Bishop Hill Nurse's Dimbleby lecture
Feb 29, 2012 Royal Society Paul Nurse gave the BBC's prestigious Dimbleby lecture last night, addressing science and its place in society.
I sensed that Nurse was desperately trying to keep his political side under wraps, as is only appropriate for such an occasion, but I think it's fair to say that hints of his activism crept to the surface occasionally. The presumption that the most likely solutions to global warming would come through some kind of world action and regulation of the nation state was one such, although it is fair to say that he also noted the problems of scaremongering by those with a predisposition towards world government.
I was struck also by this quote.
It is the ability to prove that something is not true which is at the centre of science. This distinguishes it from beliefs based on religion and ideology, which place much more emphasis on faith, tradition and opinion. As a scientist I have to come up with ideas that can be tested. Then I think of experiments to test the idea further. If the experiment does not support the idea then I reject it or modify it and test it again.
The contrast with the CAGW hypothesis is striking. Being able to test a hypothesis in principle seem to me to be very different to actually having tested it in fact. Global warming to me looks more like a "higher speculation" than a working hypothesis.
The full lecture is here.
Bishop Hill
The text of the lecture is here.
Reader Comments (80)
Nicholas Hallam, at 10:05, you're right, one version of Gareth's "3. If the experiment does not support the idea then reject it or modify it and test it again." is the introduction of ad hoc hypotheses that Popper disapproved of so much. That being said, other people have pointed out that the difference between an ad hoc hypothesis that changes an existing hypothesis, and the proposal of a new hypothesis is not completely clear-cut. Also, it has been shown (e.g. by Feyerabend) that in some cases progress in science has arisen as a result of people introducing ad hoc hypotheses - as a rule for progress in science, strict avoidance of ad hoc hypotheses is probably more of a handicap than a help.
Jeremy Harvey
I think the problem with ad hoc hypotheses to a Popperian is two-fold: methodological and epistemological.
From the point of view of scientific method, the introduction of the ad hoc hypothesis to protect a favoured theory prevents the scientist asking the fundamental question of why does the theory break down in the circumstances under examination. Science progresses through making bold new conjectures, not by patching up old ones.
From the epistemological point of view, the ad hoc hypothesis reduces the explanatory content of the theory in question by making it consistent with an increasing number of possible observations. In the limit, the theory becomes so lacking in content that it is compatible with all possible experience. This is what has been happening, I would argue, with the AGW theory.
I know that some people have argued that occasionallly the introduction of an ad hoc hypotheses has been conducive to scientific progress. I should be interested to know which episodes in the history of science they have cited.
Nicholas Hallam said:
"This methodological principle seems to be a charter for what Popper derided as "ad hoc immunizing hypotheses" which we see quite frequently in climate science.
Amazing how scientists feel qualified to pontificate on the philosophy of science with so slight an acquaintance with the subject."
I'm not sure I follow that. Having an idea that can be tested and then refining or rejecting the idea is not the same as introducing a new factor in order to preserve the initial idea. Once you refine the idea it is not the original.
In terms of climate science refining it could be starting with 'CO2 drives the climate', then refining that to 'CO2 is a substantial factor in climate conditions', then 'CO2 magnifies the effects of solar cycles', and perhaps ending at 'the effect of CO2 is swamped by negative feedbacks'. All done through testing things.
Immunising the original hypothesis is instead starting at CO2 drives the climate and when the climate doesn't play ball you keep introducing natural cycles masking the effect, a reduction in aerosols and particulates, missing heat, etc while still insisting that CO2 drives the climate. You're not refining the original idea just doing a lot of hand waving.
Bringing that approach to climate science reveals some holes indeed.
Our "experiment" is surely our modelling of the climate.
As this fails practitioners appear to have simply reduced the number of dergrees of freedom. That is, if it fails, add yet another factor that will account for the error. A prime example was the "global dimming" concept that squared the circle for them when global tempratures were falling in the 1970s.
Modellers are presently scrambling to reduce the degrees of fredom again in their "search ofr the missing energy".
Gareth
I agree that it seems preferable for the scientist to refine his conjectures in response to experiment (e.g. "CO2 is the prime driver of climate" becomes "CO2 is one of the drivers of climate", rather than to invent ad hoc hypotheses (e.g. aerosols ?) to account for the failure of experiments, but this is really a retreat from a bold and surprising conjecture to one much less contentful and interesting (and therefore much more likely to be true).
This hijacked thread is yet another object lesson in the vain nature of contentious public debate over what should be well-understood scientific ideas. I don't need Karl Popper's supposed authority to know Aynsley Kellow (sp?) was incompetent, both in his construal of Nurse's statement and in his philosophical mangling of the simple point that scientists are supposed to look for ways they could be wrong in their thinking, not deny them when others point them out (as consensus clilmate scientists have been doing for many years). Readers who get this far should realize, you have just wasted your time on most of the comments here. "Bish" was too polite when he tried to scotch it early on, along the lines of "I didn't take the remark that way, so I don't see the point"--that's an invitation for everyone to run off at the mouth.
I bothered to watch it last night and it was rather as to be expected, except his line about climate alarmism. He still couldn't wait to tell his story about getting a diagnosis, trusting the doctor........we've heard that before.
You could get the impression that with climate science you can only accept the concensus, but with other branches of science he encourages "anarchy"? Well, at least new thinking.
He did well with his finale about the future of science, and his new Crick centre.
Thanks, Harry D. Part of the fun of blogs, esp. below the line, is the fact you can go off at a tangent. Remember the ducks? Besides, I don't think we are that far off-topic. Some people claim that the mere consideration of the rules of the scientific method as defined by the philosophy of science is sufficient to recognize that AGW theories are wrong. I disagree. The argument here is partly about that, and so was Nurse's program.
Nicholas: I understand the arguments about ad hoc hypotheses, and agree that they apply in some respects to climate science. I do think, however, that attempts to define a *method* for science that invariably works are misguided. Progress in science often involves creativity as well as rule-following. You asked about examples where ad hoc hypotheses had helped. Reading Feyerabend can be frustrating as he delighted in being provocative so you sometimes do not know what he was claiming. But he is quite interesting and his basic claim that new scientific ideas rarely progress in a purely logical way chimes with my experience of research. According to one example Feyerabend discussed at length in 'Against Method', the theory of heliocentrism as initially introduced and defended by Galileo was falsified by many observations made with the telescopes of the time. The theory was shored up by many things which Popper would describe as ad hoc hypotheses concerning the way in which telescopes work.
However he did make an extraordinary weasel on warming.
He urged us all to accept the "consensus" of scientists saying that those who claim that there has been no warming and those who claim "catastrophic" warming are equally "extreme" and that we should all agree with him that there is warming. (about 1/4rd of the way in). Later he went on about the extensive action we need to take to prevent it, suggesting that those opposed to that are politically opposed to regimented worldwide government control of everything and to be fair also saying that alarmists are also politically motivated by being in favour of that.
Notice that. He has quite deliberately distanced himself from the entire concept of catastrophic anthropogenic global warming (CAGW) on which the entire edifice depends. Now he is simply a "moderate" believer in minor warming rather than the series of scare stories we have been subjected to for over 2 decades. No alarmist him; man behind the curtain must have been somebody else.
In attacking "deniers" who say there has defintiely been no warming he is also deliberately erecting a straw man to oppose his new position. I don't know of anybody that certain and he made no attempt to name one. There is agreement that there has been warming since the Little Ice Age 2 centuries ago - we sceptics simply doubt whether it is catastrophic the position Nurse is now claiming to also occupy..
But if any warming is not catastrophic (indeed if it is that minor history shows that it will be beneficial as the Medieval warming was more temperate than the Little Ice Age). If he had honestly believed that he could not possibly have made the comparison to being "ill with cancer". If warming is likely to be net beneficial the claim of necessity to destroy most of our economy to marginally reduce it is clearly untrue
Nurse's analogy with Doctors and heart conditions or any other condition for that matter is at best disingenous and at worst abysmal.
When someone is treated by a Doctor, they are aware that they are not guinea pigs. Also for what are now routine operations have been arrived at by research and testing. Generally with good oversight. Compare that with the cohort of climate change scientists at the heart of the IPPC and their methodology brooks no comparison?
This is my take from the lecture. I have extracted paragraphs relevant to climate science:
This is breath-taking stuff.
Does this mean we can no longer get away with putting forward unfalsifiable theories?
Are some of our long-held beliefs about to be challenged?
Is it the public demanding simple answers here, or the government?
Initially we may have been right to trust the experts... but
This appears to be a watering down of previous standpoints?
Is this a tacit acknowledgement that not all that may have been undertaken in the name of science has always met these criteria?
Does this mean that you will no longer necessarily be writing off your career if you are prepared to challenge the establishment?
Were we misguided in out attempts to try to stifle debate?
We may not always have been terribly mature about these things.
It has not always been easy trying to revise the science.
Politicians needs to take a back seat (but who is going to tell them?)
We might have rushed into these things.
We allowed ourselves to be led by the Greens.
We may have been wrong to put so much faith in one theory: we need to consider alternative views as well or we could all find ourselves jobless.
Here's a couple of interesting paragraphs from Nurse's talk:
Well, it definitely is sensible in many contexts to go with the consensus. But is it "how science works"? That is less impeccably Popperian as a viewpoint!
And the next paragraph:
Presented like that, it sounds quite sensible - there are those who think the world is going to fry to death next year, and those who think we're headed for an ice age next month, but the consensus is neither of those, but involves some warming, doubts about how much there will be, and - implicitly - not something catastrophic. That could be the Credo of a lukewarmer. I'm not too sure, though, that it fits with the scientific consensus as diffracted through the public policy lens of e.g. the Climate Change Act...
Jeremy Harvey
No disagreement here. Traditionally, the distinction is made between the context of discovery (which can be spontaneous, creative, irrational) and the context of justification (where ideas, however they are arrived at, are open to criticism by others and by experience). The rationality of science lies in the latter.
To take an example, Kekule said that he arrived at his notion of the cyclical nature of the benzene molecule from a dream he had, in which a snake took its own tail in its mouth, though the birth of the idea had nothing to do with its correctness.
Scientific ideas can come from anywhere. There is no inductive mechanism for generating correct scientific theories. This was well understood by Logical Empricists like Hempel and Nagel, as well as by Popper and post-Popperians like Feyerabend. Science nevertheless is a rational activity - pace Feyerabend.
This is a potted history of failed IPCC climate science.
First we have Fourier, OK, then Tyndall showing CO2 warms up more than air. Unfortunately his apparatus was constant volume so much warming was from compression, as is the case for the modern PET bottle .
Arrhenius assumed CO2 is responsible for the end of ice ages and calculated imaginary 4 K climate sensitivity. Astronomer EA Milne assumes an infinite atmosphere when he solved the problem of IR absorption, and it leads to an imaginary heat generation term.
Sagan fails to understand that van der Hulst transformed albedo - optical depth data empirically assuming one optical effect when there are two. Sagan’s Equation was used by Lacis and Hansen to model clouds. It predicts the only parameter controlling cloud albedo is optical depth, hence climate science believes aerosol pollution is hiding AGW.
IPCC science is ‘settled’ by about 1993 but it's wrong. In 1997, CO2 is shown to follow T at the end of ice ages. The team has to develop a new amplification of Milankovitch delta tsi [ice albedo change, bunkum] and calibrates CO2 climate sensitivity against post-industrial warming justified by the hence the fake hockey stick and fiddling older temperatures downwards, the latest being -1 K added to older Reykjavik data.
IPCC science grew by mistake and slid into fraud. In 2007, Stott showed the amplification of delta tsi starts in the deep Southern Ocean 2 ky before CO2 rises. It was from reduction of cloud albedo: 3.5% fall produces the same warming as the IPCC's 2.88 W/m^2 they attribute to GHG-GW to the start of the industrial age.
In reality, CO2-(A)GW is probably net zero, for reasons to be revealed later!
I think Neil Crag (Feb 29, 2012 at 1:20 PM) has hit a nail upon the head. It does indeed look like Nurse has adopted a moderate line about AGW, and wants to distance himself from the alarmists. I wonder who he would put in that camp? Hansen, Santer, Trenberth, Gleick? Who is to be thrown under the bus? Who is to be airbrushed out of the picture in the best of Soviet traditions? It is as if the Lysenko scam had been exposed at the time, and leaders of the nomenklatura realised a mistake had been made. First Lysenko would have gone under the bus (perhaps even literally in those days), and more moderate scientists would be made more prominent to displace his memory. Speeches would be made to add clear water between the old position and the new. The new party line would be emphasised at every turn as if it had always been so. Pravda would help of course. I look now to the Guardian and the BBC to explain to the public that climate scientists do not talk of catastrophe, but they do see the possibility of a problem and therefore the rest of the 40-year plan must be followed without dispute. The alarmism would of course have served its purpose, and more would be counterproductive. Pity about all those who starved because of bio-fuels, and all those children frightened out of their wits, and all the resources diverted to absurd methods for mass production of electricity. We've got all sorts of institutions on board now, we've got the political class on board (just look at that Climate Change Act!), and anyway, we all know you can't make an omelete without breaking some eggs. Pass me that 'Beyond Sustainability' folder will you?
Re. disproving a negative:-
My continued existence and spotless jumper is proof that I did not spend the night walking on the surface of the Sun (nor on the Embankment wrapped in a copy either).
@ Nicholas Hallam
Thanks. I watched the show when it aired and just accepted Cox's comments (although from my physics and chemistry A levels I only recalled that electrons in orbitals needed to have different spin states to fill up energy shells).
I wasn't aware that Lubos had pulled the statement apart. The "everything is connected" meme is always a dangerous one because it can be used as a shorthand for these types of interaction (although not necessarily instantaneous interaction), but it does rather evoke the Gaia "oneness" rubbish aswell.
Hi Nicholas (@ 2:11 PM), thanks for your reply - let's just hope Harry doesn't flame us again for pursuing this discussion ;-). You're right, the context of discovery is different in principle from the context of justification. I forget whether Popper used that terminology or not, but he did allow for the context of discovery in positing what amounted to a pure moment of creative imagination, when coming up with a new theory. But most of his focus was on the context of justification.
The way I see it, though, is that the distinction between the context of discovery and the context of justification is not very clear cut. When I'm pursuing a research project, and have a new idea, I don't even really know what my new idea is or understand it until I have defined it a bit better, checked that it makes sense at some elementary level, checked that it does not conflict with things I'm pretty sure are true, re-expressed it in other language so that it can be compared to some previous theory in a fruitful way, and so on. So from its very inception, in fact during its inception, a new hypothesis is already being placed in the context of justification. Equally, "new" theories tend to evolve and change quite a bit while they are being checked, by the people who came up with them or by others. So a new hypothesis continues to be in the 'context of discovery' even while it is being tested.
"It is impossible to achieve complete certainty on many complex scientific problems, yet sometimes we still need to take action. The sensible course is to turn to the expert scientists for their consensus view. When doctors found I had blockages in the arteries around my heart I asked them for their expert view as to what I should do. They recommended a bypass, I took their consensus advice, and here I am. That is how science works."
Doctors are not expert scientists, they are practitioners and the reason they recommended a bypass was because they'd seen it succeed many times before. It wasn't a consensus view, the doctors didn't vote on it, it was a view taken from experience. If Sir Paul had asked the same doctors a hundred years ago they'd have suggested something completely different and he'd have probably died. The reason we've made these massive increases in our medical and scientific knowledge is the burning of fossil fuels to provide the energy that is the driving force of our civilisation, this man, wants us to end all that because a consensus exists among scientists with a "cause". A "cause" he clearly supports because with ineffable insoucience he's accepting that people like him are superior to the oicks in the sceptic camp. Well, Sir Paul, scientists, true scientists, don't have "causes" they look at the evidence and draw their conclusions from that.
Don't, whatever you do, believe this man has moved to a more moderate position, he hasn't, he's trying to claw back some of the respect he lost with his execrable Horizon documentary. Has he apologised for the small gaff where one of his contributors to a nodding President of the Royal Society, told the viewers that humans put 7 times more CO2 into the atmosphere than nature. I wonder if there's a consensus on that Sir Paul can point to to make it true.
timheyes
Lubos also links to Sean Carroll's twitter spat with Cox on the subject
http://storify.com/twhyntie/a-celebrity-scientist-face-off-some-background#
[Now seriously OT]
I checked up on Cox. No Fermion [non integer spin] can occupy the same quantum state as another Fermion. However, you can have many electrons at the same energy level in atoms or large masses of material in giant molecules, e.g metals or semiconductors.
The rule there is that you can have [2J+1] Fermions where J is the momentum.
If you have two such macromaterial objects, they are independent because information has to travel through space, at the speed of light. So Cox's Gaia idea is not correct. however, be careful of physicists because they are as good as lawyers iwith words in using weasel maths [eigenvectors, tensors and eigenstates....]
matthu (at 1:42 PM) does us all a favour by extracting those passages and annotating them.
Makes me think that if our Paul was to get his shorts on, he'd make a competent member of a group of schoolchildren portrayed by Marc Hendrickx' cartoon 'We're not scared anymore Mr Gore' . In it they deal with visiting speaker Al Gore's talk point by point, and send him packing. This was in 2008. The pupils might have been ahead of our Paul then, so perhaps he might not get into that class since they will have moved on. But I think the school would at least now consider him at a more junior level thanks in large part to his Dimbleby Lecture.
Cartoon pdf and further credits available here: http://climatelessons.blogspot.com/2010/12/were-not-scared-anymore-mr-gore.html
"It is far better to remain silent and be thought a fool than to open one's mouth and remove all doubt."
While I was sleeping:
Harry Dale Huffman: Pots and Kettles, Harry!
'his construal of Nurse's statement': no such word in my Shorter Oxford, Harry. Perhaps you meant 'my construing of Nurse's statement'?
But you are wrong to suggest that questions of the philosophy of science are off thread. They are central to any discussion of science, climate or otherwise, as the several interventions here show. My issue with Sir Paul was with his absolutist statement of 'proving' synthetic propositions to be untrue. Any statement about the world should be regarded as adequate in a much more tentative fashion. Newtonian physics was not proven to be untrue by Einsteinian physics - just inadequate and more limited in its validity. Many theories once thought to be 'untrue' have subsequently been found to have some validity - which we should never accept except tentatively.
Recalling the recent Lindzen lecture, and having used the same quote upthread to illustrate the nub of the deceit still perpetuated by the Royal Society, it is hugely gratifying to see Judith Curry's take on the same quote in a recent Climate Etc post:-
'Unfortunately, denial of the facts on the left, has made the public presentation of the science by those promoting alarm much easier. They merely have to defend the trivially true points on the left; declare that it is only a matter of well- known physics; and relegate the real basis for alarm to a peripheral footnote – even as they slyly acknowledge that this basis is subject to great uncertainty.'
JC comment: this is a profound statement
Quote:"From the very beginning of science there have always been such threats. When Galileo argued that the earth orbited the sun, the Inquisition did not argue back with science, they simply showed him the instruments of torture."
Absolute rubbish...I would have thought that an eminent scientist would be familiar with the events leading up to one of the most pivotal moments in scientific history, defended by the very "father of modern science" himself, Galileo Galilei.
A modest piece of research would have revealed how rational the case against Galileo was and the lack of support he had received from his peers, especially regarding his knowledge of optics and the sketchy reports they had received regarding observations of the moons of Jupiter through a telescope.
This lack of experimental evidence and support left no other option, this work was a possibility,a theory but not a fact and should be labeled as such.
In truth he was an unlikeable, arrogant man who defended a theory with scant supporting evidence, cared little for the opinions of others and even less for the consequences of his actions, you could quite easily bump into him today in any research department, carrying out the sort of science Mr Nurse is opposed to.
Jeremy Harvey and Nicholas Hallam. Dear friends, it was a pleasure to encounter your discourse on the web, and I enjoyed listening in. I have a few comments to offer with no wish to act as an Elihu: they are merely offered. First I agree that the advancement of discoveries in science has never followed a method. But method is very important for the practice of scientific observation. It is method that allows us to repeat our observations, it is method that allows us to estimate the error in our observations, it is method that bringing to light the anomalies that may form the seeds of discovery. That said, there is no method or calculus extant that allows us to turn a crank and pop out a scientific advance which could be variously, a conclusion, a refutation, or a breakthrough discovery. Second, we underestimate the accomplishments and sophistication of ancient men: they were highly accomplished in observational and mathematical skills which are all the more impressive when one considers that they lacked the advantages we know enjoy of widely disseminated knowledge and computational means. Just imagine what they could have done with access to Wikipedia and Excel spreadsheets. Third, the goal of science should be to establish and maintain knowledge. Knowledge is information, however imperfect, however contradictory. Information is knowledge only when we can estimate its imperfection and map out its contradictions. Fourth, we should fear and reject conclusions and hypotheses for as long as we are able, only submitting to them when we have no avenue of escape. We should submit to them only when they have beaten us and even then, we should be their restive subjects, alert for an opportunity of rebellion. Too many times I have seen others welcome one of them and to find out too late that they were a phantom. I confess, I have done it myself when I should have resisted longer. Fifth, never underestimate the value of a good demonstration. A good demonstration removes doubt without resorting to epistemology, compels belief and carries the day. It is also very gratifying. Please don't read anything I have offered as a criticism. I just wanted to add my two cents.
Martin, your quote is from Nurse's speech, I see. It is another interesting one!
As you say, the idea that Galileo was obviously right at the time and that people who refused to believe him were stupid or wilfully evil is simply not correct. It is however the sort of thing that often crops up in the Whig version of the history of science, whereby, more generally, everyone who turned out to be 'right' was heroic, and everyone who turned out to be 'wrong' was pig-headed or malicious. Also, in that vision of history, every theory that we now believe to be (mostly) right was pretty much obvious all along, whereas every theory that we now believe to be wrong was so clearly wrong at the time that it is scarcely believable that anyone can have proposed it.
People like Kuhn would observe that many (most?) scientists subscribe to the Whig version of the history of their field. By and large, it does not matter, because it does not interfere with understanding their current problems. However, it does tend to lead to a lack of modesty about the correctness of the theories one believes in, and a willingness to believe that everyone who believes anything else is a nincompoop or a nefarious individual. Pace Harry Dale Huffman, I think this is one reason why history and philosophy of science are relevant topics for discussing AGW theory, and relevant for discussing Nurse's speech.
I thought I was going to listen to some genetics. Instead I got a loaded agenda based lecture that accepted the 'accepted view' virtually without question. I got told that any scientist with a different view was either blind or poorly informed. By the time Nurse finished, I had the impression the world was going to be controlled from a 'super block' in London. Sorry, but there was too much politics and business running the theme.
With heart surgery analogy Paul Nurse suggests we must defer to expert opinion on global warming. A question may be put to him: would he agree to heart surgery according to a procedure tested only on a computer model of the human body?