Michael E. Mann

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Michael E. Mann
Mann4.jpg
Born (1965-12-28) December 28, 1965 (age 47)
Amherst, Massachusetts
Nationality American
Education A.B. applied mathematics and physics (1989), MS physics (1991), MPhil physics (1991), MPhil geology (1993), PhD geology & geophysics (1998)[1]
Alma mater University of California, Berkeley, Yale University
Occupation Climatologist
Employer Pennsylvania State University
Known for Temperature record of the past 1000 years
Hockey stick controversy
Lead author on the IPCC Third Assessment Report
Awards Philip M. Orville Prize (1997)
NOAA Outstanding Scientific Publication (2002)
AAG John Russell Mather Paper of the Year (2006)
American Geophysical Union Fellow (2012)[2]
2012 Hans Oeschger Medal[1]
Website
Mann's home page
RealClimate

Michael E. Mann (born December 28, 1965) is an American physicist and climatologist, currently director of the Earth System Science Center at Pennsylvania State University. He is well known as lead author of a paper produced in 1999 on temperature trends over the last thousand years, which introduced new statistical techniques for hemispherical climate reconstructions and produced what was dubbed the "hockey stick graph" because of its shape. He was one of 8 lead authors of the "Observed Climate Variability and Change” chapter of the Intergovernmental Panel on Climate Change (IPCC) Third Scientific Assessment Report published in 2001, and the graph was highlighted in several parts of the report. The IPCC acknowledged that his work, along with that of many others who contributed substantially to the reports including lead authors and review editors, contributed to the award of the 2007 Nobel Peace Prize to the IPCC, jointly with Al Gore.

He was organizing committee chair for the National Academy of Sciences Frontiers of Science in 2003 and has received a number of honors and awards including selection by Scientific American as one of the fifty leading visionaries in science and technology in 2002. In 2012 he was inducted as a Fellow of the American Geophysical Union and was awarded the Hans Oeschger Medal of the European Geosciences Union. In 2013 he was elected a Fellow of the American Meteorological Society, and awarded the status of distinguished professor in Penn State's College of Earth and Mineral Sciences.

Mann is author of more than 140 peer-reviewed and edited publications, and has published two books: Dire Predictions: Understanding Global Warming in 2008 and The Hockey Stick and the Climate Wars: Dispatches from the Front Lines, published in early 2012. He is also a co-founder and avid contributor to the climatology blog RealClimate.

Contents

Early life [edit]

Mann was brought up in Amherst, Massachusetts, where his father was a professor of mathematics at the University of Massachusetts (UMass). At school he was interested in math, science and computing. In 1983 he was prompted by seeing the film WarGames to write a rudimentary self-learning tic-tac-toe program which made random moves and listed losing moves which it would not repeat. Mann found a "trick" of using symmetry to reduce the number of unique moves to store so that the computer would not slow down so much.[3]

In August 1984 he went to the University of California, Berkeley, to major in physics with a second major in applied math. His second year research in the theoretical behaviour of liquid crystals used the Monte Carlo method applying randomness in computer simulations. Late in 1987 he joined a research team under Didier de Fontaine which was using similar Monte Carlo methodology to investigate the superconducting properties of yttrium barium copper oxide, modelling transitions between ordered and disordered phases.[4] He graduated with honors in 1989 with an A.B. in applied mathematics and physics.[1]

Postgraduate studies [edit]

Mann then studied at Yale University for his PhD, obtaining both an MS and an MPhil in physics in 1991. His interest was in theoretical condensed matter physics but he found himself being pushed towards detailed semiconductor work. He looked at course options with a wider topic area, and was enthused by PhD adviser Barry Saltzman about climate modelling and research. To try this out he spent the summer of 1991 assisting a postdoctoral researcher in simulating the period of peak Cretaceous warmth when CO2 levels were high, but fossils indicated most warming at the poles, with little warming in the tropics. Mann then joined the Yale Department of Geology and Geophysics and began further coursework and exams, obtaining an MPhil in geology and geophysics in 1993. His research focussed on natural variability and climate oscillations. He worked with the seismologist Jeffrey Park, and their joint research adapted a statistical method developed for identifying seismological oscillations to find various periodicities in the instrumental temperature record, the longest being about 60 to 80 years. The paper Mann and Park published in December 1994 came to similar conclusions to a study developed in parallel using different methodology and published in January of that year, which found what was later called the Atlantic multidecadal oscillation.[5]

In 1994, Mann participated as a graduate student in the inaugural workshop of the National Center for Atmospheric Research Geophysical Statistics Project aimed at encouraging active collaboration between statisticians, climatologists and atmospheric scientists. Leading statisticians participated, including Grace Wahba and Arthur P. Dempster.[6]

While still finishing his PhD research, Mann met UMass climate science professor Raymond S. Bradley and began research in collaboration with him and Park. Their research used paleoclimate proxy data from Bradley's previous work and methods Mann had developed with Park, to find oscillations in the longer proxy records. "Global Interdecadal and Century-Scale Climate Oscillations During the Past Five Centuries" was published by Nature in November 1995.[7]

Another study by Mann and Park raised a minor technical issue with a climate model about human influence on climate change: this was published in 1996. In the context of controversy over the IPCC Second Assessment Report the paper was praised by those opposed to action on climate change, and the conservative organisation Accuracy in Media claimed that it had not been publicised due to media bias. Mann defended his PhD thesis on A study of ocean-atmosphere interaction and low-frequency variability of the climate system in the spring of 1996,[8][9] and was awarded the Phillip M. Orville Prize for outstanding dissertation in the earth sciences in the following year. He was granted his PhD in geology and geophysics in 1998.[1]

Postdoctoral research: the hockey stick graph [edit]

In the spring of 1996, after defending his PhD thesis at Yale, Mann carried out paleoclimatology research at the University of Massachusetts Amherst (U. Mass), funded by a United States Department of Energy postdoctoral fellowship (Alexander Hollaender Distinguished Postdoctoral Research Fellow 1996–1998). He collaborated with Raymond S. Bradley and Bradley's colleague Malcolm K. Hughes, a Professor of Dendrochronology in the Laboratory for Tree-Ring Research at the University of Arizona, with the aim of developing and applying an improved statistical approach to climate proxy reconstructions. In 1997 he became an Adjunct Assistant Professor, teaching a course in Data Analysis and Climate Change, then in 1998 a Research Assistant Professor.[1][10]

The first truly quantitative reconstruction of Northern Hemisphere temperatures had been published in 1993 by Bradley and Phil Jones, but it and subsequent reconstructions compiled averages for decades, covering the whole hemisphere. Mann wanted temperatures of individual years showing differences between regions, to find spatial patterns showing natural oscillations and the effect of events such as volcanic eruptions. Sophisticated statistical methods had already been applied to dendroclimatology, but to get wider geographical coverage these tree ring records had to be related to sparser proxies such as ice cores, corals and lake sediments. To avoid giving too much weight to the more numerous tree data, Mann, Bradley and Hughes used the statistical procedure of principal component analysis to represent these larger datasets in terms of a small number of representative series and compare them to the sparser proxy records. The same procedure was also used to represent key information in the instrumental temperature record for comparison with the proxy series, enabling validation of the reconstruction. They chose the period 1902–1980 for calibration, leaving the previous 50 years of instrumental data for validation. This showed that the statistical reconstructions were only skillful (statistically meaningful) back to 1400.[11]

Their study highlighted interesting findings, such as confirming anecdotal evidence that there had been a strong El Niño in 1791, and finding that in 1816 the "Year Without a Summer" in Eurasia and much of North America had been offset by warmer than usual temperatures in Labrador and the Middle East. It was also an advance on earlier reconstructions in that it went back further, showed individual years, and showed uncertainty with error bars.[12] "Global-scale temperature patterns and climate forcing over the past six centuries" (MBH98) was published on 23 April 1998 in the journal Nature. In it, "Spatially resolved global reconstructions of annual surface temperature patterns" were related to "changes in greenhouse-gas concentrations, solar irradiance, and volcanic aerosols" leading to the conclusion that "each of these factors has contributed to the climate variability of the past 400 years, with greenhouse gases emerging as the dominant forcing during the twentieth century. Northern Hemisphere mean annual temperatures for three of the past eight years are warmer than any other year since (at least) AD 1400.[13] The last point received most media attention. Mann was surprised by the extent of coverage which may have been due to chance release of the paper on Earth Day in an unusually warm year. In a CNN interview, John Roberts repeatedly asked him if it proved that humans were responsible for global warming, to which he would go no further than that it was "highly suggestive" of that inference.[14]

In May 1998, Jones, Briffa et al. published a reconstruction going back a thousand years, but not specifically estimating uncertainties. As Bradley recalls, Mann's initial reaction to the paper was ""Look at this. This is rubbish. You can't do this. There isn't enough information. There's too much uncertainty." Bradley suggested using the MBH98 methodology to go further back. Within a few weeks, Mann responded that to his surprise, "There is a certain amount of skill. We can actually say something, although there are large uncertainties."[15][16] Mann carried out a series of statistical sensitivity tests on 24 long term datasets, in which he statistically "censored" each proxy in turn to see the effect its removal had on the result. He found that a dataset which would otherwise have been reliable diverged from 1800 until around 1900, suggesting that it had been affected for that time by the CO2 "fertilisation effect". Using this dataset corrected in comparisons with other tree series, their reconstruction passed the validation tests for the extended period, but they were cautious about the increased uncertainties involved.[17]

Before the publication of MBH98, Mann had been nominated to be an author on the IPCC Third Assessment Report. Late in 1988 he heard that he had been selected as a lead author for the "observations" chapter of the Working Group I report. He was to work with the numerous contributing authors in preparing an assessment of the state of knowledge of the paleoclimate record, starting by soliciting input from the leading experts in that field.[18]

The Mann, Bradley and Hughes reconstruction covering 1,000 years (MBH99) was published by Geophysical Research Letters in March 1999 with the cautious title Northern Hemisphere temperatures during the past millennium: inferences, uncertainties, and limitations.[16][19] Mann said that "As you go back farther in time, the data becomes sketchier. One can’t quite pin things down as well, but, our results do reveal that significant changes have occurred, and temperatures in the latter 20th century have been exceptionally warm compared to the preceding 900 years. Though substantial uncertainties exist in the estimates, these are nonetheless startling revelations."[20] When Mann gave a talk about the study to the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory, Jerry Mahlman nicknamed the graph the "hockey stick".[16]

Career [edit]

University of Virginia

University of Virginia [edit]

In 1999 Mann gained the position of Associate Professor at the University of Virginia, in the Department of Environmental Sciences, where he taught courses in Climate Change: Past and Future; Atmosphere and Weather; Data Analysis & Climate Change; Climate and the History of Human Culture; Ocean-Atmosphere Dynamics; Statistical Climatology; and Modeling of Climate Variability.[1]

IPCC Third Assessment Report [edit]

Mann was one of 8 lead authors of the "Observed Climate Variability and Change” chapter of the IPCC Third Assessment Report (2001), working under the two co-ordinating lead authors for the chapter.[21]

The methodologies which underlie the hockey stick graph, as well as numerous papers with similar results, became the focus of controversy. Some individuals and groups opposed to the scientific consensus attempted to use this controversy to advance their views.[22]

Penn State University [edit]

In 2005 Mann took up a tenure position as Associate Professor at Penn State University in the Department of Meteorology (with joint appointments in Department of Geosciences and Earth and Environmental Systems Institute) and also became director of the university's interdepartmental Earth System Science Center. Courses he taught included The Earth System and Global Change; Quantitative Analysis in the Earth Sciences; From Meteorology to Mitigation: Understanding Global Warming; Climate Dynamics; and Climate Modeling.[1]

Hockey stick controversy [edit]

Main article: Hockey stick controversy

A 2006 report by the United States National Academy of Sciences supported the conclusions represented by the graph, especially during the period subsequent to 1600 AD, but was critical of the manner in which results from earlier periods were communicated.[23] Mann has said his findings have been "independently verified by independent teams using alternative methods and alternative data sources."[24] More than a dozen subsequent scientific papers produced reconstructions broadly similar to the original graph, and almost all agreed that the warmest decade in the last thousand years was probably that at the end of the 20th century.[25]

Full professor [edit]

In 2009 Mann was promoted to Professor at Penn State University.[1]

CRU email controversy [edit]

In November 2009, hackers obtained a number of Mann's e-mails with climate researchers at the Climatic Research Unit of the University of East Anglia, and published them on the Internet, sparking the Climatic Research Unit email controversy.[26] Pennsylvania State University (PSU) commissioned two reviews related to the emails and Mann's research, which reported in February and July 2010. They cleared Mann of misconduct, stating there was no substance to the allegations, but criticized him for sharing unpublished manuscripts with third parties.[27][28]

Based on the CRU email leak, Virginia Attorney General Ken Cuccinelli attempted to obtain documents from the University of Virginia relating to several Mann grant applications in the Attorney General of Virginia's climate science investigation. The demand sparked widespread academic condemnation,[29] and was denied in August 2010 by a judge for failure to state sufficient cause.[30][31] Cuccinelli tried to re-open his case by issuing a revised subpoena,[32] and appealed the case to the Virginia Supreme Court. The case was defended by the university, and the court ruled that Cuccinelli did not have the authority to make these demands. The decision, seen as supporting academic freedom, was welcomed by the Union of Concerned Scientists.[33]

In October, 2010, Mann wrote an op ed in the Washington Post in which he described several past, present and projected attacks on climate science and scientists by politicians, drawing a link between them and "the pseudo-science that questioned the link between smoking cigarettes and lung cancer, and the false claims questioning the science of acid rain and the hole in the ozone layer." Calling them "not good-faith questioning of scientific research [but] anti-science", he called for all his fellow scientists to stand against the attacks.[34]

The Office of the Inspector General (OIG) of the National Science Foundation carried out a detailed investigation, which it closed on 15 August 2011. It agreed with the conclusions of the university inquiries, and exonerated Mann of charges of scientific misconduct.[35][36][37]

Awards [edit]

Mann was awarded the Phillip M. Orville Prize in 1997 for an outstanding dissertation in the earth sciences at Yale University. His co-authorship of a scientific paper published by Nature won him an award from the Institute for Scientific Information (ISI) in 2002, and another co-authored paper published in the same year won the NOAA's outstanding scientific publication award. He was named by Scientific American as one of fifty "leading visionaries in science and technology." The Association of American Geographers awarded him the John Russell Mather Paper of the Year award in 2005 for a co-authored paper published in the Journal of Climate. The American Geophysical Union awarded him its Editors' Citation for Excellence in Refereeing in 2006 to recognize his contributions in reviewing manuscripts for its Geophysical Research Letters journal.[38]

The IPCC presented Mann with a personalized certificate "for contributing to the award of the Nobel Peace Prize for 2007 to the IPCC", celebrating the joint award of the Nobel Peace Prize to the IPCC and to Al Gore. The 2007 Nobel Peace Prize was awarded to the IPCC as an organisation, and the prize was not an award to any individual involved with the IPCC.[39] The IPCC officially states that the certificates were issued "to scientists that had contributed substantially to the preparation of IPCC reports. Such certificates, which feature a copy of the Nobel Peace Prize diploma, were sent to coordinating lead authors, lead authors, review editors, Bureau members, staff of the technical support units and staff of the secretariat from the IPCC’s inception in 1988 until the award of the prize in 2007. The IPCC has not sent such certificates to contributing authors, expert reviewers and focal points."[39][40] In his 2012 book Mann noted an IPCC meeting in 2009 celebrating the prize, where Working Group 1 co-chair Susan Solomon highlighted the personal sacrifice that he and Benjamin D. Santer had made in the name of the IPCC.[41]

In 2012, he was elected a Fellow of the American Geophysical Union[2] and awarded the Hans Oeschger Medal of the European Geosciences Union.[38] Following election by the American Meteorological Society he became a new Fellow of the society in 2013, as one of the small number selected each year.[42] In January 2013 he was designated with the status of distinguished professor in Penn State's College of Earth and Mineral Sciences, an honor restricted to fewer than 10% of full professors in the faculty.[43]

RealClimate [edit]

Mann, along with Gavin Schmidt, Stefan Rahmstorf, and others, co-founded the RealClimate website, launched in December 2004. The website's purpose is to provide a site for commentaries by working climate scientists, "for interested public and journalists." It is part of The Guardian's Environmental Network.[44]

Publications [edit]

Mann has been organizing committee chair for the National Academy of Sciences 'Frontiers of Science' and has served as a committee member or advisor for other National Academy of Sciences panels. He served as editor for the Journal of Climate and has been a member of numerous international and U.S. scientific advisory panels and steering groups. He is the lead author or co-author of over 90 scientific publications, the majority of which have appeared in leading peer-reviewed scientific journals.[27] Between 1999 and 2010 he served as principal or co-principal investigator on five research projects funded by the National Oceanic and Atmospheric Administration (NOAA) and four more funded by the National Science Foundation (NSF). He was also co-investigator on other projects funded by the NOAA, NSF, Department of Energy, United States Agency for International Development, and the Office of Naval Research.[27]

Selected publications [edit]

References [edit]

  1. ^ a b c d e f g h "Curriculum Vitae", Pennsylvania State University, accessed 15 May 2012.
  2. ^ a b "Fellows Search Results". American Geophysical Union. Retrieved 25 Oct 2012. 
  3. ^ Mann 2012, pp. 5–10
  4. ^ Mann 2012, pp. 5–6
  5. ^ Mann 2012, pp. 1–2, 6–10, 28–30
    Mann, M.E., Park, J., (1994) Global scale modes of surface temperature variability on interannual to century time scales, Journal of Geophysical Research, 99, 25819-25833.
    Schlesinger, M. E.; Ramankutty, N. (1994). "An oscillation in the global climate system of period 65–70 years". Nature 367 (6465): 723. doi:10.1038/367723a0.  edit
  6. ^ House Committee on Energy and Commerce (2006), Questions surrounding the 'Hockey stick' temperature studes; implications for climate change assessments, U.S. Government Printing Office, pp. 765–766, retrieved 2010-08-01  Unknown parameter |serial= ignored (help) (154 MB PDF).
  7. ^ Mann 2012, pp. 30–34
    Mann, Michael E.; Park, Jeffrey; Bradley, R. S. (1995). "Global interdecadal and century-scale climate oscillations during the past five centuries". Nature 378 (6554): 266–270. Bibcode:1995Natur.378..266M. doi:10.1038/378266a0.  edit
  8. ^ "A study of ocean-atmosphere interaction and low-frequency variability of the climate system". Yale University. 1998. Retrieved 2012-08-04. 
  9. ^ Mann 2012, pp. 1–2, 41, 265–266
  10. ^ Mann 2012, pp. 41–42
  11. ^ Mann 2012, pp. 40–48
  12. ^ Mann 2012, p. 48
  13. ^ Mann, M. E.; Bradley, R. S.; Hughes, M. K. (1998). Nature 392 (6678): 779–787. Bibcode:1998Natur.392..779M. doi:10.1038/33859.  edit
  14. ^ Mann 2012, pp. 48–50
  15. ^ Jones, P.D.; Briffa, K.R.; Barnett, T.P.; Tett, S.F.B. (1998). "High-resolution palaeoclimatic records for the last millennium: interpretation, integration and comparison with General Circulation Model control-run temperatures". The Holocene 8 (4): 455–471. doi:10.1191/095968398667194956.  edit
  16. ^ a b c Richard Monastersky (8 September 2006). "Climate Science on Trial - Research". The Chronicle of Higher Education. p. 10. Retrieved 2011-03-06. 
  17. ^ Mann 2012, pp. 50–53
  18. ^ Mann 2012, p. 53
  19. ^ Mann, Michael E.; Bradley, Raymond S.; Hughes, Malcolm K. (1999). "Northern hemisphere temperatures during the past millennium: Inferences, uncertainties, and limitations". Geophysical Research Letters 26 (6): 759. Bibcode:1999GeoRL..26..759M. doi:10.1029/1999GL900070.  edit
  20. ^ "News Releases : 1998 Was Warmest Year of Millennium, UMass Amherst Climate Researchers Report". UMass Amherst Office of News & Information. March 3, 1999. Retrieved 2011-03-06. 
  21. ^ J.R. Christy, R.A. Clarke, G.V. Gruza, J. Jouzel, M.E. Mann, J. Oerlemans, M.J. Salinger, S.-W. Wang (2001). "Observed Climate Variability and Change". Climate Change 2001: The Scientific Basis. Cambridge University Press. ISBN 0-521-80767-0. 
  22. ^ Fred Pearce (9 February 2010). "Part three: Hockey stick graph took pride of place in IPCC report, despite doubts | Environment". London: The Guardian. Retrieved 2010-03-08. 
  23. ^ Brumfiel G. (June 2006). "Academy affirms hockey-stick graph". Nature 441 (7097): 1032–3. Bibcode:2006Natur.441.1032B. doi:10.1038/4411032a. PMID 16810211. 
  24. ^ Warner, Frank (2010-01-03). "Penn State climate professor: 'I'm a skeptic'". The Morning Call. Archived from the original on 2010-07-06. Retrieved 2010-07-06. "And in a wide-ranging interview, Mann says that not all global warming science is settled. It's not yet certain, for example, that the heat is reducing the world population of polar bears or that it increases the number of hurricanes, he said." 
  25. ^ Fred Pearce (9 February 2010). "Part four: Climate change debate overheated after sceptics grasped 'hockey stick' | Environment". London: The Guardian. Retrieved 2010-03-08. 
  26. ^ Adam, Karla and Eilperin, Juliet. "Academic experts clear scientists in 'climate-gate'", The Washington Post, April 15, 2010.
  27. ^ a b c "Final Investigation Report Involving Dr. Michael E. Mann". The Pennsylvania State University. June 4, 2010. Retrieved July 2, 2010. 
  28. ^ Foley, Henry C.; Alan W. Scaroni and Candice A. Yekel (3 February 2010). "RA-10 Inquiry Report: Concerning the Allegations of Research Misconduct Against Dr. Michael E. Mann, Department of Meteorology, College of Earth and Mineral Sciences, The Pennsylvania State University". The Pennsylvania State University. Retrieved 7 February 2010. 
  29. ^ Walker, Julian (2010-05-19). "Academics fight Cuccinelli's call for climate-change records". The Virginian-Pilot. 
  30. ^ A judge puts a damper on Mr. Cuccinelli's U-Va. witch hunt Washington Post, August 31, 2010.
  31. ^ Fitzgerald Brendan, Court sets aside Cuccinelli investigation of UVA climate scientist, August 30, accessed December 21, 2010
  32. ^ The Cavalier Daily, October 6, 2010, Cuccinelli orders new investigation
  33. ^ Kumar, Anita (2 March 2012). "Va. Supreme Court tosses Cuccinelli’s case against former U-Va. climate change researcher - Virginia Politics". The Washington Post. Retrieved 2 March 2012. 
    Goldenberg, Suzanne (2 March 2012). "Virginia court rejects sceptic's bid for climate science emails : Environment". The Guardian. Retrieved 2 March 2012. 
  34. ^ Michael Mann, Washington Post, October 8, 2010, Get the anti-science bent out of politics
  35. ^ National Science Foundation Office of Inspector General, Case Number: A09120086
  36. ^ Efstathiou Jr., Jim (22 August 2011). "Climate-Change Scientist Cleared in Closing of U.S. Data-Altering Inquiry". Bloomberg. Retrieved 3 January 2012. 
  37. ^ "Climate scientist cleared of research misconduct". physicsworld.com, A website from the Institute of Physics. 30 August 2011. Retrieved 3 January 2012. 
  38. ^ a b PSU People page for Mann
  39. ^ a b "IPCC Statement about the 2007 Nobel Peace Prize". IPCC Press Office. Retrieved 2 November 2012. 
    "Letter from Renate Christ, Secretary of the IPCC". Michael E. Mann, Timeline Photos : Facebook. 30 October 2012. Retrieved 2 November 2012. , pdf of letter retrieved 12 December 2012.
    Mann, Michael E. (25 October 2012). "Timeline Photos : Facebook". facebook. Retrieved 28 October 2012. 
  40. ^ Bralower, Timothy; Rosenhoover, Christie (2007). "Nobel Prize Comes to Geosciences". Penn State College of Earth and Mineral Sciences. Retrieved 28 October 2012. 
  41. ^ Mann 2012, pp. 176, 319 (meeting during the Honolulu IPCC conference, 2009)
  42. ^ "Dr. Michael Mann named 2013 AMS Fellow — Penn State Meteorology and Atmospheric Science". Penn State University. 16 October 2012. Retrieved 4 November 2012. 
    "2013 AMS Honorary Members, Awards, Lecturers and Fellows". American Meteorological Society. 2012. Retrieved 28 October 2012. 
  43. ^ "Chen and Mann named distinguished professor in EMS". Penn State Live. 24 January 2013. Retrieved 25 January 2013. 
  44. ^ Pearce, Fred, The Climate Files: The Battle for the Truth about Global Warming, (2010) Guardian Books, ISBN 978-0-85265-229-9, pp. VII, XVIII.
    "RealClimate: About". RealClimate. 1 December 2004. Retrieved 2010-09-13. 
    "Welcome climate bloggers". Nature 432 (7020): 933–200. 2004. Bibcode:2004Natur.432Q.933.. doi:10.1038/432933a. PMID 15616516.  edit

External links [edit]

External images
Michael Mann with tree rings
Authority control
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