It’s Settled Then. Overwhelming Agreement on Climate Change

April 14, 2016


There is an overwhelming expert scientific consensus on human-caused global warming.

Authors of seven previous climate consensus studies — including Naomi Oreskes, Peter Doran, William Anderegg, Bart Verheggen, Ed Maibach, J. Stuart Carlton, John Cook, myself, and six of our colleagues — have co-authored a new 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.


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 12% of Americans realize that the consensus is above 90%.

Scientist Bart Verhegen:

Most scientists agree that current climate change is mainly caused by human activity. That has been repeatedly demonstrated on the basis of surveys of the scientific opinion as well as surveys of the scientific literature. In an article published today in the journal Environmental Research Letters (ERL) we provide a review of these different studies, which all arrive at a very similar conclusion using different methods. This shows the robustness of the scientific consensus on climate change.

This meta-study also shows that the level of agreement that the current warming is caused by human activity is greatest among researchers with the most expertise and/or the most publications in climate science. That explains why literature surveys generally find higher levels of consensus than opinion surveys. After all, experienced scientists who have published a lot about climate change have, generally speaking, a good understanding of the anthropogenic causes of global warming, and they often have more peer-reviewed publications than their contrarian colleagues.

Scientific consensus on human caused climate change vs expertise in climate scienceFigure: Level of consensus on human-induced climate change versus expertise in climate science. Black circles are data based on studies of the past 10 years. Green line is a fit through the data.


20 Responses to “It’s Settled Then. Overwhelming Agreement on Climate Change”

  1. mboli Says:

    No, no! You have cause and effect backward. What this shows is that non-believers in the alarmist religion have a harder time getting published.

    Furthermore you are ignoring the problem of bad siting. Scientists who are sited within areas densely populated by other climate scientists have their perceptions distorted by their environment. These surveys should throw out those badly-sited readings.

    And anyway correlation does not mean causation.

    • livinginabox Says:

      “correlation does not mean causation” – Correct, but that’s the only correct thing you said.
      We have the science – observations; palaeoclimate reconstructions; we have the instrumental record; we have phenological studies; we have the ice cores; and much more. And you sir, use rhetoric and dishonest rhetoric at that.
      Rhetoric versus evidence. There’s simply no contest.

      I refer you to the evidence: Try the IPCC.

  2. redskylite Says:

    Re the last post from “mboli” – Sir, you do attract some oddball posts and the last post is very oddball. Has “mboli” noticed that the JMA have just confirmed March 2016 was Earth’s 11th-straight warmest month on record, has she/he noticed the great tragedy of global coral reefs, the deaths through heatwave in India, the early ice melt up in the Arctic. yet she/he tries to dress it up as cranky religion. Either she/he is delusional or more likely she/he has got his or her interests tied up in the coal or oil business.

    March was Earth’s 11th-straight warmest month on record

    “Data released on Thursday shows that March 2016 was the warmest March since at least 1891, making it the planet’s 11th consecutive month to set a global temperature milestone.

    The data, from the Japan Meteorological Agency, as well as a separate analysis using computer model data, means that if April also sets a monthly record, the Earth will have had an astonishing 12 month string of record-shattering months. ”

    • redskylite Says:

      P.S Even Humble Oil, the company that preceded EXXON knew and boasted about “climate science” in the 1960’s, think you need to substitute the word “deceivers” in place of “non-believers”

      “From 1957 onward, there is no doubt that Humble Oil, which is now Exxon, was clearly on notice” about rising CO2 in the atmosphere and the prospect that it was likely to cause global warming, he said.

    • mboli Says:

      Just thirty years ago many climate scientists were predicting global cooling. The recent perception of an uptick in global warming sentiment is just a manifestation of the return to equilibrium from the recent “little ice age” of cooling sentiment.

      • redskylite Says:

        That myth is so old and debunked you should be deeply ashamed of yourself. That is truly ancient. You must be new to the denial business, not to know it.

      • greenman3610 Says:

        • mboli Says:

          Peter “Greenman” Sinclair has used this handle for many years. Proof positive that Michigan had a warmer climate many years ago.

          • dumboldguy Says:

            Tell us about YOUR handle, mboli. Is it in anyway related to “boli”, as in the balls of dung that dung beetles roll around? Or is it related to “emboli”, those pieces of crud that can break off and block blood vessels, causing strokes if that happens in the brain. Both would be fitting handles for a brain damaged denier. Just sayin’

          • fw134 Says:

            Your parody was almost subtle at first, but I think you just overplayed your hand, mboli.

          • mboli Says:

            But consider this. The statistical models that produce those 91% or 97% or whatever models have NO predictive value. Do either of these groups have a history of accurately predicting the percentage of agreement even five years out? They do no. They are not even consistent. Does the error bar from the 91% study even overlap 97? Or vice versa? If five years from now the percentage of agreement is only 60% they will just quietly adjust their models and pretend they were right all along. This isn’t science. Throwing our economy to the dogs and condemning the third world to perpetual underdevelopment on the basis of this non-science is insane.

          • dumboldguy Says:

            What? I get no thanks for suggesting that you may be a brain-damaged denier? And redsky’s well-received-by-others comment about your amateurishness as a denier is ignored as well?

            You prove our points with this comment. First you set up a “statistical model straw man” made of pure BS and beat on it weakly, demonstrating that you have little understanding of statistics, modeling, or science.

            Then you reveal your true colors with “Throwing our economy to the dogs and condemning the third world to perpetual underdevelopment on the basis of this non-science is insane”. That is one of the first pages in the Manual of Denier BS that is issued to all of you that aren’t smart enough to come up with your own slogans.

            To repeat what redsky said, “That myth is so old and debunked you should be deeply ashamed of yourself. That is truly ancient. You must be new to the denial business, not to know it”.

            Yes, I’m liking my dung beetle analogy more and more. Keep rolling that denier dung ball, mboli, but try not to go in circles.

          • mboli Says:

            Yap. The pun on “Greenland” was ham-handed and weak. Sorry about that. Thank you, @Sir Charles.

          • mboli Says:

            And thank you @fw34!

      • livinginabox Says:

        “Just thirty years ago many climate scientists were predicting global cooling. ” No they were not. There’s even p/r research on this.
        Try being honest. But of course, if you were to try that, we’d be in agreement.

  3. mboli Says:

    Yap! Thanks @dumboldguy also for playing along in fine fashion.
    My favorite was the improper siting of the climate scientists. I briefly considered improper citing of the climate scientists, because the studies start by surveying masses of scientific papers. but it was becoming too complicated and I wasn’t sure people would get it.

  4. tlr165 Says:

    As important as this is, the consensus argument just won’t work to convince climate skeptic hold-outs. They’re convinced academia’s sold out – i.e. no grant $$$ available for anyone who hasn’t already swallowed the climate change kool-aid. They’ll always trot out a dentist who believes otherwise. As Americans, we love the scrappy underdog contrarian who goes against the consensus and is eventually proved correct – at least that’s how it always works out in the moves – and that’s what they rely on to maintain the ignorance.

    I think climate scientists would be better served by describing the actual mechanism of greenhouse effect based on carbon dioxide and explain that this idea has been around since Aarhus back in the 1890s. This is nothing new. Not some scheme cooked up by a bunch of eggheads to make us all socialists.

    Explain it to people – skeptic hold-outs included – instead of talking down to them with the implication that 97% of scientists have done your thinking for you – so you don’t have to. No one likes to blindly follow anyone anywhere – why would that be any different with climate change?

    And no, carbon dioxide is not a pollutant – in fact without carbon dioxide in the atmosphere to raise and regulate atmospheric temperature, we probably wouldn’t be living on this planet. But like any good thing, too much of it can make it become a bad thing.

    The fact is we really can’t do much without someone somewhere burning something on our behalf. We can’t feed ourselves without burning something. We can’t shelter ourselves without burning something. We can’t move ourselves without burning something. We can’t heat ourselves without burning something. We can’t cool ourselves without burning something. Etcetera. That something has overwhelmingly been something carbon-based. That needs to change.

    Finally, yes, there was climate change/temperature increases way back when, way before human beings walked the earth. But I’m pretty sure those increases were also because of increases in carbon dioxide in the atmosphere – only those increases took place over thousands or hundreds of thousands of years. We’re replicating those same increases in only hundreds of years. That’s got to stop too.

    To be clear, I fully accept the reality of human-caused global climate change. But I got there only after I made it a point to understand the actual science behind it all.

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