Why Climate Deniers Have No Scientific Credibility - In One Pie Chart

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This is a guest post by James Lawrence Powell.*

Polls show that many members of the public believe that scientists substantially disagree about human-caused global warming. The gold standard of science is the peer-reviewed literature. If there is disagreement among scientists, based not on opinion but on hard evidence, it will be found in the peer-reviewed literature.

I searched the Web of Science for peer-reviewed scientific articles published between 1 January 1991 and 9 November 2012 that have the keyword phrases “global warming” or “global climate change.” The search produced 13,950 articles. See methodology.

I read whatever combination of titles, abstracts, and entire articles was necessary to identify articles that “reject” human-caused global warming. To be classified as rejecting, an article had to clearly and explicitly state that the theory of global warming is false or, as happened in a few cases, that some other process better explains the observed warming. Articles that merely claimed to have found some discrepancy, some minor flaw, some reason for doubt, I did not classify as rejecting global warming. Articles about methods, paleoclimatology, mitigation, adaptation, and effects at least implicitly accept human-caused global warming and were usually obvious from the title alone. John Cook and Dana Nuccitelli also reviewed and assigned some of these articles; John provided invaluable technical expertise.

This work follows that of Oreskes (Science, 2005) who searched for articles published between 1993 and 2003 with the keyword phrase “global climate change.” She found 928, read the abstracts of each and classified them. None rejected human-caused global warming. Using her criteria and time-span, I get the same result. Deniers attacked Oreskes and her findings, but they have held up.

Some articles on global warming may use other keywords, for example, “climate change” without the “global” prefix. But there is no reason to think that the proportion rejecting global warming would be any higher.

By my definition, 24 of the 13,950 articles, 0.17% or 1 in 581, clearly reject global warming or endorse a cause other than CO2 emissions for observed warming. The list of articles that reject global warming is here. The 24 articles have been cited a total of 113 times over the nearly 21-year period, for an average of close to 5 citations each. That compares to an average of about 19 citations for articles answering to “global warming,” for example. Four of the rejecting articles have never been cited; four have citations in the double-digits. The most-cited has 17.

Of one thing we can be certain: had any of these articles presented the magic bullet that falsifies human-caused global warming, that article would be on its way to becoming one of the most-cited in the history of science.

The articles have a total of 33,690 individual authors. The top ten countries represented, in order, are USA, England, China, Germany, Japan, Canada, Australia, France, Spain, and Netherlands. (The chart shows results through 9 November 2012.)

Global warming deniers often claim that bias prevents them from publishing in peer-reviewed journals. But 24 articles in 18 different journals, collectively making several different arguments against global warming, expose that claim as false. Articles rejecting global warming can be published, but those that have been have earned little support or notice, even from other deniers.

A few deniers have become well known from newspaper interviews, Congressional hearings, conferences of climate change critics, books, lectures, websites and the like. Their names are conspicuously rare among the authors of the rejecting articles. Like those authors, the prominent deniers must have no evidence that falsifies global warming.

Anyone can repeat this search and post their findings. Another reviewer would likely have slightly different standards than mine and get a different number of rejecting articles. But no one will be able to reach a different conclusion, for only one conclusion is possible: Within science, global warming denial has virtually no influence. Its influence is instead on a misguided media, politicians all-too-willing to deny science for their own gain, and a gullible public.

Scientists do not disagree about human-caused global warming. It is the ruling paradigm of climate science, in the same way that plate tectonics is the ruling paradigm of geology. We know that continents move. We know that the earth is warming and that human emissions of greenhouse gases are the primary cause. These are known facts about which virtually all publishing scientists agree.

Jim Powell is a science author. He has been a college and museum president and was a member of the National Science Board for 12 years, appointed first by President Reagan and then by President George H. W. Bush.

* The original version has been updated to note one additional paper.

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I realize you are a geologist and more knowledgeable in that field than I am.  Still, I find this statement a little odd:

It is the ruling paradigm of climate science, in the same way that plate tectonics is the ruling paradigm of geology.”

If there is any field in science that has a “ruling paradigm,” then surely that field is biology, with the ruling paradigm of evolution.  Life would not exist in the absense of evolution.  On the other hand, geology exists in the absense of plate tectonics, and climate exists without anthropogenic influence.

RobH writes:

  On the other hand, geology exists in the absense of plate tectonics, and climate exists without anthropogenic influence.”  

~ ~ ~ 


Think about the evolution of life on this planet and the many ways it has been intinityly intertwined with geology.

Life on this planet wouldn't be possible where it not for those floating tectonic plates and that roiling planet they are floating on and likewise our planet's life has made a huge difference to how the geology has unfolded.  Think subduction and flux, erosion control, chemical process, etc, etc, etc.

~ ~ ~ 

Grab some popcorn and do a little easy learning


How Earth Made Us Episode guide

Just a slivery of the wonder of it all.


Rob, been rereading your comment.  I realize I went off on a side show.  But, dude the more I read your comment the more confusing it gets.  Whatcha try'n to say?

RobH: “If there is any field in science that has a “ruling paradigm,” then surely that field is biology, with the ruling paradigm of evolution.  Life would not exist in the absense of evolution.  On the other hand, geology exists in the absense of plate tectonics, and climate exists without anthropogenic influence.”

I think what you might mean is: “Modern biology is based on evolution, just as geology is based on a slowly but continually changing planetary crust.” Biology and geology are both, as their names suggest, studies of phenomena. Neither could really exist without their subject matter.


Dear DeSmogBlog

Your pie chart is interesting, because it suggests that orthodoxy of “climate change” has now become so complete that no debate may be permitted. The term “climate change denier” implies just such a witch hunt.

The Royal Society was founded precisely to bring scientific enquiry to bear on topics that had previously been settled by dogma. “Nullius in verba”, the motto of the Society, means that one should trust nobody's word until it is verified. Election to the Royal Society is the highest honour for British scientists.

Like most peer-reviewed journals and most government funding bodies around the world, the Royal Society has also adopted the orthodoxy of the “climate change”. It has done so to fit in with government pressure, as has been amply documented. A substantial fraction of its members are in revolt against this decision because it violates the logic of scientific enquiry which holds NO orthodoxy inviolate. Their reasoning is set out in this paper http://www.thegwpf.org/images/stories/gwpf-reports/montford-royal_societ....

Obviously, this doesn't affect the validity of your pie chart. What are 42 scientists among the thousands of peer-reviewed articles you cite? Perhaps you should consider the evidence they present before dismissing them.

Matt Schofield

“Like most peer-reviewed journals and most government funding bodies around the world, the Royal Society has also adopted the orthodoxy of the “climate change”. It has done so to fit in with government pressure, as has been amply documented”

I have always been puzzled by claims of this sort, since most (if not all) governments I am aware of seem to be running as far as they can from any evidence of global warming for fear they might have to actually DO something about it, especially something that might upset the politicians' wealthy backers.

Why else are we always hearing about research being underfunded, research stations and research programs being shut down, and scientists concerned about the problem being muzzled?

Mr. Schofield,

The pie chart shows that there is an opportunity for the achievement of real glory in the field of climate science.  There is a greater name to be made in showing that almost everyone was wrong than in showing that almost everyone was right, and it is reasonable to assume that a good many scientists have considered the possibility of attempting that greater sort of glory. Why has no one achieved it?  Either the world's scientists are nearly all intellectually dishonest AND have engaged in a highly efficient conspiracy to suppress heterodox views – or, the majority opinion is largely right.  Isn't it possible that the latter explanation is the more plausible?


First, just so you know the marketing department at my company was shoving all kinds of articles from gwpf recommending increased oil, gas and fracking.  I think you should know that.  The gwpf sells gas.

Second, I've made it my mission to read scientific papers with dissenting positions on Climate Change.  Most, if not all are refuted, and others are, well, complete crap.  And I have done a lot of work on solving this myself.  In any case there is nothing meaningful to be read.

So please, for the love of God, if you have a paper that has any merit, please recommend it.  So far everything I've looked at is useless or already utterly refuted.

“The term “climate change denier” implies just such a witch hunt.”

No, it does not. Witch hunts are irrational vendettas conducted by a societal mainstream against a perceived internal threat.

“Climate change denier” is a term of disrespect implying that those who deny climate change are the rough equivalent of flat earthers, Holocaust deniers, and birthers – i.e., they take a position contrary to evidence and hold to it no matter how marginalized it makes them. 


Well, I would recommend actually READING the paper http://www.thegwpf.org/images/stories/gwpf-reports/montford-royal_societ....

Your pie chart suggests that no serious scientist questions Climate Change at this point, because few are publishing articles in the press. This paper details the kinds of establishment pressure being exerted on research scientists at the very top of the British Science establishment precisely to suppress alternative views. These aren't unsubstantiated “claims” but straightforward documentation of the process by which the leading scientific learned society has been nobbled by Climate Change orthodoxy. And at least 46 very senior scientists felt strongly enough about it to cause a public scandal.

The very term “climate change denier” illustrates the sense of witch hunt that you are trying to propagate. Unfortunately, scientists are no more moral or courageous than the societies that they live in - if you disagree, I highly recommend reading Cornwell's “Hitler's Scientists” http://www.amazon.com/Hitlers-Scientists-Science-Devils-Pact/dp/0142004804. It is fortunate, therefore, that senior scientists from organizations like the Royal Society with no allegiance to “Big Oil” or any of the demons that you conjure up, remain cool and determined to question your orthodoxy.

It's not MY pie chart. I have really nothing to do with this argument, just trying to make sense out of it, and perhaps learn enough to maybe cut down a bit on whatever damage I am doing to the planet and coming generations.

However, I find it interesting that you should direct me to an organization that, while lambasting the Royal Society about its lack of independence, at the same time adamantly refuses to reveal its own sources of funding.

I'm afraid I'm not impressed by double standards.

And of course you had to bring up Hitler. Haven't you heard the saying that in any internet argument someone will sooner or later bring up Hitler? That side inevitably loses.

OK, I just Googled “nullius in verba royal society climate”. Here are some other sources if you don't like giving clicks to that particular place:








Delighted that you don't like double standards. I thoroughly expect you NOT to take my word for anything. Nullius in verba, old chap.

On the Hitler point, you are wrong. Here is Hitler on the subject of Climate Warming http://www.youtube.com/watch?v=cTGLpqFGyYM

Hey, I just figured out who is behind the climate change conspiracy - it's Reality! All the AGW deniers are being persecuted by Reality, but they are determined to never accept Reality.

Kudos! Props! and all that.

I'm curious, of the 113 citations for the 24 articles rejecting global warming, how many were from other articles rejecting global warming and how many were from articles refuting their premise?

Of course they would dispute this article as well … http://skepticalscience.com/No-alternative-atmospheric-CO2-draw-down.html# It boggles my mind how times some of these climate deniers have been debunked by climate scientists and caught with their bogus petitions, etc. yet keep coming back unscathed, carrying on as strong as ever. A scientist can make one small error and science is the loser. The deniers can make serious mistakes and yet somehow science still comes out the loser!

I tend to think that geology comes first. A planets chemical composition and the precense of a carbon cycle seems to be of some vital essence for even there to be any form of evolution happening. :)

Other than that I think its always interesting to see climate in a geologically long time perspective like the HHMI holiday lectures 2012:


“To be classified as rejecting, an article had to clearly and explicitly state that the theory of global warming is false or, as happened in a few cases, that some other process better explains the observed warming. Articles that merely claimed to have found some discrepancy, some minor flaw, some reason for doubt, I did not classify as rejecting global warming.”
When you look at the methodology, the results become worthless. A conscientious, objective scientist would rarely “clearly and explicitly state” that the theory of global warming is false etc etc. By limiting the  results to that and eliminating those who expressed “some discrepancy, some minor flaw, some reason for doubt,” the results are rather predictable.
What's implied is that except for those 24 papers the others all support it. And based on his methodology that simply isn't the case.
Here's a challenge. Do the study in the other direction. Search for unequivical support of the consensus by including only those papers that “clearly and explicitly state” that the majority of the warming of the 20th century is anthropogenic, and that if we continue BAU we will be faced with temperatures over [pick a degree] and sea levels at least [pick a number] higher by [pick a date].
That's the study I'd like to see. Has any been done that asks scientists to weigh in on the ACTUAL ISSUES that divide the sides?
This study is just more propaganda fodder like Doran's study.

First, I think that this was a good idea, and you very clearly explained the methodology. Good science :-).

Couple things, neither new:

1) It would take a huge amount of time, but a more informative question would be the percent of effect that the papers assigned to the various proposed causes. As the search was done, the answer was highly conditioned by the question, making it equally valid to ask if the paper absolutely rejected any contribution by any other causal factors.

2) The other comment is that it is not surprising to me, that so few of the authors are breaking rank. It is obvious to me that there is a religious fervor to the proponents of man-made global warming, not to mention concerns about future funding. This fervor seems reminiscent of churchmen in Galileo's day.


Let's get real. We burn over 90 million barrels of oil every day, and a similar amount of oil and gas. If we convert coal and gas to oil equivalents, we burn off 300 000 litres of oil per second.This means we pump more than 35 billion tons of extra CO2 into the atmosphere per year.  If you really are willing to believe that this has no negative effects on the environment - if you actually believe in the deniers' null hypothesis: “There is no correlation between the emissions of fossil carbon and global warming”, you should also be willing to believe in the tooth fairy, that the world is 6000 years old and that it is flat. You should also be willing to believe that the world's biggest carbon profiteers - the biggest oil exporters: president Putin (Gazprom), the Saudi Royal family (Aramco), the people controlling fossil fuels in China: the princelings of the Chinese communist party (PetroChina and Sinopec), the petro tyrants in OPEC, their friends in the USA, like the Koch bros and the CEOS in ExxonMobil, Chevron, Shell BP etc are just philanthropists. And you should be willing to believe that these profiteers do not produce tons of disinformation and propaganda to protect their interests. Let's make 2014 the climate year!  http://ufbutv.com/2014/01/11/make-2014-the-climate-year/ 


Interesting research, but I have to clear some things up.

1. No one is denying a climate exists or changes. The way you've portrayed the dispute is misleading.

2. So-called 'deniers' don't dispute the underlying physics beind anthropogenic warming. So even skeptical researchers papers would fall into the catagory of 'global warming' so I'm surpised there's even 24 papers out of the collection, there should be 100%(that depends on what the researchers were studying of course).

3. The real dispute comes under the models used to predict future events, those predicted events being catastrophic and thus where the term alarmism is used. This predicted doom and pessimistic outlook enables political groups to spread fear among the population and put pressure on politicians. Because the predicted events are far into the future, the proponents of the models have no consquence for their actions as they will be long dead. Lots of things could happen to change the climate within the time frame of predictions even if the models are correct which they won't be, thus, it is very naive to use predictions to spread fear and panic and set finanically costly policies around the world. This is one of the disputes anyway.

4. So the real questions and concerns being asked by skeptics of the alarming claims, is: (1)how much are humans contributing to temperature changes? (2) Is it even worth worrying about or can there be an argument for if the effects are automatically 'bad'? (3) Are there better ways of spending public money than what is being done now under the pretence of fear and lobbying by private corporations and NGOs who receive the public money? (4) How reliable are climate predictions? (5) How can we make the scientific process more open and less of a monopoly behind closed doors? This effects us all and we have a right to see how certain researchers have arrived at their conclusions, no one should be chased out of a peer-review journal because their conclusions were less alarming. (6) How much does politics interfere with the scientific process? Among many others.

Ake, you're behaving really irrational. Why do you keep repeating the burning oil thing? No one is disputing that human CO2 doesn't go into the atmosphere or that it doesn't have an affect. The question is how much a part does it actually play? The hysteria that is occuring now - blaming every new storm on human activity for instance - is preciesly the kind of unsupported claims that spurs the skeptics on. Blaming all criticism on a conspiracy theory involving an oil corporation is convenient but the science should speak for itself.

As for the money, it goes in all sorts of different directions. Grants, 'renewable' start up companies, NGOs (non-governmental organizations). In Britain alone the tax payer is having to spend £18.3bn a year until 2050 (in total an average of £730bn will've been spent) to reduce a minuscule amount of CO2. China, India, and Pakistan do not care for any of this fearmongering about the evils of human CO2 and will continue to negate. So yet another question - is this the best way to spend nearly a trillion pounds? Why should someone be called a 'denier' or 'disinfo agent in the pay of big oil' for simply being concerned about how their tax money should be spent?

I think that the writers, 76,and Some elaboration, should get together and compare notes. One said affect where it should have been effect, and the other said effect where it should have been affect.

Also, I have been very cold and very hot, and, believe me, hot is better. If some plant-growing gas is put into the atmosphere, what is wrong with that? Growing time for crops will expand wonderfully, and isn't that a better thing to feed the world's population? That is, providing we quit taking all of the farmland away each year and paving it over, and putting in a parking lot, as Melanie sang. On top of that, the trees like it, which gives me more air to breathe, and that is fine with me.

Scientists will understand, and reasonable people will agree.