical evidence, too.

  178. Utahn says: Commenters, perhaps, posters, not so much, if the last 100 or so posts are representative.

    Henry@Utahn

    unfortunately this is the way it is.
    there are certain sites that are pro-agw who adore you and ignore me (wipe me off)

    and then there are sites who are not agw (new: acc)
    they really don’t adore you or me but at least I find they don’t ignore you or me & they don’t wipe me off

    Why don’t you study my findings and we can discuss it?

    http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming

  179. Look,

    I am not putting down the writer of this article,
    nor Christopher BH, nor Trenberth, etc

    but if you look again here,

    http://www.letterdash.com/HenryP/de-forestation-causes-cooling

    you will find cooling in Argentinia due to de-forestation
    (there is nothing else that I can think of that causes cooling, do you?)

    and then look at the results from a weather station like Grootfontein, in Namibia,
    you can view all my results here:

    http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming

    and then you read this:

    http://wattsupwiththat.com/2011/03/24/the-earths-biosphere-is-booming-data-suggests-that-co2-is-the-cause-part-2/

    If you have read the above post, you will note with me why I expected to find (some) warming in Grootfontein (Namibia) – I did select this station with a view to test a theory

    tell me if anyone of you picked up on that clue

  180. Christian Bugge Harder, Jan16 12:50am:

    This is pathetic! In your obsessive persistence, you now misrepresent my post after having spent a considerable amount of time on abusive and ad hominem attacks in your previous comments. Are there no limits? I consider this a serious academic offence.

    Just for the benefit of WUWT readers: I have no-where in my post “interpreted Trenberth (1990) to support my thesis of ENSO being the main factor about temperature rise in the last 50 years”, as you state in your opening paragraph. Also, I have not suggested that ENSO is “the main factor”, read my post. And I have only referred to Trenberth (1990) as a solid scientific reference on the regime shift in 1976/77. That’s all. Period. So I do quote Trenberth (1990) in context, contrary to your false accusation. And since you apparently have difficulty reading, I repeat: I have not used Trenberth (1990) to support any discussion on the mechanism. If you still think otherwise, provide the evidence with solid quotations from my post.

    I think that you owe Trenberth an apology for trying to corner him into supporting your case by misrepresenting my position.

    Another aspect that you are missing: the abrupt changes I have documented took place within 20 years (1977 – 1997), not the 40-50 years that you are claiming.

    Your agenda is clearly not one of exploring the science with an open mind, and I do not intend to continue a dialogue on your premises.

    Regards …. jens

  181. jens,

    IMHO, C.B. Harder is a very young and devious individual who shows up here occasionally to disseminate misinformation. The truth is not in him. There are many examples. Here is one from this article:

    http://wattsupwiththat.com/2011/09/27/getting-grled

    Christoffer Bugge Harder says:

    “…It has indeed been explained by ‘Poptech’ both that a) E&E is a science journal, b) that E&E is not a science journal, and c) that it covers both social and natural sciences. You cannot have it all these ways.”

    Poptech responded:

    “Lies. Quote where I made any such statement.”

    Harder simply fabricates things. It’s not worth arguing with someone who invents his ‘facts’ in order to win a debate that he would otherwise lose.

  182. Just looking at figure 3 again

    I wonder how much of that step change towards the end of the 80’s could be caused by the introduction of new equipment & recorders (e.g. with certain type (K?) thermo couples) that monitors temperature on a continuous basis.
    In turn, this could mean that a lot of the observed warming
    ca. 0.14 C /decade since 1974
    as established by me and others
    e.g.

    http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming

    is actually just due to much improved readings and accuracy.

    If I were to simply not accept that jump as being correct, at all,
    and eyeballing it a bit,

    I can predict that our figures of 0.14 C warming per decade could be out by as much as 30% simply because of improved readings and recordings.

    I am not saying that current readings are not good. I am saying older readings were probably too low, too infrequent, and too inaccurate, more biasedly wrong towards the lower temps.,

    leading us us to actually over-estimate modern warming.

  183. Jens,

    I have not suggested that ENSO is “the main factor”, read my post.

    with all due respect: You cannot have your cake and eat it, too. I have, in fact, read your post (several times). You are trying to claim that:

    [T]his is [...] an attempt to clarify the pattern of temperature change during the period of global warming 1960-2010 based on an empirical analysis. [...] [A]brupt changes may account for the major changes in temperature during that period. Furthermore, these regime changes coincide with major documented events in the ocean-atmosphere system as exemplified by ENSO.

    I argue, that unless there is evidence (and not only speculations) that man-made warming is the main cause for the sudden steps, then IPCC has likely got the balance between natural and anthropogenic forcings wrong.

    [S]tep changes account for the main part of the temperature changes during the 2nd half of the 20th century. The logical consequence is that natural processes have been the major cause for the temperature change during this period, leaving a secondary role to other causes such as the anthropogenic greenhouse effect.

    Are you or are you not trying to make a case that a) the rise in temperatures in the years 1960-2010 (the interval you have selected yourself, ferrgodnessake) is dominated by natural forcings, causing stepwise changes, with CO2 having a secondary role? And b) do you or do you not link these stepwise changes you claim to have identified as coinciding to mainly ENSO? (Allow me to remind you of the title of your earlier post: “Global warming – step changes driven by ENSO?”)

    If the answer to these two questions is yes, then you are certainly claiming that natural forcings – as exemplified by ENSO (i.e. the only example you really elaborate on) – are the main cause of the temperature rise in your peiod of choice, causing most of the stepwise changes you claim to identify. I have noticed that you appear to have trouble realising this, but it really should not be that hard to see for any open mind.
    If your answer is no, then there is no point in your entire post………

    As Utahn has pointed out, you have a similar problem with internal contradiction when it comes to the alleged stepwise changes themselves:

    Jens 1…basically any curve with a true trend may/will be interpreted by the step model as consisting of steps. Of course, this is trivial, and I already in my earlier post on the step changes made that caution.

    Jens 2…the presence of step changes invalidates the widely used statistical techniques of linear trend and smoothing as means of identifying the pattern of temperature variation during 1960-2010.

    If the fact that Rodionov´s step detection software will detect “steps” in almost any dataset is so utterly trivial even to you, then how on earth can you claim that the mere interpretation of the model of alleged “steps” somehow invalidates the presence of a true linear trend? And if you acknowledge that there might indeed be an underlying linear trend which is masked, then what on (this) earth in this analysis enables you to see whether this trend has a stronger or weaker overall signal than your alleged “steps”? Once again, your sources for your “regime changes” plainly do not support this thesis of yours at all>/i>, whether you like it or not.

    If you still wish to try to claim that your “steps-show-natural-forcings-dominate-CO2-1960-2010″ thesis is valid, then you need to demonstrate at least three things:

    I) That your identified steps are present not only locally, but globally (locally, atmospheric circulation patterns can indeed overwhelm signal for several decades, but globally, various sources of noise will have opposite signs on different places of the planet and thus cancel each other out much more quickly)

    II) That the stepwise change model is indeed a better description of the data than a linear model, and

    III) that your physical explanations of these steps is coherent. Again, I know you are not trying to build a complete GCM model, but when you (as you do) try to link these steps to a physical mechanism like ENSO, you really need to explain why you think ENSO is able to cause an abrupt warming in its warm El Niño phase in 1997/98, when it apparently is unable to cause any similar cooling in the many equally cold La Niña phases in the interval 1960-2010 (e.g. 1988-89 or 1999-2000).

  184. And regarding you being “academically offended”:

    To my mind, my above questions (and those of other people like Utahn or Svalgard) are perfectly legitimate, based in scientific facts and politely posed, too. So far, you have either given evasive answers that makes one wonder whether you actually understand some of the important basics, or simply ignored them, instead complaining loudly about “ad hominem attacks”. Sorry, Jens, but I´m sure you know very well that the natural sciences can be a tough environment, that extraordinary claims require extraordinary proof, and that one needs to be sceptical about one´s own results, too. It is perfectly fine that you are not a climatologist, and that you still dare to try to disprove one of the core findings of mainstream climate science, and that you chose to do so on a blog run by another climate amateur who is, a priori, sympathetic to your views – but then you really should not be surprised when your claims are being challenged by other people when your facts do not hold up, and that you also run a high risk of being wrong and even end up being laughed upon, especially when you fail to acknowledge obvious errors. The other half of your cliché about the importance of being open minded says that one shouldn´t let the brain fall out either, remember?

    If you actually wish to convince people who aren´t already convinced that the whole AGW hypothesis is wrong, a scam or a conspiracy that you have a legitimate challenge to mainstream climate science, then you need to adress the above obvious holes in your arguments. If you are happy just to preach some non-academic, seemingly plausible but unsupported bedtime stories to the choir that you would prefer not to be met with counterarguments, then it´s your choice – but then do me a favour and spare me the BS about being “academically” offended.

    P.S: I guess I should be flattered by you thinking that I, a mediocre PhD student in a field at best on the fringe of climate science, be able to “corner” an internationally recognised and distinguished atmospheric scientist like Kevin Trenberth, just by sending him a mail. But no, all I did was to ask him about ENSO and your claims. I provided a link to this post and some quotes from it, along with a couple of questions summing up the substance. You quote Trenberth among others as evidence that your regime changes are real, and you are undeniably trying to make a case that naturally forced regime changes have overwhelmed manmade GHGs. This is squarely at odds with almost all published research on the field, including the well known conclusion of the IPCC AR4 report that “Most of the climatic warming over the last 50 years is likely to have been caused by increased concentrations of greenhouse gases in the atmosphere”, of which Trenberth was a lead author. That he finds that you use his 1990 paper completely out of context and/or reach an erroneous conclusion not supported by the papers you quote should thus come as no surprise to you, and I honestly don´t understand why you think that I should apologise for anything in this regard.

    But to settle the dispute, I suggest that you write this up as a paper and submit it to a serious journal (e.g. not Energy & Environment, blogs or some non-refereed Danish language newspapers) so that competent experts in all fields might have a chance to analyse your claims. My prediction is that you will be asked many of these same questions, and possibly many more thorough ones people here have not thought of – and that after having accounted for errors and weaknesses, you will end up having no base at all for your claims about natural forcings contradicting AGW/leaving a secondary role for GHGs (surely not on a global scale).

  185. And regarding you being “academically offended”:

    To my mind, my above questions (and those of other people like Utahn or Svalgard) are perfectly legitimate, based in scientific facts and politely posed, too. So far, you have either given evasive answers that makes one wonder whether you actually understand some of the important basics, or simply ignored them, instead complaining loudly about “ad hominem attacks”. Sorry, Jens, but I´m sure you know very well that the natural sciences can be a tough environment, that extraordinary claims require extraordinary proof, and that one needs to be sceptical about one´s own results, too. It is perfectly fine that you are not a climatologist, and that you still dare to try to disprove one of the core findings of mainstream climate science, and that you chose to do so on a blog run by another climate amateur who is, a priori, sympathetic to your views – but then you really should not be surprised when your claims are being challenged by other people when your facts do not hold up, and that you also run a high risk of being wrong and even end up being laughed upon, especially when you fail to acknowledge obvious errors. The other half of your cliché about the importance of being open minded says that one shouldn´t let the brain fall out either, remember?

    If you actually wish to convince people who were not already convinced that the whole AGW hypothesis is wrong, a scam or a conspiracy that you have a legitimate challenge to mainstream climate science, then you need to adress the above obvious holes in your arguments. If you are happy just to preach some non-academic, seemingly plausible but unsupported bedtime stories to the choir that you would prefer not to be met with serious counterarguments, then it´s your choice – but then do me a favour and spare me the BS about being “academically” offended.

    P.S: I guess I should be flattered by you thinking that I, a mediocre PhD student in a field at best on the fringe of climate science, be able to “corner” an internationally recognised and distinguished atmospheric scientist like Kevin Trenberth, just by sending him a mail. But no, all I did was to ask him about ENSO and your claims. I provided a link to this post and some quotes from it, along with a couple of questions summing up the substance. You quote Trenberth among others as evidence that your regime changes are real, and you are undeniably trying to make a case that naturally forced regime changes have overwhelmed manmade GHGs. This is squarely at odds with almost all published research on the field, including the well known conclusion of the IPCC AR4 report that “Most of the climatic warming over the last 50 years is likely to have been caused by increased concentrations of greenhouse gases in the atmosphere”, of which Trenberth was a lead author. That he finds that you use his 1990 paper completely out of context and/or reach an erroneous conclusion not supported by the papers you quote should thus come as no surprise to you, and I honestly don´t understand why you think that I should apologise for anything in this regard.

    But to settle the dispute, I suggest that you write this up as a paper and submit it to a serious journal (e.g. not Energy & Environment, blogs or some non-refereed Danish language newspapers) so that competent experts in all fields might have a chance to analyse your claims. My prediction is that you will be asked many of these same questions, and possibly many more thorough ones people here have not thought of – and that after having accounted for errors and weaknesses, you will end up having no base at all for your claims about natural forcings contradicting AGW/leaving a secondary role for GHGs – surely not on a global scale, which is the scale for which the AGW claims you want to refute have been made.

  186. Jens,
    Thank you for your interesting and informative post; your temperate and patient replies to questions and challenges in the subsequent commentary are similarly thoughtful and reserved. The same courtesy and professionalism has been demonstrated by some others, but not all. It is a great pity that so often personal convictions stir the emotions and cloud judgment, a behaviour we can all observe so often in the debates over climate change.
    I’m neither mathematician nor scientist. I’ve come to this thread late, as I have to the climate change debate. Quite some years ago I accepted what we were being told by the “climate scientists” about anthropogenic-released carbon dioxide as the cause of global warming, but in the earlier part of the last decade, I started to have some doubts. At last I’ve had the time to do some reading at the detailed level, which I’m doing because I no longer have confidence in what is presented through official channels, or the media. Both avenues are full of assertion and persuasion, and precious little well-based argument. But now to your post.
    1. It seems to me that this instance of using a well-recognised mathematical tool to determine step changes, is just the kind of arms-length analysis that is too often missing in this debate. I agree with your suggestion that “major step changes in mean temperature regime may contradict the claims of the AGW theory and models” – and I applaud your use of the word “may”, demonstrating a conservative perception that some respondents to your posts seem to have missed entirely. I may have missed something, but could you indicate in more detail where or how these step changes may challenge the validity of the more recent IPCC models of temperature change? (The flatter and cooler changes measured over the last decade have clearly shown that temperature predictions of prior models have proven deficient.)
    2. Accuracy of the raw data, and instrumentation changes? I think we’re stuck with what we have historically, and that’s what we have to work with; but I’m very pleased to see that the raw data is being analysed, not some massaged set or imputed metrics for blank cells, nor those bland averages which as said by someone earlier in the commentary are like putting Paris Hilton in a burlap sack , which contain the data but lose the interesting contours and prominent features.
    3. Most of the discussion above has raged over the issue of step changes. But I thought your charts and summary points about temperature stability also very interesting. I quote:
    a. “50% of sample stations have not experienced increased mean temperature (”warming”) for more than 18 years.
    b. 70% of Europe stations have not experienced warming for more than 20 years.” This finding prompts me to ask what other zero increases in temperature over appreciable time periods, may be found in raw data elsewhere?
    4. The average person in the street would have to ask, if we started to come out of a Little Ice Age in 1680, when so much of northern Europe was so cold that the Thames itself froze, what caused things to warm up prior to the Industrial Revolution? And are not the same factors at work today? Yes, AGW may exacerbate the warming, but should we not consider that the deep forces at play between 1680 and 1850 may still be operating?
    Please keep up your good work.
    .

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