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What do the 'Climategate' hacked CRU emails tell us?

What the science says...

Select a level... Basic Intermediate Advanced

Though some of the CRU emails can sound damning when quoted out of context, several inquiries have cleared the scientists. The Independent Climate Change Email Review put the emails into context by investigating the main allegations. It found the scientists' rigour and honesty are not in doubt, and their behaviour did not prejudice the IPCC's conclusions, though they did fail to display the proper degree of openness. The CRU emails do not negate the mountain of evidence for AGW.

Climate Myth...

Climategate CRU emails suggest conspiracy

“[T]he 1079 emails and 72 documents seem indeed evidence of a scandal involving most of the most prominent scientists pushing the man-made warming theory - a scandal that is one of the greatest in modern science. […] emails suggesting conspiracy, collusion in exaggerating warming data, possibly illegal destruction of embarrassing information, organised resistance to disclosure, manipulation of data, private admissions of flaws in their public claims and much more.” (Andrew Bolt, Herald Sun)


Exhibit No. 1 of the climate conspiracy theory is a collection of emails stolen from the Climatic Research Unit (CRU) of the University of East Anglia (UEA), which appeared on the internet in November 2009.

Founded in 1972, CRU is only a small research unit with around 16 staff. CRU is best known for its work, since 1978, on a global record of instrumental temperature measurements from 1850 to the present, or CRUTEM. CRU’s land surface temperatures are combined with the UK Met Office Hadley Centre’s sea surface temperatures to form the global land-ocean record HadCRUT. CRU has also published reconstructions of pre-1850 temperatures based on tree rings, and CRU scientists have been involved in the Intergovernmental Panel on Climate Change (IPCC).

The 1,073 emails span 13 years of correspondence between colleagues at CRU. Much of it is mundane, but in this digital age it took only a matter of hours for contrarians to do some quote-mining. Contrarians alleged that the CRU scientists had manipulated temperature and tree ring data to support predetermined conclusions, that they had stonewalled Freedom of Information (FoI) requests for data, and that they had corrupted the peer review and IPCC processes.

The story was quickly dubbed “Climategate”, and it spread rapidly from arcane contrarian blogs through conservative columnists to the mainstream media. The hyperbole was turned up to eleven. Conspiracy theorists had a field day, claiming that anyone even mentioned in the emails, or remotely connected to CRU, must also be part of a conspiracy. In this way, the Climategate conspiracy theory snowballed to include the entire field of climate science. The Climategate emails were held up as “the final nail in the coffin of anthropogenic global warming”, and the media were only too happy to play up the controversy.

The CRU scientists have been cleared

In the months that followed, there were several inquiries into the allegations resulting from the emails. When a few of the more suggestive email quotes are reeled off by pundits without much context, they can sound pretty damning. But each and every one of these inquiries has found no fraud and no conspiracy.

The most comprehensive inquiry was the Independent Climate Change Email Review led by Sir Muir Russell, commissioned by UEA to examine the behaviour of the CRU scientists (but not the scientific validity of their work). It published its final report in July 2010. This inquiry was no whitewash: it examined the main allegations arising from the emails and their implications in meticulous detail. It focused on what the CRU scientists did, not what they said, investigating the evidence for and against each allegation. It interviewed CRU and UEA staff, and took 111 submissions including one from CRU itself. And it also did something the media completely failed to do: it attempted to put the actions of CRU scientists into context.

The Review went back to primary sources to see if CRU really was hiding or falsifying their data. It considered how much CRU’s actions influenced the IPCC’s conclusions about temperatures during the past millennium. It commissioned a paper by Dr Richard Horton, editor of The Lancet, on the context of scientific peer review. It asked IPCC Review Editors how much influence individuals could wield on writing groups. And it reviewed the university's FoI processes and CRU's compliance with them. Many of these are things any journalist could have done relatively easily, but few ever bothered to do.

The Review also commented on the broader context of science in the 21st century. To paraphrase from Chapter 5: the emergence of the blogosphere requires significantly more openness from scientists. However, providing the details necessary to validate large datasets can be difficult and time-consuming, and how FoI laws apply to research is still an evolving area. Meanwhile, the public needs to understand that science cannot and does not produce absolutely precise answers. Though the uncertainties may become smaller and better constrained over time, uncertainty in science is a fact of life which policymakers have to deal with. The chapter concludes: “the Review would urge all scientists to learn to communicate their work in ways that the public can access and understand”.

The Review points out the well-known psychological phenomenon that email is less formal than other forms of communication: “Extreme forms of language are frequently applied to quite normal situations by people who would never use it in other communication channels.” The CRU scientists assumed their emails to be private, so they used “slang, jargon and acronyms” which would have been more fully explained had they been talking to the public. And although some emails suggest CRU went out of their way to make life difficult for their critics, there are others which suggest they were bending over backwards to be honest. Therefore the Review found “the e-mails cannot always be relied upon as evidence of what actually occurred, nor indicative of actual behaviour that is extreme, exceptional or unprofessional.” [section 4.3]

So when put into the proper context, what do these emails actually reveal about the behaviour of the CRU scientists? The report concluded (its emphasis):

Climate science is a matter of such global importance, that the highest standards of honesty, rigour, and openness are needed in its conduct. On the specific allegations made against the behaviour of CRU scientists, we find that their rigour and honesty as scientists are not in doubt.

In addition, we do not find that their behaviour has prejudiced the balance of advice given to policy makers. In particular, we did not find any evidence of behaviour that might undermine the conclusions of the IPCC assessments.

But we do find that there has been a consistent pattern of failing to display the proper degree of openness, both on the part of the CRU scientists and on the part of the UEA, who failed to recognize not only the significance of statutory requirements but also the risk to the reputation of the University and indeed, to the credibility of UK climate science. [1.3]

These general findings are more or less consistent across the various allegations the Review investigated. Its specific findings are summarized in the following rebuttals: "Did CRU tamper with temperature data?", "What does Mike's Nature trick to 'hide the decline' mean?", "Climategate and the peer-review process", "Were skeptic scientists kept out of the IPCC?", and "Climategate and the Freedom of Information (FOI) requests".

The science is unchanged by Climategate

The argument that Climategate reveals an international climate science conspiracy is not really a very skeptical one. It is skeptical in the weak sense of questioning authority, but it stops there. Unlike true skepticism, it doesn’t go on to objectively examine all the evidence and draw a conclusion based on that evidence. Instead, it cherry-picks suggestive emails, seeing everything as incontrovertible evidence of a conspiracy, and concludes all of mainstream climate science is guilty by association. This is not skepticism; this is conspiracy theory.

In reality, Climategate has not thrown any legitimate doubt on CRU’s results, let alone the conclusions of the entire climate science community. The entire work of CRU comprises only a small part of the evidence for AGW. There are all sorts of lines of evidence for global warming, and for a human influence on climate, which in no way depend on the behaviour of the CRU scientists. Global warming has been observed not just on land but also over the oceans and in the troposphere, as well as being confirmed by many other indicators such as ocean heat content, humidity, sea level, glaciers, and Arctic sea ice. And while the hockey stick tells us that humans have caused a profound disturbance to our climate system, we don’t need it to know that humans are causing global warming. The pattern of warming we observe is the same as that long predicted for greenhouse warming: the stratosphere is cooling, nights have warmed faster than days, and winters faster than summers.

But this reality doesn’t fit into the narrative that the contrarians would like to tell: that AGW is a house of cards that is falling down. It is very difficult to attack all of these diverse lines of evidence for global warming. Instead they tend to focus on some of the better publicized ones and try to associate them with a few individuals, making a much easier target. Yet while contrarians have been nosing around in scientists’ emails, the actual science has, if anything, become more concerning. Many major studies during 2009 and 2010 found things may be worse than previously thought.

Far from exposing a global warming fraud, “Climategate” merely exposed the depths to which contrarians are willing to sink in their attempts to manufacture doubt about AGW. They cannot win the argument on scientific grounds, so now they are trying to discredit researchers themselves. Climategate was a fake scandal from beginning to end, and the media swallowed it hook, line, and sinker. The real scandal is the attacks on climate science which have done untold damage to the reputation of the scientists involved, public trust in science, and the prospects of mitigating future warming.

Advanced rebuttal written by James Wight

Update July 2015:

Here is a related lecture-video from Denial101x - Making Sense of Climate Science Denial

Expert interview with Kevin Trenberth

Last updated on 14 July 2015 by pattimer. View Archives

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The House of Commons report on the emails stolen from CRU has vindicated Phil Jones -- he has "no case to answer":

The focus on Professor Jones and CRU has been largely misplaced. On the accusations relating to Professor Jones's refusal to share raw data and computer codes, we consider that his actions were in line with common practice in the climate science community. We have suggested that the community consider becoming more transparent by publishing raw data and detailed methodologies. On accusations relating to Freedom of Information, we consider that much of the responsibility should lie with UEA, not CRU.

In addition, insofar as we have been able to consider accusations of dishonesty--for example, Professor Jones's alleged attempt to "hide the decline"--we consider that there is no case to answer. Within our limited inquiry and the evidence we took, the scientific reputation of Professor Jones and CRU remains intact. We have found no reason in this unfortunate episode to challenge the scientific consensus as expressed by Professor Beddington, that "global warming is happening [and] that it is induced by human activity"

Official statement from Climatic Research Unit (CRU)

In an interview with Andrew Freeman, historian Spencer Weart puts Climategate and the global warming skeptic phenomenon in perspective:

"...we've never before seen a set of people accuse an entire community of scientists of deliberate deception and other professional malfeasance. Even the tobacco companies never tried to slander legitimate cancer researchers."

George Monbiot reveals the most damaging email in The Knights Carbonic. Here is an excerpt, revealing the depth of the climate conspiracy:

"Then began the most hazardous task of all: our attempt to control the instrumental record. Securing the consent of the scientific establishment was a simple matter. But thermometers had by then become widely available, and amateur meteorologists were making their own readings. We needed to show a steady rise as industrialisation proceeded, but some of these unfortunates had other ideas. The global co-option of police and coroners required unprecedented resources, but so far we have been able to cover our tracks.
Our co-option of the physical world has been just as successful. The thinning of the Arctic ice cap was a masterstroke. The ring of secret nuclear power stations around the Arctic Circle, attached to giant immersion heaters, remains undetected, as do the space-based lasers dissolving the world’s glaciers.
Altering the migratory and reproductive patterns of the world’s wildlife has proved more challenging. Though we have now asserted control over the world’s biologists, there is no accounting for the unauthorised observations of farmers, gardeners, bird-watchers and other troublemakers. We have therefore been forced to drive migrating birds, fish and insects into higher latitudes, and to release several million tonnes of plant pheromones every year to accelerate flowering and fruiting. None of this is cheap, and ever more public money, secretly diverted from national accounts by compliant governments, is required to sustain it."

Another amusing parody is Newtongate: the final nail in the coffin of Renaissance and Enlightenment ‘thinking’ which scrutinizes the private correspondance of Isaac Newton to cast doubt on Newtonian physics and integral calculus.

MediaMatters examines many of the claims coming out of "Climategate", exposing how the emails have been distorted and misrepresented.


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Comments 1 to 25 out of 89:

  1. As stated above: "However, the crucial question is whether these emails reveal that climate data has been falsified." It's your website, but, for what it's worth, I disagree with your line of reasoning here. I think the crucial question is: was this scientist attempting to mislead? And if so, what was his motivation? Also, could this same motivation broadly exist in the climate science community. If we are intellectually honest, we have to address this question. I think reasonable people could agree that the climate issue has been so politicized over the last decade that it is often extremely difficult to discern the truth. I appreciate the efforts of this site to attempt to coherently dispute the disputers. I do, however think that the recently publicized e-mails by a "ranking" member of the non-skeptic climate community are harmful to the cause of discerning the truth, at least for those people who have not drawn a final conclusion about the evidence, which apparently concludes that anthropogenic CO2 + feedbacks = catastrophy, and that climate sensitivity is a solved problem.
  2. As i see it, there are two parts in this story. One is the behaviour of the few scientists involved in the stolen emails, the other is the broad impact on climate science. Starting from the latter, which i think is the topic of this post, i can see no impact whatsoever. Luckly, science is not a matter of a few guys or a few experiments. So even if some fake science could have made it's way through the selection of the scientific community, it does not affect climate science as a whole. And even admitting (i do not) scientific misconduct by those CRU scientists, are we allowed to doubt of hundreds of other? Not for sure, each of us is responsible of its own actions and there is nothing in the emails pointing to a much broader involvement of the whole community. Here is the link to the first part of the problem. What did they actually do? I mean, actions, not words. At the very least, from the emails we can't deduce anything and there are no facts elsewhere confirming any action. There is some not appropiate wording, but nothing regarding arbitrary data manipulation. While I can understand that they might be "condemned" for their personal attitudes i strongly disagree to involve the science. Finally, a political consideration. Before a couple of decades ago, global warming was not a political issue. But then, when the "risk" of concrete actions became too high, it switched to a political issue. The explicit interest was to confuse the two planes, politics and science. This is not new, indeed, we've seen this happen before (mainly in the USA i admit). Who is responsible? Not scientists for sure, they kept doing their work while were being involved in the arena. Some of them even started to be advocate, which is definitely a right for anyone. Should we conclude that AGW is now politics and not science? Not at all. The solution of the problem is politics, indeed; its assessment is science.
  3. Nicely put Riccardo, but unfortunately the few scientists involved were in positions of high authority which changes the dynamic somewhat. Public confidence will take a dive regardless, boosted by those who have opted out because their work has been (so they say) misrepresented/misused.
  4. Whenever scientists fight disclosure - as is evident in the emails - everyone should be concerned. As for it being a couple of scientists, given they control the main temperature history used by the IPCC the fact that they are few in number is somewhat less relevant than the position they hold. I'm no scientist but it seems to me that in the CO2 caused global warming debate the temperature record is of a certain significance. I don't see why the temperature record including unadjusted data and methodologies should not be publicly available. After all we wouldn't trust a government to run an election, count the votes and then tell us who won. The main thing that the emails demonstrate is that the politics and science are very tightly intertwined. This serves politicians more than scientists.
  5. There's an elegant counter to the skeptic argument that scientists adjusted ground temperature data to bias it toward warming. Giorgio Gilestro simply plotted all the adjustments made to each of the GHCN/CRU individual temperatures. The average adjustment is... zero degrees. And a nicely uniform, normal distribution around zero.
  6. "What do the 'Climategate' hacked CRU emails tell us?" It tells us what we already known since long; the science behind climate changes is far from well understood - if it was then it would not be any interesting Nature/Science articles left to write and the whole area would "degrade" into an engineering discipline taught as an academic subject at universities where one could graduate as a climate engineer. However we dont have any graduated climate engineers - only climate researches.
  7. RE:#6 batsvensson. From your attack on science articles it sounds like you have absolutely no experience with academic scientific research so I suggest you start doing the homework yourself and tell us all why it only takes excerpts from two leaked emails over 13 years to prove that the whole of climate science is far from settled.
  8. "While some of the private correspondance is not commendable"... It is more than that. The authors said they were going to erase emails subject to a Freedom of the Information Act request. That is a felony.
  9. Michael949, please stick to the facts. None of them ever said they were going to delete the email.
  10. Regarding "hide the decline": If it is true that tree rings are definitely inaccurate after 1960 (having compared them with the instrumental temperature record), shouldn't we question the entire data set, as that might be flawed too?
    Response: This is a good question and is explored in Tree-ring proxies and the divergence problem. In short, tree-ring proxies show good agreement with other proxies before 1960 and also show good agreement with tree-ring proxies that don't show divergence (eg - at lower latitudes). This indicates divergence is a purely recent phenomenon (and hints that there's a good chance it's anthropogenic in cause).
  11. Riccardo : '' None of them ever said they were going to delete the email.'' Maybe not, but this quote is rather close (from Phil Jones). Close enough for me!: ''If they ever hear there is a Freedom of Information Act now in the UK, I think I'll delete the file rather than send to anyone...''
  12. Argus, did it never happen to you to say in a private conversation "if he does this i'm going to kill him" or "i love this thing, i'm going to steal it" or something like this? Wow, that's incredible.
  13. One thing is how it seems these emails mentions intentions to make graphs fit the claims of Co2 and global warming, another thing is to loose the raw data? Woops, that was unfortunate. Which basically takes just about all the evidence on this website, and invalidates it. Seems it is back to the drawing board. At the moment, too much of the world do not accept the lack of raw data, and the whole thing is being looked looked into.
  14. kblood, the raw data were not lost by the organizations that are actually responsible for collecting and keeping them. The U. of East Anglia was only one of many consumers of those data. The data still are available to the U. of East Anglia, and even to, say, you! A big list of links to the data sources has been compiled at RealClimate, for your convenience.
  15. kblood, you're claiming that failure of a small research unit to efficiently maintain backups of copies of data obtained from a primary source still able to supply the data in question invalidates all of the research findings presented here at Skeptical Science? Can you demonstrate how the loss of copies of a a few years' temperature data invalidates the work of thousands of persons working in a plethora of fields pursuing numerous lines of inquiry? No, obviously you can't. You make a ridiculous charge, harmful to your own credibility. Take a few moments to read what others write here, rejectionists and skeptics included. Get calibrated, please.
  16. It's particularly silly to complain about "loss of data from UEA" since there are now a whole bunch of replications of the same results using 100% publicly available data from GHCN. If you don't like the UEA temperature reconstruction, use the one from GISS or NCDC or any of the various open-source efforts that people have developed in the past few months. They all show the same thing. Link 1 Link 2
  17. nice to see what the supporters have been saying confirmed, but many will say the judgment was rigged. Inquiry backs scientists in global warming row
  18. Good to hear that the second enquiry into CRU has (generally) backed them. I know the so-called skeptics will be shouting 'whitewash' again, but they must be ever-so desperate now for something to come out of the final enquiry - not that anything will, of course, but surely the more intelligent of them will be questioning some of their scepticism ? That is, will they be true sceptics or so-called skeptics ?
  19. Here's a link to the report from that second inquiry: the Oxburgh Report.
  20. Obviously the whole point of the hacking was to look for dirt to publish. I'd love to know how many other people got hacked with nothing published, because there was no dirt to find. I know the answer might be "none", but equally, it could be hundreds.
  21. Here’s a link to the final and most comprehensive inquiry: the Muir Russell report.
  22. There have been five major investigations by experts into the climategate frenzy, and none of them found any evidence whatsoever of fraud, or misconduct. Yet the conservative media is still cherishes the nonscandal as if it is the latest news. I find this amusing and laughable. Why won't the conservative media stop? Its so irratating seeing this worn out climategate tantrum persisting. Does anyone have any explanations for this?
    Response: That's six investigations, actually:
    1. February 2010. the Pennsylvania State University released an Inquiry Report that investigated any 'Climategate' emails involving Dr Michael Mann, a Professor of Penn State's Department of Meteorology. They found that "there exists no credible evidence that Dr. Mann had or has ever engaged in, or participated in, directly or indirectly, any actions with an intent to suppress or to falsify data". On "Mike's Nature trick", they concluded "The so-called “trick”1 was nothing more than a statistical method used to bring two or more different kinds of data sets together in a legitimate fashion by a technique that has been reviewed by a broad array of peers in the field."
    2. March 2010. UK government's House of Commons Science and Technology Committee published a report finding that the criticisms of the Climate Research Unit (CRU) were misplaced and that CRU’s "Professor Jones’s actions were in line with common practice in the climate science community".
    3. April 2010. University of East Anglia set up an international Scientific Assessment Panel, in consultation with the Royal Society and chaired by Professor Ron Oxburgh. The Report of the International Panel assessed the integrity of the research published by the CRU and found "no evidence of any deliberate scientific malpractice in any of the work of the Climatic Research Unit".
    4. June 2010. Pennsylvania State University published their Final Investigation Report, determining "there is no substance to the allegation against Dr. Michael E. Mann".
    5. July 2010. University of East Anglia published the Independent Climate Change Email Review report. They examined the emails to assess whether manipulation or suppression of data occurred and concluded that "The scientists’ rigor and honesty are not in doubt".
    6. September 2010. UK Government responded to the House of Commons Science and Technology Committee report, chaired by Sir Muir Russell. On the issue of releasing data, they found "In the instance of the CRU, the scientists were not legally allowed to give out the data". On the issue of attempting to corrupt the peer-review process, they found "The evidence that we have seen does not suggest that Professor Jones was trying to subvert the peer review process. Academics should not be criticised for making informal comments on academic papers".
  23. Re: Karamanski (22) It is a time-honored feature of American politics to repeat a lie so often that it becomes the truth. A feature we now see adopted by the MSM (controlled by their corporate masters). The X-Files featured this prominently back in the '90's with their running theme of plausible deniability. Oh, crap. Mod beat me with a much more literal response. Oh, well. The Yooper
  24. Since the rebuttal for climategate addresses the cynicism of the skeptics towards climate science another good rebuttal should debunk the argument "climate scientists exaggerate to get more funding". I know this defies the comments policy, but I see this argument everywhere in skeptic blogs and conservative op-eds. I would really like to see this argument get shot down. Do you think a rebuttal for this argument would be a good idea for Skeptical Science?
  25. Karamanski, well there are many articles addressing whether scientists have exaggerated or not (e.g. 'Is the IPCC alarmist?')... so the issue has been covered from that side; predictions of impacts were lower than what has actually been observed, ergo the predictions were not exaggerated. I'm guessing you may mean to go at it from the other direction, how money is allocated... but that is a much trickier thing to pin down given thousands of in and out fluxes of research cash around the world. A third approach would be reviewing the results of research by scientists not in the climate field. If climate scientists were exaggerating AGW's impact on Arctic sea ice then biologists would find that seals and bears are not facing adverse impacts, oceanographers would find that the Arctic ocean was not acidifying, botanists would not find plants growing further North of their previous ranges, et cetera. Yet all these other scientific fields are finding results which support what the climate scientists are saying. Ergo, the 'skeptic' argument really becomes a claim that nearly all members of multiple branches of science all over the world are engaged in a vast conspiracy to exaggerate AGW. Which most people are rational enough to see for the complete lunacy it is.

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