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New Detailed Analysis of Global Temperature Data Does Not Support Significant Role for Carbon Dioxide

The Intergovernmental Panel on Climate Change (IPCC) has stated that: Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations, mainly carbon dioxide.  This conclusion is based on output from global climate computer models known as General Circulation Models (GCM). 

David Douglass and John Christy, in a paper recently accepted for publication and already available on the internet, have come to a different conclusion.  By considering observed, as opposed to modelled, temperature changes and at different latitude bands they conclude that:

1. El Nino and La Nina effects in the tropics have a more significant affect on global temperature anomalies than carbon dioxide, in particular it was an El Nino event that drove the 1998 global temperature maximum.

2. Variations in global temperatures since 1978 have mostly been due to climate effects in the northern hemisphere (northern extratropics) and these effects cannot be attributed to carbon dioxide.

3. Carbon dioxide has contributed a small amount to an increase in global temperatures but without what is commonly referred to as feed-back. 

David Douglas and John Christy are practicing climate scientists from the Department of Physics and Astronomy, University of Rochester, and Department of Atmospheric Science and Earth System Science Center, University of Alabama, respectively.  Their paper entitled ‘Limits on CO2 Climate Forcing from Recent Temperature Data of Earth’, was recently accepted for publication in Energy and Environment. 

A regular at this blog, Cohenite, comments on the Douglass-Christy paper in a fairly technical note already posted at the community webpage of this blog, and entitled ‘Temperature Trends and Carbon Dioxide’, suggests that there is no evidence for a contribution from carbon dioxide to global temperatures and that the role of the sun has been underestimated.

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193 Responses to “New Detailed Analysis of Global Temperature Data Does Not Support Significant Role for Carbon Dioxide”

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  1. Comment from: NT


    The recipe I found is this:

    * Compute area averaged total SST from Niño 3.4 region.
    * Compute monthly climatology (1950-1979) for area averaged total SST from Niño 3.4 region, and subtract climatology from area averaged total SST time series to obtain anomalies.
    * Smooth the anomalies with a 5-month running mean.
    * Normalize the smoothed N3.4 by its standard deviation over the climatological period 1950-1979.

    The original task you assigned me was:”So that YOU can determine the long-term effects of ENSO, download that data, insert it in a spreadsheet, and using the monthly data or the annual average NINO3.4 from Trenberth and Stepaniak, calculate a the running total of the data. Plot the running total”

    So this is why I was asking questions. Obviously what you asked me to do wasn’t actually relevant. Hence my assertions that the running total abnormaly favoured past years.

  2. Comment from: NT


    Bob, why didn’t you just stick with Trenberth et al 2002, Figure 3?
    It shows the Global temp anomaly with the ENSO signal removed (based on Nino 3.4)

  3. Comment from: SJT


    “NT: I thought I answered your question about intent of adding the monthly or annual NINO3.4 values. It’s a significantly positive number, so the dominance of El Nino events over La Nina events implies that ENSO is not an equally weighted oscillation and that it contributed to the rise in global temperature over the term of that data set.”

    That is weird. An oscillation is by definition something that is not what you are describing.

    “is the repetitive variation, typically in time, of some measure about a central value ”

    An El Nino is not a forcing. If there is a positive change, it’s from some external source. Maybe a forcing. Maybe CO2?

  4. Comment from: NT


    SJT, why must you make it so obvious you are my sock puppet… Sheesh. :)

  5. Comment from: SJT


    Your doing my best. :)

  6. Comment from: cohenite


    Trenberth’s ENSO deducted temp trend is ~+0.0925C per decade; before allowing for SF; DC obtained +0.07C per decade prior to deducting SF; as I noted earlier, in a 1994 analysis DC had obtained an ENSO free trend of +0.09C per decade; Lucia’s ENSO removal from 2001, is of course still a -ve trend. NT, after you add the 3.4′s up why don’t you divide them by the number of years?

  7. Comment from: Bob Tisdale


    NT: Sorry, I can’t spend a lot of time now, but I’ll be back in a couple of hours. I posted a detailed description of that process of converting the Global SST to annual change, etc., here:
    http://bobtisdale.blogspot.com/2008/05/annual-and-long-term-impacts-of-el.html

  8. Comment from: cohenite


    “Maybe CO2?” Right, off you go Will; get a correlation; don’t get lost in space.

  9. Comment from: cohenite


    Will; “an El Nino is not a forcing.” But its precursor, the upwelling ‘oscillation’ is.

  10. Comment from: NT


    Bob, thanks for the discussion.
    I’ll look over your plots in more detail tomorrow.
    I am thinking that this whole issue comes down to what is driving what. Is El Nino an ‘embedded’ cycle that is driven by historic temps, or TSI, or a cycles within the ocean, or if the additional CO2 is preventing the oceans from ‘cooling’ like they used to. This is a pretty complex question and won’t be answered soon I fear.
    Either way I would be suprised if there wasn’t evidence of the ENSO signal in the global temps, it would be more surprising if it wasn’t there.

    Thanks again, it is pleasant to have a reasoned discussion and I hope you haven’t viewed my posts as antagonistic, as they weren’t meant in that fashion.

  11. Comment from: NT


    Cohenite, you may need to look at your definition of Forcing.

    I know this is from Wikipedia, but it’s probably closer to correct than not:

    “In the context of climate change, the term forcing is restricted to changes in the radiation balance of the surface-troposphere system imposed by external factors, with no changes in stratospheric dynamics, without any surface and tropospheric feedbacks in operation (i.e., no secondary effects induced because of changes in tropospheric motions or its thermodynamic state), and with no dynamically-induced changes in the amount and distribution of atmospheric water (vapour, liquid, and solid forms).”

    So for the upwelling to be a forcing it would have to be sourced from some external source.

  12. Comment from: Bob Tisdale


    SJT: Thanks for correcting my use of the word oscillation. However, until they change the phenomenon known as El Nino-Southern Oscillation (ENSO) to El Nino-Southern Random Noise (ENSRN), I will continue to use the word oscillation in my comments. (sarcasm off)

    Regarding your comment about El Nino and La Nina events not being forcings: I checked this thread and can’t find that I made any reference to El Nino-La Nina events being forcings. Also, if your view of the factors that determine global surface temperature (as determined by measured sea surface temperature and land surface air temperature) are limited to radiative forcings, then maybe your view needs to be expanded. Thermohaline circulation/meridional overturning circulation is known to effect global temperature, yet it would not fit the definition of a climate forcing that NT posted. In fact, RealClimate, in its definition of one of the THC/MOC phenomena, the Atlantic Multidecadal Oscillation (AMO), writes this: “This pattern is believed to describe some of the observed early 20th century (1920s-1930s) high-latitude Northern Hemisphere warming and some, but not all, of the high-latitude warming observed in the late 20th century.”
    http://www.realclimate.org/index.php?p=38

    With respect to your attempts to tie El Nino to greenhouse gases, I suggest you research the topic. Here, let me help:
    http://faculty.washington.edu/kessler/occasionally-asked-questions.html#q16
    Refer to Bill Kessler’s (NOAA/Pacific Marine Environmental Laboratory) answers to questions 16 and 26.

    Now you could research it a little further and find papers that state that there is an AGW footprint in ENSO and I could provide others that say there’s not. Do we need to do that? I hope not.

  13. Comment from: Robin Edwards


    Thanks for your comments, Cohenite, Oct 7th.

    I’ll just say that I do understand enough about statistics to have written a general purpose stats program, and sold perhaps a 1000 copies. Thus I hope I can legitimately make some statistical comments.

    I’ve had some direct communications with Steve McIntyre, who originally provided me with Mann’s 1998 data set that he had managed to discover, and even with Mann himself! – though not by email. I sent him an old-fashioned airmail and got an immediate email reply with URLs for his data! I’m also been in contact with various other climatologists (Vinther, Moberg, Phil Jones, Christy and Spencer, Will Alexander and so forth, who have been and still are very forthcoming).

    The findings I believe I’ve made from Mann’s 1998 data are totally independent from those discoveries of Steve, and are not in any way dependent on knowledge of the bristlecone pine story, fascinating though that is. I started from the premise that the data have to be accepted as they were, whatever reservations one might have about their validity or relevance. I thus presumed that Mann et al had the attributes of honesty and transparency. Although there is some doubt about the clerical accuracy of the published data – disclosed originally by Steve McIntyre – I have accepted all Mann’s data as being genuine observations (or proxies if instrumental observations were not available) which he had chosen as being as far as possible representative of the Earth’s climate state for the years in question. If you have ever looked at the actual data you will no doubt have been astonished at the tremendously diverse scales, both in values and dispersion, that he used. I could write a long essay on them.

    I merely standardised all the data, allotting them equal weights (though I have worked with the column weightings that Mann gives), and then computed the standard statistics (as if they were independent observations, not time series) to give a feel for their relative dispersions, etc, and using the column names I assembled them into what I deemed to be “homogenous” groups (eg ice cores, coral fluorescence, temperatures, precipitation, etc), and averaged over the members of each group. The average data can be plotted, their variance computed, and further operations carried out, in the knowledge that no individual series can dominate the outcome /unless/ it is strikingly different from the other members of the group.

    As you might expect, not all groups produced the same signal, and indeed the standard plots were not all that informative, due to large year to year differences.

    However, using the industrial quality control technique of forming the cumulative sums of historical data the messy patterns resolved into understandable plots, making it possible to understand at least in part, what might be gleaned.

    If you’ve followed Steve’s analyses you’ll be familiar with the problems of diverse time periods and the bizarre “calibration” method Mann used, and which Steve comprehensively demolished in his paper in E & E. The calibration seems to have been necessary to enable the final ordinate values (of the composite series) to have a label “Temperature” put on them. However, looking simply at the behaviour of the standardised data wrt time, the units are of no consequence. Thus the non-dimensional units of averaged standardised values are sufficient to disclose any interesting feature of the data. Making the simplest separation into groups can be done by putting all the actual temperature data (in fact all but one of the 13 columns had been manipulated before being included in the data base – but no matter, they were all subsequently standardised – ), and allotting the remaining 99 columns to the “proxy” data. What emerged? First, for the purposes of this very short report, I used only those years for which all 112 columns were complete. Well, the standard time series plots were rather nonedescript, as you might expect, but the cumulative sums are a revelation. Most striking is that the two groups show the same general pattern. Taking the temperature data first (as being the more reliable), from 1820 to about 1887 there is no discernible trend (the cusum plot is effectively straight). Then a sharp upward event takes place, with stable temperatures until the early 1920s, when another more gradual upward change occurs, being complete at about 1930. From there until about the mid 1970s a stable period ensued, briefly interrupted by years 1939 to 1942 (the war years which were cold). Then a downward event occurred together with some mixed signals to the end of the data (1980).

    With the amalgamated proxy data the period 1820 to 1868 was stable, and then an abrupt upward event occurred, to be followed by about 45 years of stability. Another slightly less sharp upward change occurred beginning at about 1922, followed by a very stable period to the end of the data (1970).

    There is a most striking similarity between the two plots, though the first temperature data change took place about 30 years later than the proxy average.

    From the “hockey stick” perspective the most striking thing is the tremendous stability of both sets over the period 1920 to 1970/1980.

    Thus, Mann’s actual data show no sign whatsoever of “catastrophic” increases in this period, in total contrast to his very sharply increasing temperature plot.

    How on earth did he generate his HS from these data except by making some sort of blunder? It just does not exist.

    I cold expand indefinitely on this topic, with much more detailed analyses (I did them years ago) using small subsets of the data, such as coral fluorescence values (columns 1-9), or treeline data, etc. Unfortunately I have no idea how to post GIFs for you to look at :-((

    So there you are – some of my findings to contemplate or ridicule, as you see fit. If you can discover anything different in Mann’s data I shall be really keen to see it, and to learn of your analytical methods.

    Cheers, Robin

  14. Comment from: cohenite


    NT; re: forcing; what Bob said; in addition, how can CO2 which has been dug up, sometimes very close to the surface, and then emitted into the atmosphere by Al Gore’s jet engines be any different, in a forcing sense, from deep cold water which comes from kilometers beneath the sea surface, when, if that upwelling ceases, then SST increases with consequent change to the CO2 partial pressure and the sea surface becomes a net emitter of CO2?

  15. Comment from: Derek D


    I love the fact that so many scientists are so socially inept. You guys argue and one-up each other as if all the science in the world had the influence on people or governments that tens of billions of dollars does. For all of your intellegence you all miss the point, and stick to arguing from a familiar place, just like the common idiot. And despite your assertions of dominance many of you are all clearly desparate for approval and viciously defensive to anyone that threatens it.

    AGW is crap. You’re an idiot if you believe it. A big freaking out of touch dumber than dumb totally snowballed IDIOT. It’s about money and power, not science. And even if it was about science, scientists are easily bribed with money. If you can’t follow the money, and see the attempted power grab, then you are so freaking dumb, all the climate knowledge in the world won’t help you tie your shoes.

    And I could give two craps who agrees or disagrees. I’m smarter than all of you because I said so. Argue that…!

  16. Comment from: Robin Edwards


    Hello, Gordon (Robinson),

    Perhaps you’ll see my Looong message to Cohenite, where I try to answer some of the points you raise. I’m not re-inventing the wheel, because I use entirely different and totally independent methods. Incidentally,I did all this stuff years ago, when Steve McIntyre and Ross McItrick. were just beginning their investigations. I’ve followed their work closely for years, and have discussed it face to face with Ross in London. I’ve not done anything connected with Mann’s data for several years now, and had to dredge up the plots I made long ago in order to answer Cohenite appropriately . I’m up to speed, I think, with Steve’s current work, and his thinking on Mann’s latest publication. Unfortunately, the scale of the data sets used puts my methods, using totally different software that lacks a high level statistical language (Steve uses “R”)
    which is too heavy going for me, though I can read most of the code but NOT write it :-(( ) at a considerable disadvantage because of the necessary manual interventions.

    What I would really like to find is the actual numbers that Mann et al used at the final stage of the plotting process to generate their (in)famous curve, but I’ve been unable to locate anything numerical at all. The plot itself is useless to me, lacking a digitiser, and anyway the scales that I’ve seen printed are far too difficult to digitise.

    Can anyone help, please?

    Cheers, Robin

  17. Comment from: cohenite


    Robin; fascinating; you are, no doubt, aware of the Ian Jolliffe kerfuffle about MBH’s inappropriate use of PCA? What are your views on that? Also, no doubt, you have looked at Mann’s 2nd paper and the statistical methodology he uses in that, which has been occupying SM’s time (I must say in respect of Mann’s 2nd report, that is the closest I’ve seen Steve come to being really angry); the flaws I’ve read about being manifest in the 2nd HS paper are too many to note, but my favourite is how a proxy is not discarded if an instrument correlation cannot be found in the proximate grid; rather a grid instrument from anywhere can be used. Your thoughts? And may I suggest that a commonsense post on the exotic statistical methods used by Mann would be a pleasure to read, so why don’t you do one and submit it to Jennifer?

  18. Comment from: NT


    Cohenite. I assume because that CO2 would have been secured otherwise. Coal, gas and oil, where in no hurry to return to the surface. In fact over geological time there has been a progressive loss of carbon from the biosphere due to burial. The only CO2 that was returning was either through volcanic events or through orogenic activity.

    Robin, better still why don’t you write a paper, and submit it to a journal. Not many people read this blog and if it is as important as you say you need to disseminate it to as wide an audience as possible.

    Bob, thanks for the link. No I don’t want a paper duel, If you go back to what I wrote, I stressed that there was more work to be done. Then I stated my opinion.

    Bob, I don’t make the definitions of forcings. I have no power over the people at RealClimate.

  19. Comment from: NT


    Guess this all means the DC paper that started this thread is pretty lightweight and will deservedly be ignored.

  20. Comment from: cohenite


    NT; as I noted DC obtain pretty much the same CO2 signal as Trenberth, he of the Eddington semi-infinite model that AGW is predicated on; but if we look closer we see Trenberth got a SF undeducted CO2 signal of ~ +0.092C per decade for the period 1950-98; DC got a SF undeducted CO2 signal of +0.07C per decade for the period 1979-2008; lucia got a SF undeducted CO2 signal of ~-0.045C per decade for the period 2001-2008; now that’s a trend. Bob’s work shows that there is a strong correlation between ENSO and temp trend with no need for a lag, which again, according to Trenberth, is minimal anyway. HadCrut show there was a temp increase of +0.52C from 1900-2000, or +0.052C per decade; that trend was not correlated with CO2.

    Jan Pompe; if you’re reading, I just got hold of a report by Dr Ir. E. van Andel which details that Rob van Dorland Miskolcz confirming experiment; it’s being distributed by Ray Evans so I presume you’ve got a copy; again front page news stuff doesn’t even make the msm. AGW is definitely not about the science.

  21. Comment from: SJT


    “he of the Eddington semi-infinite model that AGW is predicated on”

    A lot of standard physics is based on your obsession with ‘semi-infinite’, whatever that means. My understanding is that if it’s only partly infinite, it must be finite. Perhaps you don’t understand that many concepts are ‘infinite’, but converge, or the ‘infinite’ components become vanishingly small. PI would be an example, perhaps. It’s well and truly infinite, in the number of digits you can give it, but those additional digits after the decimal point are purely of academic interest after the first ones, depending on the precision you need.

  22. Comment from: SJT


    “I just got hold of a report by Dr Ir. E. van Andel ”

    What does he say about this theory?

    “Now, I must confess that I cannot follow FM in his terms “radiation pressure”, his “Virial theorem” or his “Kirchhoff law”.”

    :) Comedy gold.

  23. Comment from: Jan Pompe


    cohenite: “I just got hold of a report by Dr Ir. E. van Andel which details that Rob van Dorland Miskolcz confirming experiment; it’s being distributed by Ray Evans so I presume you’ve got a copy;”

    HE probably got it from David Stockwell that’s a fuller (draft) of the material I mentioned earlier. Ken Gregory and I have found some typos in it I’m still going through it there is some Dutch English that needs cleaning up. (I grew up with parents fluent in Dutch English). I’m bit short of time at them moment.

    His difficulty with Ferenc’s terminology notwithstanding his analysis of the atmospheric profiles shows that the downward radiation is equal to the radiation absorbed in the lower atmosphere.

    As for the virial Ferenc’s term is not strictly related to the Clausius virial theorem and he was surprised when I ran an analysis on the TIGR profiles and found it held to .5%. He then clean up my calculations with a better calculated profile and more accurate planetary radius etc and found it holds to 40 ppm. I guess it makes a good sanity check for atmospheric profiles that the USST76 fails miserably which a result that is out by a factor of 85%.

  24. Comment from: cohenite


    Jan; I like his finding that CO2 IR absorption exhausts at about 65cm; that would be about the height of some of the AGW gnomes.

    Will, what’s this about PI; I don’t do Personal Injury law, but you’re right, it is an infinite source of clients; people just keep falling flat on their faces; must be all the CO2 at about 1/2 a metre.

  25. Comment from: Louis Hissink


    Jan:

    Ray Evans got it from David Stockwell?

    Interesting….;-)

  26. Comment from: SJT


    “HadCrut show there was a temp increase of +0.52C from 1900-2000, or +0.052C per decade; that trend was not correlated with CO2.”

    That’s because CO2 has been building up over the century, and other forcings have to be taken into account. Read the IPCC report on attribution.

  27. Comment from: Robin Edwards


    Replying again to Cohenite, no, I don’t have any access to Jolliffe’s work, so can’t comment. In fact the peculiar PCA procedures used by Mann et al don’t really worry me at all. I simply disregard all the complex and debatable maths and rely solely on the numbers that have been published. I /never/ apply any smoothing techniques, having learned long ago that any attempt to sanitise data on these lines simply loses information rather than enhances it. Thus I have to confess that the chief topic in this blog at the moment leaves me rather cold! I have to to say that my software includes three smoothing mechanisms, put there at the request of a client, but I just don’t use them apart from the moving average facility, which can be informative from time to time for complete data sets or to check the published work of others. Cusum technology is remarkably robust to occasional shortcomings in data, such as the ubiquitous missing value syndrome or a grossly strange value. What it does very successfully is to provide what my employers used to term the “helicopter viewpoint”, meaning that it addresses the long term propensity of the data to change (or not). It has absolutely no useful predictive ability, and I never attempt to forecast the future ;-)

    Regarding your suggestion about writing something on Mann’s methodology and computing I could not possibly do that. All that you could ever wish to know has been (and is being) reported by (mainly) Steve McIntyre on ClimateAudit, which is most interesting site.

    I’ll keep reading this site – very intriguing.

    Cheers,

    Robin

  28. Comment from: Jeff Id


    Robin,

    I have been working on demonstrating a serious flaw in the math used to sort temperature proxies and create hockey sticks. What I am doing that is new is demonstrating how the method demagnifies historic data in relation to the calibration range.

    http://noconsensus.wordpress.com/2008/10/08/id-goes-mythbuster-on-hockey-sticks-cps/

    I think when this becomes fully developed and published it could force the recalculation or retraction of every hockey stick graph.

  29. Comment from: Gordon Robertson


    Derek D said…”I’m smarter than all of you because I said so. Argue that…!”

    No you’re not.

  30. Comment from: Gordon Robertson


    Robin Edwards said…”So there you are – some of my findings to contemplate or ridicule, as you see fit. If you can discover anything different in Mann’s data I shall be really keen to see it, and to learn of your analytical methods”.

    Interesting analysis, Robin. Have you looked at the recent work of Loehle? He omitted the tree ring data because he felt they had problems, namely, tree ring width can reduce in warmer weather due to a lack of rainfall.

    http://www.ncasi.org/publications/Detail.aspx?id=3025

    There’s a link on that page where you can download the PDF file. Loehle claims he found ample evidence of the Medieval Warm Period and the Little Ice Age. Of course, realclimate. org cherry-picked the results and Loehle corrected them. You may have to look for the corrected version as well.

    I’d be interested on your take of Loehle’s work.

  31. Comment from: Bernard J.


    Comment from cohenite
    Time October 6, 2008 at 8:59 am

    “Bernard J, I see, over at Deltoid, is calling for Monckton to be beheaded”

    Cohenite.

    I have never suggested that Monckton be beheaded, nor have I implied any other violent act be perpretrated on Monckton. Nor have I described myself as “beacon of civilised discourse”.

    You are promoting mendacious lies.

  32. Comment from: Bernard J.


    I would like to tip my hat and acknowledge that Cohenite has addressed my complaint over at Deltoid:

    http://scienceblogs.com/deltoid/2008/10/the_australians_war_on_science_21.php

    It seems that both he and I have a deficit of irony-detection at times, because my French revolution metaphor was taken by him in a way that I hadn’t intended it to be taken, just as he was apparently being somewhat Socratic with his ‘beacon’ statement.

    I withdraw my comment about mendaciousness, but I continue to think that Cohenite was being somewhat mischievous in his post above in not explaining the context of my comment. To be expected from a lawyer I guess, although I would have thought that the context of my comment would be passed on in any reference to my Deltoid post.

    I would not have ever guessed that anyone would seriously suggest from reading my post that I was countenancing beheading and pass this message on to others, especially as in my mind I was referring to Monckton perhaps being tapped on the shoulder and told to be a little more circumspect in how he draws unfavourable attention to the UK peerage.

    However I admit that my allusion to guillotines was a metaphor that could easily be misconstrued even by people not being mischievous, and that I should have been more explicit in the tenor of my intended meaning.

    For future reference though, I do not support violence, and if anyone ever imputes such from any comment I make, whether clearly ironic or not, I suggest that they do so with reference to the context of any statement.

    This is my Deltoid response:

    —————–

    Cohenite.

    Well spotted, but I was actually referring to the aristocracy dissociating themselves from their colleague lest they lose favour with the commoners and find a republic is a serious attraction to the UK public.

    My very bad though for picking a metaphor that included the French revolution and ‘beheading’. However, as a wise man once said, I thought my revolution comment “would be taken with the necessary grain of ironic salt; I stand corrected.”

    Seasoning aside, if the British blue-bloods persist in allowing such muddled-thinking amongst their ‘best’, the weight of history may one day not be able to prevent a dissolution of the country’s current sociopolitical structure.

  33. Comment from: Robin Edwards


    Gordon Robertson wrote “I’d be interested in your take on Loehle’s work”.

    Well, I’ve downloaded it all, thanks to your link, and have to say I’m a mite disappointed! I can of course reproduce his conclusions about the MWP ad LIA by simply looking at the plot of his data. They look quite reasonably spiky, as one expects from anything related to climate, but when I looked at the cusum plot it was /instantly/ obvious that the data were not “as found”, but heavily smoothed. This pretreatment is always recognisable from cusum plots merely from /their/ lack of spikiness. Then I read the summary of his paper – can’t get at the whole thing – and saw that the data had all been treated by using a 30 year smoother. Unfortunately, this ruins what can be deduced from cusums about sudden change. That of course is what smoothing of any sort is all about! It is used to disguise unpalatable amounts of noise, disregarding completely the fact that the most interesting signal may be in the noise that the smoothing system takes out, and that we cannot know what the cause of the noise is. It could be old-fashioned iid “gaussian” with mean zero, but it could be a reflection of the vicissitudes of the complex and unforecastable things that are caused by the drivers of climate. Further, the more you smooth the greater are the problems with the start and end of the series. Inevitably you have to resort to guessing.

    Another problem is “outliers”. No doubt you’ve addressed this one, probably without reaching an acceptable conclusion. Again, in my software I’ve implemented a couple of procedures, but in reality the only reason for discarding data is knowing that it is in error from sources other than the data values themselves. A typical scenario is the transposing of digits, which happens to result in a “strange value”, say 28 instead of a more reasonable 82. This stranger may indeed by picked up by suitable outlier detection techniques but if you don’t contact the owner of the data with your suspicions you really have no proper grounds for rejecting it.

    You’ll guess that smoothing frustrates me. If I need it I can do it myself, but with a heavy heart. Simplification of real data for the convenience of those who choose not to try to understand that nature is not all smooth curves or linear models is an unwelcome aspect of current popular science, in my opinion. It tries to gear things to the level of science correspondents of newspapers, whose editors further manipulate them to form headlines, or to make them “understandable” to politicians, who are very seldom proper scientists.

    So, where are the original data, I wonder. Those are what I’d really like to see.

    Cheers, Robin

  34. Comment from: Jeff Id


    Robin Edwards and Gordon Robertson,

    I also have checked some of Loehles work out. The difference between his papers on climate and others is that he isn’t doing any post data sorting. Therefore smoothing just makes it easier for your eyes to see trends.

    Not that smoothing is correct, all I’m saying is that smoothing hasn’t affected the overall trend as in a Mann paper. The data were pre-calibrated and therefore scale was unaffected by smoothing.

    His approach is pretty minimalist as far as typical data molestation in this field. Craig is a forester by trade so he has an excellent handle on tree growth. He has also recently issued papers on the non-linearity of tree response to temp.

    As far as my two cents, these are the best representations of climate I can find. The number of proxies is not complete enough to draw conclusions from and the calibration was done by other scientists so I couldn’t review that.

  35. Comment from: Robin Edwards


    Thanks for your comment Jeff. It’s good to know that the Loehle data are reliable, and collected by an expert. Thanks.

    No doubt the true main signal is coming through after smoothing, tho’ I’d still really like to see the untouched data!

    Cheers, Robin

  36. Comment from: Jeff Id


    Me too. I don’t think that even Craig Loehle had access to that though. (Just guessing)

    BTW: I just did a post which I used Mann’s favorite CPS method to extract positive and negative hockey sticks from his groups own proxies.

    I also demonstrated temp rises and falls in historic points as well as sine waves just for fun. All of it used the M08 group math and data sets.

    http://noconsensus.wordpress.com/2008/10/11/will-the-real-hockey-stick-please-stand-up/

  37. Comment from: Robin Edwards


    I’ve looked at your post, Jeff, and replied there. Really great stuff. Surely there must be a case for trying to construct something publishable in a mainstream climatological journal. If not, E & E would surely be pleased with it.

    I’ve often contemplated writing something about the tendency of climate to change in steps from one regime to another. I did try once, with “Weather” the journal of the Royal Meteorological Society – must have been about 8 years ago, I suppose, but the referee clearly didn’t like my conclusions, though the editor did! I don’t think the ref understood what I was doing. Must use smaller words next time.

    Cheers, Robin

  38. Comment from: Gordon Robertson


    Robin Edwards said…”I did try once, with “Weather” the journal of the Royal Meteorological Society… but the referee clearly didn’t like my conclusions…”

    Peer review sucks. It’s initial motivation was to keep nutcases out of scientific journals but it has now focused on supporting popular paradigms. Of course, Einstein would be rejected out of hand these days.

  39. Comment from: Jan Pompe


    Robin and Gordon: ” It’s good to know that the Loehle data are reliable, and collected by an expert. Thanks.”

    I think the important thing about Loelhe’s data is that the proxies have been validated as actual temperature proxies. Tree rings are uncertain to be temperature proxies as there is a band where temperature is optimum above which there is slow growth.

  40. Comment from: New Detailed Analysis of Global Temperature Data Does Not Support Significant Role for CO2


    [...] THE REST HERE [...]

  41. Comment from: Robin Edwards


    I’m still hoping for some clues about how to access Craig’s primary data. I have seen some articles to blogs by him, but of course no contact details there. Must be patient, I suppose.

    Meanwhile I’m still enjoying Jeff’s amazing work, and hope to read even more eventually.

    Cheers, Robin

  42. Comment from: Gaia – Counting Cats in Zanzibar


    [...] Jennifer Marohasy [...]

  43. Comment from: franko


    To help beginners get this propaganda into perspective, it is desirable to look at the data. One independent statistician (at Cardiff University) recently decided to do just that, with data from the past 30 years or so around the world. He used technical forecasting expertise to project it five years to produce forecasts. He has not found ANY EVIDENCE OF WARMING. I sorry to shout that last bit. Beginners should also note, that although CO2 emissions are based on very rough guesswork, and we could no doubt do with some quality assurance checks on CO2 measurements, it is generally accepted that atmospheric CO2 levels have been increasing during this 30 year spell. The IPCC (pxss be on it) models projected very substantial temperature rises in this circumstance. Now, beginners, where should we go from here? Massive distortion of our economy? Massive injection of resentment across the world against industrialised whitey? Big conference in Copenhagen?

    Here is the report from that statistician, not infected with Climate Munnchausen Syndrome: http://www.cf.ac.uk/maths/subsites/zhigljavskyaa/climatechange/time-series.html

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