People try to paint climate scientists as members of a cabal  or conspiracy to hide the truth, but this idea is often promoted by thinktanks, politicians, bloggers, journalists and some economists, members of a tight social network themselves. Their emails are not usually subject to FOIAs, but the FOIA Facts research fortuitously found unexpected data.
Email to Ed Wegman highlighted close relationships between UK's main climate anti-science charity, Global Warming Policy Foundation (GWPF ), its counterparts in the US and Canada, and some key Congressional staffers. Many email addresses were quite familiar, with a few surprises, including involvement of AIER, a previously unnoticed thinktank .
In the English-speaking machinery of climate anti-science, GWPF is the main UK gear, seen to be well-meshed with AEI , CATO , CEI , CFACT , GMI , Heartland Institute(HI) , ICSC , IER , Mercatus (GMU) , PERC , SEPP  plus staffers for Rep. Joe Barton (R-TX) and Senator James Inhofe (R-OK), among others.
In October 2010, USA Today's Dan Vergano sent FOIA requests to George Mason University (GMU), which gave them to Ed Wegman for reply. The American Tradition Institute  ( David Schnare , Chris Horner , etc) published the full sequence in May 2011 , then Vergano put separate files online in 2013, two noted in FOIA Facts 2 . Regarding Peter Spencer, who managed the Wegman Report's creation  for Rep. Barton, Wegman wrote  to GMU FOIA officer Phil Hunt, forwarding a message from Patrick David Henderson,  Chair of GWPF's Academic Advisory Council: 
'VIA EMAIL on October 19, 2010
Dear Phil: This is the only email on my GMU account that even has Peter Spencer's email. Note that this is from the past August.
Date: Thu, 12 Aug 2010 13:18:03 +0100 From: Patrick David Henderson <EMAIL> Subject: Reviewing the IPCC
To: (list of people enumerated later)
Dear All, As you know, the expert committee appointed by the InterAcademy Council to review the role and functioning of the IPCC is due to report at the end of this month. Against this background, you might be interested to see the three attached documents* which were submitted as evidence to the committee. The respective authors are Gordon Hughes, Ross McKitrick and me.* Although we are all professors of economics, each of these submissions follows its own distinctive line of argument: they are in fact complementary. Taken together, they present a strong case for change, alongside specific proposals for giving effect to it.'
In addition to his long-time gmu.edu email, by September 2005 Wegman began to use a gmail account through which he handled all Wegman Report communication. Henderson sent to both accounts. Wegman had resumed attacks on climate science in 2009, speaking more, giving Fred Singer , Jeff Kueter  (GMI) and Don Easterbrook  slots at his Interface conference, §0.3 , §A.6.4.  This single email proves nothing about any earlier conversations, except that Wegman claimed no more such messages arrived via gmu.edu. The fortuitous find was GWPF's recipient list.
GWPF's Director is Benny Peiser , a social (sports) anthropologist known for his inept failed attempt  to refute Naomi Oreske's 2004 essay on consensus in climate science.  In 2007, Mr. Klaus-Martin Schulte , then an endocrine surgeon at the NHS and King's College London, tried again, and likewise failed . Perhaps his obvious endocrinology expertise was even less relevant to climate than Peiser's. That attempt was orchestrated by Robert Ferguson  and especially the Viscount Christopher Monckton,  an in-law of Lord Nigel Lawson , the Chairman of the GWPF Board .
Henderson's To: list included many long active in climate anti-science, a few new names and some people that seemed irrelevant to climate anti-science, perhaps past associates he wanted to convince and may well not have expected or wanted this email. People are listed by groupings, tagged as Heartland experts or speakers, DeSmogBlog database, SourceWatch, Wikipedia, or Other. Mention in earlier reports is tagged as c , s , f . Use Full Search on the PDFs. Many of these people have moved among thinktanks or have many more affiliations, have attended Heartland or other conferences together. This is a very tight-coupled social network, but is not so explicit as the open list of contributors to IPCC reports.
Relevant scientists are scarce in this list, but it certainly includes many economists associated with politics and/or thinktanks, some with strong ideological bents that seem to make non-scientsts spend their time casting doubt on science they find inconvenient.
|Name||Co||Field||Orgs||H ||D ||S ||csf||W ||O||O|
|Lawson, Nigel||UK||Politics & journ||GWPF BoD Chair||D ||S ||cs||W ||1 ||2 |
|Peiser, Benny||UK||Social anthy||GWPF Director||H||D ||S ||c||W |
|Henderson, D.||UK||Economics||GWPF AAC Chr||H||D ||S ||1 ||2 |
|Hughes, G. A.||UK||Economics||Edinburgh U||1 ||2 ||3 |
|McKitrick, R.||CA||Economics||U Guelph, GMI||H||D ||S ||csf|
|Carter, Robert||AU||Marine geology||HI, ICSC||H||D ||S ||cf||W ||1 |
|Courtillot, Vin.||FR||Geophysics||U of Paris||D ||S ||W ||1 |
|Dyson, Free.||US||Physics||IAS Princeton||H||D ||S ||cf||W ||1 |
|Happer, Will||US||Atomic physics||GMI Chr, Princeton||D ||S ||cf||W ||1 |
|Lindzen, Rich.||US||Atmos. sciences||M.I.T.||H||D ||S ||cf||W ||1 |
|Plimer, Ian||AU||Geology||U Adelaide||H||D ||S ||W ||1 |
|Reiter, Paul||FR||Med. Entomol||Pasteur Inst||H||D ||S ||W |
|Tol, Richard||IE||Economics||E&SRI||S ||W |
|TO:||A. THINKTANKS||INVOLVED |
|Green, Ken.||US||Environ sci & engr||AEI,ELC, Reason||H||D ||S ||1 |
|Hayward, S.F.||US||American Studies||AEI, DONORS||D ||S ||W ||1 |
|Lynch, Kerry||US||Economics||AIER ||1 ||2 |
|Illarionov, A.||US||Economics||CATO||H||S ||W |
|Niskanen, W.||US||Economics||CATO (d 2011)||S ||W |
|Michaels, Pat||US||Ecol climatology||CATO, WCR, GMU||H||D ||S ||csf||W ||1 |
|Ebell, Myrion||US||Economics?||CEI, CHC, FoF||H||D ||S ||csf||W |
|Horner, Chris||US||Attorney||CEI, CHC, ATI||H||D ||S ||sf||W ||1 |
|Lewis, Marlo||US||Government||CEI||H||S ||cf||1 |
|Smith, Fred||US||Political writer||CEI||H||S ||W |
|Morano, Marc||US||Political Science||CFACT, Inhofe||H||D ||S ||c|
|Driessen, Paul||US||Attorney, PR||CFACT, Atlas+||H||D ||S ||f||W |
|Bast, Joseph||US||-||HI President||H||D ||S ||cf|
|Miller, Dan||US||Journalism||HI Publisher||H||f|
|Taylor, J. M.||US||Attorney, journ.||HI E&CN Editor||H||D ||S ||f|
|Harris, Tom||CA||MechEng->PR||ICSC, High Park||H||D ||S ||cf||1 ||2 |
|Bradley, R. Jr||US||Polit. Economy||IER, CATO, CEI||H||D ||S ||1 |
|Murphy, R. P.||US||Economics||IER, Reason||H||D ||W |
|Morriss, A. P.||US||Economics||U AL,Mercatus,IER||H||1 ||2 ||3 |
|Goklany, Indur||US||Electrical Engr.||PERC, AEI||H||D ||S ||f||W |
|Singer, Fred||US||Physics||SEPP, IHS(GMU)||H||D ||S ||csf||W ||1 |
|TO:||B. US CONGRESS||INVOLVED|
|Spencer, P.||US||Managed Weg Rpt||House(Barton)||H ||cs|
|Dempsey, M.||US||Paper 02/23/10||Senate(Inhofe)||c||1 |
|Lungren, D.||US||Paper 02/23/10||Senate(Inhofe)||c||1 |
|Wegman, E. J||US||Statistics||GMU||D ||S ||csf||W |
|Corcoran, Ter.||CA||Journalist||FP,National Post||W ||1 ||2 |
|Bhandari, J.||SG||Journalist?||von Mises of CA||1 ||2 |
|Rosett, C.||US||Journalist||WSJ, now FftDoD||S ||W ||1 ||2 |
|Barfield, C.||US||Economics||AEI||S ||1 |
|Diewert, E.||CA||Economics||UBC, (Fraser)||1 |
|Griswold, D. T.||US||Politics, econ||CATO||W |
|Kraske, H. Q.||US||?||1818 World Bank||1 |
|McCarthy, E.||US||Economics||1818 World Bank||1 ||2 |
|Vasquez, Ian||US||Int'l Studies||CATO||W ||1 |
Most of these were familiar, as seen by the high density of H, D, S, and csf tags. A new addition is the American Institute of Economic Research  (AIER), which seems a tax-exempt 501(c)(3) public charity that runs a for-profit investment subsidiary. That may bear further scrutiny, but AIER's relevance here is in some its various “educational” materials:
2001 A Climate of Opinion: The Kyoto Protocols and Atmospheric Science, ?
This Economic Education Bulletin cites Robert Essenhigh , Arthur Robinson , John Christy , the Greening Earth Society , John Daly , Indur Goklany , Richard Lindzen , Frederick Seitz , the OISM Petition . Readers can assess the quality of “education” provided by this 501(c)(3) entity.
2005 Economics, Climate Change Issues, and Global Salvationism , D.Henderson
2009 Climate Science, Economics, and Policy , David Henderson
AIER ran a conference in 2007 with PDF Proceedings also sold as a book , and unlike Heartland Conferences, some participants are quite credible, but readers might guess the likely results given the mix of participants:
2008 GlobalWarming Debate Science, Economics, and Policy , Kerry Lynch, Ed.
'with content by Michale J. Rizzo (sic, AIER), Carl Wunsch (M.I.T.), David S. Chapman (U Utah, Geology and geophysics), William R. Cotton , William M. Gray , James I. Mills (Architecture & Planning, U Utah), David Henderson , Ross McKitrick , Claudia Rosett , Kenneth P. Green , Robert H. Nelson (Environmental Policy, U MD), E. Calvin Beisner , Richard S. Lindzen. '
Also participating were Edward J. Kane (Finance, Boston College), Robert O. Mendelsohn  (Economics, Yale), Gilbert E. Metcalf (Economics, Tufts U), Gordon E. Michaels (CTO Oak Ridge National Laboratory), Richard L. Stroup (PERC , CATO , Mont Pelerin ), Peter J. Wilcoxen (Economics and Public Administration, Syracuse U).
People can study the PDF of the proceedings, which include statements such as these in the Introduction, by AIER Senior Economist Michael J. Rizzo:
'Just as important, the scientific consensus is not as strong as the popular one. The state of scientific knowledge is less certain than the media and others often suggest. …
Climate science is extremely complex for three reasons, …
First, it is an immature science….
Second, climate science is virtually the “science of everything.” …
Third, modern climate science relies on large, complicated models that seek to describe and predict the climate system, but these models are inherently unreliable and unstable. For instance, climate models predicted three to six times more warming than that which has occurred to date. Complexity does not ensure accuracy. (In this regard, climate models are reminiscent of the failed macroeconomic econometric models that were popular a generation ago.)
Thus, even a broad climate “consensus” may prove fragile. …
According to the scientists at our conference, identifying mankind’s role in the climate question is not easy and might not even be possible for decades. Potential natural sources of climate change include solar variability, aerosol variation, changes in cloud cover, greenhouse gases, changes in land use, and natural variability from factors such as El Niño and the oceans’ thermohaline circulation. Changes in any or all of these may be sufficient to account for the changes in global mean temperature since 1880.
Evidence abounds to suggest that CO2 is far from the most important contributor to global warming. Previous interglacial periods were much warmer and had far lower concentrations of CO2 in the atmosphere; and it might eventually be demonstrated that CO2 concentrations lag temperature increases. When the temperature change is within a few tenths of a degree, it is difficult to identify the particular causes.'
Some economists can be Merchants of doubt  about science, not just a few old physicists.
A future post may review the 3 attachments by Hughes , McKitrick  and Henderson, included with Henderson's email. Some suggestions might actually have been useful. Some rely heavily on McKitrick's opinions of the IPCC and claims to statistical credibility.
The attached spreadsheet  is a map of people X (activities and organizations), similar to Appendix A.6 in older PDF , wherein many of the abbreviations are explained. Most of the people listed above are strongly connected via shared activities and organizations involved in climate anti-science, with far too many to show in a simple table. Many of the same people appear again and again.
Update 06/13/13: A few of GWPF's Advisors  are also involved with the Instiute for Economic Affairs  (IEA), another well-connected thinktank . From IEA's list , those in common include David Henderson, Professor Sir Gordon Peacock and Sir Samuel Brittan. IEA's list also included IER's Robert L. Bradley (on email list) and George Mason Unversity's Walter E. Williams , for whom Nancy Mitchell Pfotenhauer  was a research assistant. Unlike GWPF, but like many US thintkanks, IEA has had serious tobacco involvement , confirmed by checking the files mentioned in Fakery 2 , fn203, and searching the LTDL . Clearly, IEA has been involved with Philip Morris, RJ Reynolds, and British American Tobacco since the 1980s and getting money.
Update 06/13/14: Lord Lawson's climate-change think tank risks being stripped of charitable status.