Richard Lindzen on IPCC and climate dispute, 2001

From Testimony of Richard S. Lindzen before the Senate Environment and Public Works Committee on 2 May 2001

“I have been involved in climate and climate related research for over thirty years during which time I have held professorships at the University of Chicago, Harvard University and MIT. I am a member of the National Academy of Sciences, and the author or coauthor of over 200 papers and books. I have also been a participant in the proceedings of the IPCC (the United Nation’s Intergovernmental Panel on Climate Change). The questions I wish to address are the following: What can we agree on and what are the implications of this agreement? What are the critical areas of disagreement? What is the origin of popular perceptions? I hope it will become clear that the designation, ‘skeptic,’ simply confuses an issue where popular perceptions are based in significant measure on misuse of language as well as misunderstanding of science. Indeed, the identification of some scientists as ‘skeptics’ permits others to appear ‘mainstream’ while denying views held by the so-called ‘skeptics’ even when these views represent the predominant views of the field.”

“Some problems with the IPCC would appear to stem from the media and advocacy groups. The media reports rarely reflect what is actually in the Summary. The media generally replace the IPCC range of ‘possible’ temperature increases with ‘as much as’ the maximum – despite the highly unlikely nature of the maximum. … However, there is evidence that even the bottom of the range is an overestimate. [IPCC includes a number of observer NGOs with early privileged access to information, which makes green pressure groups the main communication channel between IPCC and the media – AH]”
“The misuse of the IPCC summaries, however, is not entirely accidental. The IPCC does a number of things which encourage misuse.
  • Use a summary to misrepresent what scientists say.
  • Use language which conveys different meaning to laymen and scientists. [Very important but rarely discussed point! – AH]
  • Exploit public ignorance (and the embarrassment about this ignorance) over quantitative matters. [Ignorance of the politicians and their fear to reveal this ignorance are politely not mentioned – AH]
  • Exploit what scientists can agree on in order to support one’s agenda.
  • Exaggerate scientific accuracy and certainty.
  • Exaggerate the authority of undistinguished scientists. [Very polite! More precisely, IPCC allow pseudo-scientists and outright charlatans to pose as scientists – AH]
  • Pose leading questions (WG II’s Impact Report).”


“The IPCC was created to support the negotiations concerning CO2 emission reductions. Although the press frequently refers to the hundreds and even thousands of participants as the world’s leading climate scientists, such a claim is misleading on several grounds. First, climate science, itself, has traditionally been a scientific backwater. There is little question that the best science students traditionally went into physics, math and, more recently, computer science. Thus, speaking of ‘thousands’ of the world’s leading climate scientists is not especially meaningful. Even within climate science, most of the top researchers (at least in the US) avoid the IPCC because it is extremely time consuming and non-productive. Somewhat ashamedly I must admit to being the only active participant in my department. None of this matters a great deal to the IPCC. As a UN activity, it is far more important to have participants from a hundred countries – many of which have almost no active efforts in climate research. For most of these participants, involvement with the IPCC gains them prestige beyond what would normally be available, and these, not surprisingly, are likely to be particularly supportive of the IPCC. Finally, judging from the Citation Index, the leaders of the IPCC process like Sir John Houghton, Dr. Robert Watson, and Prof. Bert Bolin have never been major contributors to basic climate research.”


“Climate change is a complex issue where simplification tends to lead to confusion, and where understanding requires thought and effort. Judging from treatments of this issue in the press, the public has difficulty dealing with numerical magnitudes and focuses instead on signs (increasing v. decreasing); science places crucial emphasis on both signs and magnitudes. To quote the great 19th Century English scientist, Lord Kelvin, “When you can measure what you are speaking about and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind.”


Russian scientist Mendeleev said even more succinctly: “Real science begins where the measurement begins” (“Настоящая наука начинается там, где начинаются измерения”).

“Indeed, the whole issue of consensus and skeptics is a bit of a red herring. If, as the news media regularly report, global warming is the increase in temperature caused by man’s emissions of CO2 that will give rise to rising sea levels, floods, droughts, weather extremes of all sorts, plagues, species elimination, and so on, then it is safe to say that global warming consists in so many aspects, that widespread agreement on all of them would be suspect ab initio. If it truly existed, it would be evidence of a thoroughly debased field. In truth, neither the full text of the IPCC documents nor even the summaries claim any such agreement. Those who insist that the science is settled should be required to state exactly what science they feel is settled. In all likelihood, it will turn out to be something trivial and without policy implications …”

“… Such an approach effectively deprives society of science’s capacity to solve problems and answer questions. Unfortunately, the incentive structure in today’s scientific enterprise contributes to this impasse. Scientists associate public recognition of the relevance of their subject with support, and relevance has come to be identified with alarming the public. It is only human for scientists to wish for support and recognition, and the broad agreement among scientists that climate change is a serious issue must be viewed from this human perspective. Indeed, public perceptions have significantly influenced the science itself . Meteorologists, oceanographers, hydrologists and others at MIT have all been redesignated climate scientists – indicating the degree to which scientists have hitched their futures to this issue.”


“That said, it has become common to deal with the science by referring to the IPCC ‘scientific consensus.’ Claiming the agreement of thousands of scientists is certainly easier than trying to understand the issue or to respond to scientific questions; it also effectively intimidates most citizens. However, the invocation of the IPCC is more a mantra than a proper reflection on that flawed document. The following points should be kept in mind. (Note that almost all reading and coverage of the IPCC is restricted to the highly publicized Summaries for Policymakers which are written by representatives from governments, NGO’s and business; the full reports, written by participating scientists, are largely ignored.) In what follows, I will largely restrict myself to the report of Working Group I (on the science). Working Groups II and III dealt with impacts and responses.”


Selected quotes, original emphasis is preserved.