Memorandum submitted by Peabody Energy Company (CRU 52)




1. Peabody is the world's largest private sector coal company.

The Attempt to Present a "Nice Tidy Story" of Unprecedented 20th Century Warmth

2. The CRU emails, however, reveal that the authors of this material did not present a neutral view of the science. In particular, they downplayed the considerable uncertainty inherent in trying to approximate temperatures from proxy data over a 1000-year period, they suppressed contrary information, and they suppressed dissenting views in ways that made even their own colleagues uncomfortable. Thus, in one representative email written during the preparation of the TAR, Keith Briffa stated that "I know there is pressure to present a nice tidy story as regards 'apparent unprecedented warming in a thousand years or more in the proxy data' but in reality the situation is not quite so simple."[1] He went on to say that "I believe that the recent warmth was probably matched about 1000 years ago."[2] Similarly, another key researcher, Ed Cook, in a lengthy email bristling at the effort to eliminate the MWP, wrote that "I do find the dismissal of the Medieval Warm Period as a meaningful global event to be grossly premature and probably wrong."[3]

3. These concerns, however, were brushed aside in the final TAR. The TAR's version of the temperature record of the last 1000 years was based on the now infamous "hockey stick" study of Mann et al., a study that purported to show 1000 years of slightly declining global temperatures followed by a sharp increase in the 20th century. The hockey stick paper concluded that the 1990s were the warmest decade and 1998 was the warmest year in a millennium. The hockey stick graph was the single most important piece of information in the TAR. It was Figure 1 of the Summary For Policymakers of the TAR appearing on page 3, and it was widely relied on by advocates.[4]

4. Despite its prominence in the TAR, the hockey stick has now largely been discredited, with both the National Research Council ("NRC")[5] and the independent Wegman Report[6] rejecting confidence in the conclusion that the 1990s were the warmest decade and 1998 was the warmest year in a millennium. Although the hockey stick paper was cited in AR4, its significance was downplayed, and EPA did not cite the paper in the Endangerment Finding or TSD.

5. However, the same people who gave that paper such prominence in the TAR - despite the misgivings expressed internally within the group - continued to dominate paleoclimate research and were again the leading authors of the AR4 paleoclimate material. Indeed, perhaps stung by criticisms of the hockey stick and by the appearance of so-called "skeptics" who questioned the central conclusions of the TAR, the drafting of at least the paleoclimate chapter of AR4 became more of a political than a scientific process.[7]

6. Thus, the two coordinating lead authors of Chapter 6 of AR4, Jonathan Overpeck of the University of Arizona and Eystein Jansen of the University of Bergen in Norway, openly coached contributors to produce materials that would serve a public policy agenda. As just a few examples, the CRU emails show that Overpeck instructed his colleagues to make sure that text was "FOCUSED on only that science which is policy relevant" and that would support pre-conceived summary bullet points.[8] The pair also advised authors to include graphics that would be "compelling" and that the "sign of ultimate success" of a graphic would be that it was so compelling that it would be selected for use in the policymaker's summary.[9] They told authors to "pls DO please try hard to follow up on my advice" to only refer to the MWP and the Holocene Thermal Maximum in a "dismissive" way.[10] They expressed satisfaction with a graphic that described the MWP as heterogeneous - meaning that warming was not uniform on a planetary scale - not because it was accurate but because it read "much like a big hammer," driving home the point they wished to make.[11] Moreover, although the hockey stick could no longer be relied on as a principal source of authority, authors were instructed that "[w]e're hoping you guys can generate something compelling enough" for the summary material for policymakers, "something that will replace the hockey-stick with something even more compelling."[12] Yet new research that reexamined the data on which the IPCC relied has challenged the IPCC's dismissal of the MWP as non-heterogeneous, concluding that the IPCC's conclusion in this regard was, at least, "premature" and based on limited data.[13]

7. The examples of this type of behavior abound.

The "Trick" to "Hide the Warming"

8. Much attention has been placed on Jones' now-famous email in which he stated that "I've just completed Mike's Nature trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) amd from 1961 for Keith's to hide the decline."[14] The trick he and Mann performed was to hide a decline in temperatures appearing in tree ring data in the latter part of the 20th century. Unless this trick were used, their multi-century proxy temperature reconstructions would show an embarrassing decline in temperatures at the end of the reconstruction, a decline that was not paralleled in the record of directly measured temperatures, which showed an increase. To hide the decline in the proxy data, Mann and then Jones grafted on actual temperature data to the end of their proxy reconstructions rather than using the same proxy data as had been used throughout the reconstruction.

9. This trick makes the graphic presentations of the proxy reconstructions misleading, since the effect is to make it seem as if the proxy data shows rising 20th century warming when it doesn't. But the real deception in the trick was in hiding what became known as the "divergence" problem. The accuracy of tree ring data as proxies for temperatures can only be confirmed by comparing the proxy temperatures yielded by the tree rings with temperatures directly measured during the period when direct temperature measurements could be made. If the proxy data are contradicted by actual data, as they are for a significant period of the time when direct temperature measurements exist, the accuracy of the proxy data over the entire period of the proxy reconstruction is called into question. Thus, the divergence problem undermined faith in the ability of the proxy reconstructions to provide conclusive or even meaningful information about paleoclimate temperature conditions, even as the IPCC was relying on these reconstructions to conclude that temperatures in the 20th century had reached unprecedented levels in the last 1000 years. As one email candidly said, "[t]he issue of why we dont show the proxy data for the last few decades (they dont show continued warming) but assume that they are valid for early warm periods needs to be explained."[15] These concerns, however, were given short shrift. Although divergence was discussed in AR4, the conclusion was reached that the results of the proxy temperature reconstructions remained valid and showed that 20th century warmth was likely unprecedented in 1000 years. If divergence was not a significant issue, however, one wonders why it was necessary to perform "tricks" to hide the problem.[16]

10. More importantly, after AR4 was issued, at least three studies have been published reanalyzing the data used in the proxy reconstructions cited in AR4, including two by authors whose reconstructions were used in AR4. These studies concluded that, in fact, the divergence problem makes the reconstructions unreliable.[17] According to one study, the divergence problem "serve(s) to impede a robust comparison of recent warming during the anthropogenic period with past natural climate episodes such as the Medieval Warm Period or MWP."[18] Another study found that the divergence problem makes it "impossible to make any statements about how warm recent decades are compared to historical periods."[19] Another concluded that the divergence problem "is of importance, as it limits the suitability of tree-ring data to reconstruct long-term climate fluctuations, particularly during periods that might have been as warm or even warmer than the late twentieth century."[20]

11. It would seem, therefore, that the IPCC should have been more cautious in dismissing the divergence problem. It would also seem that the IPCC may have understood that there was something to hide after all.

What to Make of the Current 11-Year Trend of No Warming?

12. According to temperature data on which both EPA and the IPCC rely, the earth has experienced no warming over an 11-year period.[21]

13. EPA stated that warming caused by anthropogenic GHG emissions will not necessarily be uniform but instead could be muted by natural forces for a period of a decade or two. In particular, EPA cited two recent studies that attempted to show that the GHG models on which the IPCC, and therefore EPA, relied show sufficient natural variability to accommodate periods of no warming.[22]

14. Each of these studies has flaws discussed in the body of the Petition that result in an overstating of the likelihood that the models can account for the lack of warming. But even taken at face value, these studies should provide little comfort to EPA. One of the studies found that during the first half of the 21st century, there is a 1 in 10 chance of a zero (or negative) trend in temperatures through 10 years of data. The other study found that for the entire 21st century there is a five percent chance of a zero (or negative) trend through 11 years of data. Given these very low odds, and given that this trend occurred in the first decade of the 21st century and we have already experienced an 11-year trend of no warming, these studies hardly provide reassuring support for the underlying accuracy of the models' long-term predictive capacity.[23]

15. Adding to the questions about the accuracy of climate models are new results that show water vapor variations in the lower stratosphere play a large role in the variability global temperature trends over scales of several decades-influencing recent trends by some 25% to 30%. The physics governing lower stratospheric water vapor content are quite limited in current climate models, and the observed trends are poorly simulated.[24]

16. In fact, the CRU emails reveal that the lack of warming has caused leading IPCC scientists to question the assumed physical understanding of the climate system on which the models are based. Just last fall, even after the studies that EPA relied on had been produced, Trenberth conceded that the lack of warming exposes science's basic lack of understanding of the climate system: "Saying it is natural variability is not an explanation. What are the physical processes? Where did the heat go?"[25] Trenberth concluded that either the understanding of the climate system reflected in the climate models is wrong:

How come you do not agree with a statement that says we are no where close to knowing where energy is going or whether clouds are changing to make the planet brighter. We are not close to balancing the energy budget. The fact that we can not account for what is happening in the climate system makes any consideration of geoengineering quite hopeless as we will never be able to tell if it is successful or not! It is a travesty![26]


17. Or else the data is wrong:


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. The CERES data published in the August BAMS 09 supplement on 2008 shows there should be even more warming: but the data are surely wrong. Our observing system is inadequate.[27]


18. Or perhaps both. It is, moreover, particularly relevant that Trenberth stated that "[t]he fact that we can not account for what is happening in the climate system makes any consideration of geoengineering quite hopeless as we will never be able to tell if it is successful or not!" Trenberth's reference to "geoengineering" here includes reducing GHG emissions.[28] In other words, Trenberth stated that the flaws in the climate community's understanding of climatic forces that are exposed by the lack of warming is so fundamental - and the extent of natural variability must be so great - that it cannot be demonstrated that reducing GHG emissions will reduce warming.


Abject Lack of Transparency

19. The CRU materials also show a determined effort to stonewall attempts by third parties to obtain basic information underlying the scientific studies that were used in the IPCC reports. A considerable volume of transatlantic email traffic between the CRU scientists and their American counterparts was devoted to figuring out strategies to avoid producing information that could be used to critique their work, even when the information was requested under the American or United Kingdom Freedom of Information Acts ("FOIA").[29]

20. The emails reveal that these scientists refused to disclose information that would allow their studies to be replicated and critiqued because they saw themselves in a battle with "skeptics" who they considered to be "bozos" and "morons" and perpetrators of fraud.[30] They appeared to be particularly concerned that putting their information in the public domain would expose their work to criticism. As Jones said in one now-famous email, "We have 25 years or so invested in the work. Why should I make the data available to you, when your aim is to try and find something wrong with it?"[31] Jones' view was echoed by Mann. As Jones reported, "Mike Mann refuses to talk to these people and I can understand why. They are just trying to find if we've done anything wrong."[32]

21. Indeed, concern over communications these scientists had had concerning the drafting of AR4 was so great that they mutually agreed to destroy those communications in order to avoid disclosure under FOIA. Thus, on May 29, 2008, Jones sent an email to Mann under the subject line "IPCC & FOI," asking that Mann delete his emails with Briffa and advising that he would make the same request to Eugene Wahl and Caspar Amman. Wahl and Amman co-authored a paper that attempted to rehabilitate the hockey stick. As shown in the Petition, publication deadlines were improperly manipulated in order to include the paper in AR4.[33] Jones wrote:

Can you delete any emails you may have had with Keith re AR4? Keith will do likewise. He's not in at the moment - minor family crisis. Can you also email Gene and get him to do the same? I don't have his new email address. We will be getting Caspar to do likewise.[34]


22. Later in the same thread, Mann responded to Jones that he would "contact Gene about this ASAP."[35] Several months later Jones reported that he had in fact "deleted loads of emails."[36] One is forced to wonder what damaging admissions were made in these now-deleted emails concerning how AR4, in fact, was prepared.

23. After the efforts of these scientists to stonewall data requests were exposed to public scrutiny through FOIA and now through release of the CRU material, many of them were forced to admit that their actions were not in the best interests of science. Wigley told Briffa that "many *good* scientists appear to be unsympathetic" to the reasons advanced for the stonewalling.[37] Overpeck wrote in relation to one information request that "it would be nice if he could have access to all the data that we used-that's the way science is supposed to work."[38] And now John Beddington, the British government chief scientific adviser, has recently said, "I think, wherever possible, we should try to ensure there is openness and that source material is available for the whole scientific community."[39]

Publication Abuses

24. The CRU scientists and their American colleagues engaged in a variety of practices to manipulate the peer-reviewed literature to favor publication of papers that supported their views and to discourage publication of papers that contradicted their views. As Mann told a New York Times reporter, "[a] necessary though not in general sufficient condition for taking a scientific criticism seriously is that it has passed through the legitimate scientific peer review process."[40] That being the case, these scientists took steps to ensure that "skeptics" did not have access to peer-reviewed literature.[41]

25. For instance, enraged that the journal Climate Research had published a paper presenting evidence that the MWP was global and as warm as today, these scientists discussed organizing a boycott to strong-arm the journal board into firing the offending editor. Jones wrote that the journal needed to "rid themselves of this troublesome editor."[42] Wholesale changes ensued at the journal.[43] Similar action was taken at Geophysical Research Letters after publication of an offending letter. Mann reported back to his colleagues that the problem had been solved: "[t]he GRL leak has been plugged up with new editorial leadership there,"[44] as if the appearance of a paper that did not support their view of the science was a "leak" in the peer-reviewed journalistic community that had to be "plugged."[45]


26. Dr. Briffa had it exactly right when he reported to his colleagues that "the needs of the science and the IPCC" "were not always the same." In fact, the IPCC process has been revealed to be as much about advocacy as about science. And the CRU material is only one thin slice of information concerning the drafting of the TAR and AR4. It seems that every day new revelations appear about flaws in the accuracy of the IPCC's conclusions and in the process that was used to select information that would, and would not, be included in the reports.


Peabody Energy Company

February 2010

[1] CRU email 938018124.txt (Sep. 22, 1999) (emphasis added).

[2] Id.

[3] CRU email 988831541.txt (May 2, 2001) (emphasis added).

[4] See discussion in our Petition of this matter at section IV(C)(3).

[5] National Research Council, Surface Temperature Reconstructions for the Last 2,000 Years (National Academy Press 2006) ("NRC Report").

[6] Edward Wegman et al. Ad Hoc Report on the "Hockey Stick" Global Climate Reconstruction. ("Wegman Report") (July 27, 2006) available at /07142006_ Wegman_Report.pdf.

[7] This matter is discussed more fully in our Petition at section IV(C)(1)(c).

[8] CRU email 1121392136.txt (Jul. 14, 2005) (capitals in original) (emphasis added).

[9] Id.

[10] CRU email 1105670738.txt (Jan. 13, 2005).

[11] CRU email 1105978592.txt (Jan. 17, 2005).

[12] CRU email 1116902771.txt (May 23, 2005).

[13] Jan Esper and David Frank, The IPCC on a heterogeneous Medieval Warm Period, 94 Clim. Chng. 267-272 (2009).

[14] CRU email 942777075.txt (Nov. 16, 1999).

[15] CRU email 1150923423.txt (Jun. 21, 2006).

[16] The "trick" and the divergence issue is discussed more fully in our Petition at section IV (C)(2).

[17] These studies are discussed in our Petition at section IV (C)(2)(d).

[18] Rosanne D'Arrigo, et al., On the 'divergence problem' in northern forests: a review of the tree-ring evidence and possible causes, 60 Glob. Planet. Chng. 289 (2008).

[19] Craig Loehle, A mathematical analysis of the divergence problem in dendroclimatology, 94 Clim. Chng. 233 (2009).

[20] Jan Esper and David Frank, Divergence pitfalls in tree-ring research, 94 Clim. Chng. 261, 262 (2009).

[21] Resp. to Comm. Vol. 3 at 3.

[22] Resp. to Comm. Vol. 4 at 23-24.

[23] These studies are discussed more fully in our Petition at section V(B).

[24] Susan Solomon et al., 2010.  Contribution of Stratospheric Water Vapor to Decadal Changes in the Rate of Global Warming.  Sci (forthcoming 2010) published online at 1182488v1.pdf

[25] CRU email 1255523796.txt (Oct. 14, 2009) (emphasis added).

[26] Id. (emphasis added).

[27] Id. (emphasis added).

[28] Trenberth has publicly (and recently) referred to attempts to "reduce emissions... or reduce the amount of carbon dioxide in the atmosphere" as "geoengineering." See Physics Today letter 2/09, at Trenberth/trenberth.papers/GeoengineeringPhsToday.pdf.

[29] This issue is discussed more fully in our Petition at section VI (C).

[30] CRU email 1146062963.txt (Apr. 26, 2006); CRU email 1147435800.txt (May 12, 2006); CRU email 1107899057.txt. (Feb. 8, 2005).

[31] Email provided by Warwick Hughes to whom the email was sent.

[32] CRU email 1091798809.txt (Aug. 6, 2004) (emphasis added).

[33] See the Petition at section VII (D).

[34] CRU email 1212073451.txt (May 29, 2008) (emphasis added).

[35] CRU email 1212063122.txt (May 29, 2008).

[36] CRU email 1228412429.txt (Dec. 3, 2008) (emphasis added).

[37] CRU email 1254756944.txt (October 5, 2009).

[38] CRU email 1252164302.txt (Sept. 5, 2009) (emphasis added).

[39] As quoted in Ben Webster, Britain's chief scientist John Beddington calls for engagement with climate skeptics, The Times, Jan. 27, 2010, available at

[40] CRU email 1254259645.txt (Sep. 29, 2009) (emphasis added).

[41] This issue is discussed more fully in our Petition at section VIII(A).

[42] CRU email 1047388489.txt (Mar. 11, 2003).

[43] The threats to boycott the Journal of Climate Research are discussed in our Petition at section VIII(A).

[44] CRU email 1132094873.txt (Nov. 15, 2005).

[45] The Geophysical Research Letters matter is discussed more fully in our Petition at VIII(A).