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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. 101
    MapleLeaf says:

    Regarding the validity of the HadCRUT dataset following this CRU fiasco. Pielke Snr is now trying to claim that it is a myth that the GISS, CRU, NCDC and Japanese global SAT datasets are independent. This sounds like typical obfuscating from Pielke.

    Is my argument below (made on a CBC thread) close to being right?

    Of course most of the raw data are the same. Why on earth would they all use completely different station data, they do not have the luxury of cherry picking the stations they want (nor should they)? In fact, they all need to use as much data as possible to maximize coverage of the globe. There are only a finite number of weather stations around the globe. Where the methods are independent is how they process the data. How they account for the urban heat island effect, how they account for changes in station location, instrumentation and observations times? They all also have different QC criteria and procedures. So even if they had exactly the same data, they could arrive at very different very answers depending on how they processed the data and what assumption are made. The fact that they do not speaks to the robustness and validity of the global SAT record.

    Is someone in the know could speak to this I’d be very grateful. Thanks.

    The long term (~30 yr) trends in annual RATPAC, UAH, RSS and NCDC temperatures are all between 0.15 C and 0.17 per decade (up until 2008, sourced NCDC annual report for 2008). Those in denial about AGW really need to give their heads a shake.

  2. 102
    Jim Bouldin says:

    Steve McIntyre, who you have mentioned on these threads, takes serious issue with your explanation of the “hide the decline” statement.

    Imagine our surprise.

    The usefulness of tree-ring data and/or reality of AGW are not the issues here. McIntyre is leveling charges of impropriety and fraud

    Mmmm hmmm. That’s what Steve McIntyre does for a living: impersonating a scientist and casting aspersions.

    and quite frankly, his explanation makes a lot more sense than the one posted on this website.

    Sense is in the mind of the beholder. If you trust things that either McIntyre or the Discovery Inst. say, then you don’t know much about either one.

  3. 103
    SecularAnimist says:

    It is really appalling to see the denialists just plain MAKING UP STUFF about what was in the stolen emails.

    Not only do they not care about the scientific reality of anthropogenic global warming — they don’t care about any sort of reality about anything.

    All they seem to care about is that “their team wins” — and if they think that just plain making up outrageous, slanderous lies and posting them on every blog they can find will help the Ditto-Head team “win” then that’s what they will do.

    It is really very depressing.

    As far as I can tell, the major legitimate scientific question about anthropogenic global warming is whether or not it is already too late for even a rapid phaseout (far more rapid than anything actually contemplated by the major governmental and corporate powers of the world) of all GHG emissions to prevent a global catastrophe, given the effects that we are already seeing from the emissions that have already occurred (not to mention the continued additional warming that will result from those emissions).

    I tend to think that it already is too late, but that doesn’t mean we shouldn’t try, or that rapid action might not prevent a nightmarishly hideous outcome from being something far worse. But to have any hope of doing that, we need the best intelligence and ability and determination of which human beings and human societies are capable brought to bear on the problem.

    Instead, we have stupidity, ignorance, dishonesty — and above all, rapacious, conscienceless GREED — being brought to bear.

  4. 104
  5. 105
    TimTheToolMan says:

    Looking at Mann’s revised paper without the tree ring data previously linked to by Gavin, does this not imply that natural variation can now account for over 1C change in global temperatures? And we’re only really looking at a single historical cycle too so there is not really too much to suggest the natural swings cant be larger? Timeframes look similar at about the 1400AD mark.

  6. 106

    timmy: Isn’t Tree ring data somewhat important to AGW theory?

    BPL: No. What gave you that idea?

  7. 107
    patrick cobb says:

    well, i think a major PR offensive is long overdue. the longer this “scandal” is allowed to be spun by the wingnuts on conservative talk radio and fox news, the harder it will be to repair the damage. you scientists should be on the new networks, stating your case and addressing some of the more “incriminating” emails that lead some to believe that you tried to cover up the evidence..COME ON! you’re losing the PR battle.

  8. 108

    Pat: The science isn’t settled, it’s not concrete, neither side is right and more research is required.

    BPL: And you know this how? “Neither side is right?” But you, I assume, know what is right? Please describe it for us.

  9. 109


    It’s over a THIRD of all reliable observed temperature records. It seems pretty clear that Tree Ring data is virtually worthless

    Did you miss the point that this was just one set of trees, not all the tree ring data, or even a substantial minority of it?

  10. 110

    “Response: That’s actually the easiest thing to demonstrate (we should have a link there though). How do we know recent CO2 increases are due to human activities. – gavin”

    Well. Not so easy. The changes in 13C/12C ratios indicate that the co2 is from biogenic sources. These include sources other than anthropogenic sources. There is no way to differentiate between natural biogenic and anthropgenic (from fossil fuels) co2 on the basis of stable carbon isotope ratios alone.

    14C is problematic as it’s concentration in co2 can change due to changes in cosmic radiation which is the source of all 14C from non-nuclear sources.

    [Response: But then you’d see equally large changes in other cosmogenic isotopes like 10Be or 36Cl and you don’t. Yet mysteriously the mass balance, the decrease in oxygen, the increase in ocean carbon etc all match up with the anthropogenic cause. Note that continuing to argue about this point is the hallmark of someone who will never be convinced about anything, and therefore is not worth discussing with. Please do not go down that route. -gavin]

  11. 111
    Marion Delgado says:

    Again, thanks to Gavin for doing this. He’s made enough extra effort that what might have been just a loss of his valuable time will probably end up being referred back to again and again, saving other scientists and their defenders countless hours of repetition.

  12. 112
    Ike Solem says:

    Popular Mechanics did have an interesting take on this, but one quote raises some eyebrows:

    “I saw a statement from the moderators that “science doesn’t work because people are polite at all times. Gravity isn’t a useful theory because Newton was a nice person.” Such statements—while true—could lead readers to conclude that the apparent misconduct revealed in the stolen e-mails is normal, and within the bounds of ordinary scientific discussion. I believe that would be a mistake.”

    I’m not sure what ordinary scientific discussions consist of – where does an organic chemistry professor who tells his grad student to wait six months to graduate so that he can file for a patent on her research fit in?

    Scientific misconduct is a serious charge, usually involving outright fabrication of data. Tossing such phrases around lightly is unwise – but if you overhear a professor instructing a grad student to falsify data, and if the grad student almost suffers a nervous breakdown as a result, and also refuses to falsify the data as instructed – well, that would infuriate any normal bystander, I think.

    Climate science has largely avoided such problems because it is based on things like meteorological and oceanographic data, and there is a century-long effort to optimize that data collection in order to provide everyone from the military to sharecropper farmers with accurate forecasts.

    There has never been any real financial reward for biasing that data in any particular direction – until the fossil fuel interests realized that climate science might end up drastically reducing fossil fuel demand, and eventually put them out of business entirely – and that’s when the distortion of the science and the smear tactics appeared, much to the shock and dismay of “collegial team player” climate scientists anywhere.

    Since these attacks began, they have always been broadcast and supported by various media outlets – but the stories today all seem to focus on a few talking points – and alternative opinions are not sought. It’s almost like one story was written, and then passed around to a bunch of reporters who parroted it without doing any background investigation to speak of.

    Why? The most probable answer is that conflicts of interest are dominating the media coverage, largely due to diversified shareholder interests, such as owning a sizable chunk of both the New York Times and the fossil-fueled Calpine power corporation, i.e. Harbinger Capital, ahem. They want to build a massive new fossil fueled power plant in Hayward, California – and that project would be shut down by binding emissions limits, along with a lot of other fossil fuel projects.

    Regardless, the most honest (and humorously serious) take on this issue I’ve seen yet comes from the Director of Molecular Biophysics at Oak Ridge National Laboratory:

    Summation: “Only by fact-based reinforcement do ideas gradually receive a solid consensus.”

  13. 113
    Spencer says:

    Maybe I’m ideological, being from a different branch of science, but am I the only one that is stunned that “Freedom of Information” has been evoked and semantically debated in a scientific discussion? A law from a nation is or was being used to attempt to put science on display? Is this common in other disciplines? And that, what I’m lead to believe is, a critical data set, consists of supposedly “proprietary” data? I’m dumbfounded by this, does this original data have some sort of financial value that could be fixed with a one time payment or something? If there were historical agreements, could new ones be made?

  14. 114
    george hanson says:

    With the release of full scientific data to back up the pro-warming results, what else would need to be explained if the data were released with full study results and conclusions also. If data was lost and destroyed then no scientific conclusion can ever be made. There can be no scientific conclusion. If other labs CRU has worked with have privacy contracts, then if their info cannot be released to back up a scientific study, without study data, there can be no scientific results if it cannot be backed up how the conclusion was arrived at. That is learned in the first schools days of science class. No scientist can dispute this fact.

  15. 115
    harry says:

    Gavin wrote in response to the CRU FOI refusals:
    “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”

    According to wikipedia, “It was not free to share that data without the permission of its owners because of confidentiality agreements, including with institutions in Spain, Germany, Bahrain and Norway, that restricted the data to academic use. In some cases the agreements were made verbally, and some of the written agreements had been lost during a move.”

    It should be noted that the requests were initially made by a published academic, which tends to contradict the “only for academic use” restriction, and that the excerpts of agreements published by CRU were not supportive of any harsh restraints. I’d use the CRU website as a source, but it seems to have deleted all the associated pages …

    So unless Gavin can supply any significant substantiation of his claims, they don’t seem to bear up to the facts as presented by CRU itself. Of course if Gavin is privy to all the verbal agreements, or has found all the lost ones, then he has a tremendous opportunity to help out those hopelessly overworked researchers at CRU who seem to lose things a lot.

    By the way, a link to the “many public declarations of various met stations” regarding this data would be handy, I’m sure you have it at hand since you’ve claimed their existence so stridently.

    [By the way, it is normal practice to indicate when you edit a post – please make the effort]

    [Response: Apologies, doing this on an iPhone and it is not as easy as usual… There is a link to the uk met office policy further up the thread somewhere. -gavin]

  16. 116
    Firkas says:

    Gavin, et al:

    I just read the editorial at
    Please do not fall victims to the harassment of those lunatic denialists.
    I wish there was a way to mark down irrelevant comments, so that the signal to noise ratio improves.

    Denialists appear to be centrally organised and directed, and can be seen at full work in the comments at

  17. 117

    #82 Mark Sawusch asks,

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

    Please read Arthur Smith’s (Ph.D. – Physics) “smackdown” on this false notion.

  18. 118
    Norman says:

    This is the one that disturbs me. It seems an intentional deception in the program code. Can anyone explain why they did this?

    ; PLOTS ‘ALL’ REGION MXD timeseries from age banded and from hugershoff
    ; standardised datasets.
    ; Reads Harry’s regional timeseries and outputs the 1600-1992 portion
    ; with missing values set appropriately. Uses mxd, and just the
    ; “all band” timeseries

    [edit for space]

    [Response: This was discussed earlier. It was an artificial correction to check some calibration statistics to see whether they would vary if the divergence was an artifact of some extra anthropogenic impact. It has never been used in a published paper (though something similar was explained in detail in this draft paper by Osborn). It has nothing to do with any reconstruction used in the IPCC reports. – gavin]

  19. 119
    Ray Ladbury says:

    Once the denialists are done with character assassination, there is still one additional matter they have to deal with. Now what was it. Oh yeah… the evidence. There’s still mountains of it, and still no one has shown even the slightest indication that any of it is tainted.

    This issue will not go away, no matter how many accusations you make, no matter how much mud you throw and no matter how many better men than you you trash. Science is about evidence. It doesn’t go away just because you want it to.

  20. 120
    Steve says:

    I have to LOL about all this hubbub and who is getting rich off global warm and who isn’t. It won’t matter much in a few million years one-way or the other. The earth and the universe will ensure one way or the other that the human species is extinct by then. Also the earth has been covered with ice and tropically warm from pole to pole before humans even existed. So the last 14000 years have been good for the human special but maybe it’s time to stand aside and let the next one come up as we fade away. Remember no one get out alive from life anyways.

  21. 121
    Gail says:

    Oh dear. I just started to pay attention to all this tree ring stuff. And I’m no expert. But I’ve been saying for some time the trees have gone into irreversible decline thanks to atmospheric pollution from fossil and biofuel emissions.

    Check out the pictures on my blog here and elsewhere: The trees on the East Coast dropped leaves over a month early this autumn. The conifers are rapidly losing needles and becoming bare.

    Just like a starving person gets thinner, the biomass of tree trunks shrink because they can’t photosynthesize and produce chlorophyll. Their stomata are damaged by invisible toxins in the air, like ozone, and nitrous oxide. The cumulative foliar damage is lethal to vegetation.

    Before you know it – and vast numbers of states are declaring agricultural states of emergency with the FDA because of widespread crop failure – these poisonous gases in the atmosphere are going to kill us – people – too!

  22. 122
    Brian Dodge says:

    John Cooknell — 2 December 2009 @ 2:48 PM, quoting Terry Marsh
    “The river floods of summer 2007 were a very singular episode,….. ”

    “Floods 2008
    In August and September 2008 there were major floods in parts of the UK when exceptionally large amounts of rain fell in very short periods. We have looked back at what happened, meteorologically, and also at our own forecasts and warnings during both periods.”

    “Floods, snow and gales batter Britain
    • One month’s rainfall in 24 hours
    • Storm prompts 100 flood warnings”
    “The storm, which comes a week after the heaviest snowfall for 18 years wreaked havoc on the UK’s transport network, also brought strong winds, with gusts of up to 60mph in coastal areas.”, Tuesday 10 February 2009 11.48 GMT

    “Northern England and Wales mop up after flash floods
    A sudden torrential downpour of rain and hail hit the city in the afternoon, bringing back unwelcome memories of the great flood of two years ago, when two people died and the clean-up bill cost millions of pounds.”, Thursday 11 June 2009 14.28 BST

    “Hundreds rescued from U.K. flooding
    Raging floods engulfed northern England’s picturesque Lake District on Friday following the heaviest rainfall ever recorded in Britain, forcing hundreds to evacuate.”
    Last Updated: Friday, November 20, 2009 | 10:12 PM ET
    CBC News

    If I may be permitted to paraphrase the late Everett Dirksen – a singular even here, and a singular event there, and pretty soon you’re talking about real trends.

  23. 123
    Gail says:

    Oh dear. I just started to pay attention to all this tree ring stuff. And I’m no expert. But I’ve been saying for some time the trees have gone into irreversible decline thanks to atmospheric pollution from fossil and biofuel emissions.

    check out the pictures here . The trees on the East Coast dropped leaves over a month early this autumn. The conifers are rapidly losing needles and becoming bare.

    Just like a starving person gets thinner, the biomass of tree trunks shrink because they can’t photosynthesize and produce chlorophyll. Their stomata are damaged by invisible toxins in the air, like ozone, and nitrous oxide. The cumulative foliar damage is lethal to vegetation.

    Before you know it – and vast numbers of states are declaring agricultural states of emergency with the FDA because of widespread crop failure – these poisonous gases in the atmosphere are going to kill us – people – too!

  24. 124

    Adam says, on 2 Dec 2009 at 4:52 PM:

    “Most of the raw data is available from GHCN (there is adjusted data available from there, too).

    Quite correct. And since this is STILL not being understood by so many people, I think the “data sources” page needs to be updated to include a pointer to this raw data. At present, only the monthly data is linked from that page.

    May I suggest that Global Historical Climatology Network – Daily (at NCDC) also be listed, or else the ftp site for daily data. Caution. The files here are very large.

  25. 125
    Rob Z says:

    What angers me is how the scientific community does not understand how very serious these attacks are, despite how completely unfounded they are. There are millions of dollars being spent by conservative organizations and conservative media outlets. You guys are getting steamrolled by an enormous force that is just getting geared up. They are going to continue publishing more and more garbage in the months ahead. A few timid blog posts aren’t going to stop the onslaught. You need to fight back hard with everything you’ve got, or say goodbye to funding of this research. Don’t underestimate how far people like Rupert Murdoch will go to shut you down.

  26. 126
    jimvj says:

    The IR spectra taken from space ( referenced in the “6 Easy Steps” is not available now.

  27. 127
    Neil Pelkey says:

    Dear Hank Roberts,

    The changes in the senor reading from F11 to F13 are well documented.

    There has been appreciable increase in the melt since 1995

    Professor Steffan’s weather stations overheat on a regular basis and the data are interpolated from other points. You could read the metadata if you like.

    As to cherry picking, Why present the lowest melt against the highest melt. Why not first year vs last year.

    As to the y axis reads 10^6 Km^2 melt area. This would mean that 30 million square kilometers melted in 2007. is should be kilometer melt days or something similar not 10E6 km2–see steffen 2008. I know it is a typo, and this is nitpicking. Peer review would likely have caught that.

    Finally the linear projection is silly. 1987-2006 gives a negative slope. So does 79 to 96. Was the ice sheet increasing rapidly over that time? Clearly not.

    None of this implies that I think or do not think the greenland ice sheet is shrinking or growing. My issue is presenting really messy data as clean, clear and incontrovertible, when it is messy spatially interpolated, temporally smoothed and colored for maximum impact. (Please don get me wrong, I like color and thing Tufte is a graphical Luddite.)

    Also do not think I have issue with the steffen research–they are clear about what they do and share their data.

  28. 128
    NikFromNYC says:

    Copenhagen Temperature 1881-2007

  29. 129
    jonc says:

    Gavin, thank you for your response to my comment #54. You said “Thus there will always be a height somewhere below that where the CO2 absorption starts to kick in.”

    I don’t follow the argument, because it is my understanding that the composition of the atmosphere is uniform because of turbulence up to 80km. So while the amount of H2O drops, the CO2 drops by the same amount. Above that layer is mostly H2, with presumably more H20 than CO2, although it is so thin it probably doesn’t matter. So I don’t follow your reasoning why CO2 masking would always be present.

    [Response: No. CO2 is well-mixed. Concentrations are ~380 ppmv near the surface and in the upper troposphere. H2O is not (since the saturation concentration is a strong function of temperature). So surface water vapour concentrations are up to 16,000 ppmv going down to 10 ppmv in the upper troposphere (and down to ~3ppmv in the lower stratosphere). So at the upper levels there is actually more CO2 than water! – gavin]

    It sounds like you are talking about an optical depth of the atmosphere at the frequencies in question. I did a quick google of that, and it leads to an article with the conclusion that because of convection the atmosphere is effectively transparent at the frequencies in question, in other words no greenhouse effect. That would explain all the dispute in the comments that I didn’t have time to follow about convection. So that would appear to be another gap in the 6 steps that needs to be clarified, which is the relative roles of radiation and convection.

  30. 130
    Chris says:

    Could someone please link me to a comprehensive argument or review for “runaway” climate change? I concede global warming and man’s contribution to it, but am skeptical about the runaway variety, its probability, etc.

  31. 131
    Sandy Kay says:

    “[Response: My information is that it was a hack into their backup mailserver. – gavin”

    funny, that “hacker knew just where to go, what files he needed with great specificity, all nice and organized too. It is clear this was no hacker, although that “narrative” benefits the CRU crowd in deflecting the issues raised in their emails.

  32. 132
    Ben F says:

    First, I like the links list to the various data sources. It’s very useful and the effort that went into it is appreciated.

    Second, the e-mail controversy: the thing in the e-mails that jumped out at me was one by Mike MacCracken. He seems to be saying that massive SO2/Sulfate pollution from India and China may be offsetting what would ordinarily be increased temperatures due to CO2. (Quote follows) First, do you think he’s right about that? Second, if that’s the case (that SO2 can have a major cooling affect), what impact did the death of the Soviet Union and the shutting down of the vast majority of it’s highly polluting heavy industry have in the late 80s and early 90s? Was it produce large amounts of SO2? Did that production decline in a major way? If yes, how do you go about distinguishing the impact of that change from the impact of the rise in CO2?

    [Response: It’s a very good question. We don’t have great estimates of Asian SO2 emissions – though we do have satellite measures of associated pollutants that don’t match up with ‘official’ numbers. Increases in SO2 lead to sulphate formation which does offset warming from the CO2, but there are distinct fingerprints – regionally, altitudinally and spectrally, that allow you to distinguish the components. SO2 emissions in the US, Europe and Russia are all down over the last twenty years (due to the collapse of communism and to the Clean Air Acts), and the global numbers seem to indicate a slight decline globally – but the regional aspects of SO2 changes is probably having an effect. More work definitely needed on that. – gavin]

    In any case, if the sulfate hypothesis is right, then your prediction of warming might end up being wrong. I
    think we have been too readily explaining the slow changes over
    past decade as a result of variability–that explanation is wearing thin.
    I would just suggest, as a backup to your prediction, that you also do some checking on the sulfate issue, just so you might have a quantified explanation in case the prediction is wrong.
    Otherwise, the Skeptics will be all over us–the world is really cooling, the models are no good, etc.

    [Response: Not sure about this. I have thought about the difference that revised SO2 emissions would make, but the impact on very short timescales (ie. 10 years or so) is slight and probably not detectable – precisely because natural variability is relatively large. It remains to be seen what the actual effect is (we should have a better idea in a few months). – gavin]

  33. 133
    BH says:

    Re: AJ #80

    It is oddly appropriate that an editorial on an Intelligent Design website ( is run by the Discovery Institute, in case you missed it), in combination with Steve McIntyre’s vitriol, is more convincing to you than Gavin’s calm reasoning. Better luck next time.

  34. 134
    Andrew says:

    From the Washington Post:

    “I can’t see either of these papers being in the next IPCC report,” Jones writes. “Kevin and I will keep them out somehow — even if we have to redefine what the peer-review literature is!”

    In another, Jones and Mann discuss how they can pressure an academic journal not to accept the work of climate skeptics with whom they disagree. “Perhaps we should encourage our colleagues in the climate research community to no longer submit to, or cite papers in, this journal,” Mann writes.

    “I will be emailing the journal to tell them I’m having nothing more to do with it until they rid themselves of this troublesome editor,” Jones replies.

  35. 135
    Jeffrey says:

    re: the Trenberth comment about not being able to account for the lack of warming at the moment: I’m seeing this everywhere – blogs & mainstream, with varying slants; none positive.

    I’ve read the assorted comments attempting to explain that Trenberth comment; unfortunately, speaking to deficiencies in measuring the energy budget/heat flux or zero/first order explanations, doesn’t particularly translate well for the questioning layperson. Any other dumb’d down explanations?

  36. 136
    Jim Ryan says:

    Hi Gavin,

    I’m a scientist (not a climate scientist) and I have been engaging with AGW skeptics on the Spectator blog in the UK – yes, you’re right I am a masochist!. The levels of ignorance, assertion and deflection are extraordinary and I think I may be wasting my time. However, the blog is run by a well known journalist who apparently broadly acccepts AGW but contends there is a lot of room for doubt. My argument with him is that AGW is almost certainly true and that his level of doubt (skepticisim) should reflect the consensus. Inevitably i’ve been dragged into a whirlpool of ‘skeptical’ bloggers who have a distict abiltiy not to listen to the science. Hope you don’t mind but I’ve presented them with your 6 easy steps to CO2. One response, found below, should amuse you but I would appreciate a rebuttal from a scientist in the field as there are technical aspects I cannot address. I suspect it won’t make a difference but one never knows and she is convinced ‘you all cheat’. Keep up the great science!

    [Response: Thanks. Your correspondent’s points are all beside the point. Details below. – gavin]

    Well, I put that all in. The CO2 = AGW is not so much in dispute per se, just the scale. I think CO2 is a bit player, far smaller than the natural variation. To support that, I go to the historical record. The data are in dispute, but the glaciers in greenland DO uncover trees, the viking graves are in permafrost, so there is definitely a case. For the little ice age, there are the frost fairs. They happened, they deserve to be accounted for. Scale and causes of natural variation: unknown. Number of natural influences: unknown. Claimed CO2 effect of those variations: nil, as far as I know. Sum of natural variation (from what norm?) currently: unknown. Therefore, CO2 contribution, currently : unknown.

    [Response: This is a logical fallacy. The existence of natural variation does not imply that human forcings are negligible. Furthermore, even if the attribution of 20th C change to CO2 and other human drivers was zero (which it isn’t), the potential change of climate based on the much larger forcings projected for the future would still be a concern. – gavin]

    Reliability of computer models: Zilch. That’s an opinion, based on some knowledge of the field.

    [Response: Argument from personal incredulity, and not correct in any case. These models do have skill in many different measures – including in predictions ahead of time. – gavin]

    Signs that the CO2 = AGW effect is working, in actual observation: Well, not much. Predicted troposphere temp changes, not seen.

    [Response: See above, but this point is based on a confusion about what the fingerprint of GHG forcing is, and ignorance of what has actually emerged from the analysis. (See here). – gavin]

    Proof of CO2 sensitivity, nope.

    [Response: ‘proof’ only exists in mathematics. But evidence that climate sensitivity is non-negligible is plentiful. – gavin]

    Observations of radiation budget, currently not showing CO2 effect, but early days.

    [Response: Not true. See Harries et al (2001). – gavin]

    So, you can prove it by the sensitivity and the radiation budget, and by quantifying the natural variation. That’s what I want to see. Is it asking too much?

    [Response: No, but that exists – see IPCC AR4 Chapter 6 and 9. – gavin]

    For proof by fiddling the temperature record and comnputer models is not enough.

    [Response: This is just a smear. – gavin]

  37. 137
    Peter T says:

    I think the piece by Peter Keleman gives far too much ground away. Certainly science (or any other field of inquiry) thrives best when there is a high degree of open-mindedness and a critical attitude to new data. But to continually stress the role of uncertainties is to ignore how very firmly founded – and how interconnected – our knowledge is in many domains. We sek new information largely to clarify issues at the frontier – we are rightly sceptical where people put forward an interpretation that contradicts really central understandings (as one scientist remarked “if your thesis can be shown to conflict with the second law of thermodynamics, you have no hope – it is doomed”).

    That AGW is right is not a surprise. It is an unwelcome consequence of well-established understandings of how the universe works (noting that that still leaves open lots of critical issues about precise degrees and effects).

    We are entitled to be increasingly sceptical about other explanations unless they not only posit a plausible alternative mechanism for warming, but also posit simultaneously a mechanism for suppressing the effects of CO2, or (less likely) propose some verifiable dampening effect for CO2-induced warming or (really unlikely) offer some alternative entire scheme of physics.

  38. 138
    Julian Tol says:

    This question is only for people who agree with the following statement:

    “The DOMINANT cause of climate change is carbon emissions from human activity”.

    My question is:

    What OBSERVABLE climatic events would have to be OBSERVABLE (as opposed to modeled) for you to become convinced that the statement above in NOT true?

    [Response: You need to be more precise. The dominant cause of climate change at the moment is CO2 (but the impacts of the other greenhouse gases, aerosols and land use etc. are important as well), and the risk of further large climate changes is related to the continuing increase in CO2 more than any other factor. So the question you need to ask yourself is, given the continuing human-caused rise of CO2, it’s very well characterised radiative effect and the evidence that climate sensitivity to radiative changes is non-negligible, what would convince you that continuing increases in emissions is not a substantial risk? (For me, you would have to provide substantial evidence that the three points above were wrong because there is already substantial evidence that they are not). – gavin]

  39. 139
    John Mason says:

    Re #119:

    The Cumbrian floods of November 2009 were caused by a specific synoptic setup – a warm conveyor. In short, these occur when a quasi-stationary front trails from the UK well to the SW, bringing along warm moist air from way down in the subtropics. The moisture drops out as the air moves up over the mountains of the Western UK/Ireland. Given that warmer seas lose more moisture via evaporation and warmer air can carry more moisture, it is likely that such conveyors are bringing more intense rainfall, and will bring even more in future. This is likely to be one of the key effects of a warmer world in terms of the UK. Another key conveyor brought 261mm in 48 hours to North Wales in February 2004 – see

    – although this was nowhere near the total involved in the recent event.

    Cheers – John

  40. 140
    chris says:

    Jeffrey 3 December 2009 @ 4:03 AM

    I think Trenberth is referring to a sort of sub-level of uncertainty that lies underlies a broader certainty of understanding.

    There are (at least) two major examples of this in climate science:

    (i) sea levels. There’s rather good evidence that sea levels are rising a bit over 3 mm per year at the moment (highish certainty [*]). This must be the result of some combination of heat accumulation (thermal expansion) and mass increase (polar ice sheet and mountain glacier melt), and the summation should match the observed sea level rise if the “budget” is properly “closed”). Each of the latter can be estimated independently; however each of the latter measurements has greater uncertainty than the more easily measured total sea level rise. So there is a sub-level of uncertainty in the precise partitioning of sea level rise within its (less easily measured) components. The greater uncertainty in the latter doesn’t negate the lesser uncertainty in the former.

    (ii) Radiative forcing and it’s precise partitioning.

    This is similar to (i) but more complex. We have rather good evidence that the net forcing from raised CO2 is equivalent to an equilibrium warming near 3 oC (plus/minus around 1 oC) per CO2 doubling. The forcing is the result of a radiative imbalance between incoming solar radiation and outgoing longwave IR emitted from the earth’s surface. Partitioning this to the components (solar radiation reflected to space; solar radiation reflected by surface; solar radiation absorbed by clouds; surface emitted LWIR; surface LWIR reflected from the atmosphere…and so on)…is very complex (see Figure 1 here [**]). The nett top of the atmosphere radiative imbalance that we can estimate reasonably well from theoretical analysis combined with paleoproxy analysis (that allows us to estimate the expected equilibrium temperature response to doubling CO2), is a small number that results from the summation of many large numbers.

    So the uncertainty in this summation of many large numbers to give a net TOA forcing has a lot of uncertainty since tiny errors in the large numbers (solar radiation emitted from the earth surface; LWIR absorbed by the atmosphere etc; see Figure 1 [**]) result in large errors in the summed TOA radiative forcing (i.e. “closing the energy budget”). However that doesn’t mean that we don’t have quite a good handle on the estimate of the total radiative forcing from independent analysis.

    Trenberth’s problem (if I am interpreting his email correctly), is that we need to understand the component forcings and their responses if we want to assess whether geoenginering approaches will have any chance of being successful. That makes sense since geoengineering approaches (blast sulphurous aerosols into the atmosphere) affect sub-components of the total radiative forcing (.e. we assume they mostly reduce solar radiaiton reaching the surface), but we need to know by how much, and if that’s all they affect, before we start pumping the stuff into the atmosphere.



    [**] Trenberth, K. E., J. Fasullo, and J.T. Kiehl, 2000: Earth’s Global Energy Budget. Bull. Amer. Met. Soc. 90, 3, 311-323.

  41. 141
    John S says:

    I’ve read through all three volumes of comments, and it will be the HARRY_README file that brings down CRU. Your explainations:

    “HARRY_read_me.txt. This is a 4 year-long work log of Ian (Harry) Harris who was working to upgrade the documentation, metadata and databases associated with the legacy CRU TS 2.1 product, which is not the same as the HadCRUT data (see Mitchell and Jones, 2003 for details). The CSU TS 3.0 is available now (via ClimateExplorer for instance), and so presumably the database problems got fixed. Anyone who has ever worked on constructing a database from dozens of individual, sometimes contradictory and inconsistently formatted datasets will share his evident frustration with how tedious that can be”

    are laughable. Harry was trying to write programs to interpret existing CRU databases to reproduce previously published results, with no success!

    And that is supposed to make us more confident that the rest of CRU’s work output is more sound than Harry’s impossible task? Hardly.

    [Response: On the contrary, he did do this with success – witness the release of the CRU TS 3.0 and discussions in the emails over final tweaks and validations to the product. It’s certainly been my experience that I am more inclined to note down problems and frustrations than the fixes, because as soon as you have dealt with one bug, you need to go on to the next. Much the same level of complaint exists in the development of climate models, but weird behaviour, overloads and mysterious crashes all get dealt with eventually. You are getting a peak behind the curtain here, and it might not seem to be the same as the narrative presented in scientific papers (but see Medawar’s comment on that which remains as true today as it was in 1964), but the process of science is about finding problems and fixing them – however mundane that might seem. – gavin]

  42. 142
    iain says:

    Since climate scientists who accept the theory of AGW are increasingly suspected/smeared as being in collusion with big money, it may be worth noting, in the light of the doubts raised by Prof. Karlen, that Karlen himself has links to finance from the energy industry. That does not validate or invalidate his comments. He is a genuine (albeit now retired) scientist who merits answers as such. But fair’s fair: let’s share some scientifically irrelevant and possibly baseless skepticism around evenly on all sides.

  43. 143
    Andrew Dodds says:

    SecularAnimist –

    Yes, it is unbelievable. The difference between what is in the emails and what the denialists say is in the emails is vast.

    And the latest meme is that the data was leaked by some ‘heroic insider’. As far as I know there is zero evidence whatsoever for this, it is purely a conscience salve for those who normally rail about the inequities of file-sharing.

  44. 144
    Theo Hopkins says:

    “Beat the crap out of …. etc”?

    This expression of honest anger is better – at least for me – than many of the careful rebuttals posted here by Gavin. :-)

    Well,I like Gavin’s rebuttals, too, but this email shows the anger and frustration of the climate science community.

    I know one person who’s science feeds in (marginally) to climate science. Now a retired professor who I work with on a charity. Normally he is the quietest and most self-effacing man, but the way his and his colleagues have had their work, which merely pushed the descriptive knowledge in his field fractionally forward, picked over by others with no appropriate qualifications for political reasons, absolutely determined to find fault, will turn this calm man into an angry man.

  45. 145
    Walter Manny says:

    Nowhere in this thread do I see a discussion about what it means that Jones has resigned [temporarily, but is there a way back?] and that Mann is under investigation by his university [“reviewing concerns”]. That could be that I have not explored the thousands of recent entries closely enough, though.

    I see an ironic insistence on the terms “denier” and “denialists” being heaped on the skeptic camp as never before, and an underlying anger. Anger is invariably motivated by fear, and it would be interesting to hear what the AGW proponents here are afraid of, since there appears still to be an insistence that AGW theory is settled science. I have been impressed by the sea change in the way dissent has been handled at RC, to be sure, but I’m curious about why Jones in particular has not been tossed out of this club for his transgressions. “There’s nothing to see here”, and “let’s move on” in the face of resignation and investigation, has never been a compelling argument.

    [Response: If you want to see uncontrolled anger, then you should see the email we are getting – it’s pretty appalling stuff. As said further up the thread, investigations are useful for people to sort through the barrage of nonsense and false claims in an atmosphere that is more conducive to rational discussion. I am confident that both investigations will exonerate both Mann and Jones of any scientific impropriety. And give that ‘settled science’ stuff a rest. We have never made any such claim. – gavin]

  46. 146
    j gordon says:

    This is my only comment on a blog, because this seems like a thoughtful place. I especially like comment #57. It seems to me that all this discussion about the minutiae of the data revealed in the leaked info from CRU, while generally intelligent and well meaning misses the point at the moment; as does the argument that it it illegally gotten, therefor we should ignore it. Governments have fallen on a lot less. I had not heard any of the the names involved before this and I generally agree with the prevailing climate theory, but this story is about trust.

    1. Phil Jones is finished, next year he will be lucky to have a job at a junior college in Siberia or a back office at an extreme liberal think tank in Colorado (a nicer place). You cannot show this degree of arrogance, disregard for ethical behavior, number of don’t tell anybody emails, and possibly illegal (FOI, delete emails, erase data) actions and survive. He breached his trust with the scientific community. He should take responsibility for his actions, apologize and disappear quickly.

    2. The CRU data is finished. It is truly a shame, I am sure many people worked long and hard for over 30 years to make it the best they could, but, overnight Phil Jones actions destroyed it. Politically, it cannot now survive. I noticed the moderators harsh comments about the low quality of some of the dissenting climate papers. If someone submitted a paper for peer review, and, asked about the supporting data said; “We threw away the raw data years ago, many of the disparate data series merges, interpolation and normalization are undocumented over the years, and my own subroutines are none of your business”, what would you say? Right or wrong, this is how the public now sees it. Don’t waste time trying to defend it, you will only discredit yourselves. It is about trust.

    3. I noticed that several of the sponsors of this web site received emails from Phil Jones. I am dismayed to not see a response to the effect of “Dear Phil, I am a professional scientist, working hard to find honest answers to difficult and important questions. I do not erase data, delete emails, stone wall FOI requests or participate in cabals. Have a nice day.” I hope that these emails exist.

    I do not write to attack anyone, my only agenda is the science of science. I am a retired, old computer scientist, who happened to see this story, and then, having nothing better to do, followed many of the links. I hope you can survive this, you are our store of serious knowledge on this subject. But, if you think that just because you are innocent, that this will blow by you, wake up! However they got it, your perceived enemies now have the raw meat that they need. If you think that you will receive the support of the climate change community; I tell you this, if your institution thinks that their funding is in jeopardy or a supporting politician feels their base is eroding, you are history.

    Forget about the minutiae for now, make sure that your own ethics are squeaky clean and your own data clean and well documented. Publish everything, along with the code for the models and algorithms that go along with it. This is the era of open source; some of us old Fortran geezers might even help with that code. Surprise everybody and take responsibility for any transgressions that might have occurred. It is about trust.

    Learn from Dr. Jones mistake, don’t circle the wagons, and think about the following:

    Good Luck

  47. 147
    Adrian Midgley says:

    @Manny @143 I have not seen a sea change in the way dissent has been handled at RC.

    Nor is there any need for one.

  48. 148
    Theo Hopkins says:

    “The science is settled”.

    That “the science is settled” is constantly used by sceptics as a quote to say that the science is _not_ settled.

    Did _anyone_ actually ever say “the science is settled”? If so, who, where, why and when?

  49. 149
    John Cooknell says:

    cc 119 brian dodge
    thanks Brian but what trend?

    The Climate Statement from the esteemed scientists Prof. Julia Slingo, Chief Scientist, Met Office
    Prof. Alan Thorpe, Chief Executive, Natural Environment Research Council
    Lord Rees, President, the Royal Society

    Includes these 2 phrases as indicators of climate change.

    In the UK, heavier daily rainfall leading to local flooding such as in the summer of 2007;

    Increased risk of summer heatwaves such as the summer of 2003 across the UK and Europe;

    So is Climate Change indicated by an extremely wet summer causing summer flooding, or summer drought like 2003 caused by increasing numbers of heatwaves.


    [Response: Just repeating your point over is not moving a discussion forward. There is strong evidence that heavier rainfall is becoming more intense and that is a predicted impact. As are increases in heatwaves. Individual examples of that are just examples, not proof. If a newspaper wants to report on increasing crime rates and they illustrate their story with a single example of someone who was mugged this is not assumed to imply that this case is because of the trend, merely that it exemplifies it. This case is no different. – gavin]

  50. 150
    chris says:

    Walter Manny,

    It’s not surprising that Professor Jones has considered it appropriate to step aside while a review of the situation takes place, and an acting director (Professer Peter Liss) stands in.

    You live in an odd world Walter. A world in which “anger is invariably motivated by fear”! There seems to be an undercurrent of wishful thinking in your message. If only life were so simple, eh?….that it would conform to wishful non-sequiturs and false logic.