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CRU Hack: More context

Filed under: — gavin @ 2 December 2009

Continuation of the older threads. Please scan those (even briefly) to see whether your point has already been dealt with. Let me know if there is something worth pulling from the comments to the main post.

In the meantime, read about why peer-review is a necessary but not sufficient condition for science to be worth looking at. Also, before you conclude that the emails have any impact on the science, read about the six easy steps that mean that CO2 (and the other greenhouse gases) are indeed likely to be a problem, and think specifically how anything in the emails affect them.

Update: The piece by Peter Kelemen at Columbia in Popular Mechanics is quite sensible, even if I don’t agree in all particulars.

Further update: Nature’s editorial.

Further, further update: Ben Santer’s mail (click on quoted text), the Mike Hulme op-ed, and Kevin Trenberth.

1,285 Responses to “CRU Hack: More context”

  1. 51
    Lamont says:

    “It seems pretty clear that Tree Ring data is virtually worthless”

    Okay, so throw it out.

    See post #3 above and Proc. Natl Acad. Sci USA 105, 13252–13257 (2008).

  2. 52
    lgp says:


    1) There was no “security breach” at CRU that “stole” these files
    2) The files appear genuine and to have been prepared by CRU staff, not edited by malicious hackers
    3) The information was accidentally or deliberately released by CRU staff
    4) Selection criteria appears to be compliance with an or several FOIA request(s)

    Being that you have insider insight from conversations with the principals involved, why don’t you tell us how they were released, instead of letting commenters continue to flog the meme that they were “stolen” by “denialist hackers”?

    Or are you saving that story for the investigations :-)

    [Response: Speculations based on your wishful thinking but without any facts are not worth very much. The police investigation is ongoing and I’m sure will report in due time. – gavin]

  3. 53
    BJ_Chippindale says:

    re: Number 8

    I’ve been trying to work out the proper context to take the comments made in WUWT’s Trenberth v Karlen interchange myself. It would be useful to get some notion of where that goes off the rails (if it actually did). The technical side of it is rather opaque. Eschenbach is doing the analysis (for Watt).

    My reading so far is that there is some snail mail is taken out of the purported “conversation” and not reported.

    Karlen has some specific complaints/questions about the reproduction of the Nordic data and compares the IPCC version to Nordklim, and then gets into a whole litany of “issues”. Eschenbach can’t find the graphic involved and reproduces it from data – this way:

    I cannot find the NORDKLIM graphic he refers to, so I have calculated it myself. I used the NORDKLIM dataset available at I removed the one marine record from “Ship M”. To avoid infilling where there are missing records, I took the “first difference” of all of the available records for each year and averaged them. Then I used a running sum to calculate the average anomaly. I did not remove cities or adjust for the Urban Heat Island (UHI) effect. Here is the result:

    Which leads to a graph that that may or may not represent Northern Europe properly.

    Reading further into the mail he is basically saying that the warming doesn’t actually exist.

    The Satellites show this as nonsense, but the details of how he is getting to nonsense are… difficult to tickle out of the interchange.

    So could I second the request for it to get some of your attention?


  4. 54
    jonc says:

    One logical gap in the 6 steps that I did not see discussed in the comments is how much of the radiation that CO2 could absorb is already being absorbed. For example, this graph shows the transmission at different wavelengths across the sprectrum.

    It should various dips and labels them with the molecule that causes each dip. What would be needed to complete the argument is to show the frequencies that CO2 absorbs where the absorbtion is not already complete. In other words, a for example 2% rise in CO2 would only cause a 1% increase in absorption if 50% of the frequencies absorbed by CO2 are already blocked at 100%.

    [Response: Actually it’s pretty easy once you think about it. Water vapour is the main overlap, so let’s assume for arguments sake that at specific humidities that are typical of surface air completely saturate a particular frequency. Note that water vapour decreases rapidly with height. Now the surface water vapour will radiate at this frequency as well – some will go up, some will go down. The stuff that goes up will encounter less water vapour at each stage. By the time you get to the upper troposphere the water vapour level is down by 3 orders of magnitude – and will not be anywhere close to saturating the band. Thus there will always be a height somewhere below that where the CO2 absorption starts to kick in. Thus you are never going to be fully saturated in the whole atmosphere. The forcing values you read about (~4W/m2 for a doubling of CO2) takes that all into account. – gavin]

  5. 55
    Joe says:

    Re comment 37 Adam says:

    ““So, no, those sceptical of AGW can’t simply “make their own process” because that process is entirely dependent on what the raw data was and why it needed homogenizing in the first place.”

    So (a) download the raw data that’s freely available and (b) ask the respective met services where it isn’t, for the data that isn’t….”

    You’re also missing the point, Adam. The raw data is NOT available, nor is it gridded. What’s available are sets of data which have already been homogenized. The RAW data consists of measurements from a few tens of thousand separate recording stations all over the globe, going back over a couple of centuries.

    To give a (very) rough idea, say there are 20000 stations involved, each taking a maximum and minimum reading daily for the past 100 years. That’s around 1.5 BILLION individual readings to collect – do you want to volunteer to type them into a spreadsheet?

    Collecting the raw data is NOT simply a matter of “a few phonecalls and Bob’s yer uncle” – it would take a massive effort in terms of manpower and time. When the herculean efforts to collate this data started (I believe it was through the CRU?) it’s unlikely anyone really appreciated how important that raw data might become to policy – it was only science at the time, after all. On that basis, it’s may actually be understandable that it wasn’t retained but that doesn’t alter the fact that the resultant datasets are no longer verifiable.

    Perhaps it should be a global priority (probably too late for Copenhagen unfortunately) to recreate that raw data as a universal resource of known provenance and quality? A pure database of the direct readings, locations and major site changes would be invaluable for future research. With global co-operation it could probably be done in a year or so for a few hundred million (pretty small change in the circumstances).

  6. 56
    manacker says:

    Joe wrote (26)

    “Incidentally, I also believe that anyone honestly suggesting some global Big Brother conspiracy between Science and Government is a first class fruit-cake with a side-order of nuts (probably served in tinfoil).”

    I would agree. There does not need to be a “global Big Brother conspiracy between Science and Government” (plus a lot of corporations and individuals that anticipate a potential profit from AGW).

    Just a collusion of interests, human nature and several hundreds of billions of dollars at work. That’s all.


  7. 57
    Brian says:

    Gavin, thanks for putting up the data sources page. The following was from a commencement address given by Richard Feynman in 1974.

    “It’s a kind of scientific integrity,
    a principle of scientific thought that corresponds to a kind of
    utter honesty–a kind of leaning over backwards. For example, if
    you’re doing an experiment, you should report everything that you
    think might make it invalid–not only what you think is right about
    it: other causes that could possibly explain your results; and
    things you thought of that you’ve eliminated by some other
    experiment, and how they worked–to make sure the other fellow can
    tell they have been eliminated.

    Details that could throw doubt on your interpretation must be
    given, if you know them. You must do the best you can–if you know
    anything at all wrong, or possibly wrong–to explain it. If you
    make a theory, for example, and advertise it, or put it out, then
    you must also put down all the facts that disagree with it, as well
    as those that agree with it. There is also a more subtle problem.
    When you have put a lot of ideas together to make an elaborate
    theory, you want to make sure, when explaining what it fits, that
    those things it fits are not just the things that gave you the idea
    for the theory; but that the finished theory makes something else
    come out right, in addition.

    In summary, the idea is to try to give all of the information to
    help others to judge the value of your contribution; not just the
    information that leads to judgment in one particular direction or

    As a layman, it seems to me that some scientists on both sides of this issue have forgotten this.

  8. 58
    Francis says:

    Gavin: First, thanks again for your hard work on this issue. Second, you have a very funny typo in a response to a comment in the prior thread, when you write that you’re waiting with “baited” breath for a response. What’s your bait, cheese, and you’re the cat to the commenter’s mouse? (The correct word is “bated”, a shortened form of “abated” meaning “held”).

    My actual question is with regard to annual variability in the global climate and Trenberth’s work. Is it the case that we do not have enough sensors deployed, and if we did we could find the “missing” heat that was recorded in one year (like 1998) but not in a later year at the existing set of sensors? What would a global sensor grid look like that would, in the aggregate, eliminate the variability/noise and give just the change in signal?

  9. 59
    dhogaza says:

    Is everyone on this “we do science” site braindead? re: comment 9, no, champ, tree rings form on the outside of the tree as layers of growth are added to the wood already grown.

    The point being made was that growth rates vary as trees get bigger, and this needs to be accounted for along with other growth factors during the analysis.

    Didn’t anybody here take 7th grade science?

    They probably didn’t teach you that in 7th grade science …

  10. 60
    Hank Roberts says:

    “Timmy” — you are copypyasting old talking points already addressed repeatedly. Please re-read the first sentence in the opening post and try to post something new.

  11. 61
    Petro says:

    Curious Timmy observed:
    “It seems pretty clear that Tree Ring data is virtually worthless”

    Ok, what you get if you remove the data coming from tree rings? Exactly similar result: we are living in the hottest area for at least two thousands year. This was told previously in this thread.

    What will you like remove next from the proxies? Glaciers? Arctic ice? Poleward migration of animals and plants? Bore holes? How come you are not realizing that all the proxies for past temperatures gives the same conclusion about current time?

    Or do you have some scienctific stuff in your sleeve to show other? Please show and tell.

  12. 62
    Corey Simmonds says:

    I would also like some further comment on the nature of Eschenbach’s report on the Trenberth vs Karlen exchange. I certainly don’t take this as any kind of reason to doubt climate change, and, indeed, take note of the fact that the entire blog seems to be nothing but a zealotry-filled hack-job of the present “debate” over climate (the term “Climategate” literally appears in the title of every second or third post).

    I’d find it more likely that the author simply lied or doctored data than anything else, and yet, not really knowing how to go about checking the data myself, I’d still like some comment on the matter from someone who might really know something here about the allegations of this particular blogger.

  13. 63
    CF says:

    Gavin 1: “My information is that it was a hack into their backup mailserver.”

    Gavin 2: “Speculations based on your wishful thinking but without any facts are not worth very much. The police investigation is ongoing and I’m sure will report in due time.”

    Earth to Gavin 2: Please tell Gavin 1 that he is making you look two-faced. Gavin 1, speculations based on your wishful thinking OR YOUR PRIVATE UNNAMED SOURCES are not worth very much.

    [Response: Feel free to ignore anything I have to say on the subject then. – gavin]

  14. 64
    Hank Roberts says:

    Cruel Clever Cat

    Sally, having swallowed cheese,
    Directs down holes the scented breeze,
    Enticing thus with baited breath
    Nice mice to an untimely death.

    –Geoffrey Taylor

  15. 65
    Mark A. York says:

    RE#41 Bobby they had faulty sensors because the cooling didn’t jibe with the sea level measurements. In other words it was wrong and they knew it for a valid reason, found out where and fixed it. This is how science is self-correcting not some wild conspiracy. These casual comments taken into a sceptic political frame don’t work well as science.

  16. 66
    blueshift says:

    What’s all this about climatologists turning tricks for Russians? I used to uncritically accept that the only thing that affected Earth’s temperature was weather I drove a SUV or a Prius.

    Seriously though, I’d like to add my thanks for RC’s efforts to add context. Specifically, Gavin you have been excellent.

    Also, is there a way to see more of the inline responses than the most recent 5? These responses are often as informative as the main article, at least for my level of knowledge.

  17. 67
    M Yoxon says:

    Can’t find anything I disagree with in the linked article by Peter Kelemen – I find it a little odd that you’ve endorsed it as he does seem to disagree with your opinion of the seriousness (or otherwise) of the issue. I remain convinced that these events demand an independent enquiry, and that they are having a seriously damaging effect.

  18. 68
    RandyL says:

    Being a lay person and reading almost all the entries on RealClimate over the past year or so I would like to offer a bit of advice, please. This entire topic and many of the related issues to this have worn thin on value and content. I think enough has been said and discussed. The denialists may never be pursuaded no matter how much evidence or factual information is presented. My concern now is that anyone who has even aa a speck of concern about GW will be seen as a fearmonger or alarmist. I stongly suggest that RealClimate end all blogging and content creation for a period of time and let frenzied battles be fought elsewhere; all the while the experts on here can take a rest and get back to doing what they do best. Just a thought.

  19. 69
    Corey S says:

    The problem with that, Randy, is that denialists give ammunition to people like James Inhofe, who have the power to stop action from being taken on this issue.

    They never sleep, and so, sadly, neither can people like the RC contributors. I really feel for all the climate scientists out there right now taking flak over the whole CRU email business, especially when most or all of it is nothing but unsubstantiated quotes taken completely out of context. It must really be tiring to continually have to combat something so completely inane, especially when it detracts from real conversation.

    I guess all I’m really trying to say is: we appreciate you guys are RC. Keep up the good work!

  20. 70
    John Cooknell says:

    On the 24th November the British Met office issued a joint press statement on Climate Science I can only think this is in response the the CRU hack incident.
    Authors were those of the highest reputation:-
    Prof. Julia Slingo, Chief Scientist, Met Office
    Prof. Alan Thorpe, Chief Executive, Natural Environment Research Council
    Lord Rees, President, the Royal Society

    This statement included the following passage:-

    “Year-on-year the evidence is growing that damaging climate and weather events — potentially intensified by global warming — are already happening and beginning to affect society and ecosystems. This includes:
    In the UK, heavier daily rainfall leading to local flooding such as in the summer of 2007.”
    Anybody reading this passage is left with the strong impression that the floods of 2007 were caused by Climate Change.

    I was unlucky enough to be directly involved in the Avon/Severn flooding I did keep up to date with any science reporting of the likely cause.

    However the only authoritative scientific analysis produced on the 2007 floods was produced by CEH a part of Prof. Alan Thorpe’s National Environmental Research Council.

    And I quote from this report:
    Lead author, Terry Marsh, comments: “The river floods of summer 2007 were a very singular episode, which does not form part of any clear historical trend or show consistency with currently favoured climate change scenarios.”

    Mr Marsh adds: “The exceptional river flooding last summer fuelled speculation that flood risk is increasing due to global warming. Due to the inherent variability of the UK climate, any extreme hydrological event cannot readily be linked directly to climate change.”

    So what do I make of all of that, why did these esteemed people feel they have to rush out statements that don’t bear up to even the simplest critical examination.

    They are not fools, so why do it? What is possessing them?

  21. 71
    Deep Climate says:

    The <a href="; link to the 2005 RC post on peer review is indeed very timely and it’s worth quoting in the current context:

    [A] deeply flawed paper can end up being published under a number of different potential circumstances: (i) the work is submitted to a journal outside the relevant field (e.g. a paper on paleoclimate submitted to a social science journal) where the reviewers are likely to be chosen from a pool of individuals lacking the expertise to properly review the paper, (ii) too few or too unqualified a set of reviewers are chosen by the editor, (iii) the reviewers or editor (or both) have agendas, and overlook flaws that invalidate the paper’s conclusions, and (iv) the journal may process and publish so many papers that individual manuscripts occasionally do not get the editorial attention they deserve. [Emphasis added]

    Today we understand better just how closely certain authors, editors and reviwers (the same folks wearing different hats) are willing to co-operate with think tanks and astroturf groups linked to fossil fuel interests and others opposed to regulation of greenhouse gases.

    So I hope no one will object to my reposting this case study involving Friends of Science, Talisman Energy and the de Freitas brothers (as it’s also buried deep in the previous CRU thread).

  22. 72
    RaymondT says:

    Gavin, I hope you win a prize for your excellent website. I don’t know of any other website where someone can learn in a more efficient and stimulating way about climate. The email exchanges are most informative and the personal attacks are few. Nice Job.

  23. 73
    Dan says:

    The WSJ is about to come out with yet another lying editorial saying that climate scientists have a vested interest in “alarmist” research results because that’s how they get more funds (this after 8 years with an anti-AGW administration; yeah WSJ that really makes common sense…not!). Gee, where have we heard that completely unsubstantiated and blatantly anti-science crap before? It’s the old “If a lie is repeated over and over again it must be true!”, a foundation of the cowardly denialists.

  24. 74
    manacker says:

    I agree with M. Yoxon (67) that the recent events can have a seriously damaging effect if there is an attempt to cover things up. What is needed now is an independent inquiry and total transparency.

  25. 75
    Jody says:

    Okay, here’s my latest question. Derek Lowe at Pipeline, he’s a working scientist too, takes the CRU to task for deleting their version of the original data (even though its still stored elsewhere) because this means there’s no way to see what’s been done to the corrected data:

    What we have left, as far as I can see, is a large data set of partially unknown origin, which has been adjusted by various people over the years in undocumented ways. If this is not the case, I would very much like the CRU to explain why not, and in great detail. And I do not wish to hear from people who wish to pretend that everything’s just fine.

    As a layman, am I right in reading this and going “huh?” If the original data exists with other organizations, if the research papers talk about the adjustments to data that were made (as with the tree-ring proxy papers), then isn’t this a empty criticism? I don’t want to start a fight between two blogs; I just thought I’d come back to the climate scientists and ask if you want to know how another group of AGW scientists proxied their data, what’s the procedure?

  26. 76
    Arthur Krolman says:

    John Cooknell,

    You show evidence of foolishness in the British Met Office 11/24 statement. Then you make the conclusion: “they are not fools”. Perhaps this was a typo? Please explain.

  27. 77

    #41 Bobby:

    Because science cannot *prove* anything, typically the language used in the IPCC and other scientific writings will sound as if scientists are not convinced or the uncertainties are larger than the reality. I have always maintained that it is this type of language that gets scientists into trouble. Skeptics have jumped on this language issue. ExxonMobil and its front groups (CEI, Heartland, GMI, etc.) are quite skilled at highlighting the very small uncertainties while hiding or minimizing the certainties. This has been a well-documented and highly successful strategy for them.

    Many claim that the IPCC and climate scientists are “alarmist” but, they are, in fact much too conservative. Data since the IPCC reports bears this out. See the Copenhagen reports.

    Conspiracies are more fun than reality but are rarely true.

  28. 78
    Molnar says:

    “I stongly suggest that RealClimate end all blogging and content creation for a period of time and let frenzied battles be fought elsewhere; all the while the experts on here can take a rest and get back to doing what they do best.”

    That would be a mistake. The proper response to increasing noise is to strengthen the signal, not to stand down and hope it goes away.

    If the investigation shows that the CRU scientists are clean, it might be possible to sue some of the “climategate proves that AGW is fraud” people for libel.

  29. 79
    CM says:

    cc81 (#8), BJ Chippindale (#53), Corey Simmons (#62),

    IMHO, what Eschenbach thinks he sees in an e-mail exchange between Karlén, Trenberth and Jones is not worth anybody’s time. The moderators here certainly have better things to do.

    If Karlen, a seasoned “skeptic”, has found something wrong with the IPCC data, no doubt he’ll tell the world (if he hasn’t already?). That might or might not be worth discussing here.

    If Karlén thinks there’s anything inappropriate in those mails, no doubt he will bring that too to people’s attention. Unlike Eschenbach, who has to rely on reading other gentlemen’s stolen mail and second-guessing them, Karlén has after all had those emails in his mailbox for over a year. But it doesn’t look from the blog post as if Eschenbach actually bothered to get his take on it.

    As a professor emeritus of physical geography, Karlén presumably does not need need a dilettante like Eschenbach either to tell him what his mail means or communicate his findings to the world.

    And if Eschenbach has a valid point of his own to make about climate stations, he should write it up in a way that would make it worth someone’s notice. (Hint: not between the lines of other people’s correspondence.)

  30. 80
    AJ says:

    Steve McIntyre, who you have mentioned on these threads, takes serious issue with your explanation of the “hide the decline” statement. The usefulness of tree-ring data and/or reality of AGW are not the issues here. McIntyre is leveling charges of impropriety and fraud, and quite frankly, his explanation makes a lot more sense than the one posted on this website.

    [Response: This is simply false. The ‘decline’ was discussed first in Briffa et al 1998 and the full dataset is available here including data up to 1994. Claims that this was hidden or unavailable are simply untrue. McIntyre is doing a bait and switch with another later update by the same author. – gavin]

    If there is some “engineering explanation” for hybridizing the dataset for that plot, then the rebuttal to the solar-correlation in the paper by Laut (2003) on the previous thread (Something is X in the state of Denmark) must also then be nonsense, since it is the basis of his criticism. Either the CRU AND those Danish researchers were deceitful, or neither. Which is it?

    I studied those solar-correlation papers, Laut’s rebuttal and his letter carefully. In the area of thermal radiation, I have a decent knowledge base (doctorate in thermal/fluids), and see nothing to justify the hyerbolic and personal criticism in his letter. In fact, despite his best attempts, a correlation does seem to exist, and why wouldn’t there? But I digress, the point of this post is to help me determine which of the climate researchers is trying to pull wool over my eyes…

  31. 81
    Neil Pelkey says:

    Dear Thomas Lee Elifritz,
    Thank you for supporting my point by being condescending to results you do not like. A linear regression through a limited set of data points cherry picked to give the results I wanted, is not laughable, it is sad. But it is precisely what it presented in figure 9 of the Copenhagen report. You might read before sounding off. I know it is not was rigorous as wikipedia, but it is a good read.

  32. 82
    Mark Sawusch says:

    Any comments on this paper in the physics literature claiming that conventional greenhouse gas theory violates the 2nd law of thermodynamics?

    [Response: Nonsense start to finish. – gavin]

  33. 83
    Hank Roberts says:

    Neil Pelkey complains of Fig. 9 of the Copenhagen Report:

    “Figure 9. The total melt area of the Greenland ice sheet increased by 30% between 1979 and 2008 based on passive microwave satellite data, with the most extreme melt in 2007. In general 33-55% of the total mass loss from the Greenland ice sheet is caused by surface melt and runoff. For 2007, the area experiencing melt was around 50% of the total ice sheet area. The low melt year in 1992 was caused by the volcanic aerosols from Mt. Pinatubo causing a short-lived global cooling (updated from Steffen et al. 2008).”

    The cite is to:

    Steffen, K. et al., (2008) Rapid changes in glaciers and ice sheets and their impacts on sea level. In Abrupt Climate Change: A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research 60-142 (U.S. Geological Survey).

    That publication cites quite a few papers by Steffen; it may be this one:

    Nghiem, S.V., K. Steffen, G. Neumann, and R. Huff, 2005: Mapping of ice layer extent and snow accumulation in the percolation zone of the Greenland ice sheet. Journal of Geophysical Research, 110, F02017, doi:10.1029/2004JF000234.

    (Or not; anyone know for sure?)

    Neil P, what’s your problem with that figure? You make a strong claim of something wrong there. Can you support your claim it’s cherry-picking? What data set are you aware of from which they could have picked cherries?

    You wouldn’t make a claim like that up, would you?
    Show us your source please.

  34. 84
    lgp says:

    Gavin 1: You stated “My information is that it was a hack into their backup mailserver.” Can you reveal the source of your information? Have you been interviewed yet in the investigation? Have you revealed the source’s name to the police investigators or are you witholding evidence that would help solve this heinous crime that has the “alarmists” up in arms?


    [Response: The police are indeed involved, and that would imply they have prima facie suspicion of some criminal act. I’m not going to comment further on this. – gavin]

  35. 85
    Andrew Adams says:


    “Year-on-year the evidence is growing that damaging climate and weather events — potentially intensified by global warming — are already happening and beginning to affect society and ecosystems. This includes:
    In the UK, heavier daily rainfall leading to local flooding such as in the summer of 2007.”
    Anybody reading this passage is left with the strong impression that the floods of 2007 were caused by Climate Change.

    Obviously you can’t take any specific instance of extreme weather and link it directly to climate change but I think what the author was suggesting was that the flooding in 2007 is an example of the kind of events which are expected to be more common from now on due to climate change.

  36. 86
    harry says:

    Steve wrote:
    “Your argument regarding the reason for the freedom of information requests is disingenuous. This is because the next logical step for those requesting data, after learning they were proprietary, was to ask for it directly from the separate agencies that own it, not the CRU”.

    I disagree. CRU’s stated reason for not releasing its data was that they were restricted by outstanding agreements with suppliers. The logical thing to do is to ask for evidence of these restrictions. CRU was unable to supply evidence for their FOI denial, which points once again to their flouting of the FOI.

    [Response: Not true, and not supported by the overseeing FOI officer, and not consistent with the many public declarations of the various met services that state quite clearly under what circumstances they grant access to restricted data. – gavin]

  37. 87
    Rod says:

    Has anyone looked into the possible effects of nuclear testing on tree ring formation? The Yamal region is due east of a major Soviet testing site that was quite active in the early 60s.

  38. 88
    Adam says:

    Joe #55

    “You’re also missing the point, Adam. The raw data is NOT available, nor is it gridded. What’s available are sets of data which have already been homogenized. The RAW data consists of measurements from a few tens of thousand separate recording stations all over the globe, going back over a couple of centuries.”

    Most of the raw data is available from GHCN (there is adjusted data available from there, too). For a link see the data sources page on this site. That covers over 90% of the data as used n CRUTEM3.

    “To give a (very) rough idea, say there are 20000 stations involved…”

    Actually, for the CRUTEM3 dataset it’s 4138 (with about 200 more in an earlier version). The data go back to 1850, but not for all stations.

  39. 89

    Neil, why post an abstract to a conference report when you can post an actual paper :

    Surface melt area variability of the Greenland Ice Sheet: 1979-2008.

    Now would you please explain from this paper how you infer : “This is likely to lead to a massive expansion in the greenland ice sheet triggering a new ice age”, from a paper that discusses regional and temporal variably of Greenland ice as possibly related to natural oceanic current variations?

    You are literally grasping at straws. I doubt you fool anyone here.

  40. 90
    Bill says:

    re#85/#70……….Isolated extreme weather events like this have occurred somewhere in the country in most years .Its in the historical record. There is no evidence of increased frequency but only in increased media reporting.

  41. 91
    Phil. Felton says:

    jonc says:
    2 December 2009 at 1:13 PM
    One logical gap in the 6 steps that I did not see discussed in the comments is how much of the radiation that CO2 could absorb is already being absorbed. For example, this graph shows the transmission at different wavelengths across the sprectrum.

    It should various dips and labels them with the molecule that causes each dip. What would be needed to complete the argument is to show the frequencies that CO2 absorbs where the absorbtion is not already complete. In other words, a for example 2% rise in CO2 would only cause a 1% increase in absorption if 50% of the frequencies absorbed by CO2 are already blocked at 100%.

    The spectrum you showed is at too low a resolution to be any use, the segment below is more useful. Note that the upper graph is for CO2 and the much more sparse spectrum below is for H2O ( both from the side of the main absorption band of CO2). Not much overlap:

  42. 92
    Larry Johnson says:

    Why should we trust anything we laypersons read on RealClimate now that we know that way that Mann has characterized your and his attempts to ‘actively shape’ opinion in the way you deal with comments, etc.? Are you changing the policies you have in place with regards to the way you use RC? Otherwise, it seems like it has become less of a science blog and more of a political advocacy blog. ‘Filtered science’ or something like that.

    [Response: RC is a moderated forum to try and increase the signal to noise ratio in the comments and allow space for scientists involved to interact directly with the public who have genuine questions. Without moderation you end up with a series of increasingly angry, repetitive shouting matches that do not allow any space for real discussion. If you want a free-for-all, there are plenty of places on the web for that. If you want somewhere where the scientists involved can be consulted and answers and context provided, then I think we do ok. We make no secret of the fact that we have a pretty mainstream view of the science and we don’t have much patience for the crank stuff that gets brought up all the time elsewhere. That is ‘filtering’ of a sort, but it is not political filtering, and we don’t advocate for specific policies here at all. We think we provide somewhere unique, but no one is forced to read us, so if you don’t like our style, go elsewhere. -gavin]

  43. 93
    Mesa says:

    If you look at the GISTEMP data, the number and location of thermometers varies wildly throughout the past 100 yrs. The magnitude of the homogeneity corrections is similar to the magnitude of the warming. How are we to have any confidence in this process, especially if you restrict the data to thermometers that have been around for 100 yrs continuously **no warming is evident**? IE the warming is a byproduct of the thermometer sampling (replacement of colder thermometers by warmer) and correction process (unusual UHI corrections). This is highly unsettling, especially in the light of recent events. Any thoughts?

  44. 94
    NikFromNYC says:

    Climategate now outranks Global Warming by a factor of two on Google.

  45. 95
    Doug Bostrom says:

    So that’s it, is it? The Grand Conspiracy turns out to be email “boo yahs!” of the sort exchanged by ball players before a game? “We’ll smash ’em flat!”, which if literally true would be bad form but in fact is overenthusiastic expression of the sort nearly all of us engage in on practically a daily basis.

    Meanwhile, other than the datasets and discussion involved in the Grand Conspiracy we have mountains of other data and findings, all pointed in the same general direction. Presumably the Grand Conspiracy is divided into Marxist-style cells, so that when one basement is raided by McIntyre and crew, the work of destroying the global economy and getting free rooms and rubber chicken at conferences can continue unabated, by folks sneaking around changing tide gauges while yet another group flies into space and subtly tweaks the GRACE instrumentation while yet another bunch is busily creating fake 2,000 year old trees while yet -another- group goes up and engages in hiding behind instrumentation shacks and doing calisthenics while flasks are being opened on Mauna Loa.

    All of the data and observations are under the control of the Grand Conspiracy, we just don’t know who is pulling the strings. Probably the rulers of Atlantis, is my guess.

    Something like that?

    I didn’t even bother reading about the East Anglia fiasco until a couple of days ago, because I was fairly certain it would turn out to be the usual suspects getting into a psychotic lather about something insignificant, as usual.

    Sure enough.

  46. 96
    Joe says:

    Re 82 and Gavin’s response:

    Gavin, please be careful – to rubbish a published paper by providing that wiki page is heading onto thin ice (which has nothing to do with CO2 in this case ;) )

    The rebuttals on the wiki page consist of one reply which appears only available from a blog site (Jörg Zimmerman on ) and one (Arthur Smith) which is only available from Cornell University Library and has, itself, been rebutted by Kramm, Dlugi and Zelger ( ) in the same library.

    Unfortunately, I don’t seem to be able to retrieve the papers at the moment and I’m also 3/4 of the way through a fairly nice Chianti (sans liver or fava beans so I don’t want to comment on the papers themselves until I’ve (a) read them and (b) remembered how to type reliabubly.

    I’ve made no bones in my posts about being sceptical regarding climate change orthodoxy, although I’m loathe to call fraud / conspiracy / whatever and I object (almost strongly enough to protest) at being lumped with labels such as “denier”, “denialist” (wtf sort of americanizationalism word is that????) or even “sceptic” – unless the last is awarded as the badge of scientific honour that its lexiconic roots imply. I certainly respect how even-handed you’ve been by not simply refusing (hopefully) reasoned dissenting opinion.

    So I’d hate to see an interesting and commendably open discussion here potentially hijacked by cries of foul-play based on perceived dual standards.

    [Response: It is not a question of dual standards, but of standards. There is a difference bewteen a good paper and a bad one based on how careful the arguments are, how compelling the evidence and the appropriateness of the conclusions. G&T fail on all counts. Pretending that science is a democracy and that all opinions need to be weighted equally is just a recipe for letting the flat earrhers and the tinfoil hat brigade control the scientific agenda. G&T’s paper is rubbish, and Arthur Smith’s rebuttal tells you why. It isn’t a matter of opinion. -gavin]

  47. 97
    manacker says:


    I believe the jury is still out on whether it was an outside hacker or and inside whistleblower who released the CRU emails (some recent blog releases seem to lean in the direction of an insider).

    The U.S. Whistleblower Protection Act is enforced by the U.S. Office of Special Counsel. There are also a number of individual state laws.

    In the U.K. Whistleblowers are protected for public interest, to encourage people to speak out if they find malpractice in an organization or workplace. Malpractice could be improper, illegal or negligent behavior by anyone in the workplace.

    An outside hacker might have a harder time trying to get protection under these laws than an insider.

    It will be interesting to see what the inquiries reveal.


  48. 98
    Mats Almgren says:

    So far only the email exchanges between Karlen, Trenberth and Jones have in any way shaken my opinions. cc81 in #8 asked for some comments on this exchange, and was supported by #53. Some kind of reply was attempted in #79, but not really on the issue of these exchanges.

    I recently heard Wibjörn Karlen state that little warming has occured after around 1940, which I then thought was just nonsense, but after seeing the evidence he puts forward in these emails I cannot help starting to wonder.

    This point requires some attention.

  49. 99
    Jonathan Fischoff says:

    Gavin, I have noticed a distributing pattern in the discussion of Mike’s nature trick in articles like the one in Nature. On the one hand you have people explaining the trick is fine and good thing to do like in the Nature article. However, they never explain why the trick was done. On the other hand you have Steven McIntyre explaining that the trick was done to hide a lack of correlation in the later part of a temperature reconstruction. His argument is clear and provides a lot of details. In light of the information from CA I am unable to see why the trick was a good thing. Could you go into this in more detail? Could you also explain why the Briffa reconstruction does not appear to employ the trick, even though Mike say’s he used the trick because of advice from Briffa?

    [Response: The reason why any of this was done is simply presentational. It doesn’t have anything to do with the reconstructions themselves (annual estimates of the historical climate anomalies). But when you want to show the longer term changes, people smooth records to ‘hide’ the interannual variaibility which can obscure the long term trends. When you smooth you need to take information from a number of years on either side, but obviously there is a problem near the ends. This problem is worse if you have two time series that overlap, but are in some sense commensurate. This is the problem that various ‘tricks’ have been developed to deal with. However, there is no right answer – each solution; not doing anything, zero padding, minimum roughness, using the instrumental data etc – makes assumptions. My opinion is that any of these are fine as long the assumptions/methods are made clear and the impact of that assption in any particular context can be examined. -gavin]

  50. 100
    Bill K says:

    I think it’s a good thing Phil Jones stepped down as director. (He’s still working there, right? So it’s not even like they fired him.) I don’t think Climategate is the final “nail in the coffin” or whatever breathless pundits called it, but it did reveal serious improprieties on the part of Jones et al. Climate Science is science only in a weird sense of the word – it’s really just a blend of statistics and modeling, closer to what economics people do than a scientist (who has to worry about testing/experimentation, reproducibility, controlling variables and so forth). If we had many copies of earth to experiment with, then climate science would be a real science.

    Therefore, it’s critically important that doing bad things like what Dr. Jones did do not happen in a field that is almost entirely government by the data – willfully and knowingly hide the data from people that might find problems with it.

    Gavin, one of Jones’ emails about hiding from FOIA requests was directed to you (, but I didn’t see a response in the hacked emails archive. How did you respond to this email? Did you push for transparency, or did you go along with Jones’ desire for secrecy?

    [Response: This email was one that was part of the discussion on a paper that I co-authored with Jones (and it’s a pretty good paper). The appendix in that paper discusses the source of the IPCC (1990) schematic on climate of the last 1000 years or so, and I had suggested putting in a point about how the reviewing and sourcing in the more recent IPCC reports was much better than it was in 1990. Other people didn’t agree, so we didn’t put it in (it’s still true though). His updating me on the ongoing FOI stuff was incidental. I don’t see that it called for any response, and I don’t think I responded. – gavin]