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Wednesday, 10 June 2015

Consensus and Conspiracy

This post expands on my recent Google+ post (for which there is some text overlap at the start) and draws on my all-purpose philosophy of science article.

Recently American presidental hopeful Rick Santorum has used the "I'm not a scientist" defence to justify why he's allowed to disbelieve in human-caused global warming. Sounds bizarre ? That's because it is. Especially since Rick has expanded this to justify why the Pope shouldn't talk about it (because he's not a scientist), but apparently Rick should (because he's not a scientist).

"Fox News host Chris Wallace pushed Republican presidential candidate to expand on his criticism of Pope Francis for talking about climate change.... “if he’s not a scientist, and, in fact, he does have a degree in chemistry, neither are you …So, I guess the question would be, if he shouldn’t talk about it, should you?” "

It's not often I agree with Fox "News" about anything, but I've been saying this for a while. The "I'm not a scientist" defence is fine provided you don't then express an opinion about scientific matters - or at the very least also state that your opinion isn't as valid. You don't somehow magically become more qualified to have a scientific opinion by not being qualified to actually do science. That's not how it works.

Just to clarify, the Pope doesn't exactly have a degree in chemistry, but he does have something more than a high school qualification. Still, he isn't a scientist. But that's not really the point - the point is that Rick Santorum certainly isn't a scientist at all. He's a lawyer. Even weirder, apparently it's OK for him to go against the scientific consensus, whereas the marginally more qualified Pope is somehow making a mistake by agreeing with most scientists. Cue confused animal meme.

"To that Santorum essentially said that politicians have to talk about things they’re not experts in all the time so anything is fair game. ...  And Santorum pushed back that fighting action on climate change is about defending American jobs."

Yes, politicians have to talk about things they're not experts in. But you wouldn't formulate a financial strategy without consulting the bankers. Rick, you're either saying that a) you're more qualified than the experts but non-experts shouldn't talk about science, which is self-contradictory, or b) you understand the scientific consensus but just don't care about it. Which is like saying that if a team of engineers have told you a dam is about to burst and flood a town, you don't need to evacuate that town.

At this point, Rick, I see no way to avoid labelling you as an idiot.

"At one point, Wallace notes that “somewhere between 80 percent and 90 percent of scientists” who have studied the issue agree. But Santorum is having none of it, calling it a “speculative science” and saying that he doesn’t believe anyone who is so sure of their facts. “Any time you hear a scientist say the science is settled, that’s political science, not real science, because no scientists in their right mind would say ever the science is settled.”

Yes Rick, I agree you shouldn't believe anyone who says an issue is settled. But perhaps you should believe everyone if they say an issue is settled. If a single engineer says the damn will burst, then perhaps you've got a problem or maybe you've just hired an incompetent engineer. If, however, 45 out of a team of 50 engineers say the dam will burst, treating that opinion as mere speculation is a recipe for disaster.

Note what we mean by "settled" here. Amid the continuous furore about whether there's been a slowdown in global warming in the last 15 years or not, or whether it's ocean temperatures or ground temperatures or whatever that we should be monitoring, or individual scandals and allegations of fraud, there's been one single shining constant statement that pretty much every climate scientist has agreed on for decades : it would be a good idea to reduce carbon dioxide emissions as quickly and as much as possible. The rest is just detail.

I'm going to try and avoid climate change specifically for much of the rest of the post, though there will be a few references. Really I'm more interested in the implication that it's OK to disagree with the scientific consensus.

Well, of course it is - up to a point. Scientific consensus does not claim to be the definitive truth, set in stone for all time. It does, however, claim to be the best, most-well informed conclusion possible. Decisions which ignore the consensus view aren't necessarily wrong, but they are based on inferior lines of reasoning (we'll get back to how science achieves and justifies such an exalted status shortly). Even the very word "consensus" implies that some scientists disagree, but when a non-expert chooses to act in a way that goes against the mainstream grain, they ought to have a very good reason for doing so.

The problem is that in practise they usually don't. The two main alternatives to following the consensus are to claim that either scientists are, against all evidence to the contrary, stupid, unqualified and ignorant, or that there's a conspiracy.

1) Scientists don't understand science.

This is what the first argument boils down to. It's essentially saying that scientists understand things just enough to come up with a clever theory, but then somehow they decide to abandon all the logical thought that got them there and jump off the cliff of sanity and be eaten by the Sharks of Madness. Or that every single one of them has somehow just plum forgot about some "obvious" piece of the puzzle that some dude on the internet has been smart enough to uncover. Essentially, the argument goes, scientists don't understand their own theories. It's a mind-wrenchingly silly idea that's somehow very popular with certain Republican politicians.

Basically, this is saying that the people who discovered electricity, created particle accelerators and the internet, discovered how to cure diseases and pretty much made the modern world have no idea how the thing works. Apparently it was all just blind luck with no understanding of theory at all.

Creationism provides a superabundance of such absurdities. Apparently, scientists are clever enough to measure radioactive decay and cunning enough to use atomic theory to flatten cities, but aren't clever enough to realise that it means the Earth is only 6,000 years old. They can design instruments capable of measuring distant galaxies, but don't realise that those galaxies are either very much closer than they think and/or that the speed of light has altered just so as to make the Universe still be only 6,000 years old. Or they think that scientists are just clever enough to understand that time is relative, but don't realise that this too means the Universe is 6,000 years old.

Sadly this line of thinking is by no means limited to Creationists. Most people with radically different alternative ideas espouse much the same thing - which is why I came up with the idea of Wegener's Law*. Anyone comparing their idea to Wegener's (initially ridiculed) idea of continental drift ought to instantly loose the argument. Much like Godwin's Law (anyone who mentions the Nazis instantly loses the argument), you can prove anything you like with extreme examples. Most of the time it's a false comparison.

* Well, guideline, like any debating tactic. But "Wegener's Guideline" lacks pazazz. 

2) It's a cover up !

A conspiracy can take many forms with many different proposed motivations. All of them have one thing in common : they allow you to claim anything. If you think people are simply lying about something, you can make up whatever you like in its place. Which, at a stroke, makes rational debate impossible.

The most blunt form of this is that They don't want you to know The Truth. That form of un-thinking is usually safely confined to the internet where it belongs. However, a much more subtle variety of conspiracy theory has very successfully embedded itself into mainstream thinking : scientists aren't being truthful about climate change because they don't want to expose how badly they've got things wrong, or because their funding depends on following the herd (a false consensus), or even that there is no consensus at all and that's the conspiracy.

The first option is to totally misunderstand the scientific method. Disproving ideas is the heart and soul of discovery. Yes, people who've invested a lot of time and effort into one idea aren't going to be particularly keen on overturning their own work - that's human nature. But by the same token, there most certainly will be people interested in overturning their competitor's work. That's part of the reason peer review (see link for a personal experience) is so important : scientists like to disagree with each other. Something which can stand up to your rival trying to shoot it down is a lot more likely to be correct. Peer review isn't perfectly objective, it's just a damn sight more objective than not doing it at all.

The second option - trying to follow the herd for funding - is by far the most dangerous, because it's the only one that comes close to plausibility. There is a real danger of establishing a false consensus. That's why it's so important that scientists pursue alternative ideas and that there is always some level of funding for this. Indeed, if the alternatives weren't examined, it wouldn't be science at all. But consensus doesn't just magically happen - it happens because lots of people disagreed with each other, considered lots of ideas, had a big row and eventually, largely independently, reached the same conclusion. You don't reach a consensus without at least considering the alternatives first.

In the specific case of climate change there's another factor - absolutely no-one in their right mind would want humans to be the cause of global warming. So the claim here is that thousands of scientists who all want to disprove each other and have no interest in seeing humans destroy the planet must be trying to fool everyone into this awful conclusion to justify their own funding. Yeah, as opposed to, oh, I don't know, oil companies. Now of scientists and oil companies, who do you suppose has the most money at stake ?

The third option - that the existence of a consensus is a lie - is similarly ridiculous. If there wasn't a consensus, there'd be an awful lot of angry scientists who'd be shouting quite loudly about it if people were falsely proclaiming that there was. There aren't, so there is. That still doesn't mean the consensus is necessarily correct, but denying that there is one is an act of desperation.

How a consensus is reached

Slowly and painfully. It is not a democratic process where everyone votes for what they think is most likely and decide to run with it. Unlike electing a government, there is (ideally) no constraint that everyone has to play ball and Obey The Consensus whether they want to or not. Nor does it involve everyone having a big discussion to try and sort things out. A consensus, when done properly, is what most people honestly think is the most likely explanation. It isn't The Truth, it never claims to be the final answer, but it still claims to be the best source of information on which to make a decision - precisely because it isn't reached in a democratic way.

A consensus is reached by everyone brutally attacking everyone else's ideas until all the other ideas have slunk away to lick their wounds and soothe their battered, aching limbs. A consensus isn't the winner of some Athenian democratic election. It's more like a Roman gladiator who's faced down vicious tigers and hordes of screaming barbarians and had his limbs hacked and face mutilated but keeps going.

Image source.
Now in this analogy it's very rare indeed that the victorious gladiator actually kills all of his opponents. He may have cut their legs off or knocked them unconscious but generally they're all still very much alive. And it's just about possible that someone is going to surgically replace the missing limbs of one of the apparently broken theories with a machine gun, and said theory will rise again to blast our unfortunate gladiator into smithereens. Is this likely ? No, you twerp. They didn't have machine guns in Roman times. If you were to bet on a fight between the gladiator and one of his wounded opponents, you'd be wise to choose the gladiator.

A consensus arises not because all alternatives have been disproved (though a few might be) but because they have been shown to be much less likely than the main idea. People often keep researching unlikely ideas long after most people have discredited them - and that's a good thing. We have to have disagreements to make progress, by definition. And, crucially, experts in a field have to be allowed to investigate alternatives - but just because they are doesn't mean that there isn't a consensus.

An expert is like someone sitting in the front row of an arena. They're the ones prepared to fork out the most cash (in realty : invest years of their lives studying to understand something as fully as possible) to get the best seats and look at the action in all its gory detail. They might - on occasion - spot a wounded competitor reaching for a dagger. The people further away are progressively less and less interested and/or able to understand what's going on. And there's nothing wrong with that. Maybe those people aren't much interested in gladiatorial combat [science] but are huge fans of mock naval battles [errr... architecture, sure, why not].

The point is that just because some members of the audience are at the back when one particular show is on in the arena, doesn't mean they couldn't be in the front when something different is happening. And vice-vera. When science is under scrutiny, it's the scientists opinions that matter most. When it's social work, you tell the scientists to shove off and you listen to the social workers instead. Being expert in one area doesn't make your opinion on other subjects more important than anyone else's... but it does mean that your opinion counts for more in your specialist area.

Thus, the people at the back can hardly see anything of what's going on in the arena itself. If they're sensible, they'll bet on the gladiator if he's ordered to keep fighting. Sometimes they might hear people in the front start cheering for someone else. At that point they should expect to find that perhaps one of the competitors isn't so wounded after all, or perhaps someone new is entering the arena : the consensus is changing. But unless that happens, it would be foolish to bet on anything other than the consensus. The people at the front, by and large, are cheering for the least-wounded gladiator.

This even holds if you include the effect of the crowd's support on the contestants. Experts might shout out useful advice ("he's behind you !") and so give a theory a way to stave off death for another minute. Non-experts cheering may at least encourage the gladiator to keep going a little longer. But, if a bigger, stronger, faster gladiator enters the arena, then no amount of cheering will save the once-proud hero. He's doomed. The better theory always wins eventually, though it can take considerable time.

Occasionally, audience members (even experts) can be so blinded by the heroic efforts of one fighter that they'll persist in cheering for him when he is, in fact, quite dead. They live in the optimistic hope that he's merely unconscious, but no amount of cheering will revive him. Eventually, even these devoted fans have to admit defeat - though usually their numbers first dwindle to such small levels that the rest of the audience has forgotten about them by that point.

Finally, no human gladiator can last forever. It's interesting to consider whether the trend thus far of inventing better and better theories - bringing on bigger, better gladiators - will last forever, or whether one day we'll reach a Final Gladiator. Some sort of robotic uber-mech with a nuclear power source, able to sweep away whole ranks of human gladiators with lasers for eyes, perhaps. Or maybe our theories will just keep getting better and better, never reaching ultimate truth.



If you aren't an expert in something, but need to make a decision on a specialist area, by far and away your best bet is to go with the consensus. Consult many experts. If they're all saying something very similar, then the chances are that you're on sound footing. It's not certain - there are almost never any guarantees - but this is the best source of information you've got. Anything else is using an inferior source of knowledge.

Experts aren't omniscient. The price of being the best source of information is that that's limited to a very narrow field of expertise, and specialist knowledge takes a long time to acquire. Those experts who think they are somehow an elite because they happen to know a lot about a very small area of research ought to go back to the Apology* :

"Last of all I turned to the skilled craftsmen. I knew quite well that I had practically no technical qualifications myself, and I was sure that I should find them full of impressive knowledge. In this I was not disappointed. They understood things which I did not, and to that extent they were wiser than I was. But, gentlemen, these professional experts seemed to share the same failing which I had noticed in the poets. I mean that on the strength of their technical proficiency they claimed a perfect understanding of every other subject, however important, and I felt that this error more than outweighed their positive wisdom. So I made myself spokesman for the oracle, and asked myself whether I would rather be as I was - neither wise with their wisdom nor stupid with their stupidity - or possess both qualities as they did. I replied through myself to the oracle that it was best for me to be as I was."

* Seriously, why isn't this compulsive reading in all primary schools ?

So, to finish, let's return to climate change. I am not a climate scientist, so my opinion is at best equivalent to someone cheering from the second tier of an arena. Or in this case booing since I would desperately like the idea that humans are causing global warming to be false. Yet that theory still stands. It's been jeered at by scientists and is still being jeered at by the public, but it still stands. Could it be, therefore, that all of these scientists who'd prefer it to be false, who take a lot of stick from the public for defending a very unpleasant theory, who are continuously defending it against rich oil companies and politicians... could it just possibly be that they're doing this because they really believe the theory is correct ?

That doesn't tell us that it is correct. But the alternatives, as we've seen, are that scientists have a very peculiar and wholly implausible kind of incompetence, or are lying. Neither of these looks remotely likely. Attempts to confuse the issue by drawing attention to every petty disagreement look, to me, like attempts to discredit something people would rather was not true because they'd rather it was not true, not because of what the facts really say. That's why for me, although I'm not a climate scientist, I side with the consenus. I hope I'm wrong... but in the worst case :


  1. Rhys, what objective evidence do you point to that the consensus you claim to Agree with actually exists?
    Is it the Cook et al paper?
    With respect to an overview of the published science within the IPCC reports and solid challenmges to its conclusions ( 95% certainty etc,)this is a very good Critique.

    I note you use the term Climate Change and have not isolated out the question of Anthropogenic Global Warming due to Mans emmisions of CO2. It is this second question and not the more generalised concept of Climate Change where the Consensus claims get much more sketchy.
    I would be interested if you have read Polyanis , the republic of science, Judith Curry blogged about it here.

    1. I suggest you re-read this post more carefully. It's very explicitly NOT about the evidence for and against climate change, but in the perception of the experts. There are tonnes of good evidence-based articles about climate change - this isn't one of them, nor do I intend to ever write one because I'm not a climatologist !

  2. Hi Rhys,
    My question is regarding the Consensus which you refer to, is that just your perception from casual experience? On evidence Based Climate Science again, the ones related to CO2 and AGW are not empirical they are based on modelling assumptions.
    Regarding Conspiracy, convention does not require conspiracy merely group think.
    Thanks for your Reply,

    1. Well, group think is a subtler beast; it does deserve more careful handling, but I find it extremely difficult to believe it could occur on a global scale between different competing institutes (especially in the case of climate change, where, as I said, no-one in their right mind would want AGW to be correct).

  3. Hi Rhys,
    Climate Change is possibly hugely scary, another Ice Age would be terrible, Warming beyond a survivable level would equally be terrible..
    You are a scientist, I am a Philosopher regarding the Co2 AGW hypothesis I would much prefer the scientists to do science without political or faith based emotionalism taking over.
    This gets back to the Crux of the matter The IPCC are hassled from alarmists who claim them to conservative and the Anti´s I suppose we could call them who will never be satisfied.
    What concerns me most is that Great Physicists like Freeman Dyson and William Happer say a case for CO2 has not been made empirically and remain Skeptical.
    Thanks for the other Link, I am not sure there really is a Consensus, A false consensus is a different category I would argue, The other catagory which is also so contentious is this idea of Settled Science?
    I have been busy looking at Energy retrurned on Energy Invested the past few days, finite resources ( fossil Fuels ) and the need to replace energy sources is a hugely pressing problem and one I worry about much more than CO2 AGW, of course if the prodcuction of renewables is pursued as it must be inevitably emmisions become an academic point, without renewables life gets very difficult.