I absolutely, totally agree. Thank you for this. If only every so-called journalist who parrots the "end of the earth unless we do something" understood a tenth of what you have written here.

I remember when I worked for a stockbroker. The technical analyst (who was also the head of research, and a really, really smart guy) rolled out a new model for us to all input our growth forecasts for the various sectors of the market which we covered: the model was then supposed to produce a forecast for the market as a whole. Well, the day after we all uploaded our forecasts was very interesting. We received increasingly desperate emails from the tech analyst/head of research, asking first this, then that analyst to add fudge factors to various bits of their forecast, because the overall forecast was obviously coming out weird. Eventually we got to the stage where I felt like saying, "OK, just tell us what you want the forecast to be: it'll be a lot easier than this farce." I wonder how often that happens in science computer modelling.

Even if it doesn't happen quite so blatantly, it happens, even if only subconsciously.

A computer is a very very useful tool for throwing your own knowledge back at you with flashy coloured lights added. As long as you remember that, you can do some great things with it. The moment you let yourself be fooled by the coloured lights into thinking that the information you're seeing didn't come out of your own head in the first place, you're doomed. Well, no: you're just wrong. But you should be doomed, though. You'd be doomed if I had my way. Grr.

Just to be pedantic, if I input some source data such as a client's income, the tax rates and allowances into my excel sheet, and press a few buttons and it tells me how much tax they should pay, have I not just used my PC to give me some new information?
If I have a large table of data, and I sort it according to a criteria, and get excel to do a graph of it, from which I can spot the trend and extrapolate the future trend, haven't I gained new information?
OK, not "brand new", of course, but isn't all information simply "data made meaningful"?

Information may be data made meaningful, but it's always the human who makes the information meaningful. If your spreadsheet tells you your client needs to pay 200% of his taxable income as tax, you know something has gone wrong. If your future trend turns out to be wrong, the "information" you think you have gained is actually disinformation. The point about climate models is that we don't really have a basis for deciding whether the results of the models actually are useful information. (Actually, we have some inkling: historical data such as the medieval warm period, and the little ice age that was around in Dickens' London, when people skated on the Thames in winter, indicates that large temperature variation is nothing new.)

Also, I think Jo makes a good point about bias, even unconscious bias. Michael Crichton gives the example, from the medical field (since he is a doctor), of the two strangers who get to talking at the airport. To their horror, they discover that each is taking part in a double-blind test of a new drug. Even this chance encounter could result in the entire experiment being invalidated. Contrast this with climate studies, where the scientists who test the data are the same ones who come up with the theory which says how much to adjust the data because of, for example, the heat island effect (the effect of urbanisation, which increases average temperature: many weather stations which were way out in the country when they were set up a hundred or more years ago are now in suburbia: their temperature data needs to be adjusted by some factor. How much to adjust? The same scientists who are testing their theory, decide how much to adjust the raw data. Problematic, no?).

While everything Stephen says is correct, I was actually making a more fundamental point than that.

> if I input some source data such as a client's income, the tax rates and allowances into my excel sheet, and press a few buttons and it tells me how much tax they should pay, have I not just used my PC to give me some new information?

No, you haven't. You have used your PC to process existing information. The data that comes out is the same data that went in, only in a different form. The important thing to bear in mind is that you could have done it with a pen and paper — and no-one thinks that paper gives them new information when they write on it. You could even do it (in theory) using nothing more than your own brain, which just goes to show that you're not getting any new information.

What makes a computer so useful, of course, is that it's so damn quick, so it can do what would take us five thousand sheets of paper and ten large bottles of ink in a couple of seconds. That's great. And, yes, when you're doing something like tax calculations, the distinction I'm drawing here can amount to hair-splitting. But it's not hair-splitting when it comes to computer models that are supposed to tell us about the future. It is vitally important to recognise that all a computer model can show us is the beliefs, theories, instructions, and mistakes of the person who programmed it. That's all. Yes, it can show us that information in huge detail; yes, it can show us results of that information that we might never otherwise realise; yes, it can do more manipulation of that information than a thousand of us could do in our lifetimes; but it doesn't give us any information that didn't either come out of the head of its programmer or result from a finger slipping and hitting the wrong key.

The problem with computers is that they are extremely good at making information appear new. Doing a million calculations in a second obviously leads to output looking totally different to input, and it's seductively easy to think that the output is something new. It isn't. While computers are now so insanely fast that it is impossible in practice for mere humans to do the same calculations on paper, it is important that the scientists who use models remember that, in theory, they could do the same thing with a pencil.

No computer has ever been built that can do anything more than add 1 to or subtract 1 from a number.

You know, on second thoughts, I think I've completely screwed up my paper-to-ink ratio there.

I think it's quite misleading to say 'No computer has ever given any human being any new information'. At the very least, the result of a computer program gives you one piece of information - what the result of that program is.

no-one thinks that paper gives them new information when they write on it.

No, but the interaction of my brain and the paper and pen can tell me things I didn't know - colloquially, 'information'. If my wife encodes a note to her lover in Rot13, and I decode it, I've learned something new about the world.

> I think it's quite misleading to say 'No computer has ever given any human being any new information'.

Misleading? But it's absolutely true.

> the result of a computer program gives you one piece of information - what the result of that program is.

If I program a computer to process basic arithmetic and then type "1+1=" into it and "2" pops up on the screen, are you seriously telling me that the computer has created new information for me?

Either I've coded correctly, in which case the result of the computer program is merely a permutation of information already in my own head, or I've made a mistake, in which case all the program's result does is alert me to a mistake that I made — i.e. the information comes from me, even if unintentionally. If my pen slips while I'm writing, leaving a mark that I did not intend to make, that doesn't mean the paper is trying to tell me something.


> the interaction of my brain and the paper and pen can tell me things I didn't know

Absolutely not. You can use pen and paper as a handy tool to help yourself figure something out using your brain. The interaction tells you nothing; you tell yourself something, and the interaction makes it easier for you to do so.

> If my wife encodes a note to her lover in Rot13, and I decode it ...

... then you have learnt something new about the world from your wife, not from the paper. You'll be telling us that phones speak to you next.

I think our definitions of "data" and "information" are possibly at variance here. Perhaps you are using specific definitions which apply to your field of expertise? My definitions go something like this, correct me if I'm wrong:
I am presented with a series: {1,2,3,4,5}. That is what I would call my data. Whether I use Excel or pen & paper, say I want to know what the 20th value in the sequence will be, I plot a graph and draw a line and extrapolate. The result is that the 20th value in the series will be "20". This, I define as "information" derived from my manipulation of the data. It is not merely another piece of datum, as it was not given to me at the start; I have manipulated the initial data and arrived at it as a conclusion, and the tools I used to arrive at it are, as you say, irrelevant. However, I was not given the series {1....20}, only {1...5}. "20" was not included as part of the source data, therefore "20" is indeed "new information". Therefore, if I used a computer to process my original data, then I would say that that computer is indeed the tool that has given me the new information. Are we agreed, disagreed, or are our definitions of "data" and "information" at variance to begin with?

One more point: My definition of "information" does not include any claim about its accuracy, that is not the argument that I am making at all. For all I know, the series in my example above might be {1,2,3,4,5,9,17,45,78...}, or {1,2,3,4,5,4,3,2,1,2,3....}.
I'm only making this point because your post relates to models of global warming, and in this context, some people might take the word "information" to mean "known, true facts". I'm applying it in a strict sense of "what can be assumed or extrapolated from the given data".

> therefore "20" is indeed "new information".

OK, if we use your definition of "information", that's fair enough. But my point still stands.

> I have manipulated the initial data and arrived at it as a conclusion, and the tools I used to arrive at it are, as you say, irrelevant.

Absolutely right: you have gained new information using tools. The tools themselves have not given you information, any more than a screwdriver can assemble an Ikea table for you.

> if I used a computer to process my original data, then I would say that that computer is indeed the tool that has given me the new information.

No, no, no: the computer is the tool that you have used to give yourself new information.

Like I said, if you're talking about tax calculations, this distinction doesn't really matter. When you're claiming to predict the future, it's crucial.

Using your definition of "data made meaningful", there is still a massive difference between new data and existing data given new meanings. The important thing to remember about a computer model is that it will never contain any information based on data other than what was originally put in. The belief that a computer model can somehow tell you what will happen in 2050 is erroneous: all it can tell you is the implications of your own theories when combined with current and past data.

Tom Tyler: I agree with you that the problem here is of different definintions of 'data' and 'information'.

Squander Two: Misleading? But it's absolutely true.

No, it's misleading, because it's only true for a very restricted sense of 'new information'. In a sense its true that a computer program (or model) has inherent in it all of the information you'll ever get out of it. But the result I get by running the program can be 'new information' to me, because I didn't know it before, and if no-one has ever run the program it can be new information to everyone. If there's a correspondance between the program and the rest of the world, then the result will also give me new information about the world. So if I write in Haskell:

fibs = 0 : 1 : [ a + b | (a, b) <- zip fibs (tail fibs)]

...then the result of 'fibs !! 43' will be information about the result of the program, but because there's a correspondance between the program and the world, it also tells me the 43rd fibbonacci number.

Ekmi, that's only almost true.

> the result I get by running the program can be 'new information' to me

Yes, but the point is that that new information doesn't come from a computer. It comes from a programmer. The fact that the programmer may not have known the information as such doesn't change its origin.

> If there's a correspondance between the program and the rest of the world, then the result will also give me new information about the world.

No, the result will give you new information about the correspondence between the program and the rest of the world. It is only when you already know the real-world result (as in your example) that you can be sure that the program has told you something about the world — i.e. the information you have discovered is that your model-to-real-world correspondence is 1:1.


Just to be clear, the point of my post was not that we should never trust computer models. It was that we shouldn't trust the conclusions of scientists who use computer models but can't answer those questions. Plenty of scientists can answer those questions, and they should be taken seriously.

>...because there's a correspondance [sic] between the program and the world...

Ah, but that's precisely the point. How do you know there is a correspondence? If you know because you wrote the program, then you have simply used the computer to express knowledge which you already had, and which you could have expressed in other ways (using a calculator, or pencil and paper). If you don't know, but believe there is a correspondence, because of your theories etc (eg climate models), then using a computer rather than pen and paper cannot improve matters; it cannot create correspondence. Only you can, with your knowledge. And in the case of climate science, we don't have the knowledge. So using a model to give a false sense of authenticity is wrong. Feynman was famously skeptical of models.

OK, I can see we've been arguing at cross purposes here, essentially we're in total agreement on the essence of the matter, it's just that we've applied different definitions to our terms, which has caused the confusion.

"The important thing to remember about a computer model is that it will never contain any information based on data other than what was originally put in". - Yup, no disagreement at all, there. All you can get out is based on what you put in.

"The belief that a computer model can somehow tell you what will happen in 2050 is erroneous: all it can tell you is the implications of your own theories when combined with current and past data" - Yup, exactly my view, which is why I posted that my definition of "new information" has nothing to do with its eventual accuracy. The guys who are inputting global warming data into their models, can only come out with theories based on their data, which might be right or wrong. My definition of "information" in this context, is simply "what the data predicts", its accuracy relies entirely on the uniformity of the inputted data, which cannot be proven in this context.
Personally, I am inclined to think that part of the problem re predicting global warming is that our current data relates to too short a period of time. It's like trying to predict the 200th value of the series {1,2}. We need to know whether the series continues {1,2,4,8,16,32}, or {1,2,3,4, 2, -1, 0} before we can start inputting it into our models.

Squander Two: the new information doesn't come from a computer. It comes from a programmer. The fact that the programmer may not have known the information as such doesn't change its origin.

Again, you're right in a restricted sense for a particular meaning of information. Its not obvious to me that it's a particularly useful one from the perspective of a climate scientist. In the sense that scientists use it, I think you can in fact 'get information' from a computer program.

Anyway, I think it's clear that 'Either the answer is "None" or the scientist knows nothing about computers and should be ignored at all costs' is an absurdly strong claim.

Steven: Ah, but that's precisely the point. How do you know there is a correspondence?

So your point, basically, is that the problem of induction is a problem? Good point and welcome to first-year philosophy of science.

> you're right in a restricted sense for a particular meaning of information.

So how about you argue with my meaning, then, rather than quibbling over vocabulary? As I explained above, changing the terminology doesn't change the point.


> Its not obvious to me that it's a particularly useful one from the perspective of a climate scientist.

So what? Basic principles of computer programming are what they are. Whether they're useful to climatologists doesn't change that. In what kind of insane world would we change or abandon established knowledge because it wasn't useful to a particular group of scientists? You abandon knowledge because it's disproven, not because it's awkward.


This is nothing to do with the problem of induction. No-one's saying that you can't use the laws of physics to predict how an engine works. No-one's even saying that you can't use the known laws of meteorology to predict weather — obviously, you can. My point, yet again, is that there are a lot of scientists out there who present their conclusions from computer models as facts even though they have given insufficient thought to the questions in my list.

The problem of induction is that there is no logical way of concluding that the next raven we see will be black simply on the basis that all ravens we have ever seen have been black. This is a trivial problem: all it really shows us is that logic isn't inductive; that doesn't mean that inductive reasoning is totally invalid, just that it's arguably weaker than deductive reasoning. However, the key thing is that we have seen lots of black ravens and no non-black ravens. That's the sort of correlation we can base inductive reasoning on with confidence, even if it's still not 100% reliable. When you're using a computer model to make claims about what will happen 100 years from now, where are all your black ravens? To be reasonably confident that the model will be accurate in the future, you need it to have been repeatedly accurate in the past. To be reasonably confident that the model will make an accurate hundred-year prediction, you need it to have made accurate hundred-year predictions in the past. Until the model's more than a hundred years old, that can't happen. At the moment, a lot of scientists are claiming that the next raven they see will be black even though they've never seen a raven, never met anyone who's seen a raven, and only even heard about the existence of ravens a couple of days ago.

Squander Two: You're trying to use an ordinary word in an odd way and then pretend that there is no other meaning for it. What can I do except argue over that word?

As for arguing with your meaning, this seems like a fair summary:

The belief that a computer model can somehow tell you what will happen in 2050 is erroneous: all it can tell you is the implications of your own theories when combined with current and past data.

If your theory corresponds to the real world, your model will tell you what will happen in 2050. This idea is the entire point of modern scientific enquiry, so I suspect that climate scientists are aware of it.

Right, so when I agreed to use Tom's definition of "information", that was me pretending that it could only have one meaning. Whatever.


> If your theory corresponds to the real world, your model will tell you what will happen in 2050.

No. If your theory corresponds perfectly to the real world, your model will tell you what will happen in 2050. If it corresponds very closely to the real world (as Newtonian mechanics, Relativity, and Quantum Theory do), your model will tell you what will probably happen in 2050. If it corresponds only approximately to the real world, it might tell you what will happen in 2050 and it might not, and you can't tell which.


> I suspect that climate scientists are aware of it.

Speaking as a programmer, I am painfully aware that otherwise intelligent people's brains leak out of their ears when they are faced with a computer. As I said, I'm not just talking about climatologists here, though they're the most obviously guilty. A lot of scientists take imperfect, approximate theories, bung them through computers, and act as if the end result is somehow more accurate than what went in. You're implying that climatologists don't make this mistake, but I put it to you that a bunch of people who can't accurately predict the weather more than two weeks in advance are making fairly concrete predictions about climate in a century's time.

Anyone who can make reliable climate predictions even six months in advance stands to make a fortune from farmers, water companies, and electicity companies, all of whom pay well for that sort of information. We'll know when a climatologist comes up with a reliably and verifiably accurate model because he'll quickly become very rich.

so when I agreed to use Tom's definition of "information", that was me pretending that it could only have one meaning.

Yes, you said that, and then carried on arguing as if your version of 'information' was the only important one. But as you say, whatever.

You're implying that climatologists don't make this mistake

Actually all I'm implying is that climatologists have probably thought hard about the science of climatology. It's surprising to me how random people on the internet think they can easily catch out highly-qualified experts.

a bunch of people who can't accurately predict the weather more than two weeks in advance are making fairly concrete predictions about climate in a century's time.

It does seem strange, but on the other hand I (and I would guess you) know next to nothing about the science of climatology. At a guess I'd say it's like boiling a pan of rice - it's hard to say how each grain will behave over the short term, but easy to predict the macro-scale result. That said, I think it's pretty difficult to understand the subtleties of a field unless you're actually part of the research community, following the literature.

> Yes, you said that, and then carried on arguing as if your version of 'information' was the only important one.

I never understand these bizarre points that inevitably arise in online arguments. This conversation is actually written down, you know, right here. Everyone can see what I wrote.


Of course professional climatologists have thought hard about climatology. And I'm a professional computer programmer. Why bow to their expertise but not mine?

The problem with computer modelling (and I should reiterate that this is a problem affecting lots of science, not just climatology) is that it's a separate discipline to the sciences that use it. Just because a scientist knows lots about their field, doesn't mean they're an expert on computability.

And no, it's not just some random person on the Internet who thinks there's a problem. As Stephen mentioned, Richard Feynman described the modern trend in computer modelling — towards using the models to generate, not merely to test, [insert your preferred term here] — as a disease.

And then you want to assume that experts in their field aren't going to make major mistakes. History's against you here. Experts in their field have insisted that cholera epidemics are unrelated to water supplies, that continental drift is impossible, that the cosmos and Planet Earth must be governed by two separate sets of physical laws, that BSE can't infect humans, that aether exists; Einstein himself insisted that the Quantum Inseparability Principle was impossible. Not long ago, most scientists believed in astrology; the first geodesic survey of the Earth was part of an effort to find the ideal locations for observatories in order to make better astronomical observations in order to make more accurate astrological predictions. Scientists, like other humans, will believe any old crap.

Just to be clear, which of my list of questions do you not think we should ask scientists?

Why bow to their expertise but not mine?

Because your expertise is in neither climatology or computer modelling? Please correct me if you have a PhD in either of those fields.

I also don't think that Feynman will be particularly familiar with the current trends in climatology and computer modelling, as (1) he wasn't a climatologist, and (2) he's been dead for almost twenty years.

you want to assume that experts in their field aren't going to make major mistakes.

No, I think they're less likely to make mistakes than someone who knows next to nothing about their chosen subject.

It's interesting that ekmi uses Haskell for his example, a functional programming language that goes out of its way to eliminate side-effects and which wraps all interaction with the real world via monads, (and the occasional call to unsafePerformIO). In other words a language determined to be as deterministic as possible by limiting and regulating any interaction with the real world. And why? Because the moment the real world intrudes you lose all guarantees about what will happen.

Sound familiar?

the moment the real world intrudes you lose all guarantees about what will happen.

David: Denying the possibility of constructing scientific theories about the real world is a radical position, but a consistent one. Although it seems a little extreme to me to reject the whole of modern science because you're upset about the existence of global warming.

On the contrary ekmi. I don't dispute the existence of global warming, nor do I deny the possibility of constructing valid scientific theories. I certainly don't reject modern science. These are the kind of extreme position that you seem to be taking. I'm just old enough to remember the expected "new Ice Age", and also the infamous "Club of Rome" and the laughable projections they came out with.

Chaotic systems are extremely sensitive to the initial values and the rulesets applied. I don't think it unreasonable to ask questions about these, but I do find the extreme defensiveness of their proponents to be more enlightening than the results of their models...

These are the kind of extreme position that you seem to be taking.

Really David? I don't remember rejecting modern science or saying anything as extreme. I'm honestly curious what you meant by this.

I don't think it unreasonable to ask questions about these

Neither do I - science proceeds through criticism. All I'm arguing is that critics who know almost nothing about a subject are unlikely to be accurate or interesting. I'm astonished that this is a controversial position. If climate scientists have been defensive, it's probably partly because they've been subject to a lot of politically-motivated criticism from people who know very little about climate science.

I'm just old enough to remember the expected "new Ice Age"

Hooray! I love that talking point! Next could you claim that Urban Heat Islands contaminate the surface record plzkthx.

I note you didn't answer the question.


> Please correct me if you have a PhD in either of those fields.

Ah, that old chestnut. No matter that I make a living out of knowing how computers work, what they're capable of, how and why software goes wrong, and how to debug it; no matter that I used to be in charge of statistical analysis, forecasting, and explaining to operations management what can and can't be concluded from statistics for the UK arm of a rather large multinational. If I haven't got a PhD in computer modelling, you reckon I haven't a clue what I'm talking about. (My employers, incidentally, pay me for ability, not for qualifications, but, since you are so concerned about academia, I've got a degree in formal logic.)

Please note that a lot of climatologists don't have PhDs in computer modelling and a lot of the computer modelling experts who therefore do that side of the work for them don't have PhDs in climatology.

I didn't say that Feynman said anything about climatology. And the trend I referred to was the trend towards using models to generate rather than to test data. Feynman was perfectly familiar with that trend, which was already well underway while he was alive. The trend has only continued since. Some people think that, the more powerful computers become, the more valid it becomes to base conclusions on data generated by them. That is a fallacy. The more powerful computers become, the better they get at making unoriginal data appear original. They are still incapable of making original data.

I think your big mistake is in thinking that this is about climatology. It's not. It's a fundamental question of scientific method.

The problem with climatologists is certainly not that they use computer models. There's nothing wrong with using computer models. The problem is that I have yet to hear anyone give an explication of how they used a model to arrive at the conclusion that the Earth is being irreparably and dangerously heated by human beings that doesn't contain at least one step in the process that makes me sputter incredulously. As a rule, first-year philosophy of science is enough training to spot the flaws.

> If climate scientists have been defensive, it's probably partly because they've been subject to a lot of politically-motivated criticism from people who know very little about climate science.

Now, that really is misleading. It's not climate scientists who have been defensive; it's some climate scientists who have been defensive. Some of the people whose criticism they've been so defensive towards have been other climate scientists. To accuse every climate scientist who disagrees with the disastrous-global-warming-caused-by-humans scenario of political motivation while accusing none of the others... well, without some evidence presented, that's just slander, isnt it?

Squander Two: No matter that I make a living out of knowing how computers work, what they're capable of, how and why software goes wrong, and how to debug it; no matter that I used to be in charge of statistical analysis, forecasting, and explaining to operations management what can and can't be concluded from statistics for the UK arm of a rather large multinational.

So what you're saying, basically, is that you have a PhD from the graduate program of life?

I'm afraid that I don't think it matters that you have a lot of mostly unrelated experience. When you're criticising research into climatology with computer modelling what matters is your understanding of climatology and computer modelling, and your familiarity with the current research in climatology with computer modelling. As far as I can tell you have respectively none and none. You've suggested that climatologists are misusing their computer models. I don't know how you are so sure about this give that you aren't familiar with the research literature.

On another point, I think its quite disingenuous of you to pass off all of this as your own insight, since 'modelling isn't a science' is a another well-worn talking point for global warming denialists.

To accuse every climate scientist who disagrees with the disastrous-global-warming-caused-by-humans scenario of political motivation [is] just slander, isnt it?

It certainly is, Squander Two. Fortunately it's a claim you have taken from your imagination. Do you really have a degree in formal logic? - this seems like an instance of the fallacy of the undistributed middle.

Oh, and answering your question: I know almost nothing about computer modelling and climatology, so I don't know or particularly care.

Yes, you've made it very obvious that you don't care.


> you have a lot of mostly unrelated experience.

My post, contrary to what you seem to think, is about computer programming. I am a professional computer programmer. How on Earth is that unrelated?


> When you're criticising research into climatology with computer modelling ...

As I've repeatedly said, I'm not. I have suggested a list of entirely reasonable questions that should be asked of anyone who is claiming to draw scientific conclusions in any field from the results of a computer program. I've said that scientists in any field who can't answer the questions should have their claims treated with suspicion — not disregarded entirely. As I said earlier, there are plenty of scientists who are able to answer those questions quite reasonably. I know for a fact that lots of climatologists expend a lot of effort on tackling the problems raised by those very questions.

Some others arguably worry less about the questions than they should.

A major problem is that most laypeople have no idea that anyone ever even needs to consider these questions. That ignorance of how computers work creates a problem with the way conclusions pulled from models are perceived by the media and the public. I don't flatter myself that this blog is read by millions, so don't expect my advice to have a significant effect on public undserstanding, but my post was not addressed to scientists; it was intended as a handy guide to non-programmers and non-scientists that I hoped would provide some insight into how imperfect the process of coding by a team can be. I used an example from climatology once, where I thought an example was needed to make it clearer what the question meant.


> 'modelling isn't a science' is a another well-worn talking point for global warming denialists.

Modelling is more engineering than science, I'd say. That's not in any way a term of derision, just an observation.

The word "denialist" is a bit loaded: makes it clear that the person using it is engaged in a political argument, not a scientific one. I don't think Einstein was ever described as a "quantum theory denialist". He was simply on one side of a perfectly reasonable scientific debate, and it doesn't usually occur to people engaged in reasonable scientific debates to use terms like that. You said above that "science proceeds through criticism" and then you go and use a term intended to insult anyone daring to raise such criticism.


> Fortunately it's a claim you have taken from your imagination.

Oh, certainly you didn't make that claim. You implied the far stronger claim that there are no climate scientists who disagree with the disastrous-global-warming-caused-by-humans scenario.


> I think its quite disingenuous of you to pass off all of this as your own insight

Then you certainly have completely misunderstood my post.

At no point have I tried to pass this off as any sort of insight, let alone my own. It's not an insight: it's very very very basic knowledge of programming. Try and find a computer programmer who thinks that any of the questions (apart from the one joke) on my list is at all unreasonable. Bet you can't.

The word "denialist" is a bit loaded

True, but I think 'skeptic' is rather too charitable. It suggests (as you do) that the global warming debate is just a matter of the normal process of science. In fact there seems to be quite a strong consensus among climatologists about the existence of anthropogenic global warming, and many of the 'skeptics' are politically-motivated dupes or bought-and-paid-for hacks. 'Skeptic' also suggests an admirable resistance to irrational ideas, and implies that 'skeptics' are just too damn independant to agree with global warming. This is especially ironic when you notice that they all parrot the same dozen talking-points, at least four of which I've seen in this thread.

Oh, certainly you didn't make that claim.

Then why did you imply that I had?

ekmi, you say:
All I'm arguing is that critics who know almost nothing about a subject are unlikely to be accurate or interesting. I'm astonished that this is a controversial position.

You also say:
I know almost nothing about computer modelling

So are you not damned by your own admission?

are you not damned by your own admission?

David: Not really, since I haven't made any claims about the field of computer modelling. I do know a bit about computers, which is why I felt able to argue with Squander Two's point about getting new information from a program.

OK, that's a fair point. But does it not also apply to Squander Two though? All 3 of us appear to be computer programmers, we all have a better understanding than most about the prevalence of bugs in computer systems. These bugs are highly likely to affect the models. I simply don't believe these models are worth the uncritical reverence given them by the mass media.

For what it's worth, I do think we are able to get new understanding from a computer program. I also think global warming is happening, although I think the anthropogenic component is being exaggerated by some people with ulterior motives, (and dismissed by others with opposite ulterior motives).

Modern Science is all about coming up with a theory, using it to predict some outcome, and then testing whether the theory holds. It should be just as true for climate modelling as it is for the action of gravity bending light around the mass of the Sun. The difference is that the number of variables in a climate model is vastly greater, (all identified?), their interactions more complex, (all identified?), and the effect of a bug more destructive.

> In fact there seems to be quite a strong consensus among climatologists ...

Consensus is immaterial. As Michael Crichton pointed out (and no, I don't agree with everything he says, but he's bang on the money with this one), science is about being right, not about being in the majority opinion. It would never occur to any scientist to say that there is a consensus that photons behave in some ways like particles, or that there is a consensus that penicillin kills bacteria. When you've got proof, you list your evidence. When you haven't, you can always fall back on weak claims about consensus.

That isn't to say that climatologists are wrong. It's to say that, whether they're right or wrong, their rightness or wrongness is comepletely independent of any consensus.


> many of the 'skeptics' are politically-motivated dupes or bought-and-paid-for hacks.

The only reason people disagree with you is because they're part of a conspiracy? Grow up.

And you accuse others of presenting arguments based on insufficient scientific knowledge, then make an argument like that?


> 'Skeptic' also suggests an admirable resistance to irrational ideas, and implies that 'skeptics' are just too damn independant to agree with global warming. This is especially ironic when you notice that they all parrot the same dozen talking-points

Or, alternatively, they could all be concentrating on the same issues because those are the areas where the science is weak.

Meanwhile, those who believe that humans are irreparably and disastrously heating the Earth also have the same few talking points. Again, they could all be saying the same things because they actually believe they're true. In fact, I'm sure they are.

It's rather odd that you first mention consensus — i.e. the fact that lots of people all agree with each other is evidence that they're right — and then complain about "[parroting] the same dozen talking points" — i.e. the fact that lots of people all agree with each other is evidence that they're wrong.

> the number of variables in a climate model is vastly greater, (all identified?)

Nope, not all.

> their interactions more complex, (all identified?)

Again, not all.

As far as I'm aware, there is still some debate about whether the Earth's climate is a chaotic system.

The only reason people disagree with you is because they're part of a conspiracy? Grow up.

The idea that some people are paid to advance certain opinions is not anything like a conspiracy theory. Get a grip.

That said, my main point doesn't rest on whether global warming skeptics are mostly honest and clever or stupid liars. What's significant to me is that they're mostly not climatologists, and that climatologists mostly agree that human-caused global warming is happening.

Consensus is immaterial.

It might be immaterial if you're a climatologist, since you can judge the evidence for yourself (although I'd guess that scientists also value the opinions of other well-qualified people). People like me who know almost nothing about climatology can't follow the literature but still have to judge for ourselves what to believe. I think in that case that the opinion of the great majority of qualified experts is a good guide.

[you say that] the fact that lots of people all agree with each other is evidence that they're wrong

Actually I just find it amusing that the same few specific arguments keep popping up from people pretending that they thought of them on their own.

More pedantry: Sq2, you asked which of the questions you listed might NOT be valid? I re-read them, and (as you know, I'm not a computer programmer nor a climatologist etc etc, so I'm asking out of pure curiosity) - one of your questions is
"What workarounds did you use (in order to fix any bugs)?" - My point is, if the workaround WORKS and does not affect any of the other parameters or formulae, why should it be a problem and why should it need to be disclosed?

Ages ago on some accountancy site, someone proposed an Excel formula - you input a taxpayer's UTR (uniform tax reference) except for the "check digit", and it tells you what the check digit is - in other words, they had cracked the HMRC's code. So, I copied this formula and I tested it against 30 real clients' UTRs. It worked, except when the real check digit was (say) "9", in which case it came out in this formula as "11", which could not be right, as it needs to be one digit only.
I studied the formula and I couldn't quite see where it was going wrong, so I devised a workaround, (something like "if result is "11" then result should be "9"), which worked.
Now I understand that this probably means that the formula I started from was not the real formula which the Inland Revenue had devised. I had to tweak it to make it work. Yet, the end result was that it worked. (or at least, for the sake of this argument, let us assume that it worked). Your question would seem to imply that this would still be a weakness - why?

> if the workaround WORKS and does not affect any of the other parameters or formulae, why should it be a problem and why should it need to be disclosed?

It's not necessarily a problem. That's not the point of the questions. I've said several times now, the point of the questions is to see whether the scientist has thought about them. The point lies in the "if" at the start of your question. Does the workaround affect any other parameters or formulae? Either way, the person who programmed the workaround should know the answer. If they don't know the answer, that's the problem.

> I studied the formula and I couldn't quite see where it was going wrong

That's my point. And you ask why this is a weakness?

In your example, you're comparing the result of the program to known data and adjusting accordingly. Fair enough. Can you see the difference between that and adjusting the program when the result it's supposed to give you is unknown?


> people pretending that they thought of them on their own.

And where did I do that, exactly? Would that be where I said "It's not an insight: it's very very very basic knowledge"?

> The idea that some people are paid to advance certain opinions is not anything like a conspiracy theory.

No, but, since no climatologists work free of charge, and since organisations such as Greenpeace and Friends of the Earth are now deeply involved in climatology funding, the idea that people on one side are paid to advance their ideas while everyone on the other side is completely pure of motive is a lot like a conspiracy theory.

Anyway, I think it's fair to say you've had your say. If you want to try arguing any actual scientific points, feel free. Any further repetition of your snide innuendo that the only reason anyone would mention some very basic principles of computer programming is that they're being paid by evil oil moguls will be deleted, on grounds of repetition and boredom.

your snide innuendo that the only reason anyone would mention some very basic principles of computer programming is that they're being paid by evil oil moguls

Oh please. I'd suggest readers compare this with my comment on 8.23 18/6 and ask themselves if this is a fair summary.

If you want to try arguing any actual scientific points, feel free.

What would be the point? You don't know anything about the science of climatology and computer modelling.

Anyway you're right Squander Two - this is getting repetitive. Unless you feel like answering my point on the usefulness of a scientific consensus I think I'll stop responding.

You know, there is a huge difference between not being a professional climatologist with a PhD and knowing absolutely nothing about it. Same with modelling. I know far from nothing about either subject, and have done one for a living. I did mention that, but you made it clear that you are rather contemptuous of people who merely have hands-on experience of doing something, and you've chosen to disregard the information and keep repeating that I know nothing about modelling. Not that that's really the point, because, I repeat, my post was about computer programming.

Your reason for agreeing with the consensus in a field is basically the same as David's reason for doubting the claims of a group whose consensus one day is that the new ice age is coming and whose consensus thirty years later is that the world is heating up catastrophically. If you're not an expert in the field, you use other factors to establish trust. You're going for consistency from one scientist to the next; David's plumped for consistency from one year to the next. Both decisions of how much to trust a group are equally valid, and are based on the same sort of reasoning. But you have reverential respect for one and contempt for the other.


> I'd suggest readers compare this with my comment

OK:

> Although it seems a little extreme to me to reject the whole of modern science because you're upset about the existence of global warming.

Clear implications there that people who are doubtful about global warming are rejecting the whole of modern science — in turn implying that climatology is so completely understood that it's conclusions are unassailable without abandoning the whole of modern science — and that the only reason to doubt global warming is that it upsets you, that you couldn't possibly have any scientific or rational reason for doing so.

> If climate scientists have been defensive, it's probably partly because they've been subject to a lot of politically-motivated criticism

... and a lot of scientifically-motivated criticism, too, but you either avoid mentioning that or (as in your "whole of modern science" comment) imply that it doesn't exist.

> ... another well-worn talking point for global warming denialists.

See my comments above about the word "denialist" being a politically loaded unscientific insult, with which you appeared eager to agree:

> I think 'skeptic' is rather too charitable.

> they all parrot the same dozen talking-points

You repeatedly use the phrase "talking point" and, here, "parrot" to imply that one side simply stupidly repeat things without comprehending them.

> It suggests (as you do) that the global warming debate is just a matter of the normal process of science. In fact ...

Here an implication that doubting global warming isn't even part of science.

Most of these comments are implying that any doubts of global warming are not merely wrong but stupid and/or ignorant. You have only suggested two possible reasons for this wilful or accidental stupidity:

> many of the 'skeptics' are politically-motivated dupes or bought-and-paid-for hacks.

a group whose consensus one day is that the new ice age is coming

Most of the things I've read have suggested that this is a myth. I'd be interested to see any evidence from the scientific literature supporting the idea that there was a consensus that a new ice age was imminent. I certainly don't know of an IPCC report supporting the idea of a new ice age, or a joint statement from the national academies of science for the G8 countries.

> I'd be interested to see any evidence from the scientific literature ...

Well, there's a shifting goalpost.

> People like me who know almost nothing about climatology can't follow the literature but still have to judge for ourselves what to believe.

Well, there's a shifting goalpost.

Perhaps I should say 'evidence about the scientific literature'. Just to clarify, I'm not talking about assessing the technical merit of pieces of climate research - I'm not at all qualified for that - but rather about judging the consensus amongst climatologists. What I'd like to see is anything like the IPCC report supporting the idea that there was a consensus about an imminent ice age. I asked specifically about the scientific literature because there was apparently quite a lot of alarmist reporting in the popular press.

>was apparently quite a lot of alarmist reporting in the popular press.

Was then, is now. I take it you weren't around then. I was. It's deja vu all over again.

Just to say, yes, I understood and accept the points you made in reply to my Q on workarounds.

Beautiful, quite beautiful.

ekmi,

I certainly don't know of an IPCC report supporting the idea of a new ice age

Oh dear. Perhaps the reason you never saw an IPCC report on the new ice age was that the ice age scares date from the 70s and the IPCC was formed in 1988...

Good point Pedant-General -- I half-implied something false unrelated to my actual argument. Since nit-picking is all that anyone's responded with, I think I'm probably right to suggest it's a myth that there was a scientific consensus for an ice age.

I think it would be wrong to suggest there was much of a consensus about anything beyond the basics in climatology in those days. The science wasn't that well understood, chaos theory hadn't been invented (or perhaps had only just barely been invented), computers weren't very powerful. Even three-day forecasts were a lot less reliable than they are now, let alone thirty-year forecasts. (One of my lecturers worked for a met service, and said they had to provide six-month forecasts — they knew they were bollocks, but "This is impossible" wasn't an acceptable excuse in those days.) Whether or not there was a consensus, the fact is that plenty of climatology experts did believe we were heading into a new ice age, and said as much publicly. I'm not sure why it particularly matters whether they were merely lots of climatologists or a majority of climatologists.

ekmi,

"I half-implied something false unrelated to my actual argument."

I disagree. This is relevant because it suggests the depth of your ignorance. You were clearly unaware that the IPCC is a recent creation and very definitely post-dates all discussions of an impending ice age.

I think it important that we note your apparent failure to have any basic - and verifiable - facts at your disposal. It might call into question your ability or knowledge or basis for contesting theorems that are distinctly less simple to verfiy.

PG

Squander Two,

It only matters in judging whether the current situation with global warming is similar to the ice age scare of the 70s. As far as I can tell, it isn't. Today there's seems to be a pretty broad consensus among climatologists that human-caused global warming is real. In the 70s a few scientists suggested that a new ice age might be immanent, prompting a lot of hysterical news coverage.

That said, I'd welcome evidence to the contrary. If 'lots' of climatologists thought we were heading into a new ice age, there should be lots of evidence.

>In the 70s a few scientists suggested that a new ice age might be immanent[sic], prompting a lot of hysterical news coverage.

Of course, in the 70s there were so few climate scientists that a few may have been pretty much all of them. But it's beside the point: science advances through evidence, not consensus. There was no evidence of an imminent ice age then. There's no evidence of global warming now. Computer models are not evidence.

Going to have to disagree with you there, Stephen. There was evidence of a new ice age then and there is evidence of global warming now. There is also still evidence of a new ice age now -- that evidence didn't just vanish. The problem is that some evidence conflicts with other evidence.

There's no proof of global warming.