Come on, be more skeptical!

I popped over to Bishop Hill today – something I haven’t done for a while – and noticed that Andrew (to whom I haven’t always been particularly complementary) was promoting a new paper about clouds and global warming. The paper is by John McLean, apparently a Professor of Physics – apparently not, and is called Late Twentieth-Century Warming and Variations in Cloud Cover.

Despite being written by a physicist, there are many reasons why this particular paper should be treated with a great deal of skepticism. For example, the conclusions argue that

the reduction in total cloud cover accounts for the increase in temperature since 1987, leaving little, if any, of the temperature change to be attributed to other forcings.

So, no role for anthropogenic forcings? Really? Despite what would appear to be a fairly obvious red flag, there appears to be – so far – not a single skeptical comment on the Bishop Hill post. I know that people object to the term climate science denier, but I’m starting to think that this is simply because it’s impolite, not because it isn’t true.

Let’s take this a little further, though. The basic premise of the paper seems to be that one can use the Trenberth-like energy flow diagram to determine how changes in cloud cover influence the incoming energy flux. Clouds have a total forcing of about 79Wm-2 . The paper indicates that, between about 1980 and 2000, cloud cover reduced by 4.8%, which is then interpreted as producing a change in forcing of 5.4 Wm-2 – significantly greater than the change in any other forcing. This would seem quite remarkable if true. [Update : Victor points out in this comment that this is only the influence of clouds on albedo. They also influence the outgoing longwavelength radiation and so the net cloud forcing is actually small, and a 5% change in cloud will not produce a significant change in forcing.]

Well, clouds are actually extremely complicated. Changes in low-level clouds influence albedo, while changes in high-level cloud influence the outgoing flux. This is explained really well here and indicates that cloud feedbacks are around 0.68 Wm-2K-1, but could be as low as 0 Wm-2K-1, or as high as 1 Wm-2K-1. Given that we’ve only warmed by around 0.85oC, this is hard to reconcile with clouds producing a radiative forcing of more than 5 Wm-2 over a period of a couple of decades.

So, that seems a little odd. Let’s look at the main figure though. This shows (below) the change in surface temperature and the change in cloud cover. Looks pretty good, doesn’t it? Maybe changes in cloud cover are indeed driving surface warming. Could we test this a little more? Sure. If the primary forcing is clouds, and all others are insignificant, then we should also see a similar signature in other components of the climate system – the oceans, for example. Do the oceans show rapid warming during the period from 1980 – 2000, followed by slower warming in the 2000s? No, there’s been no slowdown in ocean warming during the 2000s. How is this possible if clouds are – by far – the dominant forcing? Answer : it isn’t. Plus, if changes in cloud cover can produce a change of forcing of greater than 5 Wm-2, we’d certainly have noticed that in the ocean heat content.
CloudForcing

Now, could there be another explanation? Well, assuming the data isn’t garbage, what this could be illustrating is actually how cloud cover responds to changes in temperature – i.e., it’s illustrating cloud feedback (H/T to Karsten who pointed this out on Twitter). There’s probably much more that could be said about this paper, but I’ve wasted enough of my time, so I won’t bother. I’ll just point out that a paper that argues that there is little influence from greenhouse gases, and confuses clouds responding to changes in temperature, with temperature responding to changes in cloud cover, appears to have generated little skepticism on Bishop Hill. A regular theme amongst “skeptics” is that they are somehow excluded from discussions, and are not taken seriously. Well, if they accept dross like this without question, it’s maybe not that surprising. Maybe they should try to be actually skeptical, rather than only claiming to be skeptical.

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275 Responses to Come on, be more skeptical!

  1. Everybody should be skeptical when McLean dallies with climate science – he has form for publishing abject nonsense about El Nino and its influence on global climate. Foster et al wrote a reply http://nldr.library.ucar.edu/repository/assets/osgc/OSGC-000-000-000-521.pdf

    But back to his latest paper. Changes in cloud cover represent either internal variability or the response to external forcing. It is difficult to imaging a climate that has large internal variability at multidecadal scales but is insensitive to external forcing.

  2. Richard,
    I’d never encountered him before, but the more I get involved in this topic, the more I realise that there are some who seem capable of continually making these kind of mistakes.

    It is difficult to imaging a climate that has large internal variability at multidecadal scales but is insensitive to external forcing.

    Indeed, I think that is a point that BBD also makes quite regularly.

  3. John Hartz says:

    ATTP: The moniker “Skeptical Science” is already taken.

  4. jsam says:

    The publisher of the paper is Scientific Research Publishing (SCIRP). They’re on Beall’s List.

    Beall’s List:
    Potential, possible, or probable predatory scholarly open-access publishers
    This is a list of questionable, scholarly open-access publishers. We recommend that scholars read the available reviews, assessments and descriptions provided here, and then decide for themselves whether they want to submit articles, serve as editors or on editorial boards. The criteria for determining predatory publishers are here.

    We hope that tenure and promotion committees can also decide for themselves how importantly or not to rate articles published in these journals in the context of their own institutional standards and/or geocultural locus. We emphasize that journal publishers and journals change in their business and editorial practices over time. This list is kept up-to-date to the best extent possible but may not reflect sudden, unreported, or unknown enhancements.

    http://scholarlyoa.com/publishers/

    Derp r us.

    The other recent paper bouncing around denier-dumb is Hermann Harde’s Advanced Two-Layer Climate Model for the Assessment of Global Warming by CO2. Yup. Same publisher.

  5. Gavin says:

    McLean is not a professor (at least according to the university website), though at one point he was a graduate student there. I don’t know if he got a PhD. A rebuttal of his previous work is here: http://pubs.giss.nasa.gov/abs/fo06000k.html (Foster et al, 2010).

    Specific to this paper, he uses the ISCCP data set for the clouds, but the long term trends in that are hopelessly uncertain due to large variations in the observing network over time (see this for example: http://www.aos.wisc.edu/~dvimont/Papers/Evan_etal_GL028083.pdf) . A new update (ISCCP3) is due out soon that will be better calibrated, but this is a very hard measurement to make.

  6. Harry Twinotter says:

    Papers are not necessarily “correct”, that is true isn’t it? Anyway someone who says they are John McLean has responded to comments on WUWT.

  7. John Mashey says:

    Tim Lambert had many posts on McLean, see this search./

  8. Joshua says:

    Anders –

    ==> “Despite what would appear to be a fairly obvious red flag, there appears to be – so far – not a single skeptical comment on the Bishop Hill post.”

    I know that can’t be true – unless there are only one or two comments…because I’m told all the time, by “skeptics” (when they aren’t telling me that “skeptics” aren’t monolithic) that “skeptics” don’t doubt that ACO2 effects the climate.

  9. Joshua says:

    From BH:

    Slow down! I'm not a professor of physics (yet). I'm a PhD student in that department. I'm not sure where my "professorship" came from. This is how rumours get started …:-)

    ==> Oct 30, 2014 at 9:10 PM | Unregistered CommenterJohn McLean

  10. Clouds have a total forcing of about 79Wm-2 (well, actually clouds plus the atmosphere, which the author of this paper ignores)

    That is their cooling influence on the solar radiation. They also have an opposite warming influence on the infra-red (heat) radiation. The net influence of clouds is very small.

    But my main guess would be that Gavin is right and that the data is simply not up to par. Satellite data is great for the spatial overview, but very bad for spatial consistency. Satellites have changed enormously over the years and when it comes to cloud retrievals everything matters, your resolution, your angle relative to the Earth, your angle relative to the Sun, the frequencies used and the width of the frequency bands, how well you remove the influence of aerosols and of sun glint from the surface, the brightness of the underlying surface and your datasets about that.

    There is a Satellite Application Facility on Climate Monitoring (CM-SAF) that works on clouds and radiation. They have a tough job.

  11. Victor,

    That is their cooling influence on the solar radiation. They also have an opposite warming influence on the infra-red (heat) radiation. The net influence of clouds is very small.

    Thanks. I had a feeling there was something fairly obvious that I was missing about this whole issue. I should have noticed that.

  12. MikeH says:

    John McLean is famous for this epic fail.
    “it is likely that 2011 will be the coolest year since 1956 or even earlier”
    http://www.skepticalscience.com/mclean-exaggerating-natural-cycles.html

    He is also a member of the Heartland funded Australian Climate Science Coalition.

  13. John “Don” McLean and Bob “Vince” Carter tossed a couple of air-balls when they came up with the ENSO theory that Tamino and company destroyed a few years ago. Yet, the one thing it did do was to show how important ENSO was as a contributor to natural temperature variability. Don and Vince tried vainly to show that ENSO would lead to a long-term trend through some sort of “integration” mechanism, but all they ended up doing was score an #OwnGoal. Alas, ENSO is a phenomena that reverts to the mean .. and that mean is zero.

  14. Nick says:

    McLean has refuted himself…again. It was ENSO once, now it’s clouds. Apparently….!

    I note no reference to McLean et al 2010 in his new paper.

  15. Harry Twinotter says:

    Going by the comments by a John Mclean on Bishop Hill and WUWT, he is pushing the “persecution” line. I could be cynical and think that is the whole point of the exercise. I hope one of the science journal referred to in the comments will respond so we can get their side of the story.

  16. Harry, indeed — see here http://wattsupwiththat.com/2014/10/30/new-paper-links-warming-since-1950-to-enso-and-cloud-cover-variations/#comment-1775570

    Willis “Reed” Eschenbach is setting a pick for him as well. Nothing to really cancel out there. Do a switch from one insane theory to another. A scoreless tie !

  17. Marco says:

    McLean himself makes a brief entry, pointing out he isn’t a professor, but still a PhD student. AFAIK he lost his supervisor when Bob Carter’s affiliation with JCU stopped, and somebody apparently dumped him in the physics department. It looks like they don’t want to touch him with a ten foot pole – single authorships by PhD students in a physical field is quite uncommon.

  18. Sou says:

    There’s a small clique of science deniers in Australia. John McLean was a hanger on, firstly of Bob Carter. He’s a computer tech operator or something and is now supposedly doing a PhD thesis at James Cook Uni. He joins with them writing denier articles for Quadrant – a right wing magazine that’s been around for a long time. (It used to be mainly for literature and poetry and stuff, but also has political pieces.)

    Now it looks like John’s picked up Peter Ridd, maybe for a supervisor. Peter Ridd is a known climate science denier in Australia, and is associated with the same mob as Jennifer Marohasey. Peter is a Professor at James Cook Uni, which is where Bob Carter used to hang out. (James Cook has a lot of decent academics as well.)

    Media Watch talks about all the interconnections. There’s the ” Australian Environment Foundation”, the Australian branch of the “Australian Climate Science Coalition” which has links with the Heartland Institute. They used to have links with the right wing lobby group the IPA, and maybe still do, though not publicly. They are an incestuous lot.

    http://www.abc.net.au/mediawatch/transcripts/s3458728.htm

    I think there are more organisations than there are members of any of them – and they all share the same members. It allows them to get airplay from time to time.

    John has complained before that he’s not able to publish his nonsense in mainstream journals. He has to publish in predator journals and pay for the privilege. He won’t admit that the reason he can’t get published is because his work is bad. One of his did slip through the net, as someone’s already observed. (It was a really dumb article. The editors and reviewers should have been ashamed of themselves.)

  19. JWhite says:

    It seems contrarian luminaries will believe nearly anything, except the painfully obvious.

  20. JWhite,

    It seems contrarian luminaries will believe nearly anything, except the painfully obvious.

    Indeed, and then complain when people point this out.

  21. BBD says:

    @ Sou

    Interestingly, the McLean stuff is exactly the same twaddle that RR was peddling at your place a couple of weeks ago.

  22. Harry Twinotter says:

    I sort of figured Jennifer Marohasey was some sort of scientific opinion for hire. She is also into Australian Bureau of Meteorology bashing, she accuses them of professional misconduct on her website.

  23. miker613 says:

    Well, I saw the paper over there, and paid little attention. I tend to pay little attention when Sky Dragon types show up; I figure no one will pay much attention anyhow.
    Of course there are a lot of skeptics who believe that CO2 does nothing. There are a lot of AGW believers who think that extreme impacts that the IPCC considers unlikely or very unlikely are certain or almost certain. So what? I would rather stick to the skeptics and/or believers who know something.
    Anyhow, I see some skeptical comments there now, including McLean who seems to be cautioning a little about overreacting to his results.

  24. Joshua says:

    Miker –

    ==> “I figure no one will pay much attention anyhow.”

    Looks like you were wrong.

    ==> “Of course there are a lot of skeptics who believe that CO2 does nothing. … So what?

    A couple of things there.

    1. From what I see, many “skeptics” either repeatedly minimize the size of the “ACO2 does nothing” cohort, or selectively accept them on moment (say when they’re demonizing “realists” as sociopaths) while ignoring them the next (“hardly any ‘skeptics’ doubt the GHE). If I am right, then I think that it is meaningful that such a pattern plays out so often.

    2. From what I see, there are many “skeptics” who say that they don’t doubt that ACO2 affects the climate – and say they only question the magnitude of the effect, but who then turn around and offer arguments that are logically incoherent with such a view. I find that interesting. Do I think that they really doubt the basic physics of the GHE? Probably not. But they don’t follow through with making the logic of their arguments consistent with that belief. I think that pattern is pretty well-represented (for example, how many times have we seen “skeptics” argue that “global warming has ‘stopped’ or ‘paused’ – an argument that isn’t consistent with a belief that ACO2 necessarily has a warming effect on the climate). So, then, I think it matters. It matters that smart and knowledgeable people fall into fallacious reasoning. I think it matters because it shows just how strong the signal of motivated reasoning is in the discussions of climate change.

    3) ==> I would rather stick to the skeptics and/or believers who know something.””

    As near as I can tell, many of the “skeptics” who argue that there is no GHE generally “know something.” In fact, they often seem to be quite smart and very knowledgeable about physics. So I think that the criterion you are employing to differentiate the “sky dragons” (even if we eliminate those “skeptics” who claim to believe in a GHE but offer arguments that aren’t consistent with such a belief) does not stand up. I often see this happening, and I think that the tendency to do so is basically more same ol’ same ol’. It is a form of identity-defense. It is a variation of the No True Scotsman rhetorical device.

  25. miker613 says:

    Joshua, I just think that 95% of commenters on any politically charged issue are going to know nothing, on both sides. A brief survey of comment threads everywhere supports my view. It is surely fallacious to make claims about “skeptics” (or about “alarmists”) based on the ubiquitous 95%.

    “how many times have we seen “skeptics” argue that “global warming has ‘stopped’ or ‘paused’ – an argument that isn’t consistent with a belief that ACO2 necessarily has a warming effect on the climate” Meh. It is not a problem, or even very controversial, to say that global surface temperature has (almost) paused for a while now. Everyone agrees on that. It is also not any kind of proof that overall global warming has paused, or that ACO2 doesn’t have a warming effect. Skeptical types tend to overstate this, and of course many of them don’t know enough to understand the distinction.
    But believer types tend to understate it: a lot of climate scientists are writing papers about it, the honest ones are admitting that it was a considerable surprise, and the GCMs are failing validation. Because of the “pause”, we do not currently have any validated climate models, and no way to make confident predictions of surface temperature. James Annan recently: “And despite what some people might like to think, the slow warming has certainly been a surprise, as anyone who was paying attention at the time of the AR4 writing can attest. I remain deeply unimpressed by the way in which this embarrassment has been handled by the climate science insiders, and IPCC authors in particular. Their seemingly desperate attempts to denigrate anything that undermines their storyline (even though a few years ago the same people were using markedly inferior analyses of this very type to bolster it!) do them no credit.”

  26. Joshua says:

    ==> ” It is surely fallacious to make claims about “skeptics” (or about “alarmists”) based on the ubiquitous 95%.”

    I don’t quite get this. Don’t “skeptics” and “realists” comprise a large segment of that 95%? You seem to be simultaneously saying that most commenters are ignorant as you are saying that “skeptics” should be distinguished from the ignorant. So what criterion do you use to distinguish between “skeptics” and commenters?

    I will say, that one common reasoning error I see is when commenters in the climate-o-sphere generalize about the larger public based on their own individual perspective – and I”m not suggesting that we do that.

    ==> “: It is not a problem, or even very controversial, to say that global surface temperature has (almost) paused for a while now. ”

    I’m not talking about that. I’m talking about the statements that you and I have both seen countless times – from people like Judith Curry (you do think she’s knowledgeable on the topic, don’t you?), that global warming has stopped/paused/is in hiatus, etc.

    ==> “Everyone agrees on that.”

    Except that we often people say on the one hand they agree with that and then on the other hand say that there is no meaningful way to measure global temperature. I know you’ve seen that countless times.

    ==> “Skeptical types tend to overstate this, and of course many of them don’t know enough to understand the distinction.”

    Many of them don’t, but many of them do. I think that the majority of SWIRMCAREs and SWIRLCAREs alike really know very little about the science – but I don’t think that’s true for many of those that we see commenting in threads on blogs related to climate science. In contrast, many of them know quite a bit about the science, but nonetheless make arguments that aren’t consistent with that they know.

    I think that is important information. Why does that happen, so ubiquitously? Is recognizing the ubiquity of the pattern useful for getting perspective on the polarization about climate change?

    ==> “But believer types tend to understate it: a lot of climate scientists are writing papers about it, the honest ones are admitting that it was a considerable surprise, and the GCMs are failing validation. Because of the “pause”, we do not currently have any validated climate models, and no way to make confident predictions of surface temperature. ”

    Interesting – so here it seems to me that you are generalizing based on “believer-types,” who no doubt are that 95% you referred to as knowing nothing? So according to your logic, shouldn’t you be basically ignoring those know-nothings as you would a “sky-dragon” because “who cares?” Except now you seem to be taking notice.

    ==> “a lot of climate scientists are writing papers about it, the honest ones are admitting that it was a considerable surprise, and the GCMs are failing validation. ”

    I think that this is a tribal view. You are injecting the value judgement of “honesty” where I see scientific agreement.

    ==> “and the GCMs are failing validation. Because of the “pause”, we do not currently have any validated climate models, and no way to make confident predictions of surface temperature.”

    You followed that up with quoting Annan – as if Annan’s comment confirms your conclusion that GSMs are ‘failing validation.” Do you think that Annan believes that the relatively short-term flattening out of a longer term trend in surface temps invalidates GCMs?

  27. Lotharsson says:

    “She is also into Australian Bureau of Meteorology bashing, she accuses them of professional misconduct on her website.”

    Yes, that’s a long running hilarious saga of impressive incompetence on her part being used to drive her overwrought rhetoric. One suspects that competence is not required when one’s goal is to have some mud stick in the minds of people who lack the skills to determine competence when they see it. It’s a fascinating case study for anyone who finds that kind of thing interesting.

    There was some coverage at HotWhopper where she turns up briefly the first time in comments to reveal false assumptions and her own incompetence, and a second time to tout a new blog post which I took a more detailed look at. There was also a bit of discussion in comments at Deltoid in the August and September threads in response to one persistent Marohasy tout.

    I especially enjoyed the fact that she finally got around to reading one of the key peer-reviewed BoM papers describing their methodology loooooooong after she accused them of not having used any reasonable methodology (and after having tweeted that she hoped some of the BoM staff end up in jail for “fraud”). At this point it was quite apparent that she didn’t actually know what methodology they had applied but was nevertheless convinced it was “fraudulent” and had been deliberately created in order to falsely inflate warming trends.

    Given that, it was particularly amusing to note that the BoM’s continent wide trends show a little bit less warming than a number of other major temperature records. Apparently they’re engaged in blatant fraud to create extra warming that … er … creates a cooler trend compared to those emerging from the work of other teams!

    There was also the absolutely classic assertion that “maps and photographs” provided by the BoM are not, I repeat, not “documented evidence”. And the equally classic logic fail asserting that because there were maps and photos but no explicit documentation of a station move found, that therefore the station could not possibly have moved. (Seriously, that was her argument – but it only lasted to her very next sentence when she completely reversed herself!)

    And then there was the hubris of trying to smear the BoM’s web page responding to allegations about that station with the aforementioned documented evidence as “not being peer-reviewed”, when none of her claims of misfeasance and inappropriate homogenisation methodologies were either – and she’s been making them for something like two or three years.

    It was fascinating to observe that her argument is based on the presumption that a long term trend of an adjusted data set that is warming significantly faster than the trend of the raw data over the same period is automatically suspect, nay, evidence of obvious fraud. This argument presumes that the trend calculated on the raw data is valid over those time scales, which it is not unless it has been validated for that purpose. And since raw data is almost never valid for that purpose, that’s why the adjusted data sets are produced in the first place! Her argument also elevates the trend to the primary aspect of data being produced, rather than the historical time series being the output. This is fallacious – the trend emerges from the time series, it is not a data product itself.

    She also implied that any adjustments to a raw temperature record were illegitimate unless we have documentation of a station move, and when that position was ridiculed tried the argument from personal ignorance – she couldn’t see how a change in station conditions could possibly “change the magnitude and direction of the trend” (once again relying on an invalid comparison between trends calculated on raw and adjusted data sets – and also undermining the very rationale for Anthony Watts’ Surface Stations project 😉 ).

    There was also the earlier case where she couldn’t even correctly read or interpret the labels on a graph published in a post at The Conversation (which I pointed out here), and I may have missed it but I don’t recall any of the merry band of skeptics at her website picking up on that error.

    And none of this, of course, seems to negatively influence the opinion of her “skeptical” followers as to her supreme competence in these matters…

  28. BBD says:

    miker

    But believer types tend to understate it: a lot of climate scientists are writing papers about it, the honest ones are admitting that it was a considerable surprise, and the GCMs are failing validation.

    The bit about models failing validation is skeptikoid rubbish.

  29. miker613 says:

    I don’t think I’m being unclear, but I’ll try to do better.
    95% of commenters know nothing. Some of those are skeptics, some are believers. Looking at what they do tells you little about the know somethings. It seems that that is what ATTP is trying to say here, so I’m criticizing a little, at least until he does the same thing about the comment threads at desmogblog.
    As I said above, I don’t think the know-somethings are being inconsistent as much as fuzzy and careless with their wording.
    As for the rest of the points, no, Annan’s comment was to verify the other things I said about surprise, honesty, and the significance of the pause. As for validation, that is fairly well accepted, nothing to do with Annan: the current crop of GCMs have now failed validation at the 5% significance level, at least according to several recent papers (and Lucia’s blog tracking this for years). Global surface temperature (which was their signature prediction) has moved completely out of the range of their predictions. No random walk cherry-picking, either – they failed just as fast as they could have, as soon as they were finalized.
    Does that “invalidate GCMs”? Of course not. Someone will make better ones. But we don’t have them yet, and when we have them, they will need to be validated on the future. Right now we cannot make confident predictions.
    I wouldn’t underestimate the difficulty of fixing the GCMs, either. GCMs so far try to back-predict the last century of temperatures. The current most popular theory for the “pause” is that the heat is going into the deep ocean. If new GCMs take that into account, they are going to be unable to back-predict, as we don’t have any data on deep oceans more than a few years back.

  30. BBD says:

    As for validation, that is fairly well accepted, nothing to do with Annan: the current crop of GCMs have now failed validation at the 5% significance level, at least according to several recent papers

    Links please.

  31. miker613,
    Yes, I’d like a link too please. Also, do you mean validation in some formal sense, or do you simply mean that currently surface temperatures are almost outside the 95% confidence interval of the model (which should, by the way, happen around 5% of the time anyway, otherwise they’d make the confidence intervals narrower).

  32. miker613 says:

    http://www.academia.edu/4210419/Can_climate_models_explain_the_recent_stagnation_in_global_warming
    This is the one that I thought of first; I think I’ve heard of another but I don’t remember. But lucia has been doing this regularly for a long time, here’s one: http://rankexploits.com/musings/2014/how-or-ar5-models-doing-end-of-2013/
    I don’t mean validation in a formal sense, though it wouldn’t be a bad idea if the modellers would discuss that. I just mean what you said: that these surface temperatures should happen <5% of the time according to the aggregate models. I believe that since then, though, it's getting closer to 2% or some such and getting worse every month. Note that according to Lucia's posts, it's not just the ensemble that is failing, it's pretty much every single model in the ensemble.
    Also note that since the models are equated to actual surface temperature zeroed just before 2000 or so, it wasn't really possible to fail validation any earlier (unless temperatures went down!): it takes a while for the temperatures to work their way out of the confidence range. The models all went up and the temperature didn't.

  33. miker613,

    Note that according to Lucia’s posts, it’s not just the ensemble that is failing, it’s pretty much every single model in the ensemble.

    That doesn’t really make sense. The ensemble is there to illustrate some kind of likely range. Of course, most models with not exactly match reality. That’s why you use an ensemble. Since you mention papers that show climate models possibly failng, you should be aware that there are recent papers illustrating that you can improve the models by updating the forcings and also by trying to consider correctly aligning the ENSO events. I can’t find the links right now, but could probably do so given enough time.

  34. BBD says:

    Nope. The HvS study does not support your claim that the models have “failed validation”. This is just skeptikoid misrepresentation in the school of Christy. You cannot argue that there are fundamental problems with the models because the forcings used were wrong and this affected the model results. See Schmidt et al. (2014) Reconciling warming trends. Once solar and volcanic/anthro aerosol forcings and ENSO are adjusted to reflect what actually happened the models come into good agreement with observations.

  35. BBD says:

    miker

    I really don’t like word placement games like this:

    the honest ones are admitting that it was a considerable surprise, and the GCMs are failing validation.

    Then:

    As for validation, that is fairly well accepted, nothing to do with Annan: the current crop of GCMs have now failed validation at the 5% significance level, at least according to several recent papers

    Then, only after being challenged, this:

    I don’t mean validation in a formal sense,

    Some might call it dishonesty.

  36. miker613 says:

    Actually now I see that von Storch et al gave <2% up till 2012.

  37. miker613 says:

    “Some might call it dishonesty.” Some might object to ascribing dishonesty to using a term in an informal way instead of formal. ATTP apparently was able to discern my meaning.
    I think you mean dishonesty in an informal sense, meaning “anyone who disagrees with me I feel justified in judging them negatively.”

    And you don’t get to adjust your models afterwards. That’s known as a new model. Which is fine. But it needs to be validated all over again.

  38. BBD says:

    I don’t mean validation in a formal sense

    Nor did HvS.

  39. Lurking Reader says:

    ” the current crop of GCMs have now failed validation at the 5% significance level”
    “I don’t mean validation in a formal sense”
    “Actually now I see that von Storch et al gave <2% up till 2012"

    miker613, you appear to be shooting from the hip at this point, nigh a thought for honesty whilst scurrying about to find any modicum of data you may be able to misrepresent (HvS) to cover comments.

    If you are truly interested in honest debate, might you read the full scientific literature prior to forming opinions? But I feel that assumption may be a tad bit naive on my part.

  40. BBD says:

    Some might object to ascribing dishonesty to using a term in an informal way instead of formal.

    That’s right. Refuse to admit what you did.

  41. pbjamm says:

    >And you don’t get to adjust your models afterwards

    Rubbish. The model projections are based on assumptions that may or may not come to pass. Projections, not predictions. As I understand it models are run against a range of variable inputs but that does not mean that any of the runs gets it 100% correct. Why is it wrong to go back and rerun the model with new known inputs? Is this not how you validate the model to know if its projections are accurate?

  42. BBD says:

    And you don’t get to adjust your models afterwards. That’s known as a new model.

    Where do you get this crap from?

  43. Steve Bloom says:

    James Annan, a specialist in the filed, is worth listening to on this topic. Lucia Liljegren, a mechanical engineer, isn’t.

  44. pbjamm says:

    I would like to make my point a bit clearer. Putting new data into a climate model is not creating a new model any more than plugging different numbers into X+Y=Z is re-inventing math.

  45. Joshua says:

    mikeR-

    I’m going to let you discuss the science with others:

    ==> “Looking at what they do tells you little about the know somethings. It seems that that is what ATTP is trying to say here, so I’m criticizing a little, at least until he does the same thing about the comment threads at desmogblog”

    Looking at what the “know somethings” do tells you something about what the “know somethings” do. So I look at threads in the “skept-o-sphere” and I see arguments being made that are logically incoherent, by “know-somethings.” Smart and knowledgeable people making logically incoherent arguments. I think that tells us something. I thought I had made that point a number of times now

    ==> ” It seems that that is what ATTP is trying to say here, so I’m criticizing a little, at least until he does the same thing about the comment threads at desmogblog.”

    I don’t understand. Are you saying that ATTP is saying that that looking at what the “know-nothings” do tells you something about the “know-somethings?” Could you be more specific? Which “know-nothings” (by your definition) is he using to characterize the “know-somethings?” Would it me something like Ridley as a “know-nothing” is being used to characterize, say, Stevie Mac as a “know-something?”

    ==> “As I said above, I don’t think the know-somethings are being inconsistent as much as fuzzy and careless with their wording.”

    Hmmm. I don’t think it is a matter of being “careless.” When Judith argues that global warming has stopped – during Congressional testimony – it seems to me to be a deliberate rhetorical device. The argument is inherently unscientific and it runs counter to her arguments about how important it is to the integrity of science to be upfront with uncertainties. When she is asked about the unscientific nature of her treatment of uncertainty, she doesn’t respond or rationalizes it and continues with the same rhetoric. Seems to me that the rhetoric is purposeful – despite that it is in contrast to her stated intent. Why would she, as a scientist, repeat the same type of “fuzzy” wording related to her area of expertise, while giving Congressional testimony? Doesn’t seem logical to me that she would continue to be “careless” in such a fashion. Keep in mind, that I’m only using that as an example of a widespread phenomenon – not that what she does or doesn’t do, in and of itself, is particularly important.

    ==> “As for the rest of the points, no, Annan’s comment was to verify the other things I said about surprise, honesty, and the significance of the pause.”

    Why should we consider his opinion as verification? That seems to me to be the kind of reasoning associated with motivated reasoning – a conflation of opinion with fact.
    —————————-

    I’ve made a number of points that it seems to me you haven’t really yet addressed. I think it would help if you would quote my comments that you’re responding to.

  46. miker613 says:

    The point of the model predictions is to understand on some level what is going to happen. We are _curious_ to know what surface temperatures will be for the next hundred years. Obviously no one model will get it exactly right. Obviously even the whole ensemble can not get it exactly. However, if the ensemble has any point, it is that it will include all the likely possibilities. That’s the range of temperatures that it is supposed to be predicting.
    If the actual temperatures are outside that range, an _informal_ conclusion is going to be: these models cannot predict accurately. Annan was pretty clear about this: pretending that the models don’t _need_ to have gotten it right is ridiculous. If you don’t know what temperatures will be like for the next century, so don’t tell me you do. If you can predict it within a nice range of possibilities, so do it. And if your range turns out to be badly too small, so you failed. You need to fix your models and re-validate.

    “James Annan, a specialist in the filed, is worth listening to on this topic. Lucia Liljegren, a mechanical engineer, isn’t.” Argument from authority. Liljegren has been doing these statistical analyses for years – that by definition makes her a specialist, unless someone wants an excuse to ignore her work. Armchair skeptics (McIntyre is the obvious example) are having a considerable impact on the war for public opinion, and pretending that they don’t exist or don’t count isn’t going to work. If you have any evidence that she is doing it wrong, I’d imagine you should demonstrate it. Nick Stokes and others post over there regularly, have no problem fighting with her, and seemed to have no problem with her analyses.

  47. BBD says:

    If the actual temperatures are outside that range, an _informal_ conclusion is going to be: these models cannot predict accurately.

    And a more nuanced response would be: wrong forcings = wrong result = not indicative of fundamental flaws in the models.

    You might also be reminded that the models are not designed to “predict” the real climate accurately on decadal timescales and that claiming a model is failing because it doesn’t do something it wasn’t designed to do it stupid.

  48. miker613 says:

    All I wanted from Annan was to show that he agreed with several of my points, no more verification than that. I feel good when prominent climate scientists agree with me.
    “Judith argues that global warming has stopped – during Congressional testimony – it seems to me to be a deliberate rhetorical device.” I would just assume that she means “global surface temperature”; I know you think the distinction is critical, but that doesn’t mean everyone else does. It doesn’t mean she’s saying something “logically incoherent “.
    ‘Are you saying that ATTP is saying that that looking at what the “know-nothings” do tells you something about the “know-somethings?” ‘ Well, I thought that was the point of his post. He is pointing at a Bishop Hill post, where the host did nothing more than post a possibly interesting paper. The only point I could see is that the comments were generally approving. So what? Yet he is making comments and conclusions about “skeptics” because of it.
    “When she is asked about the unscientific nature of her treatment of uncertainty, she doesn’t respond or rationalizes it and continues with the same rhetoric.” I imagine the simplest explanation is that she disagrees with you.

  49. BBD says:

    I imagine the simplest explanation is that she disagrees with you.

    Then why not answer? The parsimonious explanation is that she cannot defend her analysis.

  50. miker613 says:

    “You might also be reminded that the models are not designed to “predict” the real climate accurately on decadal timescales and that claiming a model is failing because it doesn’t do something it wasn’t designed to do it stupid.” Oh yes they are. They are supposed to incorporate enough variability for the _ensemble_ to encompass the actual results. Each individual run will give randomly different results, but the ensemble should include all likely possibilities. You should get a probability distribution which should include what happened. Or not.
    I don’t see why this point is difficult. Do you claim to know what is going to happen to surface temperatures? Why do you think you know? Because of GCMs. Do you know approximately how much temperatures will go up, depending on CO2? Why do you think you know? Because of GCMs. Half a century from now, are you going to be willing to tell me, Well, I expected this much warming, but there was only a much smaller amount, because of __ and __ that I didn’t take into account. Or are you sure that won’t happen? If so, why doesn’t it impress you that for the first decade-and-a-half of their operation, the modellers are saying exactly that, after they were sure it wouldn’t happen?

  51. miker613 says:

    ‘ “I imagine the simplest explanation is that she disagrees with you.”
    Then why not answer? The parsimonious explanation is that she cannot defend her analysis.’
    BBD, do you have any idea of a specific example that Joshua is referring to? Do you know if Joshua said something that made sense? Do you know if she answered or not? Or are you just jumping at an opportunity to assume the worst of an opponent, as you did with me?

  52. BBD says:

    “You might also be reminded that the models are not designed to “predict” the real climate accurately on decadal timescales and that claiming a model is failing because it doesn’t do something it wasn’t designed to do it stupid.”

    Oh yes they are.

    [All together now:] Oh no they’re not!

    How do models “predict” unpredictable events like volcanism and ENSO? Because if they can’t – and they can’t – then your assertion has to be incorrect.

    Each individual run will give randomly different results, but the ensemble should include all likely possibilities.

    But the real Earth climate system is a single instance incorporating *actual* unpredictable events… which when used as model inputs, brings them into good agreement with observations. See Schmidt et al. (2014) linked above.

    Can you see the rather big problem with your assertion?

  53. pbjamm says:

    >“Judith argues that global warming has stopped – during Congressional testimony – it seems to me to be a deliberate rhetorical device.” I would just assume that she means “global surface temperature”; I know you think the distinction is critical, but that doesn’t mean everyone else does.

    miker613 she is speaking before the US congress not popping off down at the pub. It is indeed critically important in this case to be clear and accurate.

  54. BBD says:

    more skeptikoid misrepresentations from miker:

    Do you claim to know what is going to happen to surface temperatures? Why do you think you know? Because of GCMs. Do you know approximately how much temperatures will go up, depending on CO2? Why do you think you know? Because of GCMs.

    Here is well-known model sceptic James Hansen explaining how we know what we know:

    TH: A lot of these metrics that we develop come from computer models. How should people treat the kind of info that comes from computer climate models?

    Hansen: I think you would have to treat it with a great deal of skepticism. Because if computer models were in fact the principal basis for our concern, then you have to admit that there are still substantial uncertainties as to whether we have all the physics in there, and how accurate we have it. But, in fact, that’s not the principal basis for our concern. It’s the Earth’s history-how the Earth responded in the past to changes in boundary conditions, such as atmospheric composition. Climate models are helpful in interpreting that data, but they’re not the primary source of our understanding.

    TH: Do you think that gets misinterpreted in the media?

    Hansen: Oh, yeah, that’s intentional. The contrarians, the deniers who prefer to continue business as usual, easily recognize that the computer models are our weak point. So they jump all over them and they try to make the people, the public, believe that that’s the source of our knowledge. But, in fact, it’s supplementary. It’s not the basic source of knowledge. We know, for example, from looking at the Earth’s history, that the last time the planet was two degrees Celsius warmer, sea level was 25 meters higher.

    And we have a lot of different examples in the Earth’s history of how climate has changed as the atmospheric composition has changed. So it’s misleading to claim that the climate models are the primary basis of understanding.

  55. BBD says:

    miker

    You have nothing of merit or interest to say on the subject of climate models. Change the subject.

  56. Joshua says:

    Miker –

    Thanks for the direct responses:

    ==> ” I would just assume that she means “global surface temperature”;”

    But she has made that sort of statement repeatedly. As someone who talks about the importance of being up front about uncertainties, and who focuses often on what she sees as a counterproductive impact of a failure to address uncertainties, I would think that she would be careful about stepping over uncertainties when given Congressional testimony. She is a scientist who is effectively ignoring the uncertainties in the relationship between “global warming” and trends in surface temperature. Repeatedly. And this is hardly unique to her. This is a “know-something” who is making statements like a “know-nothing.” I get that you don’t think it”s important. I do.

    ==> “It doesn’t mean she’s saying something “logically incoherent “.

    Sorry, if she is saying that “global warming has paused’ based on a relatively short-term trend in surface temperatures, she is being logically incoherent, IMO. You can’t draw the one conclusion from the other. She is being purposefully logically incoherent for rhetorical purposes.

    ==> ” Well, I thought that was the point of his post. He is pointing at a Bishop Hill post, where the host did nothing more than post a possibly interesting paper. The only point I could see is that the comments were generally approving. So what? Yet he is making comments and conclusions about “skeptics” because of it.”

    But it is a blog where “skeptics” – may of whom are “know-somethings,” hang out. Admittedly, in general they know more than the average “skeptic,” and in that sense aren’t a representative sample – but that fact would seem to be actually in contrast to the point that you’re making by giving the average “skeptic” more credit than they deserve.

    ==> “I imagine the simplest explanation is that she disagrees with you.”

    ??? About what? First you say that it’s just carelessness and now you say it is disagreement? Which is it?

    You think that she disagrees with me, and instead believes that you can determine whether “global warming has stopped, or paused,” on the basis of a short term trend in surface temps? Do you think that would be a logically coherent disagreement on her part?

    I suspect that we’re reaching that ol’ blog discussion point of diminishing returns?

  57. miker613 says:

    “I suspect that we’re reaching that ol’ blog discussion point of diminishing returns?” Fair enough.

  58. miker613 says:

    BBD, paleo results are not without controversy. I know that Hansen likes them, and thinks you can derive climate sensitivity from them, and the like. But others disagree, and the models are real important in the IPCC. One can only deal with one issue at a time.
    Your other point on the models I answered already. As Annan said, the modellers were surprised and it’s an embarrassment, even though you don’t want to admit it. And as Annan said – well, see his words.

  59. verytallguy says:

    miker,

    One can only deal with one issue at a time.

    And that’s there you’re dead wrong miker. That’s the whole issue with “skeptics” – they are unwilling to look at the whole picture.

    There will always be uncertainty over individual parts of the picture, but so many different lines of evidence point to the same conclusions it’s implausible to suggest any alternative hypothesis:
    – CO2 has risen in line with industrialisation
    – basic physics (CO2 plus water vapour feedback) predicts a climate sensitivity of ca 3
    – our best integration of physics (GCMs) predicts the same
    – ice ages are incompatible with low climate sensitivity
    – OHC rises even through the hypothesised “pause”
    – sea level rise has accelerated with rising temperatures
    – glaciers are receding across the world
    – Arctic sea ice is at an all time low
    – etc
    – etc
    – ad nauseum

  60. pbjamm says:

    So lost in here somewhere is the answer to miker613’s original claim. Are the model projections outside the confidence interval and for longer than would be expected?
    If so :
    Do these models make more accurate projections when fed with observed inputs? Why were the predicted range of inputs so far of the mark?

  61. dana1981 says:

    I think it would be a good idea to correct the post – McLean as a professor is not a rumor you want to spread. For example, somebody searching for his name could come upon this post and then believe he’s a professor, then assume he’s a credible source as a result.

    I’m featuring McLean in my book as the man who made the worst global temperature prediction in history.
    http://www.skepticalscience.com/year-after-mclean-review-of-2011-global-temperatures.html

    Also worth noting as somebody mentioned above, SCIRP is a predatory publisher.

  62. Dana,
    Probably a good point. I did say apparently, but I should probably make it clear that he isn’t.

  63. miker613 says:

    “So lost in here somewhere is the answer to miker613’s original claim. Are the model projections outside the confidence interval and for longer than would be expected?” Yup. I’d like to know more about that too. I have asked Lucia if she’s doing an update.

  64. miker613,
    What James Annan actually said was said was

    And despite what some people might like to think, the slow warming has certainly been a surprise, as anyone who was paying attention at the time of the AR4 writing can attest. I remain deeply unimpressed by the way in which this embarrassment has been handled by the climate science insiders, and IPCC authors in particular.

    I don’t know enough about how it was handled in the time between AR4 and when I started blogging, so this does seem – to me – to be a little harsh, but the first part is certainly true (it was a surprise) and maybe those involved did handled it very badly. It doesn’t mean though “the models have failed”.

  65. pbjamm says:

    miker613 : “Yup. I’d like to know more about that too.”

    You made the claim without researching? Bold move.

  66. BBD says:

    miker

    BBD, paleo results are not without controversy. I know that Hansen likes them, and thinks you can derive climate sensitivity from them, and the like. But others disagree, and the models are real important in the IPCC.

    Standard denier tactics: insinuate, without any evidence, that there is “controversy” over evidence you don’t like.

    Nobody “disagrees” that you can estimate sensitivity from paleoclimate behaviour. Estimates centre on ~3C Rohling et al. (2012) within a range offering absolutely no policy wriggle-room comfort for advocates of BAU.

    Paleoclimate behaviour trumps denial, which is why you lot hate it and reject the evidence whenever it is shown to you.

  67. BBD says:

    And thanks for confirming that you were bluffing about this models failing “validation” nonsense. Now would be a tactically expedient moment for you to change the subject.

  68. Steve Bloom says:

    “Liljegren has been doing these statistical analyses for years – that by definition makes her a specialist, unless someone wants an excuse to ignore her work.”

    Wow, I’m a climate science specialist now! Thanks miker!

    And apparently I’ve been one since long before Liljegren showed up. Yet you listen to her and not to me. Selection bias? Are you, er, a specialist at selection bias?

  69. Steve Bloom says:

    While you’re at that, miker, maybe ask specialist statistician Liljegren about the formal basis for calculations of those confidence intervals. (5%… what a nice round number. Not 4,5%, not 6.3%, *precisely* 5%. Not the sort of thing one could calculate on the fingers of one hand, right? Oh wait…) They wouldn’t by any chance be just… arbitrary rules of thumb at root, would they? I’ll wait patiently for you to get back to me on that.

    OK, I need to be fair: Arbitrary rules of thumb plus four fingers.

  70. miker613 says:

    “There will always be uncertainty over individual parts of the picture, but so many different lines of evidence point to the same conclusions it’s implausible to suggest any alternative hypothesis:
    – CO2 has risen in line with industrialisation, – basic physics (CO2 plus water vapour feedback) predicts a climate sensitivity of ca 3, – our best integration of physics (GCMs) predicts the same, – ice ages are incompatible with low climate sensitivity, – OHC rises even through the hypothesised “pause”, – sea level rise has accelerated with rising temperatures, – glaciers are receding across the world, – Arctic sea ice is at an all time low, – etc”
    VTG, this isn’t a correct summary. These are evidence on _independent_ pieces of the AGW theory. Most are irrelevant.
    – CO2 risen – indeed, pretty much everyone agrees with this piece.
    – [temperatures rising for the last century – pretty much everyone agrees with this piece.]
    – basic physics… – by no means. Sensitivity without feedbacks is around 1. No one knows what the total feedbacks are. This is an active area of dispute. They try to _determine_ feedbacks and sensitivity using some of the other lines of evidence. So this one is wrong – basic physics isn’t enough for evidence.
    – GCMs – now you’re talking, they predict sensitivity of about 3. But as we’ve been saying, they are running too hot; we need to defend the models instead of using them as evidence. This is not as convincing as it was a decade ago.
    – ice ages – active subject of dispute.
    – OHC – active subject of dispute, not evidence for anything..More of an attempt to help defend GCMs, but leads to a complicated discussion of how much that affected the last century.
    – sea level rise – active subject of dispute, not much visible acceleration. But if sea level is rising, that’s because temperatures are higher. That has nothing to do with CO2 sensitivity, it’s a fact – temperatures are higher than a century ago. We’re not talking about that.
    – glaciers – same answer: temperatures are higher. We’re not talking about that.
    – sea ice – same answer: temperatures are higher. We’re not talking about that.

  71. miker613 says:

    “You made the claim without researching? Bold move.” pbjamm, sarcastic and uncalled for. I know what I know, which is what I posted. I would like to learn more, so I emailed Lucia, and would be interested in other links.

  72. Steve Bloom says:

    “others disagree”

    Oh, I just have to ask: To whose authority are you appealing here?

  73. miker613,
    I really think most people would describe your comment as a classic example of FUD.

    We may not know what the total feedbacks are, but we’re pretty confident that they’re positive.

    Another problem with your comment is that if you consider each line of evidence in isolation, then you can indeed find possible issues. Maybe there is something that we don’t understand, that we’re doing wrong, that could completely change our understanding. If, however, you consider all the lines of evidence together, than the chances that this is true in all cases is probably vanishingly small – unless you’re suggesting some kind of conspiracy.

  74. miker613 says:

    “While you’re at that, miker, maybe ask specialist statistician Liljegren about the formal basis for calculations of those confidence intervals.” Steve Bloom, I gave you a link there, there are more available there, she posts her code and her methods and her results. You could read them. But you seem to just know better.

  75. BBD says:

    WRT James Annan’s perhaps harsh words, I find some sympathy for those who didn’t see a pronounced slowdown in the rate of surface warming in 2007.

  76. BBD says:

    miker

    This is getting tedious.

  77. Steve Bloom says:

    Just to note, entirely unsarcastically, miker, your 8:00 pm comment thoroughly demonstrates your ignorance.

  78. pbjamm says:

    “sarcastic and uncalled for”
    I will grant you sarcastic.

  79. izen says:

    The idea that changes in clouds could alter the climate to be the cause of most of the observed and measured warming requires that the GHG effect of rising CO2 is much less than predicted by the current radiative transfer equations.
    As suggested by the Harde papers raising questions at Eli Rabett’s site-

    http://www.hindawi.com/journals/ijas/2013/503727/abs/

    It also needs an accurate measure of cloud cover for a suitable time period from which the trend can be derived.
    This is uncertain.

    The satellite record has problems like those that have affected the satellite temperature record. The records from different satellites have to be combined to give a clear trend which unambiguously correlates with surface temperature, or whatever other metric of the climate that you are ascribing as the effect of the trend in cloud cover.

    Clouds have no memory.
    To get a decadal trend in a reactive physical system like clouds there has to be a causative agency that has imposed that trend on cloud cover. Otherwise the claim that cloud cover has caused the surface warming is merely a description, not an explanation and subject to ATTP’s point that the causation may be reversed.
    both metrics require an external explanation.

    insolation, cosmic ray intensity and a range of other natural or cyclic causes have been suggested, but none match the observed trends either in temperature or those claimed for cloud cover well.

    Anthropogenic changes however do match the other observed trends.
    Those that might wish reject the role of CO2 need to supply an alternative explanation, not just a description (cloud cover) masquerading as one.
    Is it possible to exclude the massive influence anthropogenic sources have had on the natural sulphur cycle from cloud dynamics ?!
    (grin)

  80. BBD says:

    So this one is wrong – basic physics isn’t enough for evidence.

    A warmer troposphere is a moister one. QED. And besides, if feedbacks were weaker than supposed, paleoclimate variability becomes virtually inexplicable. What Steve said, miker. The stuff you are covering yourself in is not glory.

  81. miker613 says:

    “We may not know what the total feedbacks are, but we’re pretty confident that they’re positive.” Yeah, but positive is not the topic – he’s claiming the result is 3 instead of (say) 2 or whatever Nic Lewis gets. For that we have two basic lines of evidence. Everything else he mentioned is off topic. We’re discussing one of them here. The other is paleo, and it is just as controversial, even though we’re not currently discussing it.
    “If, however, you consider all the lines of evidence together, than the chances that this is true in all cases is probably vanishingly small” – huh? Why? Two lines of evidence leading to ECS=3, both unclear. What is “all the lines of evidence together”? Why should it be vanishingly small, or need a conspiracy?

  82. BBD says:

    Izen

    If reduction in low marine cloud is a driver of modern warming it would be as a positive feedback to CO2 forcing… it’s worse than we thought!

    🙂

  83. BBD says:

    miker

    You don’t see it yet. The lower end of the range of plausible climate sensitivity estimates – which is to say values consistent with paleoclimate behaviour – is over 2C. There’s no policy wriggle-room at this level.

  84. Steve Bloom says:

    miker, I have read them. Overconfidence in statistical methodology is a primary symptom of what’s wrong with Liljegren and McIntyre. That and confirmation bias.

    So the simple question is to you, not her, since you cite to her as an authority despite a lack of qualifications: What’s the formal basis for selection of a 5% confidence interval? If you can actually link to her doing that specifically, fine, I’ll have a look. If not, then I can only conclude you have no idea.

  85. BBD says:

    The other is paleo, and it is just as controversial

    Once again, you are playing word placement games and FUDding about. Please *stop it*.

  86. miker613,
    Let’s clarify something. I don’t think anyone is saying ECS = 3. What I believe is being said is that the best eatimate, considering all the available evidence is around 3, but there will be a range on either side of that.

    What is “all the lines of evidence together”? Why should it be vanishingly small, or need a conspiracy?

    Because, if you have independent lines of evidence that broadly give the same result but are all wrong, you need a set of independent errors to suddenly be true. For example, one could argue that it is unlikely that GCMs are wrong, but there is a chance that they are. Then one could argue that it is unlikely that paleo estimates are wrong, but there is a small chance that they are. What is then chance, then, that both GCMs and paleo are wrong. Then you can add in estimates using the greenhouse effect itself, volcanoes, and even Nic Lewis’s method (which is actually not as different to the GCM and paleo estimates as you might think). What are the chances that each of those methods has an as yet undetected error that when corrected will completely change our estimates for climate sensitivity.

    Of course, I should be careful. What I’m talking about are the kind of errors that – if corrected – would change the whole range for the ECS. It seems unlikely that we’ll suddenly discover a whole set of independent errors that will change the range for climate sensitivity dramatically. However, as it stands, it is possible that the ECS is low, given the current evidence. The current range includes that possibility.

  87. miker613 says:

    ‘And thanks for confirming that you were bluffing about this models failing “validation” nonsense.’ Whatever. You don’t seem to be listening. I think I’ve made clear what I was saying. Perhaps you have your own standards for exactly how the GCMs could be falsified, or have a link to the modellers setting those standards. Lacking that, the rest of us will have to use our judgment on what is an unacceptable deviation from their predictions. I don’t think von Storch and Lucia and even Annan – and I – are being unreasonable.

  88. miker613,
    I appreciate that you’re getting a bit of a hard time, but bear in mind that you’ve just submitted a comment in which you’ve suggested virtually of of climate science is uncertain (GCMs, paleo, sea level, OHC, sea ice, glaciers, feedbacks). Not only did you not provide any evidence for these assertions, you didn’t even attempt to quantify what you meant. Of course, all of these aspect of climate science have uncertainties, but that doesn’t mean we’re uncertain.

    Maybe you should read the most recent Hargreaves and Annan paper, because I think James Annan’s position with respect to GCMs is much more nuanced than you appear to think.

  89. pbjamm says:

    ATTP even if multiple errors were discovered there is no assurance they would all work to lower the ECS.

  90. pbjamm,
    Indeed, I was simply making the point that a major change in our estimated range for climate sensitivity would probably require a radical change in our understanding of numerous different aspects of climate science.

  91. Joshua says:

    Miker –

    ==> “I don’t think von Storch and Lucia and even Annan – and I – are being unreasonable.

    You seem to be expressing a rather strong alignment with Annan.

    Probably the most iconic and influential result arising from climate models is the prediction that, dependent on the rate of increase of CO2 emissions, global and annual mean temperature will rise by around 2–4°C over the 21st century. We argue that this result is indeed credible,

    Do you share his view on the credibility of the product of GCMs?

  92. Joshua says:

    sorry – obviously should have include ellipses after “…indeed credible…”

  93. pbjamm says:

    I think that a GCM could easily be proved wrong if you fed into it observed levels for all the variables and the results in no way resembled reality. That is not the case as far as I know for the current GCMs. What we were discussing earlier is what happens when you make some assumptions about what to feed into the model and those assumptions turn out wrong. Of course in that case the results will also be wrong (gi-go). That does not mean that the Model itself is flawed and that can be tested by (as I stated earlier) feeding observations instead of assumptions. Keep in mind there are different levels of wrong too.

  94. BBD says:

    We argue that this result is indeed credible, as are the supplementary predictions that the land will on average warm by around 50% more than the oceans, high latitudes more than the tropics, and that the hydrological cycle will generally intensify. Beyond these and similar broad statements, however, we presently find little evidence of trustworthy predictions at fine spatial scale and annual to decadal timescale from climate models.

    And quite right too. GCMs are designed to investigate the behaviour of the climate system over multidecadal and centennial timescales. Not – as I pointed out earlier – to predict climate system behaviour accurately a decade at a time.

  95. Steve Bloom says:

    miker, let’s be clear about paelo:

    It isn’t controversial, but does have error bars (of course), and the quantity directly derived from it isn’t ECS but ESS (which conflation exposes the limits of your knowledge on this subject, note). Trying to derive ECS from ESS probably is controversial, or certainly hotly disputed among scientists, so fair enough if that’s what you were attempting to refer to. Nonetheless that derivation is important to try to do since it tells us something about the potential rate of change moving forward from the present.

    The uncontroversial point remains that an equilibrium climate state of ~ 400 ppm CO2 will be 2-3C warmer than present and have approximately 25 meters higher sea level. Ignoring for the moment that CO2 is behaving differently from that, how fast the climate moves toward such a state has everything to do with how disruptive the changes will be. The evidence is piling up in favor of entirely too damned fast, to the almost continuous chagrin of ice sheet modelers in particular.

    But paleo evidence probably will never be fine-grained enough to tell us what to expect on a decadal or probably even centennial basis (maybe a bit of the latter), and as Nic Lewis has boringly confirmed projections of short-term observations will fall short, so the GCMs remain our only hope of knowing what the near future holds. As Hansen points out, paleo is the ultimate benchmark for the models, and as of now (pay *very* close attention to this point) the models (not GCMs due to computer resource limitations) are unable to manage a transition from present climate to one in equilibrium with ~ 400 ppm CO2 (i.e. the mid-Pliocene).

  96. pbjamm,
    I think that is something that many don’t understand (or don’t want to understand). Something like a GCM need various inputs. Solar, volcanoes, anthropogenic emissions. These will all influence how the GCM evolves. If you want to make some kind of projection as to what happens in the future, you need to make some assumptions as to the values of these inputs. If the GCM doesn’t match reality, you need to consider if these assumptions turned out to be correct. If not, you correct them and see how that influences the result. Perfectly normally thing to do. If you’ve corrected everything and the results still don’t match reality, then you can start to consider if there is some major issue with the model.

    Of course, in reality, no model will ever be perfect, so you’re consider – as Gavin Schmidt would say – if it is skillful, or not.

  97. izen says:

    One problem with cloud cover data is that early satellite measurements used a model of clouds that converted satellite sensor readings with the assumption that clouds could be treated as a flat plane perpendicular to the sensor. This caused any lateral view to overestimate cloud cover because the thickness of a cloud would vastly increase its ‘measured’ coverage.

    That was a model invalidated by a geometric error ?

    But talk of model ‘validation’ is a signifier that someone is using a concept of scientific computer models that is probably close to the engineering approach, or perhaps the common sense assumption of how a model should work.

    Consider two types of modelling.

    in electrical engineering there are computer models of electronic circuits. copy the component values and connections into a model, or make the circuit using the model design and if it is a valid computer model there is a match between the computer model and the real world circuitry.

    In Biology there are various models trying to explain the behavior of a complex system from a single cell response to chemical changes to oceanic ecology.
    when the model predictions and the real world diverge with such models they are not invalidated.
    Such divergence between model and observation is seen as a reason to check the accuracy of the observations both in the predicted results and the model input parameters.
    It also triggers a search for additional factors that may have been underestimated or omitted that could influence the observed data.
    Such as the geometric error in cloud cover measurements.

    Unlike engineering or simple concepts of model use, a conflict between the model output and observations is not something that converts a valid model to an invalid one. It certainly does not make the underlying physical theory that the model uses invalid, as it would in a electronic circuitry model.

    Perhaps some of the time that ‘skeptics’ talk about the observed surface temperature invalidating all but 5% of climate models, (or something) and by implication the theory they are based on, it is not a rhetorical device.
    It could be genuine mismatch between the concept of a computer model that some people hold and the real behavior and use or computer models in areas where it is the component values and complexity of connections that are uncertain, not the underlying physical theory.

  98. Steve Bloom says:

    “However, as it stands, it is possible that the ECS is low, given the current evidence. The current range includes that possibility.”

    In part because the science is moving so fast, the IPCC hasn’t been able to take on board recent ice sheet evidence (both current obs and paleo).

    There’s a new paleo paper (no time to link to it right now, but I will later) that points to ice sheet instability even with quite low temperature increases relative to present. Its formal expression and utility for models aside, it seems to me that ECS loses its utility in such a context. Maybe it should be renamed ETS.

  99. miker613 says:

    “it is possible that the ECS is low, given the current evidence.” That’s basically our disagreement. I think that the available lines of evidence are converging on a much lower ECS, maybe even slightly below 2. No problem with the IPCC, but on the very low end of their range. That should be awesomely good news for everyone, but it seems to me that many are treating it as terrible news.

  100. miker613 says:

    “Do you share his [Annan’s] view on the credibility of the product of GCMs?” Sounds reasonable. Only the numbers are getting pushed down by the “pause”, as he also says. The next generation of GCMs will probably have to be set cooler.
    From my personal point of view, if we can rule out the fat tail of higher ECSs, that alone will be good news indeed.

  101. Steve Bloom says:

    miker, demonstrating an utter inability to listen.

  102. BBD says:

    I think that the available lines of evidence are converging on a much lower ECS, maybe even slightly below 2.

    And you would be largely alone here in that assessment because it is too highly selective in its sources.

  103. miker613,

    That should be awesomely good news for everyone, but it seems to me that many are treating it as terrible news.

    Firstly, these new estimates do not rule out higher ECS values. Secondly, if you understand these methods you might realise that most of what they don’t capture would probably increase the estimates. Thirdly, it’s only good news if it’s true. If it’s not true, and we act as if it is, it could be extremely bad news.

  104. verytallguy says:

    Miker,

    Your response made my point perfectly, thank you.

  105. A hypothesis should be falsifiable, a model is a simplification and thus wrong by definition. Even if it were useful to talk about a falsified model, the process of “model falsification” is a little more complex than just finding a difference between a measurement and a model. Finding such a difference is a starting point, where one tries to understand the reasons for the difference. Once understood, the conclusion might be that another model/hypothesis is better. The reason can be that the measurements are wrong, that the way the global mean is computed is wrong, that some of the assumptions of the model are wrong (changes in insolation and volcanoes) or that some aspect of the model is wrong. In the latter case, this can be relevant for long-term global warming or more likely be relevant for the modelling of natural variability on short time scales, which is not the main aim of the models and not their strength.

    (Just for the record, the spread of a multi-model ensemble (what Lucia and Von Storch study) is not the same as the uncertainty of the model projections. One hint is already that a multi-model ensemble is used. A single-model ensemble would have too little spread because it does not cover the uncertainty in our understanding of the physical processes. Model parameters are set at the best estimate, not at a random possible value. Using multiple models relaxes this problem a little, but not fully. The real uncertainty is thus larger than the model spread. How much larger is, unfortunately, somewhat subjective. Hard, if not impossible to exactly quantify. In praxis this is not too much of a problem, because the naive falsification approach of Miker is not used in science. Scientists want to understand the differences.)

    When it comes to the slowdown of the increase in surface temperatures, the deviations are not yet statistically significant. But clearly models are wrong. See this enlightening quote from the last Climate Dialogue on the tropic hotspot by Steven Sherwood:

    If I were looking for climate model defects, there are far more interesting and more damning ones around [than the tropic hotspot]. For example, no climate model run for the IPCC AR4 (c. 2006) was able to reproduce the losses of Arctic sea ice that had been observed in recent decades (and which have continued accelerating since).

    No model, to my knowledge, produces the large asymmetry in warming between the north and south poles observed since 1980. Models underpredict the observed poleward shifts of the atmospheric circulation and climate zones by about a factor of three over this same period (Allen et al. 2012); cannot explain the warmings at high latitudes indicated by paleaoclimate data in past warm climates such as the Pliocene (Fedorov et al. 2013); appear to underpredict observed trends in the hydrological cycle (Wentz et al. 2007, Min et al. 2011) and in their simulated climatologies tend to produce rain that is too frequent, too light, and on land falls at the wrong time of day (Stephens et al. 2010).

    Finally, the tropical oceans are not warming as much as the land areas, or as much as predicted by most models, and this may be the root cause of why the recent warming of the tropical atmosphere is slower than predicted by most models (there is a nice series of posts about this on Isaac Held’s blog). What makes the “hot spot” more important than these other discrepancies which, in many cases, are supported by more convincing evidence? Is it because the “missing hot spot” can be spun into a tale of model exaggeration, whereas all the other problems suggest the opposite problem?

  106. izen says:

    @-miker613
    “I think that the available lines of evidence are converging on a much lower ECS, maybe even slightly below 2…. That should be awesomely good news for everyone, but it seems to me that many are treating it as terrible news.

    This is the C. S. Lewis critique that he made in the context of spiritual ethics.
    If people warn against some (immoral?) behavior warning of the terrible consequences, but then find that those consequences are NOT as serious as they predicted then it is evident that they were not concerned about the consequences of those actions, the objections were raised for other arbitrary or ulterior motives.

    I suspect that this is a misreading of the response, I see few treating the possibility of climate sensitivity being below 2degC as terrible.

    I do observe some warning that climate sensitivity is only a estimate of how much, how fast. The destination whatever the value is similar, the delay from a low value just a matter of decades.
    Others point out that climate sensitivity is a very blunt measure of the harm that might result from even very low values. A sub 2degC sensitivity would not have much impact on how much of Florida will flood or when. Or how many decades drought in various region might persist, when even a single decade would be catastrophic to established agricultural areas.

    The C S Lewis critique is open to its inverse.
    Most often described as ‘confirmation bias’. If for other ulterior or arbitrary reasons people wish to view a behavior as acceptable (ethical?), any evidence that it is LESS terrible in its consequences than others warn, will be welcomed.
    Not because the consequences are less damaging but because of the other reasons people favour that behavior.

  107. John Mashey says:

    Sea level rise? What’s that? Miami’s got a building boom, right atop all that lovely porous limestone.

    A good investment might be: Google Images: netherlands floating homes. When ti comes to water, the Dutch are hard to beat, although I have no idea how hurricane-tolerant these are.

  108. Vinny Burgoo says:

    What do you think should be done about climate change in your area?

  109. Lotharsson says:

    A bit late to the party, and Victor Venema (and others) have put it more precisely, but maybe this helps.

    “If the actual temperatures are outside that range, an _informal_ conclusion is going to be: these models cannot predict accurately.”

    And informal or not, it’s a completely invalid conclusion for several different reasons derived almost entirely using basic logic. A valid conclusion would look more like this:

    “Either:

    a) the model outputs were projections, not predictions, therefore it is invalid to compare the actual climate outcomes with model projections because projections, by definition, do not use inputs that match the real world inputs.

    b) the model outputs were predictions (e.g. they were supplied with the actual forcings rather than a representative scenario), but they are not expected to predict the “noise” (e.g. “natural variability”) so it’s invalid to compare them with the actual climate outcomes over time periods in which the noise almost certainly dominates.

    c) the model outputs were predictions and were made over a long enough period that noise should not dominate, but the climate itself evolved in a “not likely” fashion over that time period which is expected to happen every so often (specified by the numerical value of “not likely” here).

    d) the model outputs were predictions, were made over a long enough period that noise should not dominate, and the climate itself evolved in a “likely” fashion but the models did not include that outcome in their “likely” range.”

    One cannot conclude (d), informally or otherwise, until one can rule out (a), (b) and (c). You haven’t done that – in fact, you’ve conflated prediction and projection which blocks you from even considering the possibility of (a).

    “If you don’t know what temperatures will be like for the next century, so don’t tell me you do.”

    It’s easier to predict what the temperatures will be like for the next century than for 15 years ahead because noise dominates the latter but not the former. Your “don’t tell me you do” is an invalid conclusion based on the comparisons you cite, and it seems to rely on getting the varying difficulty of prediction over different timescales arse-backwards.

    “Do you claim to know what is going to happen to surface temperatures?”

    Your question is ill-specified. When discussing a noisy system – as any engineer, mechanical or otherwise, can tell you – the answer to the question depends on the time scale necessary to distinguish (in engineering terms) the deterministic behaviour from the stochastic – or to put it another way, the signal from the noise.

    And on this thread you are trying to argue from a period almost certainly dominated by noise that the signal is not understood because the noise was not accurately predicted. That is fallacious no matter how you try to phrase it.

    “Why do you think you know? Because of GCMs.”

    Others have pointed out not-GCM reasons. One should also note that for predicting many decades ahead we already had surprisingly good estimates created before the first GCM was created.

  110. Lotharsson says:

    “That should be awesomely good news for everyone…”

    Before you assert that, figure out how many more years of business as usual we would get as a result if we still want to stay under 2C post-industrial warming, or equivalently how many more tonnes of carbon we can burn that we didn’t think we could burn. When you do that, IIRC, it’s probably nowhere near “awesomely good news”. A 2C ECS would merely give us a bonus period before 2C occurs – one that the current evidence suggests humanity will squander.

  111. Mack says:

    Victor Venema,
    I was trying to get hold of you not so long ago, and I’d thought I’d come across your blog…..,,,but I was mistaken. It was the Ford Prefect’s blog. I wonder if ATTP here would pass my message (comment ) to you, I somehow doubt it , because he’s just bounced my two previous comments

    [Mod : not sure what your link is all about, so I’ve removed it. Victor has his own site. Maybe he’ll let you comment there. Also, I’ll try to stop bouncing your comments if you try to stop being obnoxious.]

  112. Mack, you’d better present a good case, I am a lot more strict than ATTP. My valued readers not wasting time is a lot more important than the hurt feelings of some mitigation sceptic. If you have a bad case, better send me an email.

  113. Willard says:

    > One cannot conclude (d), informally or otherwise, until one can rule out (a), (b) and (c).

    Of course you can:

    http://en.m.wikipedia.org/wiki/Abductive_reasoning
    http://plato.stanford.edu/entries/logic-nonmonotonic/

    Even statistical inference shows this wrong: all you have to show, to conclude (d), is that it’s the most X, where your X helps you decide to pick it. If (d) was an action, one could argue that it’s the most reasonable one, considering the information available and the payoff.

    Please, not a logic argument again. I have better things to do.

  114. Willard says:

    > the naive falsification approach of Miker is not used in science.

    See? No need for any logic argument to refute online falsificationism.

    Thank you, Victor.

    ***

    A question: how many more years would the most lukewarm scenario warrant us to remain on the business-as-usual course, compared to the mean estimates?

  115. Willard says:

    > the naive falsification approach of Miker is not used in science.

    “See? No need for any logic argument to refute online falsificationism.
    Thank you, Victor.”

    ?

    Need…is in the eye of the beholder of the effect that science denying propaganda has on the public.

    By the way: In our last discussion you linked me to a page in which you posted *on the order of* 10^2 comments arguing with a nonscientist who claimed that climate science was falsified. Evidently, there is a need to refute it.

    We live in a political world. The more we see more voters and politicians believing the falsification claims, the more we see governments that will do nothing for our planet’s future.

    The falsification arguments put forth by such as Miker are a prime example of what I proved to be inconsistent and invalid – these falsification arguments in question not only affirm contradiction, they become invalidated by the observation of those auxiliary hypotheses that when incorporated into the models improved the accuracy of their outputs.

    I would most certainly not agree that in this political world in which so much is as stake, it would be a good idea to let the public remain ignorant of these facts.

    A claim that a proposition or conjunction of propositions has been falsified is a proof-claim – a claim that such has been proved to be false by some standard of proof (for example, beyond all reasonable doubt), if you or anyone thinks that there exists in this world a legitimate such proof against climate science, one that commits no contradiction and has not been invalidated in the way already noted, then please show it. (I note that all the burden of proof of showing that one has a proof is on the one who claims proof – this is true in mathematics as well as outside it. I have never seen such a proof-claim against climate science that meets the burden of proof in question.)

    “A question: how many years would the most lukewarm scenario warrant to stay on the business-as-usual course, compared to the mean estimates?”

    Let’s answer this question with a question no less legitimate: How many years would the warmest scenario warrant to stay on the business-as-usual course, compared to the mean estimates?

    Russian roulette, anyone?

    Pascal’s Wager, anyone? (Some may have missed this next little gem of an article.)

    “How to bet on climate change”
    http://www.theguardian.com/science/2012/jul/03/climate-change-pascal-wager

    Quote—In terms of Pascal’s Wager, the false positive (thinking there’s a problem when there isn’t) is not so bad, but the false negative (thinking there’s no problem when there is) could be catastrophic.—

  116. Willard says:

    > Evidently, there is a need to refute it.

    Need is in the eye of the beholder. To remind people that miker613’s request does not reflect scientific practice ought to be enough.

    Logical arguments that misrepresent falsificationism are worse than wrong.

  117. Willard says:

    Also, this is inaccurate:

    Pascal’s Wager is to do with whether to believe in God or not. It says that since we can’t prove or disprove the existence of God we should wager that he does exist, because there’s a lot to gain if it turns out he does and not much lost if he doesn’t.

    Perhaps we could frame the arguments about global warming as a similar wager. If we wager that global warming is a serious problem and we need to act urgently then, in a similar way to Pascal’s Wager, there would be relatively little lost if it turns out not to be such a problem and plenty to gain if it is.

    http://www.theguardian.com/science/2012/jul/03/climate-change-pascal-wager

    First, it’s not “a lot” and “not much,” but “everything” and “nothing”. Second, Pascal had more than one argument. Third, decision theorists are still wondering if the overall argument is valid, and some argue (convincingly, in my opinion) that wagering on God’s existence makes little sense:

    http://plato.stanford.edu/entries/pascal-wager/

    As a side note, Pascal’s wager is oftentimes used by the contrarian themselves. Pascal’s wager, when interpreted very liberally, if not libertarianily, could be made to be an instance of the precautionary principle. The precautionary principles has many instances, the majority of which have nothing to do with Pascal’s wager.

  118. Willard says:

    > Evidently, there is a need to refute it.

    “Need is in the eye of the beholder. To remind people that miker613’s request does not reflect scientific practice ought to be enough.”

    Perhaps it “ought” to be the case, but what “ought” to be the case is not the case. The proof that it is not enough is in the pudding – all those countless millions of voters worldwide – including most importantly all those politicians all over the world with real power to decide whether or not we act – who actually believe the false claim that climate science is falsified and who are actively trying to increase their numbers by their incessant arguments that do commit the mistakes in question.

    “Logical arguments that misrepresent falsificationism are worse than wrong.”

    Sure, if they actually do that. But my logical arguments do not do that – they actually represent the arguments that those countless millions who claim that climate science is falsified actually use – including that person you incessantly argued with, that person who claimed that climate science was falsified. My proofs
    https://andthentheresphysics.wordpress.com/2014/10/16/environmental-bullies/#comment-35226
    simply show the contradictions that must ensue when one puts forth the argument that miker613 and those countless millions and all those science denying politicians actually believe. And, yes, Koutsoyannis also makes this mistake. In
    https://andthentheresphysics.wordpress.com/2014/10/16/environmental-bullies/#comment-35730
    I proved that when we stick to what he actually wrote and only what he actually wrote – and that means we do not go with what we think he meant, we see that he did claim falsification and thus did commit the same mistake. That absolutist statement in question that he actually wrote does not allow for future climate projections to be credible. (I say again he should not have written that statement in question and should retract it.)

  119. Quantum mechanics and relativity do not fit together. Thus in native falsificationism at least one is falsified. (It is a pity that QM and relativity are theories, if one were a measurement, then the mitigation skeptic would know the other to be falsified, can’t be anything else.)

    Don’t get out of bed, dear mitigation skeptics, you have no reason to think that the sun is up, mechanics is falsified. Don’t use any electronic equipment, now that QM is falsified your phone could explode at your head.

  120. > Perhaps it “ought” to be the case, but what “ought” to be the case is not the case.

    Then “need” might not be in the eye of the beholder, after all.

    ***

    > But my logical arguments do not do that – they actually represent the arguments that those countless millions who claim that climate science is falsified actually use [1] – including that person you incessantly argued with [2], that person who claimed that climate science was falsified.

    [1] Actually, it does not do that. The only argument it analyzes was provided by me. Koutsoyannis’ argument is not even the falsification argument (“models are falsified”), but (at best) “model reliability is falsified”. (I noticed how the modality has been stuffed in the proposition, btw.) This argument thus thus questions the implication itself, the very thing that is required by falsificationism. Koutsoyannis got everything wrong about falsificationism.

    There is a difference between a falsifiability argument and a falsification argument. A quote for a falsification argument, i.e. someone in the lichurchur saying that the models have been falsified, would still be nice. This is not the first time I ask for that.

    [2] That person was not saying that, but rather that it can’t be falsified unless we can provide falsifiers, which is what falsifiability amounts to. He was led astray by asking for necessary and sufficient reasons:

    You need to have a necessary and sufficient falsifiable hypothesis statement. So,

    1) a list of observations, which if observed, mean your hypothesis is false;

    2) a logical argument that the lack of those falsifications means that your hypothesis must be favored over all others (including the null).

    http://ourchangingclimate.wordpress.com/2014/02/17/is-climate-science-falsifiable/#comment-23897

    I had to read Popper’s Realism and the Aim to Science to him to show that this had nothing to do with falsifiability. The simple epistemological principle according to which if you wish to put forward scientific hypotheses, you ought to put forward states of affairs that would falsify them. In one way or another, you need to show some willingness to revise your hypotheses, and unless you do, you don’t even science.

    This is the most basic tenet of empiricism. Nobody should disagree with something like this.

    Equivocating with “my models exclude assumptions (I can reject as untrue by some magic)” and models-as-everything-you-need-to-make-prediction is just plain silly.

    There is something that is falsified when predictions are false.

    ***

    My first comment may be relevant here:

    > a necessary and sufficient falsifiable hypothesis statement for AGW.

    Global Warming is caused by authropogenic activity.

    To disprove that, you need to show that one of the three hypothesis are better explanations of what’s happening:

    (1) There is warming, say because greenhouse gas theory is wrong.
    (2) Even if here has been warming, it’s not global.
    (3) Even if GW is true, it’s not anthropogenic.

    Prove any of the three and you win. If you have any other suggestion, you’re more than welcome. If you have show (1), try this:

    http://scienceofdoom.com

    http://ourchangingclimate.wordpress.com/2014/02/17/is-climate-science-falsifiable/#comment-25253

    This challenge could be “refuted” by K&A’s argument: it’s possible to construct a counterfactual where everything holds except some “assumption”.

    ***

    Popper is not that tough to dodge. Just imagine if I tried to refute scientific theories without opening one single science book. I have no idea why commenters think they can pull that trick against philosophy.

    Philosophy is hard.

  121. miker613 says:

    “you’ve just submitted a comment in which you’ve suggested virtually of of climate science is uncertain (GCMs, paleo, sea level, OHC, sea ice, glaciers, feedbacks”
    I said no such thing. I said that sea ice, sea level, glaciers are irrelevant to what we’re talking about – which is high vs. low sensitivity. Any evidence from accelerated sea level is not consensus science; it is hotly disputed within the field. Ocean heat content is not consensus science, it is a very new topic and they’re just getting started and only have a few years of data. All I pointed out is that if you’re looking for evidence of the size of sensitivity, GCMs and paleo are what you have, and that’s what the IPCC uses. The others are off topic.

  122. miker,

    I said no such thing.

    I’m referring to this comment. Try reading it again.

  123. BBD says:

    miker

    Any evidence from accelerated sea level is not consensus science; it is hotly disputed within the field.

    No, it isn’t.

    Ocean heat content is not consensus science, it is a very new topic and they’re just getting started and only have a few years of data.

    Another rhetorical over-reach. But even if taken at face value, the few years of data from ARGO speak eloquently for themselves.

    All I pointed out is that if you’re looking for evidence of the size of sensitivity, GCMs and paleo are what you have, and that’s what the IPCC uses. The others are off topic.

    GCMs and paleoclimate-derived estimates of sensitivity are in good agreement (Rohling et al. 2012).

  124. miker613 says:

    “Firstly, these new estimates do not rule out higher ECS values. Secondly, if you understand these methods you might realise that most of what they don’t capture would probably increase the estimates.”
    Well, some of the new estimates do. Certainly Nic Lewis’ stuff has vastly lower probabilities of high sensitivities.
    “Thirdly, it’s only good news if it’s true. If it’s not true, and we act as if it is, it could be extremely bad news.” 100%. But it might be good news – certainly hopeful. Presumably in the next few years we will have better information, and it might turn out low. Wouldn’t that be wonderful?

    @Willard “A question: how many more years would the most lukewarm scenario warrant us to remain on the business-as-usual course, compared to the mean estimates?” Your mileage may vary, but I personally think that solar power is going to be completely competitive with fossil fuels before mid-century. Lower sensitivity means less total temperature rise, and less total damage. Low enough could totally change the economics between mitigation and adaptation.

    @Venema. These points are valuable, but I would still like more information: How do we tell when the models have done so badly that they cannot be used to provide evidence on climate sensitivity? Surely there is such a point. Von Storch obviously feels that that point has been reached already, but if you disagree, explain how you would define that point.

  125. miker,

    Well, some of the new estimates do. Certainly Nic Lewis’ stuff has vastly lower probabilities of high sensitivities.

    Do you have issues with reading comprehension? I was talking about Nic Lewis’s stuff.

  126. miker613 says:

    ATTP, I referred to that comment as well. Most of these are not relevant to calculating climate sensitivity.

    And some of them are uncertain not because I’m doubting climate science, but because they are not part of the consensus of climate science, they are active subjects of research. I tried to identify the parts that it seemed to me are still uncertain; why would that mean I’m doubting climate science?

  127. miker,

    But it might be good news – certainly hopeful. Presumably in the next few years we will have better information, and it might turn out low. Wouldn’t that be wonderful?

    Yes, it would wonderful. But it might be a f**king disaster if it’s not true. As I understand it, risk analysis doesn’t involve going “maybe it will be fine”.

  128. miker,

    And some of them are uncertain not because I’m doubting climate science, but because they are not part of the consensus of climate science, they are active subjects of research. I tried to identify the parts that it seemed to me are still uncertain; why would that mean I’m doubting climate science?

    Because your rhetoric is classic “skeptic” rhetoric. Promoting uncertainty as if there is some kind of dispute. There is little dispute about the rise in OHC. There is little dispute about the rise in sea level. There might be uncertainties as to how much each has risen, but that is how science works. Plus, what do you mean by “the consensus of climate science”? If the consensus is “we have warmed and it is mostly us” the the rise in OHC and sea level is within the consensus.

  129. miker,

    Most of these are not relevant to calculating climate sensitivity.

    Oh, and this is essentially wrong too. Sea level rise and OHC are directly related and can be used to determine the system heat uptake rate which is crucial for Nic Lewis’s ECS calculation.

  130. miker613 says:

    ATTP, why would that be a problem with reading comprehension? You said it doesn’t rule out high sensitivities. It does – you’re mistaken. The “likely” range isn’t that different, but most of the weight has moved much lower in the range. And the very high disastrous estimates (>4, say) are vastly less likely; the fat tail is pretty much not there. Nic Lewis pointed this out immediately when Gavin Schmidt made the claim that you are making.

  131. miker,
    Nic Lewis’s analysis might do that. However, what I was saying is that if you consider all of the factors that such methods cannot capture, they will probably increase the estimates.

    Nic Lewis pointed this out immediately when Gavin Schmidt made the claim that you are making.

    Yes, I know Nic Lewis keeps saying this. Nic Lewis, however, rarely (if ever) acknowledges the caveats with the method he uses. His method might produce results that suggest that high values are unlikely. If the method, however, is unable to capture certain factors that could increase these values, then you can’t claim that the method rules out these high values.

  132. miker613 says:

    I guess I have a different impression. OHC is so far only a few papers and not too much data, certainly not in the deep ocean. My guess was that most climate scientists have no opinion on it yet. Sea level rise is certainly well-known (and obvious – it is warmer), but whether it is accelerating and how much is not consensus – I think. Certainly not enough to make estimates of climate sensitivity. Maybe you can correct me. Is this IPCC-level consensus, or is it a couple of papers making suggestions?

  133. miker613,

    My guess was that most climate scientists have no opinion on it yet.

    I think you’re wrong. It is my understanding that most active climate scientists accept the OHC data.

    Sea level rise is certainly well-known (and obvious – it is warmer), but whether it is accelerating and how much is not consensus – I think.

    I believe that it is generally accepted that it has accelerated. Less than 1mm/yr prior to 1900. Something close to 3mm/yr today. Although you do have a point, I believe some active climate scientists think the IPCC conclusions on sea level rise were conservative.

  134. BBD says:

    miker

    I guess I have a different impression.

    Certainly you do, but it’s not evidence-based.

  135. miker613 says:

    I definitely could be wrong on what most climate scientists think; I don’t have access to very many of them. I’ve seen a few surveys, but not on these topics. The easiest way to judge the consensus is AR5. But things may have changed since then (and of course AR5 had a cut-off for what went into it.)

  136. > Your mileage may vary, but I personally think that solar power is going to be completely competitive with fossil fuels before mid-century. Lower sensitivity means less total temperature rise, and less total damage. Low enough could totally change the economics between mitigation and adaptation.

    How does any of this tell us the number of years would the most lukewarm scenario warrant us to remain on the business-as-usual course, compared to the mean estimates?Scratching my own itch, I fould this interactive graphic:

    Commentators such as Matt Ridley and David Rose who are keen to play down the importance of climate change, plus the editorial team at the Economist, have made a lot of noise about the fact that the new IPCC report contains reduced estimates for the ‘sensitivity’ of the climate to increased levels of greenhouse gas in the air.

    Any evidence that the climate is less sensitive to carbon than we previously thought is good news: it means we can expect less warming from any given carbon concentration, reducing the risk of dangerous impacts. But as my first graph makes clear, the gains are actually rather small. It shows four IPCC emissions scenarios, from the highest (RCP 8.5, which so far reflects business as usual) to the lowest (RCP 3PD, which involves actions well beyond the scope of what is currently seen as politically plausible, with emissions falling steeply almost straight away and humans becoming carbon negative later in the century).

    http://www.theguardian.com/environment/blog/2013/oct/07/un-climate-change-panel-graphs-ipcc-report

    Take a look at 2075.

    No wonder we are having a new round of gerrymandering, this time about “observational” this and “objective” that.

    ***

    But let’s transpose into “economic changes”: how much does this “low enough” amount to, and what is the “the economics between mitigation and adaptation”, again?

  137. miker613 says:

    Willard, the further you get in economics and politics, the further away you get from anything like a consensus. Economists agree on nothing at all. But if renewables become cheaper than fossil fuels, and I believe they will, China and India will change over to them. Do you have a business-as-usual scenario but with fossil fuel usage dropping very sharply towards mid-century?

  138. Lotharsson says:

    “Of course you can:”

    I’m using “rule out” in the sense of “eliminate as a candidate for the best inference” and “conclude” as short hand for “validly [or perhaps reasonably] conclude”. The short hand could certainly be clarified. No doubt there’s a better way to express this to people who have studied logic per se, but I wasn’t exactly aiming at that audience.

    “…all you have to show, to conclude (d), is that it’s the most X, where your X helps you decide to pick it.”

    Presumably in order to validly do this, one has to consider the space of options with sufficient diligence and coverage that one can be reasonably confident of having selected the option that exhibits “the most X”. The absence of evidence of that consideration, indeed the reliance on conflations that appear to preclude that kind of consideration, was the key point of that part of my comment.

    How would you choose to effectively convey that key point?

    “Logical arguments that misrepresent falsificationism are worse than wrong.”

    I am not sure I agree with the characterisation. My comment was attempting to show from inside miker’s apparent worldview that his argument is incorrect even if his worldview is valid. Your mileage may vary – you have a different cognitive and linguistic toolset to me – but I find that quite often it’s more effective to initially demonstrate problems with someone’s position from within their existing worldview rather than first attempt to tear the whole thing down. (I’m not saying the latter isn’t also a useful approach if you can pull it off, but it’s difficult to predict in advance what will trigger a given individual to reassess their existing confidently held positions.)

    In that sense an argument that, just like a model that fails to capture the full complexity of a system, is wrong in a strict sense may also be useful.

    “I have better things to do.”

    Focusing on the better things to do is a good life skill to practice. Glad to be of service 😉

  139. BBD says:

    There’s a direct link to that RCP visualisation tool that Willard links. Worth a look.

  140. Joshua says:

    miker –

    ==> “I definitely could be wrong on what most climate scientists think;”

    hmmm.

    I could be mistaken, but it seems that for some reason you’ve lost your confidence in interpreting what people think.

    ==> “That should be awesomely good news for everyone, but it seems to me that many are treating it as terrible news.”

  141. miker613,

    It’s quite simple, really.

    You claim that “Lower sensitivity means less total temperature rise, and less total damage”.

    Please back it up.

  142. Joshua says:

    miker –

    It’s not too late. You can walk back your insinuation that people that disagree with you about climate change are sociopaths. I mean yes, you didn’t actually say that they are sociopaths, you only said that it seems to you that they are acting in a way consistent with sociopathic behavior. But you have to admit, trying to wiggle out through that escape hatch would be pretty weak. The implication is clear.

    Walk it back. Restore your good faith stature.

  143. miker613 says:

    Joshua, these are two different subjects. What “most climate scientists think” is a discussion of consensus in the larger climate science community. You need a survey of some kind.
    “Many are treating it as terrible news” has nothing to do with scientists overall, it has to do with the public face, bloggers and such.
    My guess as to the reason for “treating it as terrible news” is similar to what ATTP said: (1) there isn’t that much evidence yet that it (low sensitivity) is true (2) we have other sufficient evidence that it isn’t true, and therefore (3) the main effect of this is really bad – it gives fuel to skeptics. Pardon a little sarcasm: This is really bad luck! Couldn’t the earth do this trick some other time?

  144. miker613 says:

    ‘You claim that “Lower sensitivity means less total temperature rise, and less total damage”.
    Please back it up.’
    Sorry, Willard, I don’t see why that needs backing up; I thought it was obvious. If fossil fuel usage will decline sharply mid-century or so, total CO2 is a fixed amount, and total temperature rise depends on sensitivity to CO2. Lacking some kind of really impressive international agreement on mitigation, which IMO just isn’t going to happen, total temperature rise depends _entirely_ on sensitivity to CO2.

  145. BBD says:

    If fossil fuel usage will decline sharply mid-century or so

    Don’t forget equilibrium, miker.

  146. miker613 says:

    Joshua, our comments intersected, but does that count as “walking it back”? Of course they are not sociopaths. They are, however, beating a dead horse, trying to get the world to do something that just isn’t even going to come close to happening. That must be frustrating and depressing.
    If they really understood, deep down, that mitigation is not a possibility, they would be jumping for joy at the chance that _maybe_ the damage will be less than they thought. Joke alert: Nic Lewis mitigated climate damage far more than the EU ever could.

  147. BBD says:

    Highly selective evidence is a weak basis for jokes, miker.

  148. Miker, there is no such point. Any discrepancies, also the ones you do not mention, lead to further research trying to understand them. That is what the science experts at WUWT call “excuses” when it comes to those discrepancies they specially like. The new understanding will lead to a new appraisal of the situation.

    The strong decrease in Arctic sea ice is certainly statistically significant. And this certainly means that the models do something wrong. Even that does not worry climatologists much. (It also does not worry the mitigation skeptics much because the discrepancy is in an inconvenient direction.) We know climate models are not especially good at sea ice. Some models are decent, but many climate modelling centers do not even have an expert for sea ice. Thus most expect that the models just need to model the Arctic better, without much consequences for the complete climate system. (I am not sure whether there is more, but more on that next year.) But you never know, once the riddle is solved, what the consequences of the improved understanding are.

    Similarly, we know that climate models are not especially good at modelling natural variability. There is a pattern of natural variability called the QBO, to model it you need a model with a very high top layer and many layers in the stratosphere. Given that we do not expect is to influence global warming strongly and modelling it is computationally expensive because of all the additional layers, for studying most problems it is ignored.

    That the deviation (“hiatus”) is thus currently large relative to the model spread, but not statistically significant, is thus again not too worrying. Still it is interesting and understanding this may lead to a better understanding of climate change. Maybe some processes are more important as previously thought, maybe we overlooked processes, maybe the measurements are wrong, that would all be interesting. Maybe nothing of the sort and it will turn out to be not interesting. Any explanation will also have to explain the temperature increase over the last century, before 1998, thus I do not give you much hope for a large change in climate sensitivity.

    There are so many possible explanations that one can almost wonder why the temperature did not decrease. We will have to wait until the dust settles. Science is unfortunately typically rather slow and the deviation we are talking about is small relative to global warming and is thus hard to study accurately.

    Hans von Storch is a competent mathematician who has made many valuable contributions to the scientific literature. Why he chose to write such a manuscript (is it accepted somewhere?). You will have to ask him.

  149. > I don’t see why that needs backing up; I thought it was obvious.

    The claim that there will be a difference is.

    Implying that this difference will make a difference isn’t.

  150. miker613 says:

    Dr. Venema, I hear you, but I find it jaw-dropping. You are explaining in some detail various issues with the models, and how science will try to work it out. That’s fine. The next generation(s) of models will be better. But how does it answer my question? The current generation of models is making predictions on ECS and they are being used as one of the main threads of evidence on its value. How badly do they have to do before you will agree that _these models_ cannot predict ECS well enough to be used?
    I’m not talking about the next set of models, as we don’t know their values of ECS.
    Are you actually saying that if surface temperatures stay stagnant (say) for the next twenty, or thirty, or fifty years, that you would continue to think that these estimates of ECS are useful? There is no point where that would change?

  151. miker613 says:

    Willard, I can’t follow what you are asking. Don’t we all agree that a smaller total surface temperature rise will make a difference?

  152. Joshua says:

    miker –

    => “Joshua, our comments intersected, but does that count as “walking it back”? Of course they are not sociopaths. They are, however, beating a dead horse, trying to get the world to do something that just isn’t even going to come close to happening. That must be frustrating and depressing.
    If they really understood, deep down, that mitigation is not a possibility, they would be jumping for joy at the chance that _maybe_ the damage will be less than they thought. Joke alert: Nic Lewis mitigated climate damage far more than the EU ever could.”

    No – doesn’t count as walking it back. Acting as if a lower sensitivity would be “terrible news” would be sociopathic behavior.

    ==> “Of course they are not sociopaths.”

    I don’t think that you really think they are sociopaths – but you’re willing to engage in a rhetorical game that rests on implying that they are – that it “seems” they’re reacting to news that ACO2 poses less of a risk, as if it is “terrible news.”

    ==> “They are, however, beating a dead horse, trying to get the world to do something that just isn’t even going to come close to happening. That must be frustrating and depressing.”

    That’s a different discussion, and a non-sequitur. I’d rather focus on your rhetoric – implying that people would consider a lower sensitivity – which you have have described as resulting in less total temperature rise and less damage – as “terrible news”

    ==> “If they really understood, deep down, that mitigation is not a possibility,”

    If they were as smart as you then they would understand, deep down, what is or isn’t possible?

    ==> “they would be jumping for joy at the chance that _maybe_ the damage will be less than they thought.”

    Mike – they don’t agree with your interpretation about the science. IMO you’ve descended in to an unfortunate rhetorical game. FWIW, I find it disappointing. I hadn’t really expected that kind of nonsense from you. And I thought you might take the opportunity to walk it back.

  153. miker613 says:

    Joshua, I don’t think you’re listening. I explained myself, so I won’t repeat it. They think it’s bad news because it harms their hope of mitigation. That’s not a non sequitur, it makes a lot of sense. But I think their hope of mitigation is completely deluded. That doesn’t make them bad people. It may make them foolish, but there are a lot of smart foolish people.

    “they don’t agree with your interpretation about the science”. Does that mean that they think lower sensitivities are impossible? Don’t we all agree that the IPCC says that they are quite possible? Why wouldn’t any rational person hope for the sensitivity to be very low?

  154. > Don’t we all agree that a smaller total surface temperature rise will make a difference?

    What difference will make that difference, miker613? How important is sensitivity in the grand scheme of things? Why focus on a measure that doesn’t give us many years more for our proverbial solar panels to save the day?

    Also, note that a lower CS may have an impact on, uh, the medieval warm period.

  155. Joshua says:

    miker –

    ==> “They think it’s bad news because it harms their hope of mitigation.”

    You seem quite certain about this.

    My interpretation is not that they think it is bad news (which seems to be moving backwards from “terrible news”), but probably that they think that the possibility of a lower sensitivity is “good news” to some extent, but less certain than you think and that the likely long-term benefit of lower sensitivity are less than you think.

    Now I’m not sure – because I think that I can’t be sure about why someone else thinks what they think. But you have allowed for no other interpretation, and you have expressed certainty, more than once now, in interpreting why someone else thinks what they think and expresses views different than what they actually think.

    You’re entitled to your certainty – but it seems ill-founded to me. It seems obvious to me that interpretations other than yours are possible. And so I see you unskeptically ignoring uncertainties.It’s identity-aggressive behavior of the type that is associated with motivated reasoning.

    Your interpretation is that a goal of mitigation drives their interpretation of the science. That looks to me exactly like “denier” talk and arguments that the only reason that “skeptics” exist is because of fossil fuel industry funding.

  156. miker613 says:

    Well, there are plenty of AGW believers available here. Let them speak for themselves!

  157. Joshua says:

    and MIker –

    => ” Does that mean that they think lower sensitivities are impossible?”

    IMO, this is another example of the same kind of rhetorical posturing.

    Consider Marcel’s comment.

    ==> “Are we not allowed to comment on the science on e.g. the BBC? On what are we allowed to talk/comment?”

    Your comment looks very similar to me. Rhetorical questions are one thing. Rhetorical questions fashioned out of straw is another. While we all get rhetorical in these discussions, IMO, it’s what you happens after you’ve gone there that makes the biggest difference.

  158. miker613 says:

    “Your interpretation is that a goal of mitigation drives their interpretation of the science.”
    Hold on a minute – that’s not right. I said that their goal of mitigation drove their _happiness level_ over the situation. They could agree with me completely about the science, but say, it’s not enough to solve the problem, and it will make the politics impossible, so we’re worse off.

  159. Joshua says:

    > “I said that their goal of mitigation drove their _happiness level_ over the situation. ”

    Is mitigation their goal? Or is developing the best policies to deal with the risk of ACO2 in the face of uncertainty their goal?

    If it is the latter – then to the extent that the risk is diminished, mitigation becomes less needed, and it is good news, not terrible news. They disagree with you about the interpretation of the “news.”

    IMO, this is like when Republicans said that Demz were happier when solider died in Iraq at a faster rate – because it harmed Bush’s political standing.

    We could find examples where Demz create sociopaths out of Repubs also – I would expect that Steve Bloom could come up with some 🙂

    Anyway, I understand that there is an important, underlying element in your argument that gets at the group identity aspect of how these debates play out. It isn’t lost on me that sometimes I find in myself a schadenfreude-like reaction related to issues where I’m strongly identified: but when you stretch that point beyond what’s reasonable with identity-aggressive rhetorical games that demonize the other “side,” (as I think you’re doing here by implying with certainty sociopathic behavior (even though you know they aren’t sociopaths) then you are not engaging in good faith, nor in a way that has any hope of being productive.

    Anyway, time to call it a night.

  160. miker613,

    The current generation of models is making predictions on ECS and they are being used as one of the main threads of evidence on its value. How badly do they have to do before you will agree that _these models_ cannot predict ECS well enough to be used?

    In a sense, I think you have this the wrong way around. The models aren’t being used to predict ECS. If all we wanted was the ECS and TCR, we wouldn’t really need models. We have paleo, volcanoes, the greenhouse effect, and even the energy budget method used by Nic Lewis. The models are really being used to project our future warming under different emissions scenarios, and to give us some information about aspects that other methods really can’t do (regional effects, etc). One can, however, determine an ECS (and TCR) for each model, but these are really just a model metric. In other words, the multi-model ensemble of the climate models gives us an indication of how we will probably warm in the future (under different emission pathways) and the range of ECS for the models can be used to determine if the model estimates are consistent with other estimates (they are).

    Of course, we do have estimates that produce lower ranges for the ECS and TCR than is produced by models. However, in the case of the energy budget methods, there are perfectly plausible arguments as to some of the estimates being biased low. Similarly, even though the models appear to be running a little hot, there are plausible arguments as to this being a consequence of certain inputs being different to what was assumed and the models averaging out decadal variability. To be clear, though, my point isn’t that the models are definitely right and the the energy budget models are definitely too low. My point is that it is too soon to make a strong statement that the range for the TCR and ECS is lower than models suggest.

  161. willard (@nevaudit) says:
    November 1, 2014 at 9:19 pm

    > But my logical arguments do not do that – they actually represent the arguments that those countless millions who claim that climate science is falsified actually use [1] – including that person you incessantly argued with [2], that person who claimed that climate science was falsified.

    “Actually, it does not do that. The only argument it analyzes was provided by me.”

    The analysis extends to all denier claims that such and such proves to be false such and such about climate science. See further below for more on this.

    “(I noticed how the modality has been stuffed in the proposition, btw.)…”

    This is not relevant. This is not a correct application of the propositional calculus. Koutsoyannis did the stuffing in what he *actually wrote* and thus I made the correct symbolism of what he *actually wrote*. See my post on November 1, 2014 at 6:52 pm for links to that comment where I made the correct symbolisms. By the use of constructive dilemma on tautologies, I mathematically proved that either the term he uses “makes” means the implication “implies” or his claim “future climate projections are not credible” is false. There is no way out here for those who deny this. (I note that the above claims on my symbolism include no attempt to prove the claims. That’s assuming and affirming what needs to be proved, that is, begging the question. I’d like to see an attempted proof that my symbolisms were incorrect under the propositional calculus.)

    “Koutsoyannis got everything wrong about falsificationism.”

    Well, yes, but that does not matter. He made a claim that he proved some set of propositions false, and he was not correct in making that claim. I simply gave a logical proof that his claimed proof *as he actually wrote it* was not a proof – his claimed proof leads with logical necessity to contradiction, and no successful proof does this. This is about people like Koutsoyannis claiming that they have a proof when they do not have a proof. They should be called out on it.

    “There is something that is falsified when predictions are false.”

    Yes, but it’s not necessarily one of the targets to be falsified of the tests. It could be one of the conjuncts in conjunction O. Let P denote a given subset of the conjunction of predictions or projections made by T given O (symbolized O -> (T -> P), where T denotes the conjunction of the targets of the test and where O denotes the conjunction of those conditions outside of T such that we never have – cannot have – the conjunction of true O and true T and false P. This definition of O makes (O & T) -> P) (tautologically equivalent to each of O -> (~P -> ~T) and O -> (T -> P) and (O & ~P) -> ~T) a tautology, suitable as an axiom.

    “Global Warming is caused by a[n]thropogenic activity.”

    Let T denote this above statement, since it is the target of the test.

    “To disprove that, you need to show that one of the three hypothesis are better explanations of what’s happening:
    (1) There is warming, say because greenhouse gas theory is wrong.
    (2) Even if here has been warming, it’s not global.
    (3) Even if GW is true, it’s not anthropogenic.
    Prove any of the three and you win.”

    Let P denotes the conjunction ~(1) & ~(2) & ~(3) and let ~P denote the disjunction (1) V (2) V (3). The claim above is that we can prove the negation of the hypothesis by this modus ponens structure: ~P -> ~T, ~P, therefore ~T. This modus ponens structure just given is tautologically equivalent to the following modus tollens structure: T -> P, ~P, therefore ~T.

    “This challenge could be “refuted” by K&A’s argument: it’s possible to construct a counterfactual where everything holds except some “assumption”.”

    It is refuted, definitively, by the general theorem of mathematical logic I keep talking about (and therefore by my trivial examples of this theorem specific to this context whose trivial proofs I spelled out – see my comment on November 1, 2014 at 6:52 pm for links to these proofs), which says that any logical system that uses a nontautology as an axiom is logically inconsistent in that one can always derive contradiction from that axiom. (A tautology is a truth functional statement true in all its substitution instances, that is, a necessarily true [not possibly false] truth functional statement.) Since it is admitted that the above ~P -> ~T or its tautologically equivalent T -> P is not a tautology (it is possible that it is false), we can derive a contradiction as I spelled out, and so ~T is not proved using that statement T -> P as an axiom. Using T -> P as an axiom makes the test invalid from the start. Again, this claimed proof leads with logical necessity to contradiction, and no successful proof does this.

    Not only that, if it turns out that we actually find that member of O (that “assumption” referred to above) and it turns out to be false, we have a false condition in O, giving us ~O, then it becomes logically impossible to prove ~T with this given test – that is, finding this assumption in question to be false invalidates this given test. To see the symbolism of this, see the further below on ~O.

    Every claim out there that such and such proves some proposition on climate science to be false uses nontautology T -> P as an axiom, invalidating the test from the start.

    Here are some alternative ways, each tautologically equivalent to the other, by the use of the axiom I suggested, this suggested axiom by definition a tautology by virtue of how O is defined: For convenience, since ~P is more easily symbolized, use the form of the above axiom I suggested O -> (~P -> ~T) or its tautologically equivalent (O & ~P) -> ~T. Given this form, first prove both ~P and O. Then by modus ponens we prove ~T. Now use the form (O & T) -> P: Given this form, first prove ~P. Then by modus tollens we have ~(O &T) and then by De Morgan we have ~O V ~T. Rule out ~O by proving ~~O (or O), then by disjunctive syllogism we prove ~T.

    Note: Proving O or ~~O is an inductive exercise and is allowed to be such, since proving ~P is also an inductive exercise. But the deductive structure must be valid. With tautology (O & T) -> P as an axiom, the deductive structure is valid. (Again, with nontautology T -> P as an axiom, the deductive structure is not valid. And note that this above comment on induction does not mean that one can claim O to be true without very honest and reasonable amounts of effort to rule out ~O.)

    Now to address the further above about ~O: For either case above, if in the process of trying to prove O (or ~~O) we find that ~O is actually the case, then for the given test it becomes impossible to infer ~T – for the given test, it becomes impossible to prove ~T, which means that the finding of ~O completely invalidates the given test.

    Note: In light of this last point, climate science deniers keep trying to use invalidated tests, not only because they use a nontautology as an axiom, but because they keep ignoring the implications of actually finding that ~O holds. (This means that conditions in O like assumptions on volcanic activity, ENSO, solar output, and so on that turn out to be false give us ~O and that therefore any falsification test that was made on those assumptions has been invalidated. Yet deniers keep trying to use these invalidated tests.)

  162. Miker, good that you find it jaw-dropping. Then you learned something. It is about understanding the climate system in its whole and how it changes. It is not about some specific graph, no matter how oft it is discussed by mitigation sceptics.

    The hiatus is at least interesting because it is seen on a global scale. Thus if the deviation becomes larger, more and more people will work on it and it will definitely improve our understanding. That is the key, not the deviation itself.

    Don’t be such an alarmist and assume that it will continue for 50 more years. If the radiative forcing by CO2 would rise and the air temperature would not, that would likely lead to an enormous imbalance in the energy budget. An enormous amount of energy would have to go into the oceans and sea level rise would be catastrophic. I hope you are not right and the hiatus will stop in time. Or even better maybe it is all just a measurement error.

  163. OPatrick says:

    Well, there are plenty of AGW believers available here. Let them speak for themselves!

    For what it’s worth I think the most likely conclusion is that you are being deliberately mendacious in your interpretations of ‘AGW believers’ ‘ responses to the assertions about lower sensitivity. You appear to be conflating objections to the way in which the confidence in lower sensitivity is being oversold, probably for politically motivated ends, with unhappiness about the (slender) chance that climate sensitivity might be lower than previously thought.

  164. BBD says:

    OPatrick

    That’s not all Miker is being mendacious about. His entire commentary here consists of ignoring or swatting away relevant information while monotonously arguing from (false) assertion that “the models” are broken. In other words, Miker is profoundly intellectually dishonest, which is of course obligate behaviour for a climate tr0ll.

  165. OPatrick says:

    Ah, but he didn’t invite me to comment on the rest of his commentary, as I’d interpreted him doing on the particular question of how ‘AGW believers’ felt about the claims of lower sensitivity.

  166. John Hartz says:

    To ensure that everyone discussing “climate sensititvity” on this thread has the same understanding of what the term means, here is how the IPCC’s defines the term per the SkS Climate Science Glossary.

    Climate Sensitivity

    In IPCC reports, equilibrium climate sensitivity refers to the equilibrium change in the annual mean global surface temperature following a doubling of the atmospheric equivalent carbon dioxide concentration. Due to computational constraints, the equilibrium climate sensitivity in a climate model is usually estimated by running an atmospheric general circulation model coupled to a mixed-layer ocean model, because equilibrium climate sensitivity is largely determined by atmospheric processes. Efficient models can be run to equilibrium with a dynamic ocean.

    The effective climate sensitivity is a related measure that circumvents the requirement of equilibrium. It is evaluated from model output for evolving non-equilibrium conditions. It is a measure of the strengths of the climate feedbacks at a particular time and may vary with forcing history and climate state. The climate sensitivity parameter (units: °C (W m–2)–1) refers to the equilibrium change in the annual mean global surface temperature following a unit change in radiative forcing.

    The transient climate response is the change in the global surface temperature, averaged over a 20-year period, centred at the time of atmospheric carbon dioxide doubling, that is, at year 70 in a 1% yr–1 compound carbon dioxide increase experiment with a global coupled climate model. It is a measure of the strength and rapidity of the surface temperature response to greenhouse gas forcing.

    Definition courtesy of IPCC AR4.

    Note: The words and terms in the above written in bold italic are also defined by the IPCC. Their definitions can be easily accessed by using the SkS Climate Science Glossary.

  167. Willard says:

    > Yes, but it’s not necessarily one of the targets to be falsified of the tests.

    In empirical sciences, nothing is necessary, ever. If we accept that the overall target is false, then we should accept that there is something wrong with what has been used to make the prediction. And we usually call this models, for the simple reasons that they encompass every single component one would like to distinguish: assumptions, theories, parameters, etc. Take for instance how miker613 phrases his model ontology:

    And you don’t get to adjust your models afterwards. That’s known as a new model. Which is fine. But it needs to be validated all over again.

    https://andthentheresphysics.wordpress.com/2014/10/30/come-on-be-more-skeptical/#comment-36079

    K&A’s equivocation should be obvious by now.

    ***

    But there’s more. Simulation runs are the product of the whole gamut, and can’t be separated by components. To invoke an additive structure and then pretend that only one of the components could have been down (how this can be known has yet to be shown) is simply fallacious. If one could separate on the one hand results that impact the assumptions and on the other results that impact the model, there would be no reason to invoke them at all, and ceteris paribus clauses would be enough.

    Either the assumptions do something to the models, or they’re useless. If they do, then they are included in the model runs, explicitly or not. In other words, one does not simply combine the model’s module to the assumptions’ module: one merges them.

    From an observational standpoint, it’s impossible to tell which component is responsible for the model runs. If we ever could tell one way or another which component is responsible for which result, we might be able to solve the climate problem. But this does not even take into account that climate models are not solvers, but telescopes into a virtual reality. Just like Holodecks.

    ***

    > Every claim out there that such and such proves some proposition on climate science to be false uses nontautology T -> P as an axiom, invalidating the test from the start.

    More than that, every test whatsoever works that way. Therefore, K&A’s deductive argument is strong enough to refute scientific testing. Well played!

    Some arguments are wrong, and some are less than useful.

  168. JH,
    Good point. People should bear in mind that the method used by Nic Lewis is really only evaluating the Effective Climate Sensitivity, not the Equilibrium Climate Sensitivity.

  169. Willard says:

    > ‘AGW believers’

    I thought only Sky Dragons were AGW disbelievers, and that miker613 was also an AGW believer.

    ***

    > His entire commentary here consists of ignoring or swatting away relevant information while monotonously arguing from (false) assertion that “the models” are broken.

    The monotony is broken by avowing beliefs about mitigation (impossible!), technological development (solar for the win!), economic impacts (no consensus!), and mental states (looks like psychopathy!). Compare and contrast:

    0. Lots of Theories
    1. No Best Practices
    2. Do Not Panic
    3. Do No Harm
    4. Future is Bright
    5. We Won, You Lost, Get Over It

    http://contrarianmatrix.wordpress.com/

    So miker613 goes from 1 to 2, 3, 4, and 5. All he needs is to add something about 0. Since he seems to presume that he’s not an “AGW believer”, there is still hope that he’ll reach that level, sooner or later.

  170. BBD says:

    The Matrix has you. Or at least that one does if you are a contrarian.

  171. Joshua says:

    I considered picking up on the “AGW believers” rhetoric but there was so much to choose from, some of the weak rhetoric got left out.

    It’s disappointing that miker who, IMO, sometimes stands out from the run-of-the-mill “skeptic” I encounter in the blogosphere by virtue of at least sometimes displaying honest-to-got skepticism (I’ve seen him take other “skeptics” to task for faux skepticism), resorted to such shallow rhetoric. When I read the technical discussions and I see what could be reasonable arguments from both sides, I sometimes use arguments made in less technical discussions as “information” to help fill in the probabilities related to an individual’s consistency of sound reasoning. Miker has taken a step back, IMO, FWIW. Not that he should care what I think, but he could recoup the lost territory by coming to terms with his rhetorical games and still not lose anything w/r/t the merits of his technical arguments. But the only way to do that is through accountability.

  172. BBD says:

    Joshua

    His technical arguments boil down to a false assertion that “the models are broken” and S is rilly, rilly low because Nic Lewis says so. They have no merit to lose. The rest is evidence *denial*.

  173. Willard says:
    November 2, 2014 at 3:59 pm

    “From an observational standpoint, it’s impossible to tell which component is responsible for the model runs……If we accept that the overall target is false, then we should accept that there is something wrong with what has been used to make the prediction…..And we usually call this models, for the simple reasons that they encompass every single component one would like to distinguish: assumptions, theories, parameters, etc…..But there’s more. Simulation runs are the product of the whole gamut, and can’t be separated by components….Either the assumptions do something to the models, or they’re useless. If they do, then they are included in the model runs, explicitly or not. In other words, one does not simply combine the model’s module to the assumptions’ module: one merges them….”
    > Every claim out there that such and such proves some proposition on climate science to be false uses nontautology T -> P as an axiom, invalidating the test from the start….
    “…More than that, every test whatsoever works that way. Therefore, K&A’s deductive argument is strong enough to refute scientific testing.”

    This last part first: It seems to me that Willard is seriously misreading my definition of my T in T -> P. And it’s my “deductive argument” that uses (O & T) -> P (or its equivalent (O -> (T -> P)) as an axiom that is the only accurate description here of what scientists do. and this includes when they make legitimate statements on science. See the example further below on Einstein’s equations. Again is must be noted that T -> P cannot be this axiom since, given a *correct* reading of my definitions of T and O, the negation of T -> P sometimes holds (this implication is sometimes false) but the negation of (O -> (T -> P) never holds (this implication is never false).

    By Willard’s use of terms like “impossible” and “every”, it seems to me that Willard is trying to argue a claim of modal necessity over a universally quantified claim with respect to the antecedent of the implication that is to be treated as the axiom in the modus tollens setup of the falsification test. It seems that his argument is this, assuming that the set of all conditions or assumptions that could ever possibly be falsified by a given falsification test contains more than one element: It is necessarily the case that every condition or assumption that could ever possibly be falsified by a given falsification test is to be called a target of the falsification test. That is, it is impossible to partition the set of all conditions or assumptions that could ever possibly be falsified by a given falsification test into two nonempty subsets T and O, where we call all those elements we put into T those conditions or assumptions that are the targets of the test and where we call all those elements we put into O those conditions or assumptions that are not the targets of the test.

    With the use of terms like “impossible” and “every”, is Willard actually trying to argue this claim of necessity over a universal quantifier, that it is *impossible* to partition a set containing more than one element into two nonempty subsets T and O and name the elements in these two subsets as described? By the above that Willard gives us, which includes use of terms like “impossible” and “every”, it seems to me that it is so.

    And if so, we would have major problems: For example, the truth or falsity of Einstein’s equations would be necessarily in the same category as the truth or falsity of such assumptions as the assumption that in a given experiment that uses Einstein’s equations, all the cables in the test equipment are properly connected. Willard’s use of terms like “impossible” and “every” would disallow us from putting these two conditions in the overall set in the different subsets T and O. (See
    “Einstein Was Right All Along: ‘Faster-Than-Light’ Neutrino Was Product of Error
    A discovery that could have upended a century of physics research was caused by a loose cable. Phew.”
    http://newsfeed.time.com/2012/02/22/einstein-was-right-all-along-faster-than-light-neutrino-was-product-of-error/
    for more on this.) Also, here is another example: The truth or falsity of Scientific Theory X would be necessarily in the same category as the truth or falsity of such assumptions as those made on phenomena that are unpredictable by humans. Also, here, Willard’s use of terms like “impossible” and “every” would disallow us from putting these two conditions in the overall set into the different subsets T and O.

    Side note: See the definition of a partition in set theory. We can always partition a set containing two or more elements into two nonempty sets and name the elements in these two subsets whatever we like, which, as I show below, is what I do – and everyone else can do – with T and O. Why Willard would argue with terms like “impossible” and ‘every” that we can’t do what we clearly can do is something I don’t understand.

    I have defined the term “target” such that not everything that could ever possibly be falsified by a falsification test is to be called a target of the falsification test. (Analogy on use of “target”: A military defines “target” such that not everything that could ever possibly be killed by a military operation is to be called a target of the military operation. There undoubtedly exist many more such examples that show that Willard’s absolutely necessary and universal use of “target” is contrary to experience.)

    Where I define “the whole shebang” to be Willard’s set of everything that could ever possibly be falsified by a given falsification test, my definitions of these sets T and O are actually such that they are the two subsets of Willard’s “the whole shebang” obtained by that certain *partition* of “the whole shebang”: Set T contains all those conditions that the falsification test is designed to test, that are the legitimate *targets* of the falsification test, that testing for their truth is the reason or purpose why the falsification test is run in the first place. Set O contains all those conditions outside of T such that we cannot have true O and true T and false P (P being the conditions of the predictions or projections). This set of definitions gives us (O & T) -> P (see my last comment on November 2, 2014 at 11:40 am for many ways of rewriting this) defined in such a way to be a tautology, which means it’s always true, that is, true in all its substitution instances, and thus is suitable as an axiom in a logical system.

    We can state that such a partition exists even if we have to make judgments calls as to what the members of “the whole shebang” are and which of these members go into subsets T and O. This reflects what scientists making legitimate scientific statements always explicitly or implicitly assume. They assume this partition of “the whole shebang” into T (which contains the scientific theory) and O, since, given the correct reading of my definitions of T and O, none of them automatically infer ~T (the falsity of something in T including possibly the scientific theory) merely from ~P if they make *legitimate” statements on science. Those scientists who thought they might have been measuring particles traveling faster than the speed of light went straight to O to find something false in O to falsify O, which they finally did after many, many months – they did not go straight to ~T, the falsity of Einstein’s equations. (Koutsoyannis’s claim “This makes future climate projections not credible” is an example of a scientist making a statement on science that was *not* legitimate, since, given a *correct* reading of my definitions of T and O, it was an example of a scientist inferring ~T merely from ~P. See my comment on November 1, 2014 at 6:52 pm for links to that comment where I made the correct symbolisms for the two links that prove that Koutsoyannis’s highly irresponsible statement above implies contradiction, given a *correct* reading of my definitions of T and O. [In those prior comments, I used different letters than T and O as variables. It should be clear to the astute reader which is which.])

  174. Michael 2 says:

    Miker writes ““how many times have we seen skeptics argue that global warming has stopped or paused”

    42.

    “an argument that isn’t consistent with a belief that ACO2 necessarily has a warming effect on the climate”

    Your comment is binary; simple minded. CO2 warms, but other factors cool. When these forces are in balance the global temperature will neither rise nor fall. A flatline temperature trend is not a challenge against AGW per se. Instead, it is a challenge on the models (and the newsmedia) predicting monotonic and catastrophic rising temperature.

  175. M2,

    CO2 warms, but other factors cool.

    The problem is as follow. We know CO2 warms. We also know that warmer air can hold more water vapour which also warms. We also can be fairly confident that a warmer world will have less ice cover which will mean a reduced albedo – also warming.

    There are only really two cooling influences. Lapse rate feedback. This, however, cannot be larger in magnitude than the water vapour feedback and so water vapour plus lapse rate is positive. The other is clouds. However, at the moment clouds are thought to have a net positive feedback and a strong negative feedback is inconsistent with paleo estimates.

    When these forces are in balance the global temperature will neither rise nor fall.

    Only if our understanding of the basic physics associated with out climate is wrong. There is no reason to expect this different factors to balance so as to cancel out any warming. They are much more likely to balance once we’ve warmed to a new equilibrium.

  176. miker613 says:

    ‘Miker writes ““how many times have we seen skeptics argue that global warming has stopped or paused”’
    MikeR said no such thing. That was me quoting Joshua.

  177. BBD says:

    M2

    Instead, it is a challenge on the models (and the newsmedia) predicting monotonic and catastrophic rising temperature.

    The models do not ‘predict’ monotonic warming. That is a basic error and an argument from ignorance. You have confused the multi-model mean with a ‘prediction’ of monotonic warming.

    This is a common denier meme and one I am surprised you haven’t been corrected on before. Still, at least now there’s no excuse for ever bringing this up here.

  178. Willard says:

    > MikeR said no such thing. That was me quoting Joshua.

    Sometimes, it’s Joshua. Some other time, it’s Judy:

    Not following your point. “Causes and implications of the growing divergence between climate model simulations and observations” – note how Dr. Curry defines the “pause”: the models are failing to match surface temperatures. That is a fact. There are a number of attempts to explain what is happening including yours, Dr. Curry suggested some others. That’s fine – but those do not rescue the models; they are _new models_. Also fine, but the new models have not been validated, will not be maybe for decades. In the meantime, we have no working models. I don’t know if there’s one single feature of the climate that we are confident of modeling; surface temperature was the best they had.

    http://judithcurry.com/2014/03/04/causes-and-implications-of-the-pause/#comment-475734

    What is the fact under question is unclear.

  179. Willard says:

    [Mod: Off-topic]

    ***

    As a side note, let it be noted that even Hempel’s reconstruction of what is a scientific explanation admits of partial explanations:

    http://fitelson.org/woodward/hempel_tm.pdf

    Notice how “background assumptions” are being introduced at the end of the paper, and how the idea that a complete explanation rests on pragmatic considerations.

  180. MikeN says:

    > and a strong negative feedback is inconsistent with paleo estimates.

    So the estimates for global warming are based on the hockey stick? We have frequently been told that the hockey stick doesn’t matter.

    I also disagree with the claim in another way, as Michael Mann has argued that there is a strong negative feedback, and that’s why the Medieval Warm Period was not as warm. He suggested a Pacific Thermostat Hypothesis of Cane as a possibility for this negative feedback.

  181. MikeN,

    So the estimates for global warming are based on the hockey stick? We have frequently been told that the hockey stick doesn’t matter.

    Nope, I’m referring to periods well before the last millenium. Milankovitch cycles for example.

    I also disagree with the claim in another way, as Michael Mann has argued that there is a strong negative feedback, and that’s why the Medieval Warm Period was not as warm. He suggested a Pacific Thermostat Hypothesis of Cane as a possibility for this negative feedback.

    This doesn’t make much sense to me. Why would a strong negative feedback be required for the MWP to be less warm than now? Any evidence?

  182. BBD says:

    MikeN

    You are confused. There is evidence that a persistent La Nina-like state characterised periods of regional NH warmth during the centuries lumped together as the MCA (Diaz et al. 2011; Steinke et al. 2014).

    Mann did not, AFIK, argue that:

    there is a strong negative feedback, and that’s why the Medieval Warm Period was not as warm. He suggested a Pacific Thermostat Hypothesis of Cane as a possibility for this negative feedback.

  183. miker613 says:

    “What is the fact under question is unclear.” Don’t know why it’s unclear; it was defined in the previous sentence. I have presented a couple of places where that fact is documented.

    But anyhow, I’m unsure of your point. This is a totally different subject than what you were trying to demonstrate: that someone was saying that “global warming has stopped or paused”. I don’t know if global warming has stopped, make no claim about it, reject any claim that I said it or supported it. That the GCMs are doing their job so badly that they may be useless for predictions, on the other hand, is something that I am suggesting.

    I see that Dr. Venema strongly disagrees, but I still don’t understand why. Does he not require model validation? How have they been validated? Global surface temperature was the thing they back-predicted best, and they couldn’t predict that forward, essentially failing as soon as they were turned loose. What do they predict correctly?
    I am repeating myself, but perhaps I’m frustrated.

  184. Willard says:

    > Don’t know why it’s unclear; it was defined in the previous sentence.

    There are two facts in the previous sentence: how Dr. Curry defines the “pause”, and that “the models are failing to match surface temperatures.”

  185. BBD says:

    For clarity, that should read:

    “There is evidence that a persistent La Nina-like state in the East Pacific characterised periods of regional NH warmth”

    Paleoclimate behaviour effectively rules out strong negative feedbacks. Such feedbacks would render the climate system insensitive to radiative perturbation and therefore highly stable. Paleoclimate exhibits a huge range of variability, demonstrating that positive feedbacks have always dominated the climate system.

  186. BBD says:

    MikeR

    That the GCMs are doing their job so badly that they may be useless for predictions, on the other hand, is something that I am suggesting.

    A false claim that you have repeated incessantly on this thread despite repeated corrections.

  187. Willard says:

    > That the GCMs are doing their job so badly that they may be useless for predictions, on the other hand, is something that I am suggesting.

    Indeed this has been the main suggestion, all the while shifting the burden of proof on Victor’s shoulders to show otherwise, in the many questions that follow.

    If miker613 does not claim that there’s a pause (“I don’t know if global warming has stopped, make no claim about it, reject any claim that I said it or supported it”), and that the pause is defined as “the models are failing to match surface temperatures”, how can he suggest anything about the GCMs?

  188. miker613 says:

    Well, I don’t understand any of the corrections. Models need validation; these failed right out of the box. What do they predict correctly?

  189. Willard says:

    > Models need validation; these failed right out of the box.

    How so? [Not that models need validation, but that they failed right out of the box.]

    Remember: miker613 “don’t know if global warming has stopped, make no claim about it, reject any claim that I said it or supported it”.

  190. miker613,

    Models need validation; these failed right out of the box.

    I think you’re confusing science and engineering. We’re not trying to design a climate for a new planet, we’re trying to understand the climate on our own under the presence of increasing anthropogenic forcings. As suggested in Hargreaves and Annan, we could wait decades to see if the projections are indeed correct, but if we did so we might end up saying “shit, they were”.

    Seriously, though, there is a massive difference between scientists who use physically motivated models to try and understand complex systems, and engineers who are using models to try and design some kind of product. If we had a time machine, and many different planets, we could try to produce a model that was validated and verified. We don’t have either.

  191. jsam says:

    Miker’s current (there are so man) fallacy is burden of proof. In denier-dom you can just chant “the models are wrong” and everyone applauds. In more sceptical realms evidence is required. He may not be so used to that.
    https://yourlogicalfallacyis.com/burden-of-proof

  192. miker613 says:

    Willard, you continue to conflate two unrelated topics. I explained the difference already.

    The signature metric for the models, as far as I know, is that they did a pretty good job of predicting the last century’s temperature anomalies. I do not know of any other metric that they can duplicate effectively.
    However, this creates a risk of the models being “tuned”, “curve-fitted”. As I saw quoted from here:
    http://www.agu.org/journals/ms/ms1208/2012MS000154/2012MS000154.pdf
    “Climate models ability to simulate the 20th century temperature increase with fidelity has become something of a show-stopper as a model unable to reproduce the 20th century would probably not see publication, and as such it has effectively lost its purpose as a model quality measure.”
    That means that in order to tell if a model is working, we have to see how it is doing on the future. Well, they aren’t matching future (from when they were set) temperatures at all. So what “model quality measure” is left? They did well on in-sample data, and very badly on out-of-sample data. That means they were curve-fitted – which is a common problem that can apparently happen very easily even to skilled modellers.

  193. BBD says:

    MikeR

    Models need validation; these failed right out of the box.

    I am really tired of the way you repeat this word placement game over and over again. You are a tr0ll using dishonesty and repetition as a weapon against reason and explanation.

    The models did not “fail”. They were forced incorrectly. This has been explained at least twice. You are pushing your luck again.

  194. miker613,

    They did well on in-sample data, and very badly on out-of-sample data.

    But this isn’t true. You’re confusing the multi model ensemble, with an individual model. Something that you really need to bear in mind is that – as your quote above indicates – models that don’t do well are rejected and the model range is then essentially set so that the surface temperatures fill inside the model range 95% of the time. If they fell within that range more than 95% of the time, they’d reduce the range until they did so. Until we know that the temperatures are outside this range for a period that makes the range inconsistent, we can’t say they’ve failed.

    The other thing that you seem to be ignoring is that there are plenty of lines of evidence that put climate sensitivity in a range that is consistent with the models. Arguing that we have to wait until we’re certain that the models are “correct” is then ignoring swathes of other evidence that also suggest that a high emission pathway would lead to significant warming in the next few decades.

  195. miker613 says:

    “If we had a time machine, and many different planets, we could try to produce a model that was validated and verified. We don’t have either.” I think that’s true. Validating the models is pretty much a hopeless task: for average surface temperature, we get on the order of one new data point per month! But therefore what? They are not validated, they can’t be used for evidence. I don’t see why telling me that the problem is hard or intractable is a reason to accept model output if indeed we have no reason to think that their output is useful.
    I would have thought that given the nature of the data we have, we need to be trying to get models that can be validated more quickly. That would mean finding metrics where you get a lot more data points per month, but which are non-chaotic enough that it’s possible to model them. I don’t know what they are, I don’t know if anyone has such a metric. I see that modellers are now working on better regional prediction; maybe that could do it. But we would have to wait till they have working models and we can see that they work.

  196. BBD says:

    Exactly the same pattern as before: ignore correction, swat everything away, keep repeating the false assertions.

  197. jsam says:

    Thank goodness we don’t need models to both know that AGW is correct and that we need to address the problem.

  198. miker613,

    They are not validated, they can’t be used for evidence.

    Nonsense, of course they can be used. Of course we can also choose to ignore them. However, we would have to do that knowing that there were other lines of evidence that are broadly consistent – in terms of climate sensitivity – to the models and knowing that a high emission pathway could lead to significant warming within the next few decades. You might think that that means we should ignore them. I disagree and, again, I think you’re confusing engineering and science.

  199. jsam,

    Thank goodness we don’t need models to both know that AGW is correct and that we need to address the problem.

    Something that I think Richard Betts has pointed out a number of times.

  200. Rachel M says:

    This is getting a bit too far off-topic and repetitive so let’s drop the subject of climate models. Thanks! Any further comments about this will be deleted.

  201. Willard says:

    [Mod: Sorry, Willard. I got in just before you.]

  202. BBD says:

    Thank you, Rachel.

  203. miker613 says:

    [Mod: Sorry, this is off-topic]

  204. miker613 says:

    Oh, well!

  205. But, but, but, my brilliant response. 🙂

    What was the topic of this tread actually? Ah, yes, changes in cloud cover.

    Anders, given that you updated the professorness of our subject of debate, could you maybe also update the statement that “Clouds have a total forcing of about 79Wm-2”? Not everyone reads the comments, the net forcing of clouds is modest and a 5% change in itself would no do much.

    The change would have to be in specific types of clouds, only the high ice clouds, or only the low boundary layer clouds above a dark ocean. If the cloud cover change would affect all clouds, then a 5% change would only be of academic interest. (Most likely not even that because this change may well be within the error margin of the trend given the difficulty of keeping satellite data temporally consistent).

  206. John Hartz says:

    ATTP & Rachel: Do either of you have the ability to determine whether or not the “Mikes” commenting on this thread share a common IPS address?

  207. miker613 says:

    ‘Do either of you have the ability to determine whether or not the “Mikes” commenting on this thread share a common IPS address?’ What’s more, you never see them together!

  208. Nathan says:

    ATTP

    Just wanted to point out that Mike took his queries to Lucia, who lovingly doused them with uncertainty for him… It’s a weird approach, where anything ‘modelled’ can’t be considered ‘evidence’… And as if there is something special about the last 15 years or so that tells us that ECS must be on the low side…

    Not sure if you’d ever comment over there.

  209. Nathan says:

    [Mod: Off-topic]

  210. anoilman says:

    [Mod: Off-topic]

  211. Rachel M says:

    JohnHartz,
    I have no reason to believe that one commenter is using two different handles on this thread.

  212. Nathan,

    Not sure if you’d ever comment over there.

    No, I don’t. I can’t see much point, to be honest.

    Victor,
    Good point. I’ve updated the post.

  213. Nathan says:

    ATTP

    Yeah, seems pointless as Lucia will just bicker over what the definition of ‘evidence’ is…


  214. No, I don’t. I can’t see much point, to be honest.

    Once upon a time Lucia’s site was kind of interesting, but no longer. They went off the rails, IMO, when they tried to quantify the trending+fluctuating temperature as red noise.

    Well, it’s not red noise. Yet, they can’t get over it, so they spend time having a pity party over some perceived injustice, interspersed with discussing what washing machine Lucia should purchase.

    You can’t make this stuff up …

  215. Steve Bloom says:

    Heck, Lucia, trusty Pars-o-matic ™ always at the ready, will bicker about what the definition of definition is.

  216. [Mod: Sorry, KeefeAndAmanda. I’d like to try to stick to the topic with this thread from now on if that’s possible. I think the logic stuff should be put to bed now. Thanks!]

  217. BBD says:

    Rachel

    A brief aside:

    I have no reason to believe that one commenter is using two different handles on this thread.

    My impression is that it would very easy to spoof an IP using something like this but I don’t have any idea how sophisticated your tools are for detecting such a fraud. HmA claims a list of >91k IPs which would be trivial enough to implement as a filter, but is this done? If it is not, my feeling is that you wouldn’t have a clue if someone were running multiple socks here.

  218. Rachel M says:

    BBD,

    I’m sure if someone really wanted to they could go through a proxy which will put them at a different geolocation and make it harder for us to spot sock puppets. But at the same time it’s just a blog and it seems like quite a lot of effort to go to just to comment on someone’s blog.

    You can also get quite a bit of information just by the types of comments people leave and the way they write. I assume John Hartz was referring to Miker613 and Michael 2 when he queried the two Mikes and I’m pretty sure they’re two different people.

  219. pinguin says:

    Rachel: I’m pretty sure JH was referring to MikeN, not Michael 2 (who I do not doubt is distinct).

    In the interests of transparency and of putting this distraction away quickly and efficiently, I would just like to ask directly, without implication of malice or talking “behind the back”:

    miker613, have you commented on this thread (and previously on at least one other) as MikeN, or is MikeN a completely distinct person?

  220. BBD says:

    Rachel

    I have an uncomfortable suspicion that there’s more than a little IP-spoofed sockpuppetry going on at climate blogs. The socks may not all appear at the same time but one after another as each is banned in turn :-).

    I think John may have been referring to Miker613 and MikeN because I wondered as well.

  221. pinguin,
    In the interests of transparency, I have no reason to think that MikeN and miker613 are the same person.

  222. Joshua says:

    Oy. It’s disturbing sometimes how much the “realist-o-sphere” resembles the “skept-o-sphere.”

  223. miker613 says:

    Don’t know MikeN, he’s not me. I’ve seen him around on other blogs. I will note that my name on other blogs is a simple MikeR; it depends on how I logged in.

    But if I could ask: what in the world are you talking about? Your question seems nuts to me, and a trifle creepy (as did Nathan’s “tracking me down” at Lucia’s blog). It sounds like a conspiracy theory, and I’d be interested to hear what it is. Am I an employee of Big Oil, brilliant enough to demoralize the enemy with my posts, but not smart enough to think of any other first name? What would be the point of this sock-puppetry anyhow? Isn’t the usual purpose something more like, I wrote a blog post and then made up some other name to praise it in the comments?

  224. BBD says:

    ATTP

    How would you tell?

  225. Willard says:

    > How would you tell?

    I would pick MikeN on my team, not miker613. The style is not the same. MikeN’s name has been around.

    IPs help too.

  226. BBD says:

    Joshua

    How much do you know about spoofing your identity? Because if the answer is nothing, as I suspect, your remark tends toward being out of order. Not for the first time.

  227. BBD says:

    Willard

    If I wish, I can have over 91,000 IPs in dozens of different countries.

  228. miker613,
    I don’t really understand the issue either. Apologies.

    BBD,
    I wasn’t really trying to tell. I was simply pointing out that there is no evidence to support any suggestion that there is any sockpuppeting going on – maybe in the hope that we could put an end to this. Joshua does have a point 🙂

  229. BBD says:

    Just for the record, I’m not interested in MikeN. I’m interested in the technical basis on which blog owners decide that individual commenters really are distinct individuals and not simply spoofed IPs running different screen names.

  230. BBD says:

    ATTP

    So it’s purely gut feel. Okay, thanks for the insight.

  231. verytallguy says:

    I agree with miker.

    A first! 🙂

  232. BBD,
    Oh no, I did check the IPs, but there was no indication of any sockpuppeting. I wouldn’t really know how to do more than that. Then it would become a gut feeling 🙂

  233. BBD says:

    It might be worth remembering that such questions can arise when someone simply wishes to preserve their anonymity in a potentially hostile environment (eg WUWT) where the host has a history of outing commenters he dislikes.

  234. BBD says:

    ATTP

    I’m not sure if I’m communicating that it is itrivially easy to spoof an IP. Or lots of them, as required.

  235. BBD,
    Indeed, hiding one’s IP address when commenting on WUWT may well be a wise thing to do. Admittedly, deciding to comment there in the first place would seem rather unwise, so there may be some kind of inconsistency there?

  236. BBD,
    I realise, but I wouldn’t know how to detect that if so.

  237. Rachel M says:

    I don’t think it’s that easy to spoof an IP and I check them using DNS tools.

  238. John Hartz says:

    I cannot help but marvel at how many comments my rather strightforward question to ATTP/Rachel about their technical ability to access the IPs of commenters has generated. After posting the question, I realized that they can access the IPs because they have access to the email address of each commenter.

    BTW, what is the central topic of the OP?

  239. Rachel M says:

    Yes, John, you’re in big trouble and it’s all your fault 😉

    This topic is off-topic now too!

  240. Steve Bloom says:

    There’s m2 also. But all three seem to have different rhetorical styles. Usually the point of getting a new IP to bypass moderation is to continue to rant in the same manner. In this instance, a comparison with past banned commenters would be more fruitful were anyone motivated to bother.

    OT: This new paper (press release) is very interesting indeed. It’s a knowledge gap I had no idea even existed. It seems like there would have to be significant implications for satellite ocean surface temperature measurements, and might it be what causes the models to miss the mark on both Arctic sea ice behavior and the transition to a Pliocene-like climate state? The paper itself is open-access (follow the link at the bottom).

  241. Steve Bloom says:

    Further to that last, IIRC a prominent feature of the “”hiatus” is a relative lack of ocean warming even while land temps continue to increase so perhaps the paper explains that to some degree?

    DS? Victor?

  242. Steve Bloom says:

    While I’m going severely OT by talking about climate science, I may as well add this one (press release) describing an ocean circulation tipping point (essentially the THC turning on) that occurred at (and basically caused) the Plio-Pleistocene transition into deeper glaciations, and which it seems we should expect to see flipping the other way given present CO2 levels and trends.

    This paper seems hugely important, and I’m a little shocked at how little notice it’s gotten.

  243. pinguin says:

    Thanks for the clarification miker. For my part, again, no offense or implication of nefarious practice was intended; I was merely confused by two similar names in close proximity. It appears that in attempting to clear the air I merely made things worse. My apologies (both to you and MikeN); I hope I haven’t discouraged you from commenting further here.

    And with that, I hope to close out this unwelcome distraction on a somewhat positive note.

  244. Michael 2 says:

    Steve Bloom revealed a website and paper:

    http://www.sciencedaily.com/releases/2014/11/141103161929.htm

    Thank you! I did not know that site existed, I have bookmarked it since it looks quite interesting.

  245. Michael 2 says:

    Steve Bloom wrote “There’s m2 also. But all three seem to have different rhetorical styles”

    And very likely different purposes for being here. I am at times deliberately ambiguous but I am consistent in my beliefs (while allowing for changes in those beliefs which I do not suggest represent inconsistency unless I continue to flip and flop among possibilities).

    Arguments reveal the margins of settled vs unsettled science. Arguments therefore reveal the areas of most interesting study, such as the link you provided about far infrared emissivity not being adequately modeled and yet another mechanism of heat retention.

    The most useful and interesting blogs therefore are, to me, the ones that promote the most vigorous arguments between possible points of view. Now that Huffpost has stopped allowing that sort of thing I almost never go there. Same with BBC and just about every left wing website and blog — one by one they drop the ONE THING that brings readers, the thing that is nearly essential to every story ever told and every movie ever made: Conflict.

    People don’t know who is right and who is wrong — the ancient method of solving this is “trial by combat” and the modern method is online arguments, ridicule and so on. Willard understands this much better than I, thus his byline, “the only way to lose is not to play”.

    But I cannot be “right” since I have not asserted a claim. I am a provocateur, compelling you into arguing so that I can discover the margins of unsettled science, the “bleeding edge”.

  246. Steve Bloom says:

    Science Daily is a press release aggregator that makes the science easy to follow since most significant papers get press releases these days. Be aware that the categorizations aren’t done perfectly; e.g. just looking at the climate category will miss some stuff, so in addition I look at the main listings, the Earth & Climate category and the global warming sub-category to make sure I don’t miss anything important. Stuff like alternative energy developments and climate-relevant social psychology are usually to be found in their own categories/subcategories.

    Also follow the twitter feeds of Ari Jokimaki and O. Bothe, who frequently catch important or interesting work that hasn’t gotten a press release. Another press release aggregator is EurekAlert.

  247. John Hartz says:

    Ari Jokimaki posts a lisiting of newly released papers about climate change on the Science Skeptical Science Facebook page on a daily basis.

  248. Steve Bloom, judging it just from the Science Daily article it seems to be an important paper. I know one of the authors and the group, thus they seem legit. Also the German regional model makes the simplification that the Earth is a black body in the infra-red. I am a bit more surprised that global models, where the radiative balance is much more important, also make such a strong simplification. But if they say so, that may well the right.

  249. miker613 says:

    @pinguin. No worries, pinguin. It just struck me as strange.
    Lots of people have good reason not to want their real names to appear on the web, or at least only when they make a careful decision to put them out there. Thus, I would think it’s a serious personal offense to “out” people without very good cause. “They disagree with me” is not very good cause.

  250. John Hartz says:

    My advice to anyone who is tempted to respond to Michael 2: DNFTT!

  251. Eli Rabett says:

    Victor, that is pretty much right, maybe you want to make an exception for areas covered with ice and snow and slightly derate for the ocean, but the more black carbon there is in the atmosphere, the better the black body assumption is.

  252. Eli Rabett says:

    miker613 speak to your buddy Willard Tony about that.

  253. BBD says:

    Steve Bloom

    Very interesting links, thank you.

    Following on from Woodard et al. I think you will find Rohling et al. (2014) of interest. Some background here.

    E. J. Rohling, G. L. Foster, K. M. Grant, G. Marino, A. P. Roberts, M. E. Tamisiea, F. Williams. Sea-level and deep-sea-temperature variability over the past 5.3 million years. Nature, 2014; DOI: 10.1038/nature13230

  254. Michael 2 says:

    ATTP writes “(in response to my comment: When these forces are in balance the global temperature will neither rise nor fall.) Only if our understanding of the basic physics associated with out climate is wrong.”

    Exactly. That seems to be the inescapable conclusion although instead of “wrong” I would suggest “incomplete”. Something changed and there’s considerable opportunity for research created by this pause. It’s nothing to celebrate, it is a “dog that didn’t bark” or in this case stopped barking.

    The reference is to a Sherlock Holmes story by that title wherein S.H. recognizes that the murderer was known to the victim’s dog. The evidence of this familiary is the *absence* of the evidence of the dog barking, which would otherwise always be the case.

  255. M2,
    I think you misunderstand my comment. Firstly, the temperatures are rising. Also, if you consider the entire climate, the total energy continues to rise. We are clearly not in balance. I was suggesting that what you had said in your comment could only end up correct if our understanding of basic physics is wrong.

  256. verytallguy says:

    M2,

    what is the difference between a “provocateur” and a troll?

  257. Steve Bloom says:

    Yes, BBD, thanks. I’ve read Rohling et al. (2014) and IIRC we’ve even discussed it before, but I’d forgotten the details. Looking again, the results are consistent, but the new paper (I haven’t gotten a copy yet) seems to go farther by finding a sharp circulation tipping point ~ 2.7 mya that acted as a positive feedback to cooling. Rohling et al. basically just hinted at the possibility.

    What’s concerning about the change is that it seems likely to be quite abrupt, unless there’s a proposal for a relatively smooth even if fast transition of the THC (I haven’t heard of one). Also, the rate of change of background forcing at the time was far less than what we have now, raising a near-future prospect of something much messier than just a reversal of what happened back then (much more than just a boost to further cooling, I expect, but paleo proxies may not be up to teasing out the details of what are essentially weather changes, however severe). More work for the modelers.

  258. BBD says:

    VTG

    Wish I’d asked that 🙂

  259. BBD says:

    Steve

    The interesting thing about R14 is that it suggests a considerable lag between the shift in ocean circulation ~2.7Ma and the onset of NH glaciation ~2.15Ma. The two were previously thought to be simultaneous, and I get the impression W14 treats them as such too. Also W14 uses cores sampling 3.3Ma – 2.5Ma which would actually miss the delayed glacial response identified in R14. More work, for sure, as you say.

  260. Steve Bloom says:

    “The ocean conveyor system, Rutgers scientists believe, changed at the same time as a major expansion in the volume of the glaciers in the northern hemisphere as well as a substantial fall in sea levels.”

    Right, BBD, that does seem to point to a potential conflict on that issue. I’ll post back after I’ve been able to compare the details.

  261. Nathan says:

    Miker613

    [as did Nathan’s “tracking me down” at Lucia’s blog}

    Apologies if it looked that way. I didn’t go and look for you. I was reading her latest ‘critique’ of the IPCC ensemble (which is pretty lame BTW) and I simply noticed your comment there, and read her reply. I thought her reply was unsatisfactory and asked ATTP if he/she had ever considered posting there.

  262. Willard says:

    > what is the difference between a “provocateur” and a troll?

    One regenerates when flamed, the other flame back.

  263. Steve Bloom says:

    Anders is a glutton for that sort of punishment, but even he needs to avoid going too far.

  264. Steve Bloom says:

    I had thought you would have said that only one has agency, Willard.

  265. Steve Bloom says:

    BBD, it looks like some of the principals will be at AGU next month, and assuming my application to cover the meeting for the Arctic Sea Ice Blog is approved, I’ll make a point of seeing if I can pin down the apparent disagreement.

  266. BBD says:

    Steve

    I’ll make a point of seeing if I can pin down the apparent disagreement.

    That would be great. It would be interesting to see what the authors say about uncertainty in the chain of causation. I can’t help feeling that the W14 press statement at SD is a bit excitable (and Yair Rosenthal has got form for that). Even if the expansion of Antarctic ice did trigger the change in ocean circulation, what made the ice sheet grow in the first place? Evidence mounts that the *formation* of the permanent Antarctic at Oi-1 cap was triggered by a drop in CO2, after all.

    Anyway, I’ll be very grateful for whatever you can find out and post up.

  267. BBD says:

    Eh? Sorry:

    ” permanent Antarctic cap at Oi-1″

  268. Michael 2 says:

    verytallguy asks “M2, what is the difference between a provocateur and a troll?”

    As I use these words, the difference is primarily the intended result and that requires a bit of mind-reading or at least successive observations to reveal the distinction.

    A troll is merely catching fish, counting coup, stirring the ant hill, that sort of thing to watch the show. There’s no personal investment in what the ants are actually doing; he gets a sense of power out of simply being able to stir ants into a frenzy. A pretty good word is “contrarian” but not in the climate sense; rather in the sense it doesn’t matter what you say he will suddenly be opposed to it and quite likely opposed to his own comments immediately preceding.

    A provocateur, on the other hand, *is* invested in the resulting activity or argumentation and stirs the ant hill to get things moving, to reveal secrets or at least things that you consider so “obvious” that nobody mentions it. Provocateurs “provoke” actions or words (usually both).

    The success of either depends upon correctly reading the consensus and then challenging it.

    Provocateur is sometimes sinister but a good professor is a provocateur persuading his students to discover things for themselves, either by playing stupid, or by declaring a thing so spectacularly wrong that his students wake up and “correct” the professor.

  269. Michael 2 says:

    Steve Bloom suggested reading
    http://www.sciencedaily.com/releases/2014/10/141025152717.htm
    “Climate change caused by ocean, not just atmosphere” referring to the thermohaline circulation of the oceans (part of which is the Gulf Stream that keeps Iceland and Europe warmer than would otherwise be the case).

    I am reminded that this is the underlying plot device of the movie “Day After Tomorrow”, northern latitudes would necessarily get colder while the equatorial latitudes would warm up producing an enormous differential where they meet, a ring of cyclonic storms girding the planet. It already exists on a smaller scale along the Aleutian Islands in particular by a combination of naturally occurring air mass boundaries and the chain of islands forming a sharp barrier between the warm Japan current and the cold Bering Sea.

  270. Michael 2 says:

    BBD says “I’m not sure if I’m communicating that it is itrivially easy to spoof an IP. Or lots of them, as required.”

    Yep. One way is to use the built-in and usually neglected “mod-proxy” in essentially every Apache webserver in existence.

  271. [Mod: About moderation]

  272. Steve Bloom says:

    BBD, I don’t see it as disagreeing with the fundamental role of CO2, and hopefully the paper won’t either. If I was publishing a new paper finding a major global circulation tipping point and resultant sharp temperature decrease when CO2 dropped well below 400 ppm, I think I’d choose to emphasize the hell out of that aspect just like they did. We’ll see how strong the connection to much-increased Antarctic ice really is. Maybe they just see that as the only plausible mechanism.

  273. John Hartz says:

    “Soot from car exhaust and cookstoves, sulfates from coal-fired power plants, methane leaked during oil and gas production, and hydrofluorocarbons (HFCs) from air conditioning are all greenhouse gases that trap heat within the Earth’s atmosphere for a short while before decaying into less virulent chemicals.

    “Cutting emissions of such “short-lived climate pollutants,” or SLCPs, will not have much impact on long-term climate change, finds a new study published yesterday in the Proceedings of the National Academy of the Sciences.

    “The study reaffirms strongly that, as far as climate change goes, the gas that truly matters is carbon dioxide. Unlike its shorter-lived cousins, CO2 sticks around in the atmosphere for decades to centuries, wreaking climate havoc.”

    The Worst Climate Pollution Is Carbon Dioxide by Gayathri Vaidyanathan, Climate Wire/Scientific American, Nov 4, 2014

  274. Steve Bloom says:

    m2, the THC and Gulf Stream aren’t the same thing, and the latter won’t (can’t) stop even if the former does.

    No, other than the trigger it’s not at all the same as the DAT scenario (which is an impossibility), although it would be unpleasant enough. The degree of unpleasantness would depend to a great degree on how fast it happens. The main thing to bear in mind is that major changes in ocean circulation will have major effects on atmospheric circulation, including on precipitation patterns. Successful adaptation to the latter is problematic.

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