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ClimateGate: How do YOU choose what to believe?

Like a lot of scientists — I’m a physicist — I assumed the “Climategate” flap would cause a minor stir but would not prompt any doubt about the threat of global warming, at least among educated, intelligent people. The evidence for anthropogenic (that is, human-caused) global warming is strong, comes from many sources, and has been subject to much scientific scrutiny. Plenty of data are freely available. The basic principles can be understood by just about anyone, and first- and second-order calculations can be perfomed by any physics grad student. Given these facts, questioning the occurrence of anthropogenic global warming seems crazy. (Predicting the details is much, much more complicated). And yet, I have seen discussions, articles, and blog posts from smart, educated people who seem to think that anthropogenic climate change is somehow called into question by the facts that (1) some scientists really, deeply believe that global warming skeptics are wrong in their analyses and should be shut out of the scientific discussion of global warming, and (2) one scientist may have fiddled with some of the numbers in making one of his plots. This is enough to make you skeptical of the whole scientific basis of global warming? Really?

The analogy that comes to mind is to evolution. Suppose a bunch of emails among paleontologists were released, showing that they had conspired to quash scientific papers about creationism; had refused to share data with creationists; and had refused to publish in journals that publish papers that deny evolution. Suppose the paleontologists were shown to have fabricated data, hidden or distorted fossil data that are hard to explain, and just generally distorted their findings to make a messy dataset look like a good, clean match to evolutionary orthodoxy. Would this make you question evolution? Should it?

Note that I’m not asking whether the behaviors described above would be acceptable (my opinion: some are, some aren’t). What I’m asking is, if you found out that some scientists were acting this way, would you throw up your hands and say “the whole occurrence of evolution is called into question by these revelations”?

The actions I’m talking about not so hypothetical, when it comes to supporting evolution: Mendel fudged his data on heritability. Several fossil finds that were used to support the theory of evolution were hoaxes or frauds. And when I was a kid it was revealed that a Smithsonian exhibit on the evolution of the horse had arranged a bunch of fossils in order by size (which seemed really convincing, because it showed a gradual, monotonic “evolution” from small to large) rather than in chronological order (which doesn’t show a monotonic progression at all).

Coming back to the “Climategate” emails: Failing to provide data when asked…that’s bad. Fudging data is completely indefensible. The emails do indeed reveal some unethical and scientifically damaging behavior by some researchers. They reveal pettyness and poor judgment by others. But they don’t disprove or discredit the theory of anthropogenic climate change, any more than the Piltdown Man hoax discredits the theory of evolution.

It’s very disheartening that some smart people are so quick to buy the arguments of the climate skeptics. Perhaps I shouldn’t be surprised: you can still find evolutionary skeptics, too, 150 years after Darwin published On the Origin of Species, and about 100 years after the case for evolution was essentially proved. There are still people out there — lots of them — who look for, and find, evidence that evolution is a hoax at worst, or an example of “groupthink” by researchers at best (search for “case against evolution” in the search engine of your choice). There are enough of these people that they sometimes succeed in quashing the teaching of evolution. I suppose there’s no reason to expect the theory of anthropogenic climate change to have an easier time of it. In fact, it will probably take longer: acceptance of evolution didn’t threaten substantial economic interests, the way acceptance of global warming does. But I don’t think the economic forces explain the phenomenon that I find so discouraging, of intelligent people with nothing at stake who are so willing to believe global warming is a hoax. These people, or at least the ones I know, don’t claim to have worked through the science and found it unconvincing or wrong; they simply choose to believe other people who claim to have done so. Why?

[I feel like I need to say a few things here at the end that a better writer would have found a way to work into the text. (1) No analogy is perfect; evolution skeptics are not exactly the same as climate change skeptics. (2) Yes, I am aware of the claims of mainstream climate skeptics: that the climate isn’t actually warming because 1998 is still the warmest year on record (misleading), that warming in recent years or decades is explained by increased solar radiation (false), that the theory of global warming depends critically on factors such as atmospheric levels of water vapor that are so unknown that the whole theory is questionable (false), and many others. Many of these, I am scientifically capable of judging for myself; others are too far outside my area of knowledge but are easy enough for experts to test that it is just impossible that everybody gets them wrong. (3) There are plenty of quickie pro-and-con discussions on climate, from every side. For a short, readable (but non-technical and thus hopefully non-persuasive) article, this one isn’t bad; for a lot more detail, including links to data and technical arguments, RealClimate.org is a great source.]

59 Comments

  1. Suppose that there is a trial by a jury. Suppose that one side, for arguments sake, the prosecution, presents their case based on falsified evidence. Furthermore, suppose the prosecution prevents the defense from presenting an argument. Few would consider justice to have been done. “The evidence for anthropogenic (that is, human-caused) global warming is strong, comes from many sources, and has been subject to much scientific scrutiny.” Misrepresented data as interpreted by those with a political and economic agenda should have no weight. Likewise, conclusions based on extrapolations (even of quality data) are faulty. I’m reminded of a quote from Disco Stu (of Simpsons fame) who once quipped "Did you know that disco record sales were up 400% for the year ending 1976? If these trends continues… AAY!"

  2. Anonymous Coward says:

    Suppose someone broke into the email of James Inhofe's staff. One of the emails reads:

    "There's obviously evidence of global warming. We need to bump up the temperatures from 1950 to 1970 and bump down the temperatures from 1990 to 2009."

    Would the critics of global warming be willing to admit global warming is real? In my opinion, climategate is so absurd as to not even be worthy of discussion.

  3. Phil says:

    Coincidentally, Paul Krugman has a new discussion of "climate rage": people who are furious at scientists who say global warming is happening (and that we are causing it). This isn't the same as what I'm talking about, in which people make a calm, non-rage-filled decision that we just can't be causing global warming. Krugman suggests that there are two reasons for climate rage: (1) "First, environmentalism is the ultimate “Mommy party” issue. Real men punish evildoers; they don’t adjust their lifestyles to protect the planet.", and (2) "climate change runs up against the anti-intellectual streak in America." Krugman might be right on both counts, for a certain type of climate change skeptic. But not the type of climate change skeptic that I find so discouraging. To name a name: Michael Crichton. (He's dead, so I can mention him without offending him.)

  4. A. zarkov says:

    "… that the theory of global warming depends critically on factors such as atmospheric levels of water vapor that are so unknown that the whole theory is questionable (false)"

    No that's a strawman. With all the feedbacks turned off we would get about only about 1C of warming from a doubling of CO2. This much is pretty much uncontroversial. The primary feedback, which the IPCC assumes is positive, is cloud cover. The cloud cover driven by water vapor. The cloud cover could be produce a negative feedback by increasing the earth's albedo. To resolve the question, we need to to understand and model the cloud physics. But we can't do that with GCM models because the cloud physics takes place on a scale much smaller than a resolution cell in the GCM models. So they run a bunch of guess models of for the effects of clouds. These are the primary drivers of the uncertainty in the climate sensitivity factor. Note the 1.5C to 4.5C for the uncertainty range in the climate sensitivity factor (amount of increase in temperature for a doubling of CO2) has remained unchanged for 30 years. This means we don't understand the cloud cover and other feedbacks any better than 30 years ago.

    "For a short, readable (but non-technical and thus hopefully non-persuasive) article, this one isn't bad; for a lot more detail, including links to data and technical arguments, RealClimate.org is a great source."

    "Hopefully non-persuasive" Obviously you don't have a open mind about this matter. And RealClimate.org is hardly a reliable source of unbiased information. Read the emails. They censor posts. Gavin Schmidt and others have conspired to keep skeptical papers out of peer reviewed journals. Again read the emails. But bear in mind the the real action is in the documents folder. Go look at the code. Look at the comments and the Harry_README file to see what a mess the the analysis is and how the the desired results were forced.

    I'm really disappointed to see you engage in the usual group think about global warming. Have you read the Wegman report? How come you don't refer people to ClimateAudit for the other side of the debate? Did you know that Michael Mann had to be forced by Congress to provide the data and codes behind the hockey stick calculation? ClimateAudit give you everything, the data and the R code they use. The other side stonewalls, and no wonder– their results are a fraud.

  5. Phil says:

    Cody: I don't disagree with anything you say, but I can't figure out how any of it applies to the climate change debate. Could you connect the dots for me? –Phil

  6. Leland says:

    Phil — What exactly is your primary point in all this ?

    Apparently you're 'disheartened' despite all the science & facts being entirely on your side (?)

    And with the government, MSM, and most academia still strongly agreeing with you… even after 2 weeks of "ClimateGate" teapot tempest.

    So why would you be even slightly concerned about a few climate skeptics — who will continue to be proven as thorough fools by your unassailable AGW scientific facts {??}

    And as you discerned, Climate skeptics are just like evolutionists… who use supernatural/mystical arguments in silly attempts to discredit ironclad physical science (?)

    Why Worry ?

    {unless…Thou dost protest too much}

  7. Radford Neal says:

    I think your analogy of evolution and climate change is not appropriate.

    Evolution is an extremely well-confirmed theory. Virtually nothing in modern biology makes any sense if you abandon evolution.

    That CO2 will have some warming effect is also very well supported by present physics. The argument (excluding some crackpots) is about how big the warming effect is. The evidence that it is big enough to constitute a crisis requiring drastic action is nowhere near as convincing as the evidence for evolution.

    Two strands of evidence are the instrumental temperature record for the last 150 years or so, and the proxy (eg, tree ring) temperature record going back a thousand years or more. Both these records are very messy, with potential systematic errors that are comparable in magnitude to the claimed trend. It may well be that no useful information about long-term variation in temperature can be obtained from these records. If any useful information can be obtained, it will only be by a very careful analysis that takes pains to avoid biasing the conclusions. The CRU emails and other documents (and plenty of previous evidence) make clear that the researchers in these areas are neither careful enough nor unbiased enough for their results to be trusted.

    Claims of a large warming effect of CO2 are also supported by other areas of climate research (eg, computer simulations of climate) that are undertaken by other researchers, whose competence and integrity are not directly called into question by the CRU emails.

    One may, however, distrust the results from these research areas also, because normal scientific scrutiny may have been inhibited by the cult-like nature of the climate science community. Would you expect the following comment from a normal scientific community?

    I am taking some heat for all this from my peers outside Georgia Tech. The climate blog police were very upset by my congratulations to Steve upon winning the best science blog award. A recent seminar speaker was apalled to be included in the same seminar series as steve and pat, and told me i was misleading my students. I got some support for what I am doing from a program manager at NSF who I spoke with recently, who appreciated my missionary work over at climate audit. Another NSF program manager is apparently not at all happy about this.

    This is Judith Curry, on the reaction to her inviting Steve McIntyre to give a seminar. Anyone who looks in detail at McIntyre's blog, climateaudit.org, will appreciate that although he's occasionally a bit sarcastic, he is doing serious analyses, and has a considerable degree of statistical sophistication. Treating him as some sort of heretic is not the sign of a healthy scientific culture.

  8. TBW says:

    Evolution and Global Warming are not in the least bit comparable. Evolution explains the historical data that we see(the fossil records), and furthermore has actually been observed in action. I believe there was a study on the Galapagos on a certain type of finch and the length of their beaks varied according to rainfall because of the types of food they were forced to rely on depending on the weather. I'm probably mangling the example a bit, but the point is that evolution as a theory explains a lot and just "makes sense". This is important to the average person or layman, evolution helps that person makes sense of the world, and perhaps most importantly the average person has no personal experience that would contradict evolution.

    The same cannot be said for Global Warming. First of all, the theory of anthropogenic global warming does nothing to explain away past variations in climate, which have been substantial. The average person knows this, he knows the Earth was warmer when dinosaurs were around, and he knows there have been ice ages, this knowledge plants the seeds of doubt. If the Earth has been much warmer and much colder in the past, why are today's climate change's because of man ? It's a perfectly valid question, and the average person doesn't dig around to find an explanation, he just notes it doesn't make sense. Then there is personal experience, who doesn't talk about the weather ? Who doesn't complain about the how bad the weather forecast was, it wasn't supposed to rain today, it wasn't supposed to snow,it was supposed to be sunny today…Again the average person knows how difficult it is to predict weather more than a few days in advance and so is naturally suspicious of someone forecasting doom and gloom 50 to 100 years from now. Now tell the average person that because of the doom and gloom forecast we should make dramatic changes to how we live, at great expense. Now reveal that some leading climate scientists have been involved in activity which on the surface at least sounds suspicious. Is it really any wonder the average person is skeptical ?

  9. Mike Kenny says:

    One of the difficulties I've had with global warming is that I have no idea how to evaluate the claims of anyone as a layperson with no science background of any kind.

    I started with an attitude that scientists needed to make predictions about climate that established they were very good at predicting what would happen.

    Then I began to question this because I don't really expect predictions so much from claims that make sense to me, like those about evolution that are descriptive and hard to test, though I suppose you can make indirect tests–falsifiable tests of hypotheses constructed based on the theory of evolution, perhaps applied to bacteria that go through many generations quickly, or something like that.

    But I am pretty bothered by this Climategate thing. I can know someone making a claim is probably trustworthy if he's made lots of predictions publicly that have panned out. I know his track record and he's not just publicizing his right predictions after they came true and hiding the ones that didn't.

    I can judge weatherman more easily than I can climate scientists. Climate scientists are in a rougher spot given the time horizons of their predictions I suppose. But I suppose they could make some shorter-term predictions to give you a sense of their ability in shorter-term areas.

    I don't know of any predictions climate scientists have made that were made publicly and were easily falsifiable and have either succeeded or not. And I don't know of the track record of such predictions if they exist–say a climate scientists makes predictions for ten years about next year's average temperatures, or seasonal weather, or violence of storms. It would be good to have a sense of how often they are right and how often they are wrong.

    I don't mean to say such predictions haven't been made, or track records kept. I merely state I don't have a clear picture of such a situation being the case, and have looked from time to time to get a sense of such predictions have been made.

  10. Sean says:

    Wait, are you arguing against the complete denialist nimrods? They're an easy target, but are not really involved.

    Climategate's importance is more between the likes of the Pielkes (http://pielkeclimatesci.wordpress.com/ and http://rogerpielkejr.blogspot.com/) and Steve McIntyre (http://camirror.wordpress.com/) versus Phil Jones, Michael Mann, and Gavin Schmidt at RealClimate.

  11. razib says:

    is AGW on as firm ground as evolutionary theory? how do we judge something like this? who has cultural fluency in both evolutionary biology and climatology?

  12. David says:

    The assumption that the email leak was not going to do much damage was naive in the extreme and indicates why the deniers' message has gained such traction. This is not about science – the papers brought into question by these leaks make up a small part of the large body of evidence – this is about politics and getting a message across. Deniers are aware of this and have a very tight media strategy. The science community seem only dimly aware of this and have an appalling strategy – witness the achingly slow response from the University of East Anglia to these leaks (which include evidence of illegal behaviour in deleting correspondence requested under the freedom of information act). Scientists need a better PR strategy – being right isn't nearly enough!

    I'm not sure about the motivations of these intelligent people out there who are deniers. George Monbiot had in interesting article a while ago in which he proposed an interesting theory, which I quote here:

    Such beliefs seem to be strongly influenced by age. The Pew report found that people over 65 are much more likely than the rest of the population to deny that there is solid evidence that the earth is warming, that it's caused by humans, or that it's a serious problem. This chimes with my own experience. Almost all my fiercest arguments over climate change, both in print and in person, have been with people in their 60s or 70s. Why might this be?
    There are some obvious answers: they won't be around to see the results; they were brought up in a period of technological optimism; they feel entitled, having worked all their lives, to fly or cruise to wherever they wish. But there might also be a less intuitive reason, which shines a light into a fascinating corner of human psychology.
    In 1973 the cultural anthropologist Ernest Becker proposed that the fear of death drives us to protect ourselves with "vital lies" or "the armour of character". We defend ourselves from the ultimate terror by engaging in immortality projects, which boost our self-esteem and grant us meaning that extends beyond death. More than 300 studies conducted in 15 countries appear to confirm Becker's thesis. When people are confronted with images or words or questions that remind them of death they respond by shoring up their worldview, rejecting people and ideas that threaten it, and increasing their striving for self-esteem.

  13. Phil says:

    Zarkov, taking your points in order.
    (1) the effects of water vapor are indeed uncertain, and produce large uncertainties in the climate models. But they are not so uncertain as to call anthropogenic global warming into question.
    (2) The commentary I called "hopefully non-persuasive" is one that _supports_ the theory of anthropogenic climate change, so I'm not sure what you mean when you say I obviously don't have an open mind. My point in calling it "non-persuasive" is that any list of simple assertions, such as this comment, or yours, or the post to which they refer, should not persuade anybody.
    (3) As I tried to make clear in my post — hard to see how you missed it, but maybe you did — some of the stuff in the "Climategate" emails is really bad, possibly including scientific misconduct and some is possibly fraudulent. I don't disagree with you on that.
    (4) I have read the Wegman report. [Note to others: the Wegman report is a well-written but non-peer-reviewed report that examines the credibility of the famous "hockey stick" temperature plot that shows a rapid increase in northern hemisphere surface temperatures over the past few decades. The report found that the statistical methods that were used to create the plot were invalid, but did not claim that the result is incorrect. In fact, in the last of the "findings" of the report, the authors point out that they were asked to evaluate the statistical methods rather than the findings, but they say "We note that according to experts at NASA’s JPL, the average ocean height is increasing by approximately 1 millimeter per year, half of which is due to melting of polar ice and the other half due to thermal expansion. The latter fact implies that the oceans are absorbing tremendous amounts of heat, which is much more alarming because of the coupling of ocean circulation to the atmosphere." It's also worth noting that since the publication of the Wegman report, the original "hockey stick" work has been re-done with proper methods and the sharp increase in temperature in recent decades is still there. The National Research Council looked into this issue at the request of Congress, and concluded (among other things) "It can be said with a high level of confidence that global mean surface temperature
    was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries."]
    (5) Hmm, why did I not refer people to ClimateAudit for "the other side of the debate." It didn't occur to me. I would not refer people to a creationist website for the other side of the evolution "debate", either. That said, the author, McIntyre, has done a good thing by getting researchers to be much more careful about the accuracy and documentation of their data, and I wish him well in that part of his efforts. Hmmm, ClimateAudit seems to be down at the moment anyway.
    (6) Yes, I know Mann was "forced" to provide his Hockey Stick code and data to Congress. I wish Congress were so interested in _my_ work!

  14. Cassoulet says:

    The non-scientific population opposed to anthropogenic theories squabbling on the internet is composed of activists ranging from Bible-Quoting-Tea-Partiers, pro-business anti-regulation free-market lovers to paranoid 9/11 truthers…
    The evidences doesn't matter, skeptic theories validate their pre-conceived vision of the world as they are far too afraid of cognitive dissonance.

  15. Here's what I think is interesting.
    There's growing consensus that expert consensus is itself grants heirarchical topness to fact claims that have expert consensus behind them.

    So we can start to expect myths to claim to have expert consensus supporting them.

    There's interest in if expert consensus has been gamed here.

    That's where I think smart, generally skeptical people are now. A proven conspiracy of a global community of experts would probably be unprecedented, but it doesn't mean the incentive isn't there.

    I think it also comes from a healthy place of how to correct even our best methods for determining reality (how to fix the chinks in "expert consensus" before we pay a heavy avoidable penalty for relying on it too naively).

  16. Leo Martins says:

    I agree with you on all accounts, which maybe I can summarize as "the science is solid. Some of these scientists made mistakes" (there are ethical problems, not scientific ones). I am completely ignorant in climate sciences, so I trust the authorities. Now some comments.

    Even though you pointed out at the end, I must stress that the comparison between climate deniers and creationists is way off the mark for, amongst other reasons:
    . we have eminent scientists skeptic of AGW (Freeman Dyson comes to my mind) but you won't find creationists with the same scientific understanding – you will find creationists who happen to be brilliant, but on other areas (should I say "further from natural sciences"?).
    . the theory of evolution is older ("more mature") than the theory of climate change: after Darwin we already had the "modern synthesis" with the incorporation of population genetics and now we are on the verve of the genomic revolution.
    . "creationists" are clearly defined while "climate skeptics" is a loose term. Maybe because the evolutionary theory is more clearly stated than the theory behind climate science (BTW _what_ is the scientific theory of climatology? Can it be stated like the Theory of Natural Selection?)
    . Nature's editorial itself (this week) didn't know how to bash the deniers, since they acknowledged that we have contrarians' papers cited in the IPCC report (this week's Science also point to these papers). So the contrarians actually are legitimate "players" – you won't find anything similar with creationists, since even when they have publications it's something completely unrelated to evolution.
    . All creationists have a political agenda (religion) while evolutionary biologists don't (possible exception to the "new atheist" movement, which don't represent practicing scientists). I am not so sure that all climate skeptics have a political agenda at the same time as I can imagine an agenda for climate scientists. Please understand that I'm not saying that they have one.
    . this kind of association is what creationists want (http://sensuouscurmudgeon.wordpress.com/2009/12/01/another-climategate-creationism-coupling). Yes, they are very aware that any wrongdoing of these climate scientists can be used in their crusade against the "imperialist" science.

    What makes the dialog so hard is that climate science is too much politically charged, so we end up jumping between scientific and political arguments. That may be why the word "denier" can refer to anything from a kook who discards anything that comes from a scientist to someone who is legitimately questioning the accuracy of projections. Please correct me if I'm wrong, but I believe that this dispute is more similar to those between systematics and phylogenetics, or between group selection and individual selection, or maybe frequentists and Bayesians… (when considering the contrarians mentioned in the e-mails, not the deniers in general). As a side note, I realized that people are dropping the term "skeptic" since skepticism is something desirable while denialism is refractory to facts.

    Ps: just saw your comment, and there is at least one post in Climate Audit worth the visit: a commentary of professor Judith Curry (http://www.climateaudit.org/?p=7826).

  17. Radford Neal says:

    Phil,

    I think your characterization of McIntyre's climateaudit.org site as akin to a creationists site is a good illustration of how cult-like climate science has become. I think no objective evaluation of McIntyre's work could possibly support this assertion. I suspect you're trusting the evaluations of people whom you shouldn't trust.

    Your quoting of the NRC report that "It can be said with a high level of confidence that global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries" is another example where you have probably swallowed a talking point without realizing how misleading it is. Few people ever disputed that the current temperatures are higher than those of earlier times back to four hundred years ago. The big issue has always been whether the Medieval Warm Period (usually seen as occuring around a thousand years ago) was warmer than at present, since if it was, that makes the present warming seem not so unusal and perhaps due to natural causes.

  18. Matt Frost says:

    Climate hawks are using the relative certainty of the historical record to insist on a specific policy (reorganization of the global economy, starting with deep emission cuts in the U.S. in order to encourage similar reductions in the developing nations), and they smear anyone who doesn't endorse their preferred policy response as a climate change "denier." Actual deniers, meanwhile, think that if they accept the warming trend, they've signed their futures over to Al Gore, so they refuse to honestly assess the science, and they smear climate scientists as power-hungry scaremongers.

    Unfortunately for the rest of us, there's a lot more science to critically assess than just whether or not carbon emissions have caused a warming trend. Between assembling a decent climate history and responding to AGW there are those "details" you mention in your post.

    A rational response to climate change should proceed as follows:

    1. Describe the historical climate record.

    2. Identify those forcing factors that explain the temperature record and assign weights to them.

    3. Predict the future paths of those forcing factors under different likely scenarios.

    4. Using a response function for each factor, estimate the likely effect on temperature of each scenario.

    5. Use persuasion, negotiation, and cooperation to achieve consensus on the collective response that best balances human welfare and environmental integrity (and no, they aren't always in harmony).

    6. Implement that response through the social instruments available to us (democratic choice, central planning, international agreements, etc.).

    The steps above overlap one another, and the conceptual taxonomy isn't crystal-clear, but there's a rough order of dependency. There's also increasing (compounding?) uncertainty in steps 1-4, as any uncertainty in the historical model infects the forcing factor coefficients, which then infect the forecasting model, etc.

    The leaked CRU data and emails correspond to point #1 on my schema. But the Nixonian paranoia on the part of some climate scientists is an indication of how overloaded the historical reconstruction model is: it's doing the work that's meant to be done in steps 3,4, and 5, so the stakes are enormous. Everybody's decided to die fighting on Mount Hockey Stick, when the really difficult analytical and normative work is still ahead.

    Even with an airtight historical record, we can't decide what to do about CO2 emissions until we know how much climate-stabilizing bang we might get for each buck of GHG reduction. The way one normally identifies a response function is to run experiments and observe the difference between those subjects given a treatment and a control group, right? We only have one planet handy, so that's obviously not an option in this case, and the the curves in graph c here have to be built from computational models.

    When the whole debate gets hung up on the historical record (and when otherwise smart people think the Scopes Monkey Trial is a useful analogy), there's been an enormous breakdown in public thought and communication.

  19. frankcross says:

    This is too binary and unfair to "skeptics." There are deniers whose minds are closed. But I think the skeptics do not dispute global warming in the abstract but believe that the projected consequences are far greater than the evidence suggests. This is where the true issue lies. And I think the emails are truly relevant to this question. They suggest to me that the scientists are not truly scientists — that they are committed to a given result rather than objective truth.

  20. Sean says:

    Whatever happened to Occam's razor?

    Is it possible that the same thing that caused the previous warming and cooling periods is at work again? Shouldn't that be the null hypothesis? Why should the null hypothesis be that humans are causing it, and if you disagree you must be some sort of knuckle-dragging creationist. Starting with human-causation as your null hypothesis sounds like an article of faith to me. Assume what you want to prove.

    We've all built complicated models. We all know that we can make the model "prove" whatever our biases are. And when millions of dollars of grant money is on the line, the temptation is too great for some; well you know the drill. Of course, this works on both sides of the argument, but as we know right now, it's easier to find a well-paid job supporting human-caused global warming than as a skeptic.

    The scientific method is founded on replicating results and peer-review. Those clowns destroyed the raw data and turned peer-review into a form of McCarthyism. To even mention that some research was not peer-reviewed when those guys were on their witchhunt sounds like an appeal to authority to me. I'm more interested in will they share their data supporting the claims in their article? Note that Mr. Hockey-Stick would not share his data at first. Interesting, that when he did, it turned out to be tweaked and amped the data up to prove his point.

    It's one thing to fake your data to prove cold-fusion, it's another thing to fake your data and twist your model and then try to destroy all who disagree.

    Last time I checked scientists were supposed to attempt to disprove their own theories; not to blackball and attack those that disagree as flat-Earthers and deniers (an excellent political echo of Holocaust deniers). So if you believe in human-driven climate warming please share the weaknesses in your own theories/data rather than telling us that the skeptics are bad people. If you won't list the question marks, then I suspect you are also playing politics.

    A scientist should be willing to say, the physics is not well-understood, the models are rough, and the reliable data series are too short to say either way. Yes maybe humans are contributing, but the data is just too noisy. Does that qualify as being a denier? I thought scientists were supposed to be conservative in making claims about their theories. Why is climate change different?

    We know why the politicians are in such a hurry, the question is why are so many scientists lining up behind them and ex-communicating anyone that dare question the Church of Anthropogenic Global Warming?

    Do the anti-string theorists call the string-theory guys creationists and deniers, or do they talk about theories and collecting data to prove or disprove their predictions? I suppose the battles would be just as ugly if string theory also became a huge political football.

  21. Nick says:

    Here's your argument: "The emails do indeed reveal some unethical and scientifically damaging behavior by some researchers. They reveal pettyness and poor judgment by others. But they don't disprove or discredit the theory of anthropogenic climate change…"

    Here's a reply: What about a possible sign that the data may not be 100% legit – just a sample of a comparison of the raw data in Australia vs. the adjusted data (used in the IPCC report & climate models)? If the adjusted data artificially shows higher temps than the raw, how can we trust the resulting models? The issue is beyond the one graph you mention and goes the the heart of what numbers are driving the models and HOW those numbers were reached – especially in cases described in the post below where there are large and seemingly artificial (stepwise increases) adjustments.

    http://wattsupwiththat.com/2009/12/08/the-smoking

  22. Bruce McCullough says:

    Phil writes:
    "Plenty of data are freely available."

    Surely you jest!

    And the "manipulation" of data was not limited to one researcher. Go here to see how the "climate scientists" managed to turn downward trending temperatures into upward trending temperatures (hint: lots of "adjustments" to the data).

    http://wattsupwiththat.com/2009/12/08/the-smoking

    And I suppose you think their statistical software is good, too. Ask yourself, why did Michael Mann write his own principal components code instead of using SAS or SPSS? Could it be because SAS or SPSS wouldn't produce a hockey stick? :)

  23. David Kane says:

    1) Thanks for posting this. I think that the number and length of the comments here indicate that this is an important topic and that there are a lot of people who want to discuss it in a statistically rigorous fashion.

    2) I would recommend a series of posts, both Andrew, Phil or whoever, that tackled discrete parts of the debate. Starting with the Darwin Zero links above would be a good start.

    Coming back to the "Climategate" emails: Failing to provide data when asked…that's bad. Fudging data is completely indefensible. The emails do indeed reveal some unethical and scientifically damaging behavior by some researchers. They reveal pettyness and poor judgment by others. But they don't disprove or discredit the theory of anthropogenic climate change, any more than the Piltdown Man hoax discredits the theory of evolution.

    How much data/model fudging would you have to see before you began to doubt the consensus view as described by the IPCC?

  24. Phil says:

    Lots of good comments here (and not many bad ones), so that's great. I do want to hit just a few points that keep coming up.
    (1) "Evolution is not a good analogy because…" I think some of these comments are right and some aren't. There are plenty of similarities and plenty of differences. Perhaps using any analogy at all was a mistake.
    (2) I agree with Matt that "Everybody's decided to die fighting on Mount Hockey Stick, when the really difficult analytical and normative work is still ahead." Whether current northern hemisphere mean temperatures are the highest in 400 years, 1000 years, or 10,000 years is a pretty minor point, when what we really care about is the _next_ 400 years or 1000 years. (For some reason the debate is always couched in terms of the next 100 years, which makes no sense to me unless we apply such a big discount rate to human suffering that we truly don't care what happens in 101 years).
    (3) Am I wrong to compare McIntyre to a creationist? Probably. I'm tempted to go back and change that statement, in fact, but it's probably better to let it stand rather than revise the historical record represented by these comments. McIntyre and people like him — by which I mean people who take a careful look at the data and try to find errors, not just general climate skeptics — are doing a good thing. It's just that the few times I've looked at McIntyre's stuff, he (a) is very quick to leap to conclusions, some of which are wrong, and (b) gives the impression of trying to play "gotcha" rather than trying to help understand what is happening with the climate or even the prediction of climate. I don't like those attitudes, and I would respect him a lot more if he used a different approach to pursue his quest for transparency of analysis and free access to data. I also think he would be more effective at achieving those laudable goals, although perhaps less effective at convincing people that global warming is not a problem.
    (4) Radford says "That CO2 will have some warming effect is also very well supported by present physics. The argument (excluding some crackpots) is about how big the warming effect is. The evidence that it is big enough to constitute a crisis requiring drastic action is nowhere near as convincing as the evidence for evolution." Good comment! I completely agree with the first sentences. I largely agree with the second, but really it depends on what you mean by "crackpot". I even agree with about 20% of the spirit of the third sentence: some scientists and many proponents of quick and major action are exaggerating the worst case scenarios as if those are the things we can expect. Sea levels might rise by "up to" such-and-such, "as many as" N people might die in drought-induced famine, and so on. This is not the way decisions should be made. Decisions should include the fact that climate change might be less severe — even much less severe — than the "best guess" from current climate models..and should also include the fact that climate change might be more severe. Where I disagree with Radford is this: if the climate predictions are anything like correct, then even climate change towards the low end of what is predicted will be disastrous unless we drastically decrease greenhouse gas emissions very soon. To justify inaction — meaning, continuing to emit at the current rate or higher — one has to be very _strongly_ convinced that the temperature sensitivity of the climate is much lower than most researchers think it is. I can understand how one could _suspect_ that the temperature sensitivity is low, or maybe even _believe_ it is low, but how can you be so _sure_ it is low? Here, the big uncertainties that are always emphasized by the climate change skeptics cut the other way: if you say the exact effect of greenhouse gases is so hard to predict in detail (I agree!) then how can you be so sure it will be very low?
    (5) A few people have said something like: "Natural climate variability is hard to estimate; maybe it was bigger in the past than we think it was; if so, anthropogenic climate change isn't such a big deal." I wish someone would explain this reasoning to me. Is the idea that anything natural is good, and climate change is natural, therefore it's good? If that's the idea, I disagree with it. Polio and smallpox and malaria are natural, but I don't think they're good.

    A few minor additional issues:
    (6) Leo Martins brings up Freeman Dyson to illustrate that even some good scientists don't believe in anthropogenic climate change. From quotes I've seen, Dyson does believe in it; he just thinks it will either be a good thing, or that we will be able to easily and cheaply combat its effects. Dyson has a good record as a physicist and a very poor one as a futurist, and I think that's the case here as well.
    (7) Sean, Bruce, and a few others are still pointing at the "hockey stick" — see, it was all fake, so maybe everything else was too! The "hockey stick" plot is not fake. See the National Research Council report that I mentioned in a previous comment; I think the report is only available for a fee but the executive summary is free.

  25. Ed says:

    I might be able to add to this because I actually do believe far out, tin foilish, scepticism on claims of mainstream science occasionally, though NOT on climate change.

    There were times in the history of science where just about the entire scientific community barked up the wrong tree, or believed theories that were just wrong. Look at phrenology, or ether, or planet x, or alot of more recent thinking on nutrition. So this can happen, though I think the wrong theory tends to be corrected before it influences public policy (though not alot of theories on race from earlier in this century!).

    You can best see this in areas where no big stakes are at stake. Look at all the theories on how best to assemble a team of players and how best to use them in professional sports, they change all the time.

    However, bad theories persist when there is money involved, and debunking them means alot of powerful people losing. So I ask cui bono. With climate change, if measures are taken to control this lots of existing businesses will wind up losing alot, and alot of people are going to have to make major lifestyle adjustments. The "green businesses" that are supposed to profit don't exist or barely exist. So the notion that climate change is some sort of scam falls apart, more powerful interests are threatened by acceptance of climate change than helped.

  26. Radford Neal says:

    Phil: …the big uncertainties that are always emphasized by the climate change skeptics cut the other way: if you say the exact effect of greenhouse gases is so hard to predict in detail (I agree!) then how can you be so sure it will be very low?

    You're confusing two issues here: What the scientific evidence says about the effect of greenhouse gases, including what the uncertainty is. And what to do.

    Only the first is the proper business of scientists (acting as scientists). It is not proper for a scientist to say to himself, "it's possible that I'm wrong, and the effect isn't so large, but just in case it is, we need to take action now! So I'll minimize the uncertainty in order to convince politicians to act." And it is not proper for scientists to ostracize other scientists who argue that the effect is lower than the "consensus" view. If these sorts of things are happening to a significant extent, and unfortunately there's good reason to think they are, then the "consensus" estimates of the size of the effect, and its uncertainty, are not trustworthy.

    This is frightening. We need trustworthy information on this issue. I'm not complacent about this. The percentage increase in CO2 is large enough that just intuitively one might worry that it will have some bad effect.

    Now, I can guess that you would say that a poor scientific culture just adds more uncertainty, so we still need to take action so as to reduce the effects if they turn out to be large. The problem is that the drastic action proposed will itself have huge negative effects. It's not a case of "better safe than sorry".

    Suppose that global warming is not really a big problem, but we take drastic action because we don't know now that that's true. How many people will die as a result? I think any realistic appraisal would say that many millions of people will die, perhaps billions if the resulting economic dislocations lead to nuclear war. If instead global warming is actually catastrophic, these deaths may be fewer than those prevented by the reduction in the warming that results from the actions taken (or they may not be fewer). But it is folly to think that proposals for things like reducing CO2 emissions by 80% do not come at a huge cost – a cost in lives, and in environmental destruction, not just in dollars or personal inconvenience.

  27. JF says:

    Phil, what would your response be to Sean's comment, specifically, "Is it possible that the same thing that caused the previous warming and cooling periods is at work again? Shouldn't that be the null hypothesis?" ?

    It seems that your stance in (4) of your most recent response is the opposite: "To justify inaction … one has to be very _strongly_ convinced that the temperature sensitivity of the climate is much lower than most researchers think it is…"

  28. Igor Carron says:

    I am sure that many readers of this comment section would not mind being provided with some context on the hockey stick controversy from wikipedia. I, for one, am rather glad that serious applied statisticians are going to take a hard look at some of these issues.

    Igor.

  29. Zubon says:

    Ed, you're looking at half the equation. You asked who loses, not who gains. There are many private actors who stand to lose money. There are many public actors who stand to gain power. Depending on their ability to influence those public actors, there are many private actors who stand to gain money. You have both public choice and rent-seeking to consider. I can make my competition's life much harder if I can get his type of pollution taxed more than mine. Maybe I can get my factory rebuilt with federal subsidies or get regulations that will make it too onerous to open competing factories. There is a large lobbying industry devoted to profiting from the billion-dollar details when public actors gain more power.

  30. William Ockham says:

    If you really want to understand what's going on, you need to read this post from Jay Rosen. He talks about a model for understanding the way journalism works (developed by Daniel Hallin in 1986). Here's the model:

    Take a sheet of paper and make a big circle in the middle. In the center of that circle draw a smaller one to create a doughnut shape. Label the doughnut hole “sphere of consensus.” Call the middle region “sphere of legitimate debate,” and the outer region “sphere of deviance.”

    Read the post to get a feel for what that model means for how journalism works, but that's not my main point. The real issue is that science has the same basic model but the rules for determining what goes where are completely different. However imperfect, there is a valid process for determining what the scientific consensus is. In politics, issues move in and out of these spheres based on ideology and power. As long as some powerful groups find it useful to question anthropogenic global warming, it will be in the sphere of legitimate debate.

    Everbody's talking about whether or not the emails undermine the case for global warming. Nobody's talking about the fact that global warming deniers hacked into these computers to get dirt on their opponents. Why is that? Why doesn't the hacking undermine the cause of the deniers? Because people don't understand the assymetrical warfare that's going on. Nobody is willing to make that charge because it would be difficult to prove, but it's fairly obvious to me that the email hacking is part of an on-going effort by people who have a lot to lose from the changes that we need to make. Those folks don't care about the Fijians whose country is going to disappear.

  31. Phil says:

    Radford, I agree with you that 'It is not proper for a scientist to say to himself, "it's possible that I'm wrong, and the effect isn't so large, but just in case it is, we need to take action now! So I'll minimize the uncertainty in order to convince politicians to act.' This is the same general theme I was trying to convey when I said 'some scientists and many proponents of quick and major action are exaggerating the worst case scenarios as if those are the things we can expect. Sea levels might rise by "up to" such-and-such, "as many as" N people might die in drought-induced famine, and so on. This is not the way decisions should be made.'

    Of course I also agree with you that attempting to quash legitimate scientific debate or discussion is immoral.

    However, I disagree with you that scientists shouldn't get involved with policy. I think we need a lot more scientific input into policy decisions, not less. Ten years ago, Andrew and I published a decision analysis paper about U.S. radon policy (radon is a naturally occurring radioactive gas that is present at dangerous levels in a small fraction of homes). We explicitly included uncertainties in many of the key parameters, and the ways in which other parameter uncertainties could also be included. I think it's a very good paper. I don't think we did anything wrong by writing it. (Unfortunately, it had no policy effect at all. But that's another story).

    Also, you said in your earlier comment that the uncertainties in global warming are too big to justify major actions. So it's funny that you're saying scientists shouldn't make policy judgments: You're a scientist, and you're making a policy judgment!

    As for your very high estimate of the number of deaths that would be caused by taking action to greatly reduce greenhouse gas emissions…boy, talk about emphasizing the worst case scenario! I hope you realize that you are doing exactly what you are criticizing some climate scientists for doing. And you have far less basis for your estimates than they do.

    JF and Sean, you ask ""Is it possible that the same thing that caused the previous warming and cooling periods is at work again? " Of course. Not only is it possible, it is definitely true. Greenhouse gases are not the only thing that affects global temperatures. Variation in solar output causes temperature variations. Atmospheric aerosols from volcanic eruptions also affect temperatures. Changes in albedo — due changes in cloud cover, formation of deserts, growth of forests, motion of continents and oceans on geologic timescales, and many other factor. — also affect temperatures. Ocean currents have big effects; for instance, an increase in the rate at which cold water from the deep ocean comes to the surface can cool the ocean surface and the air above it, which decreases temperatures and also decreases the rate of radiative cooling, but can increase the rate of cloud formation and thus change the earth's albedo. These sorts of things are the reason it is so hard to predict the details of climate change. The "null hypothesis" is not that "carbon dioxide doesn't matter", it's that all of these things matter, just like they always have and always will. Fortunately, researchers can (and do) measure the amount of radiation from the sun, the concentration of atmospheric aerosols, the sea-surface temperature and air temperature, the earth's albedo, the radiant flux, and so on.

  32. Matt Frost says:

    The ironically nicknamed "William Ockham" says:
    "Nobody's talking about the fact that global warming deniers hacked into these computers to get dirt on their opponents. Why is that? Why doesn't the hacking undermine the cause of the deniers?"

    Why should it? If the underlying physical fact of AGW remains true independent of the tweaks and fabrications of climate scientists, they should remain equally true given the skulduggery of some skeptics. This thread is ostensibly about epistemological method, and you've suggested the flimsiest of all.

  33. joe mcdermott says:

    "The evidence for anthropogenic (that is, human-caused) global warming is strong"

    This the 5,345,233 time I have seen this statement. IN NO CASE is any actual clear evidence given, not even a reference (except for references to those fakes in England)

    When I investigate myself, I find lots of speculation and computer models but no convincing solid evidence.

    I recently read an article from my school (MIT) by a professor who found that global warming was even worse than suspected due to CO2 interaction with the ocean. I eagerly read thru the material to find what he discovered. Yet another computer model!!!!

    Perhaps it is true, who knows. But I am sick and tired of the assertions without real substance. I am not interested in arguments about whether the Earth has warmed up 0.5 degrees in the last 50 years. This proves NOTHING either way. The earth temperature has fluctuated far more than that over the last 2000 years. Europe had extreme cold 1500-1800, the little ice age. Viking had farms in Greenland in 1100 in valleys now frozen, the medieval warming.

    But of course the Venetion writers in 1700 who reported freezing canals were part of the vast right wing conspiracy and payed with with gold by oil & coal executives who went back in time machines. Lief Ericson faked the Greenland farms to fool 21 century archeologists.

  34. JF says:

    Phil, thanks for the reply.

    I think you're missing the meaning in what I quote and or at least what I had in mind when quoting it. The question as I see it is not whether the null hypothesis is "carbon monoxide doesn't matter". Rather, should the null hypothesis be that any current warming or cooling is be due to natural processes. It seems from your earlier comment that you take the null hypothesis to be 1) current warming is due to humans and 2) the effect, if continued, will be catastrophically large.

    I'm not trying to be an adversary, nor trying to insinuate anything about the larger topic here. I just think that what I read in Sean's comment is opposite to what I read in yours.

  35. Steven O'Marro, says:

    Employing fudge factor remarks as REM in Fortran codes preceding corrupted and inept programming that biases the results, manipulating data to "hide the decline," "homogenizing" the Australian weather station data, blacklisting colleagues with differing opinions, withholding raw data under request for release by FOIA (both at NASA and CRU), losing raw data such that the above actions are indefensible because conclusions cannot be replicated by independent observers and making efforts to take over the peer review process is not sound science.
    Given reliance on this data by parties on both sides of the Atlantic and the obvious biases of the investigators, the only thing supported by overwhelming evidence is corruption of the scientific method with the scientist as advocate as opposed to observer. This is a vortex of global groupthink driven by an investigator bias to please the group or those supervising or sponsoring it. No conclusions can be made until science acts in a manner independent of advocacy and investigators can review data with transparency on a level playing field without fear of character assassination for the conclusions that they reach.
    The science needs to be redone…now is not the time to use flawed and biased data to make policy conclusions. If the science is wrong, trillions of dollars that could be invested to solve other problems will be wasted.
    If I as a physician and clinical investigator were offered a painful procedure to treat a diagnosis that was based upon such flawed data (which, by the way, was lost) I would certainly ask for a second opinion.

  36. Radford Neal says:

    Phil,

    I disagree with you that scientists shouldn't get involved with policy.

    I think we actually agree here. I said that scientists, as scientists, shouldn't be addressing policy, in the sense of advocating a policy, rather than predicting the effects of one. But these same people certainly can advocate in their role as citizens.

    As for your very high estimate of the number of deaths that would be caused by taking action to greatly reduce greenhouse gas emissions… boy, talk about emphasizing the worst case scenario! I hope you realize that you are doing exactly what you are criticizing some climate scientists for doing. And you have far less basis for your estimates than they do.

    I'm not claiming expertise in these estimates. There may be some real experts in some aspects of this issue, but much of the potential impact is not ammenable to scientific discussion. What level of corruption is likely in climate change programmes, for instance? I think quite a bit, but I don't claim to have any scientific proof of that. How likely is it that international trade will be substantially affected by trade sanctions against non-compliant countries, with a resulting loss of economic efficiency, leading to negative human and environmental effects? I've no idea really. I doubt anyone does.

    But even in a best-case scenario, the costs of large reductions in CO2 emissions are huge (unless we get lucky with some technological breakthrough), and it is not at all speculative to think that these costs result in lost lives and in environmental damage.

    My main point, though, was that the "high uncertainty means we need to act, just in case" argument ignores half the uncertainty – the half concerning the actual effects of the actions.

  37. Radford Neal says:

    Phil,

    One thing you said that I didn't address in my previous reply…

    you said in your earlier comment that the uncertainties in global warming are too big to justify major actions. So it's funny that you're saying scientists shouldn't make policy judgments: You're a scientist, and you're making a policy judgment!

    Actually, I said: "The evidence that [ the effect of CO2 ] is big enough to constitute a crisis requiring drastic action is nowhere near as convincing as the evidence for evolution."

    Here, I was taking as given some rough idea of what size effect is commonly regarded as big enough to justify drastic action (plus two degreees C is often heard of). Whether the actual effect is that big is then a scientific question.

  38. an applied mathemati says:

    Phil,

    First of all, as you probably know, Freemason Dyson is also a physicist: http://www.edge.org/3rd_culture/dysonf07/dysonf07

    Second, I don't see how a serious statistician can be so strongly persuaded that these models. The system is far too complex and the reasonable range of effect sizes much too small for the sort of data we have to allow for highly confident conclusions. The significance of this gap between data and desire is only magnified when one considers that the vast majority of climate scientists lack serious mathematical and statistical training

    Also, climate scientists aren't like other scientists. As the CRU emails and codes illustrates, they lack serious technical training. Furthermore, I don't think it is controversial at all to say that they have overwhelming incentives to write papers that support the "right answer" on climate change. Clearly, the only reason that the field gets so much funding and media attention is the global warming hypothesis. Also, the likelihood that the whole field's body of work is for the most part invalid (just sloppy science, not deliberate fraud as in the CRU emails) is not insignificant. There are many other examples of this phenomenon occurring. A great statistician at Stanford referred to these fields as "communities of pseudo-knowledge." A few examples, leaving some un-PC ones out:

    much of psychology (gaps between experimental data and conclusions absurdly large)
    nearly all investment managers (almost all of them add zero value)
    much of academic finance (efficient market hypothesis. this is clearly false as demonstrated by the complement of the previous example's set. the belief that markowitz deserves a psuedo-nobel prize for applying basic multivariate normal theorem to a new dataset.)

    The whole foundations of the above fields are flawed. As an academic you might reject the second example, but I really doubt the IQ of the average climate scientist is higher than that of the average investment manager. Second, true they are incentivized to lie about their skill, but this incentive is not an order of magnitude greater than in the climate scientist case given that the median unskilled investment manager doesn't make much.

    Finally, I found this response to Radford to be reminiscent of a 6 year old arguing with his nanny:
    "Also, you said in your earlier comment that the uncertainties in global warming are too big to justify major actions. So it's funny that you're saying scientists shouldn't make policy judgments: You're a scientist, and you're making a policy judgment!"

    There is no inconsistency in Radford's argument. He is not a climate scientist advising politicians. If he were, I am sure he would only present the facts.

    Also, related to Radford's argument, significantly cutting CO2 emissions would certainly lead to more children in rural China and India growing up hungry and uneducated in unsanitary makeshift shacks without running water. It is very basic economics that some sort of an energy tax would slow the amazing ascent out of poverty that these people have earned with their intelligence and hard work. I just don't believe the evidence is strong enough that we should tell them that they should be denied the sort of standard of living we enjoy.

  39. an applied mathemati says:

    I apologise for bringing up Dyson again. I hadn't read through all of the above. Also, the repetition of the technical training point was accidental.

  40. Emil says:

    "I assumed the "Climategate" flap would cause a minor stir but would not prompt any doubt about the threat of global warming, at least among educated, intelligent people."

    … time to unsubscribe from the feed … looks like my statistics-trained self is not intelligent enough to grasp the brilliance in fudging, deleting, cherry-picking data and the insight proved by systematic intimidation of your opponents.

  41. William Ockham says:

    You missed my point (probably because I didn't make it clearly). Of course, the hacking shouldn't impact the scientific debate about global warming. It most definitely should be part of the political debate. The entire problem with the conversation about global warming is that people can't separate the two discussions. I think a better analogy to the current debate than creationism is the link between cigarette smoking and lung cancer.

    The link between smoking and lung cancer was pretty clear in 1950's. Had it not been for the power of the tobacco lobby and their addicted customers, cigarette smoking would have been banned in the U.S. Much less dangerous products are banned, but tobacco is still freely available. The tobacco lobby was able to create the appearance of scientific debate up through the 90's. Now the idea that smoking tobacco is harmless has, thankfully, passed into the sphere of deviance.

  42. stephen says:

    At first glance the evolution/AGW theory analogy seems okay, but I really think it is not useful, for two reasons:

    1) Evolution theory has been around for, what, about 150 years? AGW theory has been around for about 20, 30 years or so? How long have the climate models with strong feedback assumptions been around? We know their predictions haven't been good over the last decade, not that this falsifies them, but it still matters given thats all we have so far. Anyway, I think it is to early to analogize the two theories, unless you give heavy weight to consensus alone, which itself is a stochastic process and could drastically change.

    2) Evolution theory is tautologically true if you do not assume an intelligent designer. In other words, the only alternative hypothesis to Evolution Theory is "God did it". While this may be true, it is certainly NOT a scientific claim or a testable hypothesis. With climate change, however, the alternative hypothesis to AGW theory is natural variation/low sensitivity. Actually there are many alternatives, but just to take one, can you honestly argue that the alternative to AGW theory is anywhere in the same universe as the alternative to Evolution?

    Anyway, hopefully you will agree with at least some of what I have claimed.

  43. Phil says:

    I think this thread is winding down to its natural conclusion…at least, I hope so! I am going to pick out just a couple of issues that seem ripe for more discussion, and start a new post that just focuses on them.

    But, to address some specific issues:

    (1) Predictions of anthropogenic global warming don't just rely on computer models. It's true that the computer models are a big part of the story, but it's not true that they are the whole story. (a) It was recognized in the 1800s that the first-order effect of increased atmospheric carbon dioxide would be an increase in the temperature of the earth; there were no computers, then, obviously. (b) Reconstructions of historical atmospheric carbon dioxide concentrations and surface temperatures have demonstrated high correlation between these (although there is a correlation-causation problem with interpreting these at face value). (c) Average surface temperatures have increased a lot during the last few decades, even though insolation is known (through measurements) to have been rather constant through that period; through simple energy balance equations that do not need a computer, this means that either the earth's albedo has decreased or the insulating capacity of the atmosphere has increased (or both).

    (2) Some people keep on pointing to the Climategate emails and saying "this proves the whole thing is a fraud." I guess I ought to spend more time on this, because, after all, this was the whole topic of the parent blog post! But I just don't know what I can say. If you think the emails demonstrate that _all_ of the evidence for anthropogenic global warming is bogus, I think you are too quick to believe in global conspiracies. You might also be reading way too much into the emails.

    (3) JF, I disagree with you about the "null hypothesis", which I keep putting in quotes because I don't think it's the right wording. It's basic physics that carbon dioxide has to have some effect on the transfer of energy through the atmosphere — it makes no sense to have a null hypothesis that CO2 has no effect whatsoever. The sensible question is, how big is the effect? I don't think it makes sense to think of this as a hypothesis test.

    (4) Radford, you and I probably agree on scientists-as-scientists and scientists-as-policy-advocates. But we sure disagree on the likely magnitude of climate change. Just to throw out a number (I'll try to come up with a better one, so for now this is just off the cuff), I might say there's an 90% chance that 800 ppm of CO2 will lead to extremely harmful climate change (plus ocean acidification, which hasn't even been mentioned in this thread); it sounds like you'd put the probability at, what, under 5%? Maybe under 1%?

    (5) Radford again: the question of what, if anything, should be done to reduce greenhouse gas emissions is separate from the question of whether anthropogenic global warming is happening and how big the effect will be. I happen to think that you are way overestimating what it would take to reduce emissions, in terms of societal/economic disruption, but I'd rather not get into that. The thing that is really bothering me at the moment is people who insist that they are certain, or virtually certain, that the effect of trebling or quadrupling the concentration of long-lived greenhouse gases will not be large.

    (6) "an applied mathematician" says "climate scientists aren't like other scientists. As the CRU emails and codes illustrates, they lack serious technical training." I know some climate scientists who have lots of serious technical training. You're just wrong about this.

    (7) "an applied mathematician" says that if you're not a climate researcher, you can say anything you want to policy-makers, but if you are a climate researcher it is wrong to give any advice on policy, you should "just present the facts." Right, we wouldn't want the policy-makers getting advice from the people who actually know what they are talking about! ;) Obviously, I don't agree with you.

    (8) Joe McDermot complains that everything is based on models rather than data. Joe, check out the IPCC reports, which present data and citations to more data.

  44. Radford Neal says:

    Phil says…

    I might say there's an 90% chance that 800 ppm of CO2 will lead to extremely harmful climate change (plus ocean acidification, which hasn't even been mentioned in this thread); it sounds like you'd put the probability at, what, under 5%? Maybe under 1%?

    Let's leave out acidification, which I don't know much about, and which would expand the discussion.

    If forced to make a judgement on what I know now, I'd put the probability of 800ppm being extremely harmful at least somewhat higher than 5%. (I'm not going to take the time now for intensive thought about exactly what number I'd put on it.) I think your 90% number verges on being unreasonably high. Note: by "extremely harmful", I mean serious consequences for humans (at least millions of deaths, directly and indirectly), and substantial environmental harm (eg, extinctions of many species whose ecological niches disappear). I do not mean anything like "wiping out humanity" or "destroying natural life". The really extreme scenarios one often hears about (explicitly or by implication) are very improbable.

    But the real point here is whether our judgement of this probability could be much improved if climate science operated according to normal scientific standards. I think it could. You seem to think not.

  45. Phil says:

    Radford says "But the real point here is whether our judgement of this probability could be much improved if climate science operated according to normal scientific standards. I think it could. You seem to think not."

    This just seems like you are being deliberately offensive, to no purpose that I can see. Just character assassination.

    As I said in my original blog entry, "Failing to provide data when asked…that's bad. Fudging data is completely indefensible. The emails do indeed reveal some unethical and scientifically damaging behavior by some researchers. They reveal pettyness and poor judgment by others."

    I said in a later comment, "As I tried to make clear in my post — hard to see how you missed it, but maybe you did — some of the stuff in the "Climategate" emails is really bad, possibly including scientific misconduct and some is possibly fraudulent. I don't disagree with you on that."

    And: "McIntyre and people like him — by which I mean people who take a careful look at the data and try to find errors, not just general climate skeptics — are doing a good thing."

    Your characterization of my views is wrong, and offensive.

  46. JF says:

    Me, quoting someone else: "Is it possible that the same thing that caused the previous warming and cooling periods is at work again? Shouldn't that be the null hypothesis?"

    Phil: The "null hypothesis' is not that "carbon dioxide doesn't matter", it's that all of these things matter, just like they always have and always will.

    Me: The question as I see it is not whether the null hypothesis is "carbon monoxide [oops, dioxide] doesn't matter". Rather, should the null hypothesis be that any current warming or cooling is be [oops again] due to natural processes."

    Phil: It's basic physics … it makes no sense to have a null hypothesis that CO2 has no effect whatsoever.

    Simplified version:
    Me: Let me ask you about Y.
    Phil: Here is the answer to your question about X.
    Me: Actually, I am not asking about X. I am trying to ask about Ϋ.
    Phil: Your question about X is ridiculous.
    Me: Grrr

    (I am considering this topic dead. I am not trying to solicit further comment.)

  47. Radford Neal says:

    Phil,

    I'm baffled by your characterization of my comment as offensive, and by your statement that I'm mischaracterizing your views. At the beginning of your post, I see the following:

    I assumed the "Climategate" flap would cause a minor stir but would not prompt any doubt about the threat of global warming, at least among educated, intelligent people. The evidence for anthropogenic (that is, human-caused) global warming is strong, comes from many sources, and has been subject to much scientific scrutiny.

    This seems pretty clear to me. You say that there has been some bad behaviour by climate scientists, but that you aren't going to revise your views because of this, because you don't think it indicates that the evidence as a whole is unreliable.

    In my post that you regard as offensive, I say

    But the real point here is whether our judgement of this probability could be much improved if climate science operated according to normal scientific standards. I think it could. You seem to think not.

    Which seems to me to be a pretty good summary of our disagreement. You don't think our judgements would be "much improved", because you think the bad behaviour does not undermine most of the evidence.

    So what is it that got you so hot under the collar?

  48. Phil says:

    JF: Funny!

    Sorry, I thought I had answered this to your (and anyone else's satisfaction) when I said that the "null hypothesis" should be that ALL of the phenomena that have affected climate in the past are still at work. I'm not sure why you find that answer unsatisfying. If you tell me what is wrong with that answer, I'll try to give you a better one!

  49. Phil says:

    Radford: OF COURSE I think our judgment of climate sensitivity (and its uncertainty) would be much improved if the science were done better. I interpret your statement that I believe the contrary to be an accusation that I am indifferent to the quality of the science. How am I supposed to interpret it?

  50. Radford Neal says:

    Phil,

    Either you think that deviations from normal scientific behaviour by climate scientists are enough to cast significant doubt on the reliability of the results in this field, or you don't. The opening paragraph of your post indicates that you don't.

    This does not, of course, mean that you condone scientific misconduct. It just means that you don't think it has had enough of an influence that you're going change your beliefs regarding climate change.

    That's all my comments said. I continue to be baffled by how you can interpret them as offensive.

  51. Phil says:

    Radford, we should probably take this sub-thread off-line since I doubt most people are interested in it.

    Maybe I see what you are saying. I think your characterization of my attitude can be seen in at least two ways; maybe I'm choosing the wrong one.

    I first want to make a minor point: in the comment to which I took strong exception, you referred to some climate scientists not living up to "normal scientific standards." I agree; they didn't. But in your most recent comment, you refer instead to "normal scientific conduct." I'm less sure that the conduct described isn't normal. I think normal conduct is often not what it should be, in all fields. I think the conduct may have been normal, but not up to scientific standards. Sorry to quibble.

    Moving on. Refusing to share data, trying to pressure journals to publish (or not publish) certain types of papers, failure to document data or results properly…these are bad (morally), and they are damaging to the progress of science. They make it harder for people to check for mistakes, and harder for people to critique the work in search of improvements to models or data collection.

    I interpreted your statement about climate science vis-a-vis scientific standards to be a claim that I disagree with the previous paragraph. In fact, I strongly believe in it.

    However, it's true that I don't think the "Climategate" emails, in and of themselves, reveal problems of such magnitude that the mainstream scientific conclusions on climate change should be called into question.

    To put it in the context of a more recent blog post: If someone says "I would have said there's an 80% chance that climate is at least moderately sensitive to a tripling of atmospheric carbon dioxide, but now that I've seen these email I think it's only a 5% chance," well, I disagree that this is a reasonable reaction to the emails. If someone says they've gone from 80% to 60%, well, I think they're overreacting, but this is not unreasonable.

    I just want to be crystal clear that I condemn some of the behavior revealed in the emails and I do think it hurts the ability to accurately quantify or predict anthropogenic climate change.

    If you, Radford, previously assigned a high probability to moderate (or higher) climate sensitivity, but the emails have caused you to assign a much lower probability, then you and I do indeed differ a great deal on the implications of the emails and the conduct revealed therein.

  52. A. Zarkov says:

    Phil:

    Taking your responses to me in order.

    1. We know the modelers will admit to uncertainty in the climate sensitivity of about a factor of 3. We don't know this is correct because they don't understand and cannot model the cloud physics, which is the major feedback after water vapor. A number of arbitrary choices were made in "parameterizing" the cloud physics. But as Nir Shaviv points out, we have empirical evidence that the climate sensitivity is small. Read his primer: http://www.sciencebits.com/OnClimateSensitivity

    2. Your are right on this point, and I am wrong. I thought the WSJ article was one by a skeptic that I had just read. While I try to be careful, this time I got careless and assumed it was the same article and it was not.

    3. We agree here.

    4. The Wegman report itself was in the nature of a peer review. Are we supposed to peer review peer reviews? When does it stop? That report along with the work of McIntyre debunks the hockey stick graph. Recently it came to light that Briffa had done some cherry picking with the Yamal trees. The problem here goes beyond methodology and to scientific integrity. Briffa would not release his data until a journal forced him to. Then what he did came to light. As for the NRC, I have not read that report, but I read one comment that said IPCC deleted the hocky stick from AR-4.

    5. It just didn't occur to you to refer readers to ClimateAudit? Don't you think that's quite an omission? One that suggests you might be a little biased towards AGW. Then you throw in some snark about creationism as if the ClimateAudit guys are part of some fringe element.

    6. More snark. Don't you think Mann should have released his data and methods from the get go? Isn't that the way science is supposed to work? Of course we understand why– the work was faulty and he probably suspected as much. Mann fits into the pattern we find over and over. Keep data secret. Fight FOIA requests. Disparage anyone who is critical. Try to block their publications. If AGW is so obvious, and rests on such a firm foundation of scientific fact we wouldn't see this kind of behavior. There would be no need for it. The work would speak for itself. It obviously doesn't.

  53. Phil says:

    Zarkov, responses to your most recent comment:

    1. Good primer. He comes up with a climate sensitivity of 1.2 C per CO2 doubling, plus or minus some amount that he says is unlikely to be large (but doesn't quantify exactly). A former IPCC report gave 1.5 C as the low end of their estimate; that has been revised upwards to 2 C in the more recent edition. Basically, the guy who wrote that piece is not in radical disagreement with the IPCC.

    2. De nada.

    3. Good.

    4. Wegman report is OK. It does not say the "hockey stick" plot is wrong, and later follow-up analyses with better statistics confirm the most recent several hundred years of the hockey stick, but the earlier periods are much more uncertain than the original plot says. The truth or falsity of anthropogenic climate change does not rest on the Wegman report.

    5. OK, you're entitled to your opinion.

    6. Yes, Mann should have released his data. I agree, he was likely worried about people finding fault with it. I disagree that "If AGW… rests on such a firm foundation of scientific fact we wouldn't see this kind of behavior."

  54. PI says:

    Zarkov,

    I don't know why you hold up Shaviv's estimates as somehow disproving the IPCC range of climate sensitivity, since other authors have empirical estimates too. Why do you ignore them in favor of Shaviv? Or are you under the mistaken impression that all the other estimates are purely theoretical, and Shaviv's are the only empirical estimates? (Not that any estimate is "purely empirical"; you must always assume some model of the climate system to derive a sensitivity. In Shaviv's case, he uses a simple zero-dimensional energy balance model.)

    In fact, his empirical estimates of climate sensitivity tend to be lower than the empirical estimates published by almost everyone else in the climate literature. In general they are quite crude and neglect all ocean/atmosphere and cryosphere dynamics. (Some other estimates in the literature do the same, but get higher numbers; others use more sophisticated representations of the Earth system.) His energy balance modeling neglects important aspects such as the transient response time (for the shorter term estimates) and non-CO2 forcings. He also tosses in his own, highly speculative assumptions about the strength of cosmic ray-cloud feedbacks.

    But even ignoring these problems, the existence of a wider range of estimates suggests that you're intentionally cherry-picking the lowest ones, unless you have reason to believe that all the higher ones are wrong or are simply unaware of the fact that there are other empirical estimates out there.

    For a good review of both empirical and theoretical estimates of climate sensitivity, see this paper.

  55. 'I assumed the "Climategate" flap would cause a minor stir but would not prompt any doubt about the threat of global warming, at least among educated, intelligent people.'

    That's some "ad hominem". Forgive me for remaining uncertain. "Climategate" has not changed my opinion on the notion of man-made climate change one way or the other. However, I was already uncertain.

    Peer-reviewed research is not infallible. Researchers of whatever stripe are not immune to the pressure of CV-inflation, academic orthodoxy, conflicts of interest or plain old groupthink. Instances of out-and-out research fraud are not difficult to find in the the record within the last 10 years.

    I consider it quite possible that man-made climate change is real and potentially very destructive, and that there is ample evidence of this, and that this evidence has been well-exploited by climate scientists. As I am still in the process of reviewing this literature (and hopefully, the data) for myself, and as conflicting reports are available (see, for instance: http://wattsupwiththat.com/2009/12/08/the-smoking… I will reserve judgment without worrying about being labeled "uneducated and unintelligent".

  56. A. Zarkov says:

    PI,

    I would be happy to read the Nature article but I don't have a subscription, and I'm not going to pay $32 to download it. One would think that on such an important public issue as this, it would be free.

    I never said Shariv's estimates "disprove" AGW. But your comment is fair enough. We do need to look at other empirical estimates too. I pointed to Shariv because he seems less inclined to group-think than most others, and he presents a good introduction to the subject. The issue of just much global warming (if any) can be ascribed to fossil fuel combustion is still uncertain.

    Some of my skepticism comes from prior contact with people working on global warming at a national laboratory. I saw a group leader refuse to release a paper by an atmospheric physicist because it did not conform to the party line. I witnessed GCM modelers discuss how to tune a code to get politically acceptable results.

    I also worked on global temperature data myself, and found it most inadequate to draw reliable conclusions. But all that was more than 12 years ago.

    Now recently my interest has been rekindled, and I'm afraid it looks like the political pressure on scientists has gotten worse, not better. I think the entire worldwide temperature database needs an independent audit. The adjustment process must be more transparent.

  57. A. Zarkov says:

    Phil,

    4. I just downloaded the NRC article on the hockey stick, and I'm reading through it. The abstract is pretty restrained saying that, "It can be said with a high level of confidence that global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries." Of course 1600-1850 coincides with the latter part of the little ice age, so we should not be surprised to see 20th Century warming.

    I am disappointed to see only one statistician among the authors– Peter Bloomfield. He's a good guy, but his interests tend to Fourier analysis of time series. Leo Breiman would have been the best choice if we could have only one statistician, but he might have been sick or unavailable. I know of no one who spanned the theoretical and applied worlds as well as Leo. Similarly among the reviewers I recognize only one statistician, David Brillinger. He's a great guy, but tends more towards the theoretical. I think someone like Robert Tibshirani, Brad Efron, or David Donoho (all from Stanford) would have been better choices for this particular kind of thing. Note also this statement from the report. "Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations nor did they see the final draft of the report before its release." They never got to see what went out the door– not good. In any case I will plough through the document.

    However the methodology behind the hockey stick is defective. You can drive the algorithm with red noise and get a hockey stick because of selection bias. Not on that Mann held back the validation R-squares because they were terrible.

    6. Can you point me to anything in the history of physical science to back up your claim?

  58. Eric Rasmusen says:

    It is true that only a few climatologists are implicated in the appalling emails about concealing data and pressuring journals. But just as CO2 is the just the direct driver for warming and the real action comes from indirect effects, we need to look at a second layer: the response of other climatologists.

    In my field, economics, if it were revealed that top people in the field had sent emails like this, they would be repudiated by the rest of us. I have had my PhD for 25 years and I've never heard of anything like this. There's sloppy work and contrived results, but we don't need to use FOIA to get people's data.

    But in climatology, where's the condemnation? The response seems to be, "Oh, this kind of things is just how scientists talk in private," and "Well, other scientists have reached much the same results, so this isn't really misleading," or "How dare someone leak private emails!". I don't trust *anyone* in a field that responds like that. If they say this is humdrum behavior, we can assume they do it themselves, or are so intimidated that they don't dare publish papers contrary to what the East Anglia people like to see.

  59. Andrew Gelman says:

    Eric: I know what you're saying. Actually, I was surprised to see Steven Levitt write that such behavior would not be out of place in economics; Levitt wrote, "I've seen economists do far worse things than pulling tricks in figures. When economists get mixed up in public policy, things get messier. So it is not at all surprising to me that climate scientists would behave the same way." So maybe it depends on what subfield of economics you're working in.