On 17 November 2009 a large number of emails, together with other documents and pieces of code, from the Climatic Research Unit at the University of East Anglia were posted on a Russian webserver, and announced anonymously at the Air Vent blog and at the Climate Skeptic blog  with the comment:

We feel that climate science is, in the current situation, too important to be kept under wraps.

We hereby release a random selection of correspondence, code, and documents.
Hopefully it will give some insight into the science and the people behind it.

Whoever posted this also listed some of the key emails and what they revealed (see links above).

The link had also been posted at the Climate Audit blog, with the cryptic comment "A miracle just happened", but this seems to have gone unnoticed.

Quite how this happened is the subject of speculation (it may have been a hacker, or an internal whistleblower, or a file being prepared for an FOI request1). 

Subsequent blog discussion of the emails occurred a couple of days later at Climate Audit and at the Air Vent. More details of what happened when can be found here and here 2.

The emails reveal a number of examples of alarming and unscientific practices among the climate scientists involved, in particular:

Massaging the presentation of data:

  •  942777075.txt  the infamous "trick" to "hide the decline" in tree-ring data
  •  939154709.txt  "They go from 1402 to 1995, although we usually stop the series in 1960" (also referring to tree-ring data)   
  • 1225026120.txt  "I'll maybe cut the last few points off the filtered curve before I give the talk again as that's trending down" (referring to recent temperature data).
  • 1254108338.txt "So, if we could reduce the ocean blip by, say, 0.15 degC,  then this would be significant for the global mean" ... "It would be good to remove at least part of the 1940s blip". This relates to the rapid warming before 1940 followed by cooling after 1940, which the 'scientists' would like to remove because it does not fit with their theory.
Attempting to get papers with a sceptical view on global warming rejected from journals, and not referred to in the IPCC reports:
  • 1089318616.txt "I can't see either of these papers being in the next IPCC report. Kevin and I will keep them out somehow - even if we have to redefine what the peer-review literature is !"
  • 1054756929.txt  Ed Cook discusses with Keith Briffa how to get a paper rejected even though the mathematics is correct
  • 1054748574.txt where Briffa says "I am really sorry but I have to nag about that review - Confidentially I now need a hard and if required extensive case for rejecting"
  • 1080742144.txt where Jones "went to town" rejecting two papers that had criticised his work.
Refusing to provide data and supporting information when requested, and deleting emails (all quotes from Phil Jones):
  • 1107454306.txt "The two MMs have been after the CRU station data for years. 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".
  • 1109021312.txt "I'm getting hassled by a couple of people to release the CRU station temperature data.
    Don't any of you three tell anybody that the UK has a Freedom of Information Act !"
  • 1182255717.txt "Think I've managed to persuade UEA to ignore all further FOIA requests if the people have anything to do with Climate Audit."
  • 1211924186.txt Tim Osborn informs Caspar Amman that an FOI request has been received from David Holland about papers included in the IPCC report (May 27 2008) ....
  • 1212009215.txt Jones suggests what "Keith could say" and "Keith should say" (May 28 2008) ...
  • 1212073451.txt "Can you delete any emails you may have had with Keith re AR4? Keith will do likewise.  Can you also email Gene and get him to do the same? ... We will be getting Caspar to do likewise." (May 29 2008). [Under paragraph 77 of the FOI Act it is an offence to delete information subject to an FOI request].
  • 1228330629.txt "When the FOI requests began here, the FOI person said we had to abide by the requests. It took a couple of half hour sessions - one at a screen, to convince them otherwise" ... "About 2 months ago I deleted loads of  emails, so have very little - if anything at all."
Generally offensive behaviour:
  • 1075403821.txt "In an odd way this is cheering news!" says Jones of the death of skeptic John Daly.
  • 1177534709.txt  "I looked at some of the stuff on the Climate Audit web site. I'd really like to talk to a few of these "Auditors" in a dark alley." says Ben Santer, also responsible the next one:
  • 1255100876.txt  "Next time I see Pat Michaels at a scientific meeting, I'll be tempted to beat the crap out of him."
  • 1107899057.txt  Michael Mann claims to a journalist that "The McIntyre and McKitrick paper is pure scientific fraud."
Private admissions that are at odds with public declarations:
  • 1255352257.txt Kevin Trenberth admits that "I have my own article on where the heck is global warming" and "The fact is that we can't account for the lack of warming at the moment and it is a travesty that we can't".
  • 1024334440.txt Keith Briffa says of Michael Mann's notorious 'hockey stick' picture: "I have just read this letter - and I think it is crap. I am sick to death of Mann stating his reconstruction represents the tropical area just because it contains a few tropical series."  Ed Cook replies: "We both know the probable flaws in Mike's recon,"... "It is puzzling to me that a guy as bright as Mike would be so unwilling to evaluate his own work a bit more objectively."
  • 1188557698.txt Tom Wigley acknowledges that Doug Keenan, who accuses a Jones co-author of fraud, "has a valid point. The statements in the papers  that he quotes seem to be incorrect statements, and that someone must have known at the time that they were incorrect."
  • 1255553034.txt Tom Wigley tells Michael Mann that a graph of his is "very deceptive" and says "In my (perhaps too harsh) view, there have been a number of dishonest presentations of model results by individual authors and by IPCC".
  • 1254756944.txt Wigley says to Jones "Keith does seem to have got himself into a mess  ...  how does Keith explain the McIntyre plot that compares Yamal-12 with Yamal-all? And how does he explain the apparent "selection" of the less well-replicated chronology rather that the later (better replicated) chronology?".
The Soon & Baliunas story:
In 2003, Soon and Baliunas published a review paper in the journal Climate Research, listing papers that gave evidence for the existence of the Medieval Warm Period and Little Ice Age.
  • 1047485263.txt In a sequence of emails, the climate scientists discuss their response to the Soon and Baliunas paper.  Despite words such as "junk" and "appalling", they are unable to identify anything actually wrong with the paper. Jones says "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.  A CRU person is on the editorial board, but papers get dealt with by the editor assigned by Hans von Storch."
  • 1051190249.txt Tom Wigley in an email to Mike Hulme and Phil Jones writes "Mike's idea to get editorial board members to resign will probably not work -- must get rid of von Storch too". (von Storch did later resign as editor of Climate Research).
  • 1057944829.txt An email from Chris De Freitas, editor of Climate Research,  talks about the Soon and Baliunas 2003 paper, responding to criticism from Mike Hulme regarding his role.  He says that the paper had 4 referees who made comments but none recommended rejection.  He points out that the paper is really just a literature review, and asks specifically if they can find any papers that S&B mischaracterized. Hulme and Phil Jones have no answer to this simple question.
  • 1057941657.txt Otto Kinne, from the organisation IRSC that published the journal, confirms that he has consulted the reviews of the S&B paper and that de Freitas acted correctly as editor.   In response, Michael Mann calls Kinne "disingenuous" and Tom Wigley accuses him of being a "de Freitas clone".  Phil Jones concludes "Seems like we are now the bad guys".

The affair became known as "climategate" and reflected particularly badly on Professor Phil Jones, head of CRU.  Jones was forced to stand down pending the outcome of an investigation headed by Sir Muir Russell.  Michael Mann is also under investigation by his University, Penn State.  The authenticity of the emails is not in doubt, several recipients having confirmed their accuracy.

Climategate links

Searchable list of the emails
Another searchable source of the emails
List of the emails in chronological order
Bishop Hill's summary of some of the emails
John Costella's analysis and excerpts, colour coded by author
Michael Kelly's detailed and entertaining report
David Pratt's climategate report
David Pannell's 3-part discussion

Climategate books

Climategate: The CRUtape letters, Steven Mosher and Thomas Fuller, 2010.


1. The suggestion that the file was being prepared as a response to a FOI request is no longer tenable.  The "Independent" review into the climategate emails published a list of all FOI requests relating CRU received since 2005. There was no request in that list that could possibly fit with the November 2009 file. Furthermore, the suggestion of CRU carefully compiling the dossier is absurd in view of the attitude of Jones to FOI illustrated in the emails shown above. Finally, the climategate release included all sort of things, such as a satirical cartoon of sceptical scientists marooned on an island, and it is hard to imagine a FOI request that would lead to that being included in the dossier.

2. A second release of emails occurred two years later on 22 November 2011.

3. More information was released on March 13 2013 ("Climategate 3").