Global Warming: That Pesky Data

Looks like Mann et. al. [1998] could be getting some major attention before too long. Apparently the Committee on Energy and Commerce is interested in the Hockey stick.

Letter to Dr. Mann, Dr. Hughes, Dr. Bradley, as well as letters to the National Science Foundation, and the IPCC. What are they asking for?

  1. Your curriculum vitae, including, but not limited to, a list of all studies relating to climate change research for which you were an author or co-author and the source of funding for those studies.
  2. List all financial support you have received related to your research, including, but not limited to, all private, state, and federal assistance, grants, contracts (including subgrantsor subcontracts), or other financial awards or honoraria.
  3. Regarding all such work involving federal grants or funding support under which you were a recipient of funding or principal investigator, provide all agreements relating to those underlying grants or funding, including, but not limited to, any provisions, adjustments, or exceptions made in the agreements relating to the dissemination and sharing of research results.
  4. Provide the location of all data archives relating to each published study for which you were an author or co-author and indicate: (a) whether this information contains all the specific data you used and calculations your performed, including such supporting documentation as computer source code, validation information, and other ancillary information, necessary for full evaluation and application of the data, particularly for another party to replicate your research results; (b) when this information was available to researchers; (c) where and when you first identified the location of this information; (d) what modifications, if any, you have made to this information since publication of the respective study; and (e) if necessary information is not fully available, provide a detailed narrative description of the steps somebody must take to acquire the necessary information to replicate your study results or assess the quality of the proxy data you used.
  5. According to The Wall Street Journal, you have declined to release the exact computer code you used to generate your results. (a) Is this correct? (b) What policy on sharing research and methods do you follow? (c) What is the source of that policy? (d) Provide this exact computer code used to generate your results.
  6. Regarding study data and related information that is not publicly archived, what requests have you or your co-authors received for data relating to the climate change studies, what was your response, and why?

One of the long running problems with looking into the Hockey Stick has been getting data and code out of the authors (Mann, Bradley and Huges). As I have noted previously there seems to be a pattern with regards to climate scientists and their willingness to share data (and contrary to claims in the comments to that post, not all the data and source code has been shared).

The issue here isn’t so much whether there is anthropogenic warming (there probably is some, how much I think is still somewhat of an open question, and the effectivness of various policies even more open), but the integrity and accuracy of the research that supports the climate change hypothesis. If the data are not avialable, if the original source code is lost, and/or the authors are unwilling to share (note: that in a Wall Street Journal article [Feb. 14, 2005] Mann has said he wont be intimidated into releasing his algorithm) this is a problem.

FILED UNDER: Science & Technology
Steve Verdon
About Steve Verdon
Steve has a B.A. in Economics from the University of California, Los Angeles and attended graduate school at The George Washington University, leaving school shortly before staring work on his dissertation when his first child was born. He works in the energy industry and prior to that worked at the Bureau of Labor Statistics in the Division of Price Index and Number Research. He joined the staff at OTB in November 2004.


  1. Hard questions.

    It seems that the Committee on Energy and Commerce is interested in global warming, specifically asking Mann et. al. [1998] about the data and methodology between their “hockey stick” curve. Among other things they want to know this:According to The…

  2. John Burgess says:

    It’s a huge problem of credibility.

    While the data for the long-term temperature trends (including the various highs and lows over the past 2,000 years) is not from direct measurment, but instead from indirect measurement (especially tree rings), it looks pretty solid.

    By looking at long term trends, it’s clear that today’s temperatures are below those experienced in recent historical times. If that’s the case, then you need strong data to justify panic.

    By providing no data, just a “my research says,” the work repudiates itself.

  3. Wizbang says:

    Hocky Stick Graph Creators Iced

    Steve Verdon over at OTB gives us good news. It appears that Mann et. al. have drawn the attention of the Committee on Energy and Commerce. They have a few questions to ask. 1) Your curriculum vitae, including, but not…

  4. Paul says:


  5. Hal says:

    Hmmm. Why is it that the only study the committee is interested in is Mann, Bradley and Hughes from way back in 1998? Further, why are all the questions of the form “Can you explain why you made all the errors detailed in Mcintyre and McKitrick’s Energy and Environment paper?”.

    Funny, that.

  6. Green Alps

  7. RELIAPUNDIT says:


  8. Steve Verdon says:

    No Hal, it isn’t funny in that McIntyre and McKitrick (MM) are the ones who pointed out the problems with Mann et. al. methodology. I’ve been following this from pretty early on when MM were just starting out on this research. McIntyre looked at the hockey stick and said it looked alot like some mining reports he’d seen…usually bogus reports about how a mine was just about to make all the investors super rich. As to the importance of this result it is one of the main pillars of the climate change hypothesis. Knock this out and there would be problems. Climate change might very well still be happening, but the research would have to find new evidence.

  9. […] when Brian Doherty reported at Reason that the model was flawed, at best. Steve Verdon at Outside the Beltway reports that the House Committee on Energy and Commerce is asking a few quest […]

  10. […] creators of the global warming hockey stick are –shall we say– pucked.” Steve Verdon: “there seems to be a pattern with regards to climate scientists and their wil […]

  11. ÐanØ says:

    As to the importance of this result it is one of the main pillars of the climate change hypothesis. Knock this out and there would be problems. Climate change might very well still be happening, but the research would have to find new evidence.

    I fully expect Inquistions on the other teams of scientists who find the same thing. Do keep us informed, Steve. Also let us know when Barton looks into Creation Science, John Lott’s mendacity, Fred Singer’s bull—-, JunkScience’s funding, how the Vioxx scientists tested their data, where RoyalDutchShell got their reserve forecasts…


  12. Squeaking wheel? Meet Grease!

    Two wonderful links regarding the Mann, et. al. ‘paper’ relating the inexorable rise in global temperatures over the last 40 years or so. And the great curiosity of the United States Committee on Energy and Commerce. Here is the Hockey…

  13. John says:

    If the Hockey Stick proves to be a myth then the proponents of anthropogenic global warming will have a few problems. There is a body of research that says that during the Medieval Warm Period temperatures were warmer than today and there’s a body of evidence that says that temperatures have been warmer in the last 1000 years than Mann & Bradley claim. Together they would show (a) that the recent warming is nothing abnormal and (b) temperatures rise without increases in carbon dioxide, and these would burst a few cherished beliefs.

    (Those of us who are more sceptical of claims and have investigated the data for ourselves know this is the case any how.)

    By the way, not only is 1998 the warmest year in the last 120 years but since January 2002 the temperature trend is flat – no increase and no decrease. In other words for the last three and a half years any claims that global warming is happening, let alone increasing, are simply a lie.


  14. John A says:

    Why is it that the only study the committee is interested in is Mann, Bradley and Hughes from way back in 1998?

    I think the answer is, is that this study, and its extension (MBH99) which added Southern Hemisphere proxies and became a global study, formed a key part of the scientific basis used in the IPCC Third Assessment Report in 2001. On the foundation of this study alone, came the statement about the 20th Century warming being unprecedented in the last 1000 years and that 1998 was the warmest year in a millennium. Mann wrote the key chapter in the TAR that featured his own study.

    From the TAR came the full court press to ratify the Kyoto Protocol and the current media scare over man-made climate change.

    Now multiple research teams have published clear and serious problems with the data, analysis, methodology, synthesis and hence conclusions of this key study.

    Now Congress wants to know whether it has allowed multiple millions to be misspent on worthless research. Hence the investigation.

  15. […] Looks like the ‘hockey stick’ is going under the microscope. There has been along running issue with the authors of this global warming clap trap, that being the code and data used to predict the dire warming has been hidden from the public and other researchers. More reference information here. […]

  16. Benedict says:


    Drudge is currently splashing the headline “BUSH: CLIMATE CHANGE MANMADE TO ‘CERTAIN EXTENT'”, accurately quoting – although mischaracterizing – this story from today’s Los Angeles Times (the LATimes’ story itself carries the much less sensationa…