Climate Change: A Consensus Among Scientists?

Wednesday, December 23rd, 2009

Off the back of the recent Climate Skeptics vs The Consensus image, we were curious how many scientists might make up ‘The Consensus’.

The Skeptical side claims at least 31,486 dissenters in their ranks, according to the That sounds like a lot. But is it?

Climate Change: A Consensus Among Scientists?
Of course, not all 12 million US scientists therefore agree with ‘The Consensus’. But this puts the PetitionProject’s 31,486 signatories in some kind of context.

Our maths here is somewhat coarse. Some better data suggests the ‘consensus’ figure is around 97.5% of publishing climatologists and around 90% of all publishing scientists supporting the human-induced climate theory. See this study for more details (PDF – Doran And Zimmerman 2009)

Actually, here’s how some of it looks:

Climate Change: A Consensus Among Scientists 2

Skeptical Field

Among the climate skeptic scientists, we wondered which fields of science were most represented. We expected climate and earth sciences. But we got…

Climate Consensus: Breakdown of skeptical scientists by field

In fact, when you adjust the PetitionProject’s odd categorisation – they filed ‘chemical engineers’ as chemists and physical engineers as ‘physicists’ – the total number of engineers who signed the petition, by our reckoning, jumps to 49%

Why so many engineers?

UPDATE 1: 23rd Dec 09. Thanks all for the excellent feedback (and barbs!). The language and presentation have been adapted now to hopefully better reflect our exploratory intentions.

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  • boardmanric

    As Mark Twain observed” There are Lies, Damn Lies, and Statistics”

  • gm

    Couple of comments:
    - Galileo was not wrong, but he was most certainly not in the consensus group of his age. He followed the data, not the dogma.
    - GW is now a dogma, heavily politicized and with massive business interests pushing it. Many of those who do have pure motives (saving the planet) are blinded by their dogma.

    On a personal note, as a lifelong environmentalist, I bought the whole GW thing hook, line and sinker until a friend challenged me to look at the data. I argued fiercely for it, trotting out all the usual info the GW crowd uses, then set out to prove my friend wrong.

    As a scientist, I looked at the data dispassionately and disccovered, to my great shock, that not only was there no compelling evidence for human-created CO2 causing GW, but that there is no evidence that unusual GW exists outside the usual natural cycle, there is evidence that we are now entering a cooling cycle, and there is evidence that climate change over time has been caused by many things (sun, orbit, volcanos, undersea vents, etc etc). I could go on for pages about all the very serious issues with the “science” behind GW, but others have already done this better than I could.

    The problem with the GW hysteria is that it is directing resources and political will away from proven, serious, environmental issues that are doing harm to life on Earth (e.g. deforestation, poaching, fertilizer runoff, ocean garbage, …)

    Another problem is that we may go and do something really stupid (seeding the oceans with iron, putting an aerosol sunscreen around the earth, etc) that could actually disrupt the balance of nature and cause a true global catastrophy.

    When it comes to climatology, we should think of ourselves as the Sorcerer’s Apprentice. Anything we DO is likely to cause problems. (As opposed to anything we STOP doing, which would be beneficial, like stopping destroying the Americas rainforests)

    Further, GW has now been twisted and co-opted to somehow justify misguided policies that redirect food to be used for fuel (ethanol), causing all sorts of negative, (presumably) unintended side effects.


  • Anxious Medic

    Actually, boardmanric – that was Disraeli, not Twian, and as far as your “math” on how many scientists the consensus represents – where are you getting these numbers from? If you new anything about stats a sample size of over 10 000 is a heck of a lot and more than enough to infer trends in a population, given proper randomization and requal representation from all fields, and surveying every member would be nigh impossible – that is why we have statistics. To protect yourself from bad stats, learn about stats: don’t dismiss them and call them lies.

  • João Jesus

    And this is merely the US. There are many other scientists worldwide so I think the % of skeptics would reduce even further

  • Colin Daniels

    It’s prudent to point out that the 31,000 scientist who have signed it far outweigh the scientists who are actively working on global warming research with the U.N. I’d love to see that visualized, as it would tell a different tale.

  • Bern

    Anxious Medic: You’re right, 10,000 is quite a large enough number to represent a population. The next question is: what population? Was this sample randomly selected from all scientists in the US? Or does this ‘sample’ represent “the people who not only object to ‘global warming’, but are willing to come to our website and fill in an online survey, claiming they are a scientist, but we actually don’t ask for any proof of any qualifications”?

    So, yeah. Protect yourself from bad stats. :-D

  • Brian Williams

    Since Climate Scientists are funded by government who accept de facto AGW, and are unlikely to fund a study to see if AGW exists, I’m not surprised that so few are sceptical. Turkeys don’t vote for an early Christmas/Thanksgiving do they?

    I’m more surprised that you bothered to put that figure in.

    I’d be quite interested to know the first degrees that these scientists have, particularly the Climate Scientists. I’m certainly not surprised that Atmospheric Scientists appear there. They are probably the ones with tenure.

    Have you considered how difficult it must be to fight against the orthodoxy?

    Can you imagine being a biologist who does not believe in Darwin’s theory? They aren’t likely to shout about it are they?

    Re: Engineers

    My guess is that there are so many engineers there because (a) they know enough science / stats to see through the garbage that’s being put forward (have a look at Harry’s File in the Climategate emails; Steve McIntyre of Climateaudit is an engineer. His site is so named because he wanted to audit the science; that is, get hold of the data and reproduce the results, like a good scientist / sceptic would do, and that’s what got Climategate rolling.)

    (b) they are used to working in field where sloppy thinking means death.

    (c) they are less likely to be in academia where spiteful “colleagues” will stick the knife into their careers.

  • / Minneapolis Electrician

    There are always 2 sides of the same coin, but I must say, I’m studying a great deal from your site. Sometimes others have very limited mindset, that’s why they fail to understand the other people.

  • Will H

    Hello? Chemical engineers work mostly in the fossil fuel energy industry. No oil, no gas, no coal, no job. Get it? The same applies to many mechanical and civil engineers, although in not as high %. Counting engineers as scientists is just silliness. Also let’s not pretend that all scientist know anything about climatology.

  • Johan Bazuin

    Opinions proof nothing, only facts do. The evidence isn’t good enough to assume global warming is caused by CO2.

  • Sophie
    This is a good link that mentions that only 39 of these people were climate change scientists.

  • Dal Jeanis

    While your presentation is attractive, it has two major flaws in truthfulness –
    (1) starting with the results from a survey with a mere 30% response rate, designed as inherently self-selected, and not as I read it clearly anonymous, on a subject that has potential for politically based career damage to people on the skeptic side {see England, Met Office, for one example},
    (2) going on to falsely conflate mildly positive answers on that survey, on a question with the specific words “a significant contributing factor”, with a belief or consensus by those respondents in whatever the global warming proponents are claiming this week – usually that human-caused global warming is “the primary” cause of any such temperature change. That’s just not what the respondents answered, and any claim to the contrary is disingenuous at best.

    That survey cannot thus be truthfully used as support for your estimate of 80-90% consensus of scientists with the GW industry’s political statements, and your graph above comes into focus as pretty, but propaganda.

  • Kristian

    Great website! Really puts a hole in the skeptics claims doesn’t it! It demonstrates the importance of percentage rather than simple absolute figures!

  • Phil M

    It’s funny to see the amount of people that are obviously “skeptics” or who call themselves an engineer or allude to some other professionalism……………but fail to be able to read the actual words written:

    “Of course, not all 12 million US scientists therefore agree with ‘The Consensus’. But this puts the PetitionProject’s 31,486 signatories in some kind of context.”

    Its no wonder that their confirmation bias determines their position on this subject & makes those words disappear like some sort of informational blindspot. No wonder they can’t understand climate change & the science surrounding it.