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Climate Hustle

The 97% consensus on global warming

What the science says...

Select a level... Basic Intermediate Advanced

97% of climate experts agree humans are causing global warming.

Climate Myth...

There is no consensus
The Petition Project features over 31,000 scientists signing the petition stating "There is no convincing scientific evidence that human release of carbon dioxide will, in the forseeable future, cause catastrophic heating of the Earth's atmosphere ...". (Petition Project)

Science achieves a consensus when scientists stop arguing.  When a question is first asked – like ‘what would happen if we put a load more CO2 in the atmosphere?’ – there may be many hypotheses about cause and effect. Over a period of time, each idea is tested and retested – the processes of the scientific method – because all scientists know that reputation and kudos go to those who find the right answer (and everyone else becomes an irrelevant footnote in the history of science).  Nearly all hypotheses will fall by the wayside during this testing period, because only one is going to answer the question properly, without leaving all kinds of odd dangling bits that don’t quite add up. Bad theories are usually rather untidy.

But the testing period must come to an end. Gradually, the focus of investigation narrows down to those avenues that continue to make sense, that still add up, and quite often a good theory will reveal additional answers, or make powerful predictions, that add substance to the theory.

So a consensus in science is different from a political one. There is no vote. Scientists just give up arguing because the sheer weight of consistent evidence is too compelling, the tide too strong to swim against any longer. Scientists change their minds on the basis of the evidence, and a consensus emerges over time. Not only do scientists stop arguing, they also start relying on each other's work. All science depends on that which precedes it, and when one scientist builds on the work of another, he acknowledges the work of others through citations. The work that forms the foundation of climate change science is cited with great frequency by many other scientists, demonstrating that the theory is widely accepted - and relied upon.

In the scientific field of climate studies – which is informed by many different disciplines – the consensus is demonstrated by the number of scientists who have stopped arguing about what is causing climate change – and that’s nearly all of them.

Authors of seven climate consensus studies — including Naomi OreskesPeter DoranWilliam AndereggBart VerheggenEd MaibachJ. Stuart Carlton, and John Cook — co-authored a paper that should settle this question once and for all. The two key conclusions from the paper are:

1) Depending on exactly how you measure the expert consensus, it’s somewhere between 90% and 100% that agree humans are responsible for climate change, with most of our studies finding 97% consensus among publishing climate scientists.

2) The greater the climate expertise among those surveyed, the higher the consensus on human-caused global warming.

consensus studies

Expert consensus results on the question of human-caused global warming among the previous studies published by the co-authors of Cook et al. (2016). Illustration: John Cook.  Available on the SkS Graphics page

consensus vs expertise

Scientific consensus on human-caused global warming as compared to the expertise of the surveyed sample. There’s a strong correlation between consensus and climate science expertise. Illustration: John Cook. Available on the SkS Graphics page

Expert consensus is a powerful thing. People know we don’t have the time or capacity to learn about everything, and so we frequently defer to the conclusions of experts. It’s why we visit doctors when we’re ill. The same is true of climate change: most people defer to the expert consensus of climate scientists. Crucially, as we note in our paper:

Public perception of the scientific consensus has been found to be a gateway belief, affecting other climate beliefs and attitudes including policy support.

That’s why those who oppose taking action to curb climate change have engaged in a misinformation campaign to deny the existence of the expert consensus. They’ve been largely successful, as the public badly underestimate the expert consensus, in what we call the “consensus gap.” Only 16% of Americans realize that the consensus is above 90%.

Lead author John Cook explaining the team’s 2016 consensus paper.


Update July 2015:

Here is the relevant lecture-video from Denial101x - Making Sense of Climate Science Denial

 

Last updated on 8 May 2016 by BaerbelW . View Archives

Printable Version  |  Offline PDF Version  |  Link to this page

Related Arguments

Further reading

Further viewing

The "Climate Denial Crock of the Week" video series examines the list of "32,000 leading skeptical scientists."

Naomi Oreskes gives a thorough presentation of the development of our scientific understanding of anthropogenic global warming:

Acknowledgements

Many thanks to Joe Crouch for his efforts in tracking down scientific organizations endorsing the consensus as well as links to their public statements.

Update

On 21 Jan 2012, we revised 'the skeptic argument' with a minor quote formatting correction.

Comments

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Comments 751 to 772 out of 772:

  1. qwertie @749 & 750

    I disagree that we have to follow the framing of those who still deny the consensus and to then basically censor ourselves by no longer mentioning particular studies.

    As for the details from "Consensus on consensus", they are already just a click away and - at a guess - it wouldn't matter at all if that information were also included right within the rebuttal. They'd still ignore and/or twist it to their liking.

  2. After reading way to many pages of this threads, one thing is certain, too many people are simply going to believe what they want to believe.  To deny that there are legitimate arguments on both sides is dishonest simply dishonest.

    Response:

    [DB] You are invited to pick the "legitimate argument" you feel the strongest about, and bring the citational evidence to support it, and post it on the most relevant thread here at SkS.

    [PS] You will do everyone a favour if you check your "legitimate argument" is not:

     - a strawman (ie check what science actually does say in eg IPCC WG1, rather than what someone tells you it says)

     - cherry picking data. The other common denier tactic.

    You might also like to run your argument against this list here. If you still think you have a good argument, then please comment on the appropriate thread. Given USA pull out of Paris, some good news would be welcome.

  3. True, CycleGeek @752, there are people who are so divorced from reality as to believe what they want to believe, in defiance of the actual state of affairs.

    If you yourself are not one of these people, then you will now (having read so many pages) be able to give a brief summary of the "legitimate arguments" against the existence of the scientific consensus.

    Reading this thread, and using the most strenuous skepticism, I have been unable to find any such "legitimate arguments" — so I very much look forward to being enlightened by your reply (assuming you can find any arguments that are not simply delusional and unrealistic as Monckton's ).

  4. A paper by five leading climatologists published in the journal Science and Education found only 41 out of the 11,944 published climate studies examined in Cook’s study explicitly stated mankind has caused most of the warming since 1950 — meaning the actual consensus is 0.3 percent, not 97%. http://yournewswire.com/mit-scientist-global-warming-propaganda/

    Response:

    [DB] In this venue, participants cite credible sources.  In this case, if you wish to cite a published study, then furnish a link to the actual study, and not to some news article that may or may not be misrepresenting the paper.

    Please read this venue's Comments Policy to familiarize yourself with this venue's permitted rules of engagement.  Thanks!

  5. Sorry, Rikoshaprl @754 , but the link you supply mentions the main "leading climatologist" as Richard Lindzen — an ex-climatologist who was so unscientific, that he caused major embarrassment to his colleagues at M.I.T. when he was there.  And the other climatologists your article (at yournewswire) links to, are little better!  Lindzen makes a triple fail, because his own climate predictions are now a full degree Celsius below the present day global surface temperature.   That is a colossal error by Lindzen.  And Lindzen still seems to think there has been hardly any warming, despite all the evidence to the contrary!  Lindzen is severely out of touch with reality.  And his third fail, is that he appears to hold a religious-based belief that Jehovah would prevent a global warming of more than the slightest amount.  Completely unscientific attitude there, as I am sure you must agree.  Among genuine climatologists, Lindzen is a laughing stock.

    Now to the Cook study itself.   Rikoshaprl, it appears you have not read the Cook paper.   If you had read it, then you would see that the second part of the paper consists of questioning the authors of those papers — and here, the authors themselves rate their own papers at around 97% support of the consensus figure found in the first section of the study [i.e. also 97%]

    Sorry, Rikoshaprl, but you haven't a leg to stand on.

    Perhaps you can inform us of how you came to make such a complete mistake of the real situation.   For your own benefit, you should do some reading about what is actually happening in the field of climate science — and you can learn a great deal, right here at Skepticalscience.

    Avoid foolish propaganda sites such as Yournewswire.  They will misinform you and lead you to embarrass yourself, hugely !!

  6. Just because there is consensus doesn't automatically mean that the view is correct. Historically, scientific consensus has not only been proven to be wrong, but spectacularly wrong...time and time again.

    https://theobjectiveobserverblog.wordpress.com/2017/06/09/there-are-no-climate-change-deniers/

    Response:

    [PS] This sloganeering without a  scrap of support. If you want to dispute, pick a point, back your argument with references/data. If you are taken in by the nonsense in link presented, then I strongly recommend you read here and here

    Please note that posting comments here at SkS is a privilege, not a right.  This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

    Please take the time to review the policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.

  7. The point is that scientific consensus can be wrong. Nobody disputes the following:


    • Prior to Einstein’s general theory of relativity, a magical “luminiferous aether” was considered by scientific consensus as the medium for the propagation of light. Einstein was actually still trying to work the aether into the theory of relativity as late as 1924. Evidence: https://en.wikipedia.org/wiki/Luminiferous_aether

    • Prior to the 1970’s, the scientific consensus for macro geologic processes was not plate tectonics. Evidence: https://en.wikipedia.org/wiki/Plate_tectonics

    • Prior to the 1980’s, the scientific consensus was that there was no such thing as dark energy and dark matter. Scientific consensus was that we could see 100% of the matter and energy in the universe. We now understand that visible matter and energy represent only a small fraction of the matter and energy in the universe. Evidence: https://en.wikipedia.org/wiki/Dark_energy

    • Prior to the 1980’s, scientific consensus would tell you that sauropods lived in lakes and that dinosaurs were cold blooded and extinct. We now understand these things to be entirely false.


    The point is that simply pointing to scientific consensus is not fool-proof. I think this is a valuable input to the discussion.

    Response:

    [PS] You are again indulging in the strawman arguments. Where is the claim that scientific consensus is foolproof?  The claim is:

    1/ There is a scientific consensus on the cause of current warming (and a very strong one at that)

    2/ That the scientific consensus (particularly when strong) is the rational basis for policy making (on any technical topic).

    Feel free to bring evidence against the claim but dont bother disputing non-claims.Take your sophistry elsewhere.

  8. Look, your argument is that anthropogenic causes are proved by scientific consensus. I have presented examples where scientific consensus was not just incorrect by exactly the opposite of what we know today. Although you deleted them. That's the only point. I happen to believe in the anthropotenic causes for cliimate change, but basing that upon scientific consensus is problematic. If you want to talk about logical fallacies, there you go.

    Response:

    [PS] "Look, your argument is that anthropogenic causes are proved by scientific consensus. "

    No, as repeatedly said, that is not the argument and you repeating it does not make it so. Nothing is "proved" in science. What is asserted is that the vast weight of scientific evidence supports the notion of anthropogenic cause, so much so that a scientific consensus has formed on that. It might be wrong, but until someone shows evidence that it does, policy should be guided by that consensus. Show us anywhere in the IPCC report (or peer-reviewed paper) where it is claimed that anthropogenic warming is proved by consensus. That is a nonsense statement. The papers discussed above simply a methods to determine whether a consensus exists.

  9. I agree that scientific consensus is that climate change has anthropogenic causes. I think I was pretty clear about that.

    Response:

    [PS] Great but didnt say you didnt. I am saying that you are making claim about that means that neither the article nor any scientific source actually makes. (ie a strawman).

  10. I am not going to make the argument again but post 712 sums it up splendidly. 

    TLDR: read the paper by Cook et al and you will see what the consensus is really about. Not that much shocking facts. Human activity is creating greenhouse gas and this impacts the global climate. 

    So basically I would advise any skeptic to read and think for themselves. Don't accept what is pre

  11. I can't edit, so I will rephrase that last sentence. 

    Don't just accept what is presented to you, think critical and challenge the assumptions. 

  12. Unfortunately many of the links have aged out in your "Scientific organizations endorsing the consensus" section. You might want to try updating them. Although good luck with the EPA these days...

  13. As this is your first post, Skeptical Science respectfully reminds you to pleIt  ase follow our comments policy. Thank You!

    It is one thing to establish Global Warming, it is quite another to reach fairly accurate conclusions or predictions concerning the effects.  Most projections I've seen mention a rise in sea level of maybe several inches over a 20 year period.  With that one scenario, don't you think that human ingenuity and engineering skills can meet the challenge?

    Response:

    [PS] This post is offtopic. Any responses to it, put in appropriate thread and post only a link to it. To find an appropriate thread, use the search tool or look under arguments (eg taxomony, "its not bad").

    Also please cite your sources of information. Note for instance that Stern report for instance costed adaptation. The argument is that it is cheaper to get off fossil fuels than adapt. (I assume you are happy to pay for seawalls in areas affected by typhoons and monsoon river levels to pump, in countries that have contributed next to nothing to the problem.) Please respond on "its cheaper to adapt" thread.

  14. The laws of physics are not in dispute whereas those of geology are. The laws of physics apply to an infinite number of possible events at any time: geological theories state whether certain events occurred at certain times on this one planet. The laws of history are endlessly debatable. The laws about which there is the greatest certainty are capable of mathematical formulation: those about which there is least certainty are not.
    Is there a mathematical formula agreed by the 97% in the matter of global warming according to which the future can be predicted depending on stated variables? If so, what is it?

  15. Adrian White @764 , regarding "the laws of history" [your quote] ,

    Adrian, you appear to have a very strange and peculiar definition of the meaning of the word "laws".

    By failing to use English words in a standard English sense, you render your comments rather meaningless.   Please re-state (more intelligibly) the ideas you are trying to convey.

    (B) Question: Is there a mathematical formula agreed by 97% of biologists, which will describe & predict the processes of Evolution?   If so, what is it?   If not so — then we must presume that Evolution is false (and a form of Junk Science).

    We need better communication from you, please Adrian !

  16. Climate change is real and has very clear anthropogenic causes. Countless people have died due to smog and pollution, proven. It has a negative impact on the environment, proven. CFCs and other greenhouse gases created a hole in Antarctica's ozone layer, proven. Banning CFCs helped the ozone layer heal, proven. Just because oil conglomerates will lose billions switching to renewable energy and it's more expensive for them to observe emissions regulations while mass producing plastics doesn't mean the science behind industrialization changing our climate isn't true.

  17. How is anyone against what the scientists are saying against global warming? They're telling you to, you know, drive less, use less coal/petrol/other forms of fossil fuel, don't litter, recylce, etc. To me, it seems win-win either way and so far anyone who wants to disbelieve these scientists seem to be trying to justify themselves for their environmentally destructive behaviours. Let's give everyone a benefit of the doubt and use two hypotheses:

    a) Global warming is real.
     If it is real, then if you do all the things the scientists are saying, you'll be slowing down the process. Sweet, we get extra years, we don't have to experience such extreme weather conditions/changes, etc. Good for us.

    b) Global warming is a hoax.
     If it is fake, then if you do all the things the scientists are saying, you'll be cleaning up the planet. Sweet, we get a clean planet to live on. Good for us.

    So tell me, why is it so hard for you to accept global warming?? Do you only disagree because it seems like the "mainstream" thing to do and you want to seem "different"? I never understood this.

  18. Also, this article:

    http://humanevents.com/2014/03/24/the-carbon-dioxide-level-is-dangerously-low/

    David Archibald says "higher level of CO2 is better for all lifeforms on the Earth" - OK, well, can we trap him in a room that only has CO2 in it and see how much he benefits from it? I would love to watch that. For scientific purposes.
    CO2 is a waste material for any species that requires cellular respiration - and, uh, there are heaps of species like this out there. Tell me you at least know this. In case you didn't pay attention in Biology classes in high school, the waste products of cellular respiration is H2O and CO2. That's why you have to breathe out and pee. Bottom line: humans, as well as many lifeforms that are not plants, do not benefit from high CO2 level. Who benefits from the waste products?

    He says "lucky for us, the relationship between CO2 level and temperature is logarithmic, not arithmetic" - buddy, a logarithmic relationship increases faster than arithmetic. This is where you lost all credibility. You can't even tell the difference between the two and claim to know "science".

    Lastly, our good old David is also a CEO of an oil company in Australia. You know why he keeps claiming there's no global warming? It's cos he's losing money if you believe the facts. Wake up.

  19. I can't edit my comment there, but @767, I meant "How is anyone against what the scientists are recommending against global warming".

    I sincerely believe that global warming is real.

  20. As this is your first post, Skeptical Science respectfully reminds you to please follow our comments policy. Thank You!

    Found this forum on a link posted on a POW(Protect our Winters) EM article I recieved. I consider myself an open minded person and willing to listen to many points of view and draw my own conclusions from the facts presented, regardless of my personal opinions.  My views have changed on several things over the years.  Winston Churchhill, hardly a scientist but certianly one of the biggest influencers on the course of 20th century history, once said that "if you are not a liberal in your twenties you have no heart, and if you are not a conservetive in your forties you have no brain."

    The heart creates passion, and passion emotionalizes arguements, obscuring the validity of points of contention.  One of the obscured points is the method that one of the cited studies was conducted, the Doran study, conducted by Margeret R.K. Zimmerman, as a grad student under Doran's direction.  Points that make you go huh?... 10,257 surveys were sent out. 3,146 bothered to respond.  Does that mean 7,111 questionaires were not delivered? Or that the intended recipients had no opinions, yea or nay? Only 30%, give or take, bothered to respond. Only 79 respondents answers were eventually used to come up with the 97%- the other responses supposedly did not come from "climate scientists" so they were not used.  Why were they even sent?  There are other questions that arise from the conclusions that were drawn from this study but I think the point is made.  When any survey requires closed answers the results must be considered with a skeptical eye.

    Facts are not arrived at by consensus.  If this were true, the earth would still be flat, and Giordano Bruno's burning by the Vatican Inquisition in defense of geocentrism would be justifiable. Aristotle's expansion on spontaneous generation were accepted as fact for over 2,000 years! Neaderthals are not ancestral to modern man! Micheal Bradley's assertation of Neanderthalic genitics in "The Iceman Inheritance" was laughed at and later decried as racist. Indeed, the scientific community's persecution of any one who questions the dogma of the alarmists who have made substantial financial gains espousing the global warming/end of the world would be entirely defensible.  One of Micheal E. Manns (the hockey stick guy) claims in the defamation lawsuit against Mark Styen,et al., was that it is (or should be) a crime to defame a Nobel Prize winner.  Of course he is not, and it is not.  This claim was dismissed from the suit. The financial gains to be garnered by silencing any thought contrary to the prevailing AGW theocratic dogma is too great to be allowed a voice.  This site has poo-poo'ed Judith Curry and some of her claims, but I have found more open minded and even handed writings on her site, on both sides of the issue. Humankind thinks that they are of gret consequence but the truth is we are like all other afflictions this globe has suffered, and when she tires of us she will shake us off like raindrops and without a second thought.

  21. Windrunner @770 , welcome (back) to SkepticalScience !

    If you have come to defend Dr Judith Curry's reputation as a scientist, then alas you come too late.  That ship has sailed.

    If you have come to argue that the climate scientist consensus on AGW is anything less than 99%, then alas you come 30 years too late.  The consensus has been steadily rising for many years now, and has reached 100% (or more precisely:  100% minus a few crackpots, who are entirely unable to provide any valid contrarian scientific reasoning or supportive facts).

    In addition, your "Churchillian" quote is wrongly ascribed.  There have been many versions of it -— the Twenty-First Century version is:  "If you are not a liberal in your twenties you have no heart, and if you are not a conservative in your forties you have no brain, and if you are not an environmentalist by your sixties then you have no conscience."

  22. "Facts are not arrived at by consensus"

    This is a very tiresome strawman argument. We agree. However, the important facts are: a/ the consensus does exist and b/ scientific consensus (especially when strong), is the best guide to policy.  A true scientific consensus is very seldom wrong and you would be an idiot to bet the planet on it being wrong.

    Citing pre-scientific examples of societial consensus (a very different thing) is pointless. 

    "One of Micheal E. Manns (the hockey stick guy) claims in the defamation lawsuit against Mark Styen,et al., was that it is (or should be) a crime to defame a Nobel Prize winner." Citation please. What were his actual words?

  23. I agree with the consensus research. But I want to address something to those who don't believe it. That is: is there NO CHANCE that these scientists are correct? As in zero? It's hard for me to accept that a thinking person could rule out the possibility unilaterally.

    So let's assume for argument's sake that there is some chance these scientists are right, and that climate change is as real and dangerous as they say. Maybe not even a 50% chance. Maybe just a 20% chance.

    Now put a single bullet in your 5-chamber revolver, spin the cylinder, point it at your child's head, and pull the trigger. Why not? There's only a 20% chance it will go off, and an 80% chance it won't. But of course no reeasonable person would do that because the consequences of being wrong are unthinkable.

    I would argue that climate change isn't that different. Already, low-lying countries like the Maldives and Bangladesh are losing real estate. Already ski areas in the U.S. are going out of business because winters are warmer. Some lakes have dried up completely. Thousands of square miles of ponderosa pine are dead in the southwest because winters are no longer cold enough to kill the bark beetle. Hundreds of American kids are getting sick because the Lone Star tick is no longer confined to the deep south, but has been found as far north as the Canadian border, bringing with it five diseases and an allergy to mammal meat. And this is just the beginning. Are we ready for NYC to be under water in 40 years? For our farmland to become desert? For wars over drinking water? (Those crazy liberals at the Pentagon are preparing for climate change, check ut their published studies. Maybe we should be preparing, or better yet preventing, too.)

    I happen to believe the scientists are right. But even if you don't, can you reasonably argue that there's no possibility you're wrong?

  24. A scientific consensus does not make a theory correct and it certainly does not rule out the existance of an alternative theory which better explains observations. More importantly, no scientist has made such a claim - it is a deniers favourite straw man arguement.

    The important thing about a scientific consensus it that it is the only rational basis for policy decisions, especially when it is strong. Betting on say a 20% chance of scientists being wrong is a bad bet especially when consequences for getting it wrong are terrible. The research into the consensus was to determine the strength of consensus and lay to rest the unsupported assertion by deniers that there was no consensus.

  25. The 97% mantra is debunked in this empirical analysis, including some rebuttals by actual scientists cited in the 97% claim who say their assessments were misrepresented.

    Any responses to clear up this speed bump would be appreciated.

    https://www.sciencedirect.com/science/article/pii/S0301421514002821

  26. Richard Tol accidentally confirmed the 97% global warming consensus. An "own-goal" if there ever was one.

    There is no doubt in my mind that the literature on climate change overwhelmingly supports the hypothesis that climate change is caused by humans. I have very little reason to doubt that the consensus is indeed correct.

    Own Goal

    LINK 1

    LINK2

    LINK3

     

  27. realelybritt, you should have followed the link included in the paper you referred. All this is old news. Cook et al published a response to Tol 2014, here are the highlights:

    T14′s consensus value is based on a math error that manufactures ~300 nonexistent rejection papers.

    •T14 infers data drift using an inappropriate statistic that poorly correlates with consensus.

    •Analysis of appropriate consensus statistics reveals no significant data drift.

    •T14 wrongly conflates abstract ratings and author self-ratings; differences are detailed in C13.

    •Re-analysis without T14′s errors confirms 97±1% consensus on AGW

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