Unwarranted dogmatism — The example of avian evolution

In Dogmatism in Science and Medicine,  I mention a number of fields in which the mainstream position has become so dogmatic as to constitute a monopoly, which is maintained in part by suppression of other views: excluding dissenters from conferences, from publishing in leading journals, and from funding of research, and by calling them “denialists” with pejorative association to those who deny the Holocaust (Frank Furedi, “Denial: There is a secular inquisition that stigmatises free thinking”, SPIKED, 31 January. 2007;  “Denialism” — Who are the “denialists”?).

To the already long list of fields mentioned in the book, I can add the dogma that birds are derived in a particular way from a particular line of dinosaurs: Alan Feduccia, in “Bird origins anew” (The Auk — An International Journal of Ornithology, 130 [#1, January 2103] 1-12), describes circumstances just like those concerning string theory, extinction of dinosaurs, HIV/AIDS theory, the hypothesis of human-caused global warming, etc.:

“[T]he current mantra . . . has become an unchallengeable orthodoxy: birds are living maniraptoran theropods . . . .
[T]hose who offer contrary evidence are subjects of ridicule and no longer considered scientists. . . . [O]nly supporting evidence will be recognized, while contradictory evidence is ignored or explained away . . . .
[A]ll conclusions are based on the fact [emphasis in the original] that ‘birds are living dinosaurs’. . . .
Lack of citation has become a common but disturbing mechanism of censorship . . . .
The current orthodoxy of flight origins, involving massive exaptation, stretches biological credulity and is practically non-Darwinian.
[Current dogma requires that flight was ‘learned’, acquired in some way, by creatures accustomed to roaming the ground, which seems massively improbable. By contrast, the now-minority view that used to be mainstream is the highly plausible idea that powered flight was achieved by extrapolation of near-flight behavior in creatures long used to gliding downward from high in trees]
Attempts to silence any opposition to the current unchallengeable orthodoxy are seen in the lack of citation of contrary views . . ., and polemical and ad hominem reviews that are substituted for evidence. . . .
[We] are typically accused in ad hominem fashion of not understanding cladistic methodology and, therefore, of not being scientists. But we emphatically do understand the essence of the methodology, and that is the problem — . . . the fragility and very tenuous nature of cladistic analyses”.
[Compare the denigration by HIV/AIDS vigilantes of individuals who actually understand the relevant matters better than the HIV/AIDS adherents do: researchers and practitioners like Kary Mullis, Peter Duesberg, the Perth Group, Claus Köhnlein, Juliane Sacher, etc. etc.]

Part of Feduccia’s argument concerns the validity of cladistic approaches to discovering or proving ancestry. Cladistics groups species according to large numbers of characteristics, using computers to discern similarities and lineages. As with computer modeling, this approach depends on what is fed into the computer, in this case which characteristics to encode and how to weight their significance. Feduccia points out that no amount of descriptive morphological data used in cladistic analysis can compete with, let alone supersede genetic analysis. One reason is the phenomenon of convergent evolution, which has long been known: quite different genetic lineages have led to species that look somewhat alike and behave somewhat alike, because those features happen to suit a particular environment. Therefore morphology and behavior cannot be relied on for inferences about ancestry. By contrast, genetic analysis is a direct way of demonstrating ancestry which could be invalidated only by most improbable series of mutations.

[David Hull, in Science as a Process (University of Chicago Press, 1988), describes in fascinating detail the history of cladistics, as an example of the social processes at work in scientific activity. It’s a marvelously informative book that everyone interested in scientific activity could read with profit.]

So absurd are some of the assertions and speculations by mainstream dogmatists about avian evolution that they have been pilloried by Creationists, no less; Feduccia observes that “It is chilling to contemplate that the Creationists may be the ones to sweep our own house clean”.

[The absurdities Feduccia cites can be more than matched by what believers in HIV/AIDS orthodoxy have to live with: transmission rates so low that 20-40% of African adults have to be found guilty of extraordinary promiscuity; that HIV is spread by different mechanisms in different parts of the world;  infections by bite, saliva, dental work, etc., despite even lower possibilities of transmission; That breast-fedding tgransmits HIV even though exclusive breast-feeding causes fewer babies to be “HIV-positive”; and more — see the category “HIV Absurdities” at HIV Skepticism.]

Another interesting point in Feduccia’s article concerns neoteny (“Peter Pan evolution”), the phenomenon whereby the adults of some species resemble the infants of another species. For instance, Feduccia notes that the flightless birds (ostrich, kiwi, etc.) evolved from flighted ancestors by neoteny: “they are all big chicks” and thereby “closely resemble, albeit superficially, the theropod dinosaurs”. Similarly, human adults are much more like chimpanzee babies than they are like chimpanzee adults; we humans are neotenous apes.

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Don’t take a pill if you’re not ill

And don’t go to the doctor either.

I mean don’t take a prescription drug if you’re not ill. Some vitamins and supplements can be useful, I believe, especially those that occur naturally in the body like ubiquinone (Coenzyme Q10) and for which long experience attests that they do no harm.

By contrast, I’m hard put to think of any prescription drug that doesn’t have the potential to do harm. Long-term intake of any foreign substance is likely to damage the liver, whose job is to process foreigners. Even short-term use of some prescription drugs may cause tangible harm: antibiotics, unquestionably useful when infections cannot be defeated by the immune system alone, kill beneficial bacteria in our gut as well as the harmful bacteria. On two occasions when I took Cipro against prostate infections, within a week I contracted a yeast infection (thrush), in the mouth or on the penis; the beneficial gut bacteria (intestinal microflora) guard especially against fungal infections like thrush. Too many doctors fail to advise patients taking antibiotics to also take probiotic supplements to replace the beneficial microflora killed by the antibiotic.

Science is universal, but medicine is not. For a fascinating account of differences in medical practice among developed countries, read Lynn Payer, Medicine & Culture: Varieties of Treatment in the United States, England, West Germany, and France (Henry Holt, 1988/96). For example: My first wife suffered occasional abdominal pain, and her gynecologist offered her a hysterectomy whenever she felt ready for it. Shortly after that we spent a year in England, and an eminent gynecologist there said they would not dream of doing a hysterectomy with so little indication of its necessity. Again, on a visit to Scotland I thought I had contracted a urinary tract infection. The doctor confirmed it, and said, “These things are usually self-limiting. We don’t like to use antibiotics unless really necessary. If it hasn’t cleared up in a few days, come back and see me”. I didn’t have to go back. Here in the USA, I would have been given an antibiotic immediately, quite likely Cipro.
A London hospital recently did the experiment of drastically reducing its use of antibiotics. Within weeks the rate of super-infections by resistant bacteria had declined by nearly half.

Central to the promiscuous prescribing of pills is the practice of diagnosing by “objective” test instead of felt symptoms. Jeremy Green, MD and medical historian, has described how medical practice has changed from clinical diagnosis based on how a person feels and what a doctor can observe to the use of numbers from impersonal tests — blood pressure, blood sugar, PSA (prostate specific antigen), cholesterol and triglyceride levels, and more (Prescribing by Numbers: Drugs and the Definition of Disease, Johns Hopkins University Press, 2007). As a result, “perfectly healthy-feeling adults will receive a diagnosis for a disorder that they did not know they had. . . . [F]or most people these diagnoses lead directly to the prescription of a drug they will take for an indefinite period, if not for the rest of their lives” (p. vii). In 2003, the average American filled 10 prescriptions; those over 65, an average of 25 prescriptions (p. viii).

There are many reasons why this is an irrational and harmful situation. In the first place, there is no sound evidence connecting those laboratory-test numbers with the diseases with which they are conventionally associated. In the second place, even if there were such conclusive evidence, there is no sound reason for presuming that a population-average number is optimal for every individual, yet current practice is to strive to bring everyone’s numbers to the average or even “better”. Third, any potential benefit ought to be carefully weighed against the known risks of long-term use of any prescription drug, yet this is rarely if ever done in practice.

Here’s something to ponder. If it is universally desirable to bring everyone’s blood pressure, cholesterol, blood sugar, etc., to something like the population average, why do we focus so much on bringing numbers down but not up? “High” blood pressure is routinely treated with drugs, whereas low pressure is regarded as not necessarily unhealthy or to be treated unless there are troublesome actual symptoms; and in that case, the cause of the low pressure is sought (Low blood pressure {Hypotension}; Understanding Low blood pressure — diagnosis and treatment).
Again: if one’s cholesterol level is below average, should we not try to increase it? After all, the body manufactures cholesterol, which is a needed component of cell walls, and deficiency of it might even be a cause of Alzheimer’s disease (Henry Lorin, Alzheimer’s Solved, ISBN 1-4196-1684-6).

The concept of preventive medicine is attractive. However, the knowledge is not at hand to base prevention on laboratory tests; and there are innumerable possible conditions that might be detected if every conceivable test, including imaging and colonoscopy and the like were done routinely. So in practice the only proven preventive medicine is advice that can be given without any tests: exercise reasonably, eat reasonably, don’t put on weight, avoid stress, sleep well . . . .

Anecdotes may not be regarded as scientific evidence, but they do provide information. I never had annual check-ups before moving to the United States, and didn’t start here until I became an administrator and my employer mandated an “annual physical”. I passed in 1981 with flying colors, including EKG and chest X-ray. Two weeks later I fainted in the office, and an angiogram revealed a severely restricted coronary artery. Two successive angioplasties cured that.
In 1991, I passed my annual physical with flying colors, including EKG, X-ray, blood work, etc. A few weeks later I woke up early one morning unable to breathe, and within a week I had had a quintuple coronary by-pass.
My heart problems never showed up in any of the usual ways, including stress tests. I concluded that no amount of annual testing could be relied on to find even serious potential problems, and that the range of available tests is so great that using them routinely makes no sense.

Several medical associations and many specialists have been discounting the value of routine mammograms, PSA tests, colonoscopies and the like; not only because they are not cost-effective, revealing only a tiny number of conditions needing treatment compared to the numbers of tests carried out, but also because any test is liable to produce a certain number of false positives that bring the danger of unnecessary and damaging treatment of people who never needed treatment. In a recent radio interview, medical-science journalist Shannon Brownlee said that she eschews mammograms because she believes the risk of false positive and its consequences to be greater than the risk of detecting a possible tumor only when it becomes physically noticeable.

But this post is specifically about pills.
Current practice is that your doctor will likely prescribe drugs for you to take if your blood pressure is above 140/90 or so, and if your cholesterol level is 200 or even 180 or so, and if your blood sugar is above average; and if you feel sad or “down” too much, or if you feel unpleasantly anxious too often for your liking; and in many other situations as well.

• The problem is that many of the conditions
  for which pills are prescribed do not need treatment.
• And that the pills may not even be effective
  against the condition for which they are prescribed.
• And that the pills may actually do harm.
• And that the pharmaceutical industry thrives
  because it has succeeded in making pill-taking so routine,
  especially for so-called “chronic” conditions
  that imply life-long intake of drugs.
• And that those “chronic” conditions
  are often not illnesses at all
  but perfectly natural conditions,
  in particular accompaniments of aging
  (Seeking Immortality? Challenging the drug-based medical paradigm).

Don’t take a pill if you don’t feel ill.
Don’t go to a doctor if you don’t feel ill.

You don’t get what you don’t pay for: Reliable information

The common saying, “You get what you pay for”, isn’t of course universally true, but it’s an appropriate comment in many situations. Its obverse ought to be much more commonly on people’s minds, though, with respect to public goods, things that belong to everyone and no one: national defense, roads, environmental quality, and the like.

There are also quite non-material yet crucially important public goods, for instance accurate and trustworthy information about important matters. Contemporary dishonesty and dysfunction in science and medicine  include that we lack the exceedingly important public good of reliable information about such essential matters as prescription drugs.

In the good old days, professional journals in science and medicine could be relied on to provide information that the authors and publishers honestly believed to be the soundest available. That is no longer the case. Fraud by individual authors may not be uncovered for a long time. Medical journals from well established mainstream publishers may actually be underhanded advertisements by drug companies — for example, “Elsevier published 6 fake journals”); “Elsevier had a whole division publishing fake medical journals”).

Advertisements by pharmaceutical companies have become fatally misleading in manifest substance and by means of manipulative style. Thus the Food and Drug Administration (FDA) had occasion to warn manufacturers of antiretroviral drugs against showing such scenes as “three athletic men and one woman who have just scaled a dramatic mountain peak, an athletic feat that many perfectly healthy people probably couldn’t do” (“The ‘Joe Camel’ ads of AIDS?”).
But it is clear that advertising experts and their clients believe that a significant proportion of the public can be misled by showing happy, healthy people doing enjoyable things even when soft dulcet tones mention terrifying possible “side” effects of the recommended medication. Thus ads for Viagra refer to possible “changes in vision”, which doesn’t sound quite as worrying as “may cause blindness”; and it’s misleading because in rare cases blindness has actually been reported (“FDA was told of Viagra-Blindness link months ago”, 1 July 2005;  “Viagra and Blindness: Now the FDA is accusing Pfizer of covering up eye problems”, 16 June 2010).

Listen closely to what is said in almost any ad for a prescription drug, and read the text carefully, and note two general points: First, nothing beneficial is guaranteed. Second, the possible “side” effects can be utterly frightening. Thus one medication for easier breathing only says that it may assist and that it can’t replace the chronic medication or emergency medications — while mentioning the risk of many nasty possible “side” effects, including suicidal thoughts or actions (“Are you taking these asthma drugs?”), and, perhaps most surprisingly for a medication aimed at helping breathing, adverse respiratory events in as many as 15% of those using the drug. But in TV ads these horrifying possibilities are recounted in softly lilting tones while the video shows, for example, a happy man able once again — obviously owing only to use of the drug — to take his son and grandson fishing once more.

That horrendous “side” effects are recounted in ads is obviously intended to forestall legal actions, because almost everyone understands how ludicrous it is to advise contacting one’s doctor immediately in case of an emergency. In my case, the doctor’s phone answers with a menu, in which the first, helpful (?) item is, “If this is an emergency, call the hospital” — which of course doesn’t have records of my history and medications. So what use is it to read [emphases added]:
“Headache, throat irritation, or stomach upset may occur. If any of these effects persist or worsen, tell your doctor promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Infrequently, this medication may cause severe sudden worsening of breathing problems/asthma immediately after use. If you have sudden worsening of breathing, use your quick-relief inhaler and get medical help right away. Tell your doctor right away if any of these unlikely but serious side effects occur: white patches on tongue/in mouth, signs of infection (such as fever, persistent sore throat), mental/mood changes (such as nervousness), trouble sleeping, vision problems (such as blurred vision), increased thirst/urination, muscle cramps, shaking (tremors). Get medical help right away if any of these rare but serious side effects occur: chest pain, fast/slow/irregular heartbeat, severe dizziness, fainting, seizures. A very serious allergic reaction to this product is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, sudden trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US – Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088” [symbicort].

Conflicts of interest are a pervasive fact of modern societies (see Andrew Stark, Conflict of Interest in American Public Life, Harvard University Press, 2000). The public good is in the interests only of the general public. The Food and Drug Administration is beholden to drug companies for the resources to evaluate applications for new drugs. Drug companies are beholden to shareholders, and that vested interest swamps everything else. The public-relations motto, “Where patients come first”, is nothing but a lie, promulgated not only by Merck but by countless others in the “health-care” business: Google that phrase and you find hospitals, clinical networks, insurers all disseminating the same plain untruth.

It is fallacious to imagine that free markets will always attain the best overall arrangements in practice, because truly free markets do not exist in practice. I cannot choose in a free market among providers of all the services I want; I have effectively no choices for utilities (electricity, water, phone, etc.), for example; and precious little choice (if any) for health care and health insurance.

Conflicts of interest are nowadays pervasive in science and medicine (Ethics in Science). Researchers depend on for-profit entities for support. If we want the best disinterested, objective information about anything, then we must employ people whose interest is solely to ferret out that information. That requires institutions whose resources come from public funds or from patrons, foundations or individuals, who do nothing but give the money and then stay entirely out of it. In practice, government is the only possible source, but political attitudes in the USA have not so far permitted such an approach to be put into action.

As concerns matters of health, current circumstances make it very difficult to get reliable information. Consider how much evidence it must have taken for Marcia Angell, an editor at the New England Journal of Medicine, to conclude that

It is simply no longer possible to believe
much of the clinical research that is published,
or to rely on the judgment of trusted physicians
or authoritative medical guidelines.
I take no pleasure in this conclusion,
which I reached slowly and reluctantly
over my two decades as an editor of
The New England Journal of Medicine
(“Drug companies and doctors: a story of corruption,”
New York Review of Books, 56 #1, 15 January 2009)

Angell has called for an independent, publicly funded institute to assess drugs and other medical treatments (The Truth about the Drug Companies: How They Deceive Us and What to Do about It, Random House, 2004, pp. xix–xx, 244–7). So did Michael Crichton (“Aliens cause global warming”, Caltech Michelin Lecture, 17 January 2003) , who may be best known as a writer of science fiction but who was also very knowledgeable about science and medicine and indeed had graduated as an MD (see Crichton’s autobiography, Travels).

What you don’t know may kill you, as the saying goes.
What you think you know may also kill you if it happens to be wrong.
As to health care and medication,
trustworthy information is truly hard to come by.

“Denialism” — Who are the “denialists”?

“Denialism” is a recently invented, highly disdained condition. The inventors and deployers of the term intend it as a fatal blow to anyone who does not accept a mainstream consensus.
But there have always been minority views, unorthodox opinions, heterodox beliefs, and history teaches that some of them outlasted and eventually superseded the mainstream consensus.
In science, at times a difference of opinion has persisted unresolved for quite a long time. What’s new is not that a significant number of competent experts disagree with a mainstream consensus: What’s new — in modern science — is that mainstream institutions and their representatives seek to discredit their colleagues who interpret the evidence in a different fashion. What’s new in modern science is that differing opinions are labeled heretical and that their proponents are excommunicated, even when those proponents comprise a sizable number of well qualified experts.

Iconoclastic novelty has traditionally been resisted by mainstream science (1-3). Even well-established, senior scientists who make startling claims have tended to be ignored or ostracized (4).

On the other hand, occasionally a medical or scientific specialty seizes on some new claim that quickly becomes a fad. In recent times some of those have become bandwagons: fluorocarbons as destroyers of the ozone layer, for example, or carbon dioxide emissions as cause of global warming, or a retrovirus as cause of AIDS. Here the traditional roles of conservative and iconoclast have been reversed: The mainstream consensus upholds the iconoclastic novelty virtually from the outset while a minority of specialists denies that the evidence has established the new claim beyond a reasonable doubt.

The history of science teaches quite unequivocally that no new claim should be accepted without further ado. Only time can tell whether a new claim is sound; and time can tell that only if researchers repeatedly and persistently test the claim by trying to disconfirm or to confirm the early observations, and by trying to build on them.

The history of HIV/AIDS theory and of the theory of human-caused global warming (AGW, for anthropogenic global warming) demonstrates that in these cases the mainstream misguidedly jumped to acceptance well before conclusive support for the theories was at hand. With AGW, the claim rests entirely on computer models that neglect such important variables as those associated with historical cycles of temperature (5). With HIV/AIDS, the claim is  not supported by epidemiologic data, some of which was available quite early in the AIDS era (6).

These instances also demonstrate that early wholehearted acceptance by influential mainstream organizations can stymie subsequent reconsideration even as the evidence against the theories mounts. A mainstream consensus has enormous inertia; it maintains itself through control of the institutions that fund research and publish findings.

The volte-face in the traditional conservatism of science seen with HIV/AIDS and AGW has been accompanied by an unprecedented ostracizing and persecution of sizable numbers of well established and formerly respected specialists who attempted to play the traditional role of skeptical scrutinizing of new claims. The persecution has consisted of such things as refusal of research funding, exclusion from professional conferences, and extraordinary measures to prevent publication (5).

In the past, there have been cases where once well-established scientists were banished beyond the pale when they made unacceptable claims (4). But it is unprecedented that whole swaths of mainstream practitioners, including highly accomplished individuals, are effectively excommunicated from their profession, are held up to derision and ridicule in the media, and are even branded “denialists” in specific comparison to those who deny the occurrence or nature of the Nazi Holocaust with its mass killings of millions of Jews, gypsies, and other political or social undesirables.

It seems a little remarkable that no influential or popular media have pointed out the high qualifications of significant numbers of those who have been called denialists. Here is a brief survey.

HIV/AIDS “denialists”

The most well known HIV/AIDS denialist is Peter Duesberg, who before his apostasy over HIV and AIDS had been generally recognized as one of the world’s leading cancer researchers and retrovirologists. Other highly qualified critics of HIV/AIDS theory include  Kary Mullis (Nobel Prize), Robert Root-Bernstein (MacArthur “Genius” Awardee), Gordon Stewart (professor at the University of Glasgow and epidemiology consultant to the World Health Organization) and others as well (7).

In an open letter to the scientific community in 1991, more than 30 people asked that the HIV/AIDS hypothesis be re-examined; the signatories included Mullis, Root-Bernstein and Stewart and other well-established biologists in pertinent specialties (e.g. Gordon J. Edlin, Beverly Griffith, Harry Rubin, Richard C. Strohman, Charles A. Thomas, Jr.) as well as MDs and other scientists and science writers. Within 2 years more than 350 others had added their signatures (8): biological scientists, doctors, science writers, and a number of individuals with first- or second-hand experience of AIDS.

Some of those individuals are among those who have written articles and books explaining why HIV/AIDS theory has not been established. Much of this material comes from individuals who have no personal axe to grind and who stood to gain nothing in personal preferment by criticizing the mainstream dogma, indeed some of these people paid heavy professional prices for their apostasy. Among these are science writers who began by researching stories about AIDS but found to their astonishment that the facts on the ground do not support HIV/AIDS theory; see for example the books by Jad Adams, Ellinor Burkett, Neville Hodgkinson, Jon Rappoport, Joan Shenton, Bruce Nussbaum, and also sociologist Steven Epstein (9).

A very useful source for “denialist” works up to 1993 is Ian Young, The Aids Dissidents: An Annotated Bibliography (Scarecrow, 1993).

Useful “denialist” books not among those listed at virusmyth.com include:
Harvey Bialy, Oncogenes, Aneuploidy, and AIDS
(dist. North Atlantic Books, 2004)
Richard & Rosalind Chirimuuta, AIDS, Africa and Racism
(London: Free Association Books, 1989)
John Crewdson, Science Fictions (Little, Brown, 2002)
Rebecca Culshaw, Science Sold Out (North Atlantic Books, 2007)
Celia Farber, Serious Adverse Events (Melville House, 2006)
Etienne de Harven & Jean-Claude Roussez,
Ten Lies about AIDS        (Trafford, 2008)
F. I. D. Konotey-Ahulu, What is AIDS? (Tetteh-A’Domeno, 1989)
Evan C. Lambrou, AIDS: Scare or Scam? (Vantage, 1994)
Christine Maggiore, What if everything you knew about AIDS was wrong?
(American Foundation for AIDS Alternatives, 1996)
Maria Papagiannidou-St Pierre, Goodbye AIDS! Did it ever exist?
(Impact Investigative Media, 2009)
Gary Null with James Feast, AIDS: A Second Opinion (Seven Stories, 2002)

In 2012 the Opposing Viewpointsâ Series published a volume on AIDS (ed. Roman Espejo, Greenhaven Press) that juxtaposes pro and con arguments, for instance over whether HIV causes AIDS and whether antiretroviral drugs prolong life.

————————————————————————
1.    Bernard Barber, Resistance by scientists to scientific discovery,
Science, 134 (1961) 596-602
2.    Gunther Stent, Prematurity and uniqueness in scientific discovery,
Scientific American, December 1972, 84-93
3.    Ernest B. Hook (ed).,
Prematurity in Scientific Discovery: On Resistance and Neglect,
University of California Press, 2002
4.    Chapter 9, “Luck, or the lack of it”, in
Fatal Attractions: The Troubles with Science, Paraview Press 2001;
ISBN-13: 978-1931044288
5.    Dogmatism  in Science and Medicine:
How Dominant Theories Monopolize Research and Stifle the Search for Truth,
McFarland 2012
6.    The Origin, Persistence and Failings of HIV/AIDS Theory, McFarland 2007
7.    See “Whistleblowers” at the virusmyth website;
8.    “The Group”
9.    See “Find” and  “Bookshelf”

AGW “denialists”

Wikipedia is unusually reliable in listing, in several categories, scientists who disagree with the view that human-caused emission of carbon dioxide is significantly adding to global warming.

Those who question the accuracy of mainstream projections include such competent, indeed eminent people in relevant disciplines as
Freeman Dyson, Fellow of the Royal Society, professor emeritus at Princeton Institute for Advanced Study
Richard Lindzen, member of the National Academy of Sciences, Alfred P. Sloan professor of atmospheric science at Massachusetts Institute of Technology
Nils-Axel Mörner, former head of the Paleogeophysics and Geodynamics department at Stockholm University and former chairman of the INQUA Commission on Sea Level Changes and Coastal Evolution
Garth Paltridge, former chief research scientist at CSIRO Division of Atmospheric Research (Australia) and former director of the Institute of the Antarctic Cooperative Research Centre
Philip Stott, professor emeritus of biogeography, University of London
Hendrik Tennekes, former director of research, Royal Netherlands Meteorological Institute

Those who hold that global warming is owing to natural processes include
Sallie Baliunas, astronomer, Harvard-Smithsonian Center for Astrophysics
Ian Clark, hydrogeologist, professor, Department of Earth Sciences, University of Ottawa
William Kininmonth, meteorologist, former Australian delegate to Commission for Climatology, World Meteorological Organization
Tim Patterson, paleoclimatologist, professor of geology, Carleton University (Canada)
Ian Plimer, professor emeritus of Mining Geology, University of Adelaide
Fred Singer, professor emeritus of environmental sciences, University of Virginia; professor emeritus, George Mason University; founding dean, School of Environmental and Planetary Sciences, University of Miami; founder, National Weather Bureau’s Satellite Service Center
Willie Soon, astrophysicist, Harvard-Smithsonian Center for Astrophysics

Wikipedia lists another dozen people in this category, and a dozen who either regard the cause of global warming as unknown or that it will in any case have no dire consequences.

One of the most eminent AGW “denialists” was Frederick Seitz, at one time president of Rockefeller University, former president of the National Academy of Sciences, awarded a National Medal of Science. He endorsed the Oregon Petition against accepting AGW, a petition signed by more than 30,000 people who hold some credential in science, including >7000 with PhDs and nearly 4000 with degrees in atmospheric or environmental science.

The Leipzig Declaration asserted that there is no scientific consensus over the cause of global warming. It was signed by several scores of atmospheric scientists and meteorologists, including people with impressive credentials, for instance the eminent astrophysicist Thomas Gold and William Nierenberg, former Chairman of the National Advisory Committee on Oceans and Atmospheres and of the National Research Council’s Carbon Dioxide Assessment Committee as well as Director Emeritus of the Scripps Institute of Oceanography.

Among the many books written by well qualified and well established AGW “denialists”, a reader new to the controversy might begin with one of these:
Robert M. Carter, Climate: The Counter-Consensus —
A Palaeoclimatologist Speaks (Stacey International, 2010)
Michael Crichton, State of Fear —
a novel with citations of scientific works (HarperCollins, 2005)
Craig Idso & S. Fred Singer, Climate Change Reconsidered:
The Report of the Nongovernmental International Panel on Climate Change
(Heartland Institute, 2009)
Ian Plimer, Heaven and Earth: Global Warming, the Missing Science
(Taylor Trade Publishing, 2009)
S. Fred Singer & Dennis T. Avery, Unstoppable Global Warming:
Every 1,500 Years (Rowman & Littlefield, 2007)
S. Fred Singer, Nature, Not Human Activity, Rules the Climate
(Heartland Institute, 2008;
available free at http://www.sepp.org/publications/NIPCC_final.pdf)
Roy W Spencer, The Great Global Warming Blunder:
How Mother Nature Fooled the World’s Top Climate Scientists
(Encounter Books, 2012)

Shorter pieces well worth reading include
Michael Crichton, Aliens cause global warming
(Caltech Michelin Lecture, 2003)
Andrew Montford, Nullius in Verba (On the word of no one) —
The Royal Society and Climate Change
(Global Warming Policy Foundation Report 6, 2012;
ISBN: 978-0-9566875-6-2)
Maurice Newman (former chairman, Australian Broadcasting Commission),
A dangerous method: Global warming dogma has damaged science itself
(Spectator [Australia], 24 March 2012, p. ix)