The Muir Russell final report on the Climategate emails

Posted on July 7, 2010


The Independent Climate Change E-Mails Review, July 2010

Chair:  Sir Muir Russell   Review team:  Professor Geoffrey Boulton, Professor Peter Clarke, David Eyton, Professor James Norton


1. The main findings of the Independent Climate Change E-mails Review (“the Review”) are set out in Section 1.3 below, and the main recommendations in Section 1.4. …

1.1 Introduction


2. In November 2009, approximately 1000 e-mails from the Climatic Research Unit (CRU) of the University of East Anglia (UEA) were made public without authorisation.

3. CRU is a small research unit which over the last 30 years has played an important role in the development of climate science, in particular in their work on developing global temperature trends.

4. The e-mails fuelled challenges to the work of CRU, to the reliability of climate science generally, and to the conclusions of the Intergovernmental Panel on Climate Change (IPCC). All this happened shortly before the Copenhagen Summit, and was extensively referred to there.

5. In response, the UEA commissioned two inquiries. The first led by Lord Oxburgh, into the science being undertaken at CRU, has already reported. This document is the report of the second inquiry– The Independent Climate Change E-mails Review– which examines the conduct of the scientists involved and makes recommendations to the University of East Anglia. Our inquiry addresses a number of important allegations that were made following the e-mail release.

6. The allegations relate to aspects of thebehaviou r of the CRU scientists, such as their handling and release of data, their approach to peer review, and their role in the public presentation of results.

7. The allegations also include the assertion that actions were taken to promote a particular view of climate change by improperly influencing the process of advising policy makers. Therefore we have sought to understand the significance of the roles played by those involved from CRU and of the influence they had on the relevant outcomes.

8. The Review examines the honesty, rigour and openness with which the CRU scientists have acted. It is important to note that we offer no opinion on the validity of their scientific work. Such an outcome could only come through the normal processes of scientific debate and not from the examination of e-mails or from a series of interviews about conduct.

1.2 The Review Process

9. The approach taken by the Review was to identify and investigate the allegations to which the e-mails gave rise. This reflected our reading of the emails and the comments made on them.  An online consultation was undertaken to ensure that the Team‘s initial analysis of the allegations and concerns was sound.  The method of investigation is explained in the relevant Chapters and Appendices to the report. The Review‘s evidence base is published on the website, which it intends to archive.

10. In addressing the allegations about CRU‘s impact on climate science, we sought  evidence to place these into perspective:  On handling global temperature data, we went to global primary sources and tested how data was handled.  On tree-ring temperature reconstructions, we looked at the overall picture painted in Chapter 6 of the Fourth Assessment Report of the IPCC in 2007 (AR4) and examined the influence of CRU.  On peer review, we sought independent input (from the Editor of The Lancet) on how the system works, to provide a context for our judgement.  On influencing the IPCC process, we sought advice from the Review editors on the role individual contributors can play.

11. This work provided a context in which we considered the evidence about the specific allegations made in the submissions and identified in our interviews with CRU and others.

12. Reflecting this approach, the report and conclusions are set out as follows. The heart of the report lies in Chapters 6 through 10 where the important allegations arising from the e-mail release are examined. Chapters 2 and 3 contain introductory material, 4 deals with the body of e-mails and 5 presents important contextual material. The report concludes with Chapter 11 on other governance issues.

1.3 Findings

13. 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.

14. 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.

15. 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 recognise 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.

1.3.1 Land Station Temperatures

16. On the allegation of withholding temperature data, we find that CRU was not in a position to withhold access to such data or tamper with it.  We demonstrated that any independent researcher can download station data directly from primary sources and undertake their own temperature trend analysis.

17. On the allegation of biased station selection and analysis, we find no evidence of bias. Our work indicates that analysis of global land temperature trends is robust to a range of station selections and to the use of adjusted or unadjusted data.  The level of agreement between independent analyses is such that it is highly unlikely that CRU could have acted improperly to reach a predetermined outcome.  Such action would have required collusion with multiple scientists in various independent organisations which we consider highly improbable.

18. On the allegation of withholding station identifiers we find that CRU should have made available an unambiguous list of the stations used in each of the versions of the Climatic Research Unit Land Temperature Record (CRUTEM) at the time of publication.  We find that CRU‟s responses to reasonable requests for information were unhelpful and defensive.

19. The overall implication of the allegations was to cast doubt on the extent to which CRU‟s work in this area could be trusted and should be relied upon and we find no evidence to support that implication.

1.3.2 Temperature Reconstructions from Tree Ring Analysis

20. The central implication of the allegations here is that in carrying out their work, both in the choices they made of data and the way in which it was handled, CRU scientists intended to bias the scientific conclusions towards a specific result and to set aside inconvenient evidence. More specifically, it was implied in the allegations that this should reduce the confidence ascribed to the conclusions in Chapter 6 of the IPCC 4th Report, Working Group 1 (WG1).

21. We do not find that the way that data derived from tree rings is described and presented in IPCC AR4 and shown in its Figure 6.10 is misleading.  In particular, on the question of the composition of temperature reconstructions, we found no evidence of exclusion of other published temperature reconstructions that would show a very different picture.  The general discussion of sources of uncertainty in the text is extensive, including reference to divergence.  In this respect it represented a significant advance on the IPCC Third Assessment Report (TAR).

22. On the allegation that the phenomenon of “divergence” may not have been properly taken into account when expressing the uncertainty associated with reconstructions, we are satisfied that it is not hidden and that the subject is openly and extensively discussed in the literature, including CRU papers.

23. On the allegation that the references in a specific e-mail to a „trick‟ and to „hide the decline‟ in respect of a 1999 WMO report figure show evidence of intent to paint a misleading picture, we find that, given its subsequent iconic significance (not least the use of a similar figure in the IPCC Third Assessment Report), the figure supplied for the WMO Report was misleading.  We do not find that it is misleading to curtail reconstructions at some point per se, or to splice data, but we believe that both of these procedures should have been made plain– ideally in the figure but certainly clearly described in either the caption or the text.

24. On the allegations in relation to withholding data, in particular concerning the small sample size of the tree ring data from the Yamal peninsula, CRU did not withhold the underlying raw data (having correctly directed the single request to the owners).  But it is evidently true that access to the raw data was not simple until it was archived in 2009 and that this delay can rightly be criticized on general principles.  In the interests of transparency, we believe that CRU should have ensured that the data they did not own, but on which their publications relied, was archived in a more timely way.

1.3.3 Peer Review and Editorial Policy

25. On the allegations that there was subversion of the peer review or editorial process we find no evidence to substantiate this in the three instances examined in detail.  On the basis of the independent work we commissioned (see Appendix 5) on the nature of peer review, we conclude that it is not uncommon for strongly opposed and robustly expressed positions to be taken up in heavily contested areas of science.  We take the view that such behaviour does not in general threaten the integrity of peer review or publication.

1.3.4 Misuse of IPCC Process

26. On the allegations that in two specific cases there had been a misuse by CRU scientists of the IPCC process, in presenting AR4 to the public and policy makers, we find that the allegations cannot be upheld.  In addition to taking evidence from them and checking the relevant records of the IPCC process, we have consulted the relevant IPCC review Editors.  Both the CRU scientists were part of large groups of scientists taking joint responsibility for the relevant IPCC Working Group texts, and were not in a position to determine individually the final wording and content.

1.3.5 Compliance with the Freedom of Information Act (FoIA) and the Environmental Information Regulations (EIR)

27. On the allegation that CRU does not appear to have acted in a way consistent with the spirit and intent of the FoIA or EIR, we find that there was unhelpfulness in responding to requests and evidence that e-mails might have been deleted in order to make them unavailable should a subsequent request be made for them.  University senior management should have accepted more responsibility for implementing the required processes for FoIA and EIR compliance.

1.3.6 Other Findings on Governance

28. Given the significance of the work of CRU, UEA management failed to recognise in their risk management the potential for damage to the University’s reputation fuelled by the controversy over data access.

1.4 Recommendations

29. Our main recommendations for UEA are as follows:

  • Risk management processes should be directed to ensuring top management engagement in areas which have the potential to impact the reputation of the university.
  • Compliance with FoIA/EIR is the responsibility of UEA faculty leadership and ultimately the Vice-Chancellor.  Where there is an organisation and documented system in place to handle information requests, this needs to be owned, supported and reinforced by University leadership.
  • CRU should make available sufficient information, concurrent with any publications, to enable others to replicate their results.


This is only the executive summary.  The full report may be found at: