cc: Stephen Schneider , Gavin Schmidt , Stefan Rahmstorf , Phil Jones , Tim Osborn , Andy Revkin , Henry Pollack , Gabi Hegerl , Benjamin Santer , Richard Littlemore date: Fri, 23 Oct 2009 14:15:12 -0400 from: Michael Mann subject: Re: From the Wall Street Journal: to: Anne Jolis , Joe Romm , Media Matters Erikka Knuti , DarkSydOTheMoon@aol.com, Dan Vergano , Bud Ward , george@monbiot.info, AJ Walzer , "Paul D. Thacker" , Chris Mooney Dear Anne, I will respond to these briefly. please see below. Will now be incommunicado through early next week, so this will have to do. best, Mike Mann On Oct 23, 2009, at 1:12 PM, Jolis, Anne wrote: Dear Dr. Mann, I realize you've taken that liberty. I've just sent them all an email as well inviting them to weigh in (though I've already spoken with Dr. Schneider) - great minds think alike! I take it that you decline to comment on the two questions I've just resubmitted to you: -How would you respond to the critique that, as a key part of the review processes of publications in the field of climate science, as something of a "gatekeeper," you have rejected and otherwise sought to suppress work that contradicted your work. Is this fair? Why or why not? How would you characterize your selection process for work that is or is not worthy of publication? I won't dignify that question with a response, other than to say that it betrays a deep naivety about how the peer review process in science works, and it buys into what I consider to be rather offensive conspiracy theories that impugn the integrity of editors, reviewers in general, and myself in particular. -Do you have a response to work published in 2005 by Hans von Storch that seems to indicate that the predictive capabilities of the method you used in your original "hockey stick" graph (which I do realize did not use the Yamal data) would not be able to predict current temperatures? You seem to be unaware of the fact that there were two serious rebuttals (by Rahmstorf and by Ritson et al) of the Von Storch claims published subsequently in Science See the summaries here: [1]http://www.realclimate.org/index.php/archives/2006/04/a-correction-with-repercussions/ [2]http://www.realclimate.org/index.php/archives/2006/04/addendum-to-a-mistake-with-repercu ssions/ see also what the most recent IPCC report had to say about the hockey stick criticisms: [3]http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter6.pdf First, with respect to the McIntyre criticisms so often touted by contrarian disinformation outlets: "The hockey stick reconstruction of Mann et al. (1999) has been the subject of several critical studies. Soon and Baliunas (2003) challenged the conclusion that the 20th century was the warmest at a hemispheric average scale. They surveyed regionally diverse proxy climate data, noting evidence for relatively warm (or cold), or alternatively dry (or wet) conditions occurring at any time within pre-defined periods assumed to bracket the so-called Medieval Warm Period (and Little Ice Age). Their qualitative approach precluded any quantitative summary of the evidence at precise times, limiting the value of their review as a basis for comparison of the relative magnitude of mean hemispheric 20th-century warmth (Mann and Jones, 2003; Osborn and Briffa, 2006). Box 6.4 provides more information on the Medieval Warm Period. McIntyre and McKitrick (2003) reported that they were unable to replicate the results of Mann et al. (1998). Wahl and Ammann (2007) showed that this was a consequence of differences in the way McIntyre and McKitrick (2003) had implemented the method of Mann et al. (1998) and that the original reconstruction could be closely duplicated using the original proxy data. McIntyre and McKitrick (2005a,b) raised further concerns about the details of the Mann et al. (1998) method, principally relating to the independent verification of the reconstruction against 19th-century instrumental temperature data and to the extraction of the dominant modes of variability present in a network of western North American tree ring chronologies, using Principal Components Analysis. The latter may have some theoretical foundation, but Wahl and Amman (2006) also show that the impact on the amplitude of the final reconstruction is very small (~0.05°C; for further discussion of these issues see also Huybers, 2005; McIntyre and McKitrick, 2005c,d; von Storch and Zorita, 2005)." Second, with regard to the Von Storch claims. The IPCC assessment was published prior to the publication of the two Science refutations of the Von Storch et al paper noted above, and thus were unable to assess the most serious criticisms of that work. But even at that point, the IPCC noted some serious caveats about that work, and stressed that even if the criticisms were valid (which they have been shown not to be), they would not call into question the key conclusions regarding the anomalous nature of recent warmth in a millennial+ context: Using pseudo-proxy networks extracted from GCM simulations of global climate for the last millennium, von Storch et al. (2004) suggested that temperature reconstructions may not fully represent variance on long time scales. This would represent a bias, as distinct from the random error represented by published reconstruction uncertainty ranges. At present, the extent of any such biases in specific reconstructions and as indicated by pseudo-proxy studies is uncertain (being dependent on the choice of statistical regression model and climate model simulation used to provide the pseudo-proxies). It is very unlikely, however, that any bias would be as large as the factor of two suggested by von Storch et al. (2004) with regard to the reconstruction by Mann et al. (1998), as discussed by Burger and Cubash (2005) and Wahl et al. (2006). However, the bias will depend on the degree to which past climate departs from the range of temperatures encompassed within the calibration period data (Mann et al., 2005b; Osborn and Briffa, 2006) and on the proportions of temperature variability occurring on short and long time scales (Osborn and Briffa, 2004). In any case, this bias would act to damp the amplitude of reconstructed departures that are further from the calibration period mean, so that temperatures during cooler periods may have been colder than estimated by some reconstructions, while periods with comparable temperatures (e.g., possible portions of the period between AD 950 and 1150, Figure 6.10) would be largely unbiased. As only one reconstruction (Moberg et al., 2005) shows an early period that is noticeably warmer than the mean for the calibration period, the possibility of a bias does not affect the general conclusion about the relative warmth of the 20th century based on these data. Finally, the summary of the current state of knowledge regarding the anomalous nature of recent warming, by the IPCC: The weight of current multi-proxy evidence, therefore, suggests greater 20th-century warmth, in comparison with temperature levels of the previous 400 years, than was shown in the TAR. On the evidence of the previous and four new reconstructions that reach back more than 1 kyr, it is likely that the 20th century was the warmest in at least the past 1.3 kyr. Considering the recent instrumental and longer proxy evidence together, it is very likely that average NH temperatures during the second half of the 20th century were higher than for any other 50-year period in the last 500 years. Best, Anne ______________________________________________________________________________________ From: Michael Mann [[4]mailto:mann@meteo.psu.edu] Sent: 23 October 2009 18:07 To: Jolis, Anne; Joe Romm; Media Matters Erikka Knuti; [5]DarkSydOTheMoon@aol.com; Dan Vergano; Bud Ward; [6]george@monbiot.info; AJ Walzer; Paul D. Thacker; Chris Mooney Cc: Stephen Schneider; Gavin Schmidt; Stefan Rahmstorf; Phil Jones; Tim Osborn; Andy Revkin; Henry Pollack; Gabi Hegerl; Benjamin Santer; Richard Littlemore Subject: Re: From the Wall Street Journal: Ms. Jolis, I've taken the liberty of copying this exchange to a few others who might be interested in it, within the broader context of issues related to the history of biased reporting on climate change at the Wall Street Journal Europe, Yours, Mike Mann On Oct 23, 2009, at 12:42 PM, Michael Mann wrote: Ms. Jolis, I am traveling through this weekend and have only brief email access, so can only respond w/ a very short email to your inquiry. I'm sad to report that the tone of your questions suggests a highly distorted, contrarian-driven view of the entirety of our science. The premise of essentially everyone of your questions is wrong, and is contradicted by assessments such as the IPCC report, reports by the U.S. National Academy of Sciences, etc. The National Academy of Science report (more info below) reported in 2006 that "The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence...". The conclusions in the most recent 2007 IPCC Fourth Assessment report have been significantly strengthened relative to what was originally concluded in our work from the 1990s or in the IPCC 2001 Third Assessment Report, something that of course should have been expected given the numerous additional studies that have since been done that all point in the same direction. The conclusion that large-scale recent warmth likely exceeds the range seen in past centuries has been extended from the past 1000 years in the TAR, to the past 1300 years in the current report, and the confidence in this conclusion has been upped from likely in the Third Assessment Report to very likely in the current report for the past half millennium. Since then, the conclusions have been further strengthened by other work, including work by us. Please see e.g. the reporting by the BBC: [7]http://news.bbc.co.uk/2/hi/8236797.stm [8]http://news.bbc.co.uk/2/hi/7592575.stm You don't seem to be aware of the fact that our original "Hockey Stick" reconstruction didn't even use the "Yamal" data. It seems you have uncritically accepted nearly every specious contrarian claim and innuendo against me, my colleagues, and the science of climate change itself. Furthermore, I doubt that the various authors you cite as critics, such as Pollack and Smerdon, would in any way agree w/ your assessment of this work. Misrepresenting the work of scientists is a serious offense, and would work to further besmirch the reputation of the Wall Street Journal, which is strongly been called into question in the past with regard to the treatment of climate change. I've copied my response to a number of others who might wish to comment further, as I will be unavailable to speak with you until next week. I've pasted below various summaries by mainstream news venues which reported a couple years ago that the National Academy of Sciences, in the words of Nature "Affirmed The Hockey Stick" below this message. In addition, here are a few links you might want to read to better familiarize yourself with what the science actually states with regard to the issues raised in your inquiry below: [9]http://www.realclimate.org/index.php/archives/2009/09/hey-ya-mal/ [10]http://www.realclimate.org/index.php/archives/2007/02/the-ipcc-fourth-assessment-summar y-for-policy-makers/ [11]http://www.realclimate.org/index.php/archives/2006/06/national-academies-synthesis-repo rt/ [12]http://www.realclimate.org/index.php/archives/2005/10/hockey-sticks-round-27/ [13]http://www.realclimate.org/index.php/archives/2005/05/new-analysis-reproduces-graph-of- late-20th-century-temperature-rise/ [14]http://www.realclimate.org/index.php/archives/2005/02/dummies-guide-to-the-latest-hocke y-stick-controversy/ [15]http://www.realclimate.org/index.php/archives/2006/02/a-new-take-on-an-old-millennium/ Finally, let me suggest, under the assumption that your intent is indeed to report the reality of our current scientific understanding, rather than contrarian politically-motivated spin, that any legitimate journalistic inquiry into the current state of the science, and the extent to which uncertainties and controversy have been overstated and misrepresented in the public discourse, would probably choose to focus on the issues raised here: [16]http://www.realclimate.org/index.php/archives/2009/10/climate-cover-up-a-brief-review/ Yours, Mike Mann ___________________NEWS CLIPS ON ACADEMY REPORT_____________________ from BBC (6/23/06 "Backing for 'Hockey Stick' graph") The Earth was hotter in the late 20th Century than it had been in the last 400 or possibly 1,000 years, a report requested by the US Congress concludes. It backs some of the key findings of the original study that gave rise to the iconic "hockey stick" graph.) from New York Times (Andy Revkin, 6/22/06 "Science Panel Packs Study on Warming Climate"): At a news conference at the headquarters of the National Academies, several members of the panel reviewing the study said they saw no sign that its authors had intentionally chosen data sets or methods to get a desired result. "I saw nothing that spoke to me of any manipulation," said one member, Peter Bloomfield, a statistics professor at [17]North Carolina State University. He added that his impression was the study was "an honest attempt to construct a data analysis procedure. Boston Globe (Beth Daley, 6/22/06 "Report backs global warming claims"): Our conclusion is that this recent period of warming is likely the warmest in a (millennium), said John Wallace, one of the 12 members on the panel and professor of atmospheric science at the University of Washington. Los Angeles Times (Thomas H. Maugh II and Karen Kaplan, "U.S. Panel Backs Data on Global Warming"): After a comprehensive review of climate change data, the nation's preeminent scientific body found that average temperatures on Earth had risen by about 1 degree over the last century, a development that "is unprecedented for the last 400 years and potentially the last several millennia." and The panel affirmed that proxy measurements made over the last 150 years correlated well with actual measurements during that period, lending credence to the proxy data for earlier times. It concluded that, "with a high level of confidence," global temperatures during the last century were higher than at any time since 1600. Although the report did not place numerical values on that confidence level, committee member and statistician Peter Bloomfield of North Carolina State University said the panel was about 95% sure of the conclusion. The committee supported Mann's other conclusions, but said they were not as definitive. For example, the report said the panel was "less confident" that the 20th century was the warmest century since 1000, largely because of the scarcity of data from before 1600. Bloomfield said the committee was about 67% confident of the validity of that finding the same degree of confidence Mann and his colleagues had placed in their initial report. Associated Press (syndicate with 100s of newspapers accross the U.S. (John Heilprin, 6/22/06 "The Earth is the hottest it has been in at least 400 years, perhaps even longer"): The National Academy scientists concluded that the Mann-Bradley-Hughes research from the late 1990s was "likely" to be true, said John "Mike" Wallace, an atmospheric sciences professor at the University of Washington and a panel member. The conclusions from the '90s research "are very close to being right" and are supported by even more recent data, Wallace said. and Overall, the panel agreed that the warming in the last few decades of the 20th century was unprecedented over the last 1,000 years, though relatively warm conditions persisted around the year 1000, followed by a "Little Ice Age" from about 1500 to 1850. Washington Post (Juliet Eilperin, 6/23/06 "Study Confirms Past Few Decades Warmest on Record"): Panel member Kurt M. Cuffey, a geography professor at the University of California at Berkeley, said at a news briefing that the report "essentially validated" the conclusions Mann reported in 1998 and 1999 using temperature records. The panel also estimated there is a roughly 67 percent chance that Mann is right in saying the past 25 years were the warmest in a 1,000 years. Nature (Geoff Brumfield, 6/28/06 "Academy affirms hockey-stick graph") "We roughly agree with the substance of their findings," says Gerald North, the committee's chair and a climate scientist at Texas A&M University in College Station. In particular, he says, the committee has a "high level of confidence" that the second half of the twentieth century was warmer than any other period in the past four centuries. But, he adds, claims for the earlier period covered by the study, from AD 900 to 1600, are less certain. This earlier period is particularly important because global-warming sceptics claim that the current warming trend is a rebound from a 'little ice age' around 1600. Overall, the committee thought the temperature reconstructions from that era had only a two-to-one chance of being right. and says Peter Bloomfield, a statistician at North Carolina State University in Raleigh, who was involved in the latest report. "This study was the first of its kind, and they had to make choices at various stages about how the data were processed," he says, adding that he "would not be embarrassed" to have been involved in the work. New Scientist (Roxanne Khamsi, 6/23/06, "US report backs study on global warming"): It was really the first analysis of its type, panel member Kurt Cuffey of the University of California, Berkeley, US, said at a news conference on Thursday. He added that it was the first time anyone has done such a large-scale and continual analysis of temperature over time. So its not surprising that they could have probably done some detailed aspects of it better. But it was a remarkable contribution and gave birth to a debate thats ongoing, thats teaching us a lot about how climate has changed. Science (Richard Kerr, June 30, 2006, "Yes, Its been Getting Warmer in Here Since the CO2 Begain to Rise"): In addition, none of the three committee members at the press briefing--North, Bloomfield, and paleoclimatologist Kurt Cuffey of the University of California, Berkeley--had found any hint of scientific impropriety. "I certainly did not see anything inappropriate," said North. "Maybe things could have been done better, but after all, it was the first analysis of its kind." -- On Oct 23, 2009, at 10:41 AM, Jolis, Anne wrote: Dear Dr. Mann, My name is Anne Jolis, and I'm with the Wall Street Journal Europe, based in London. I'm working on a piece about climate change, and specifically the growing questions that people outside the field have about the methods and processes used by climatologists and other climate-change scientists - and, necessarily, about the conclusions that result. The idea came from the recent controversy that has arisen once again over Steve McIntyre, the publication of the full Yamal data used in Keith Briffa's work. This of course raises questions among climate scientistis, and observers, about whether the so-called "hockey stick" graph of global temperatures , as produced by Dr. Briffa and originally by yourself, was drawn from narrow data which, and then when broadened to include a wider range of available dendroclimatological data, seems to show no important spike in global temperatures in the last 100 year . I realize this is not exactly the silver-bullet to anthropogenic global warming that some would like to read into it, but it seems to me that it does underscore some of the issues in climate science. Specifically, the publication of the data, and the earlier controversy over your work, seems to illustrate that best practices and reliable methods of data collection remain far from established, and that much of what is presented as scientific fact is really more of a value judgment based on select data. Would you agree? I'd love to get some insight from you for my article. I'll be filing this weekend, but I can call you any time it's convenient for you on Friday - just let me know the best time and number. Please note that if we do speak on the phone, I will email you with any quotes or paraphrases that I would like to attribute to you, before publication, so as to secure your approval and confirm the accuracy of what I'm attributing to you. Additionally, if you'd like to correspond via email, that's fine too. I've listed below some of the questions and assumptions I'm working on - if, in lieu of a phone call, you'd like to answer and/or respond to these, as well as share any other thoughts you have on these issues, I'd be most grateful. Feel welcome to reply at length! I thank you in advance for your time and attention, and look forward to any of your comments. All the best, Anne Jolis Mobile: +44 799 079 3569 - Given that methods in climate science are still being refined, do you agree with policy makers' and advocates' use of data such as your own? Do you feel it is accurately represented to laymans, and that the inherent uncertainties present in the data are appropriately underscored? As a citizen, do you feel there is enough certainty in the conclusions of, for instance, the latest IPCC report, to introduce new economic regulations? Why or why not? -What methods do you feel are the most accurate for predicting future climate change, for evaluatinag the causes of climate change and for predicting whether or what man can do to try to control or mitigate climate change in the future in the future? Why do you feel these methods are the most accurate? Do you feel they're given enough weight in the current debate? -What is your opinion of the value of Steve McIntyre's work? Clearly he is not a professional scientist, but do you feel there is nonetheless a place for his "auditing" in the climate science community? Why or why not? -Do you think McIntyre's work and findings are likely to change the way leading climate scientists operate? Do you think his recent campaign to get Dr. Keith Briffa to publish the Yamal data he used is likely to make climate scientists more forthcoming with their data? Do you think his work will make scientists, policymakers and advocates any more exacting about the uncertainties in their procedures, methods and conclusions when they present scientific data? -How would you respond to the critique that, as a key part of the review processes of publications in the field of climate science, as something of a "gatekeeper," you have rejected and otherwise sought to suppress work that contradicted your work. Is this fair? Why or why not? How would you characterize your selection process for work that is worthy of publication? -Do you stand by your original "hockey stick" graf, even after the publication of borehole data from Henry Pollack and Jason Smerdon that seems to contradict your conclusions? Or work published in 2005 by Hans von Storch that seems to indicate that the predictive capabilities of the method you used in your original "hockey stick" would not be able to predict current temperatures? -- Michael E. Mann Professor Director, Earth System Science Center (ESSC) Department of Meteorology Phone: (814) 863-4075 503 Walker Building FAX: (814) 865-3663 The Pennsylvania State University email: [18]mann@psu.edu University Park, PA 16802-5013 website: [19]http://www.meteo.psu.edu/~mann/Mann/index.html "Dire Predictions" book site: [20]http://www.essc.psu.edu/essc_web/news/DirePredictions/index.html -- Michael E. Mann Professor Director, Earth System Science Center (ESSC) Department of Meteorology Phone: (814) 863-4075 503 Walker Building FAX: (814) 865-3663 The Pennsylvania State University email: [21]mann@psu.edu University Park, PA 16802-5013 website: [22]http://www.meteo.psu.edu/~mann/Mann/index.html "Dire Predictions" book site: [23]http://www.essc.psu.edu/essc_web/news/DirePredictions/index.html -- Michael E. Mann Professor Director, Earth System Science Center (ESSC) Department of Meteorology Phone: (814) 863-4075 503 Walker Building FAX: (814) 865-3663 The Pennsylvania State University email: [24]mann@psu.edu University Park, PA 16802-5013 website: [25]http://www.meteo.psu.edu/~mann/Mann/index.html "Dire Predictions" book site: [26]http://www.essc.psu.edu/essc_web/news/DirePredictions/index.html