by Judith Curry

On Lucia Liljegren’s Blackboard (commonly categorized as a “lukewarmer” site), Zeke has a post titled “Agreeing.”    Zeke’s motivation for this is:

My personal pet peeve in the climate debate is how much time is wasted on arguments that are largely spurious, while more substantive and interesting subjects receive short shrift. While I’m sure a number of folks will disagree with me on what is spurious vs. substantive, I think it would be useful to outline which parts of the debate I feel are relatively certain, are somewhat uncertain, and quite uncertain.

I attempted something similar on an earlier thread “What we know with confidence,”  which was based on the conclusions of the IPCC FAR, which have been out there long enough to have stood the test of time (or not).  I also attempted to put to rest debate about whether or not the greenhouse effect exists, on the Slaying the Sky Dragon threads.

Zeke puts forth a list that is pretty consistent with the IPCC AR4, and he doesn’t get much push back from the comments (which are well worth reading).  A very different response from the earlier confidence thread here.

So lets try this again, with Zeke’s statements, and i will append my own comments, as a spring board for discussion.

Zeke’s assessment

What is extremely likely [>95% probability]

  1. The greenhouse effect is real, albeit poorly named. While reams of comments have been written on this subject (witness the whole Sky Dragon debacle over at Judy’s blog, or Science of Doom’s heroic efforts to explain every facet of the issue), I’d hope that readers here won’t argue with this one. JC: OK
  2. Carbon dioxide is a greenhouse gas. JC: OK
  3. Atmospheric carbon dioxide concentrations are increasing. Folks like Beck notwithstanding, there is no serious challenge to Keeling’s measurements, especially as they have been verified by hundreds of additional methods in the subsequent decades. JC: OK
  4. Anthropogenic emissions of carbon dioxide are increasing. We have reasonably good data on the consumption of carbon-heavy fossil fuels over the past few centuries. JC: OK
  5. The majority of the increase in carbon dioxide concentrations since pre-industrial times is due to anthropogenic emissions of carbon dioxide. This is confirmed both by the isotopic signature of the carbon and the fact that concentrations rise proportionate to emissions. JC: OK

What I think is very likely [>90% probability]

  1. A doubling of carbon dioxide, holding everything else equal, would lead to a global average surface temperature increase of about 1 C. This follows from a basic derivation of forcing from changes to absorption bands, though it is complicated by the inherent difficulty of defining what exactly a no-feedback system is. JC:  I have a problem with the way this is formulated, but agree that more CO2 will warm the surface.
  2. Stocks of atmospheric carbon have a relatively long lifetime. While any individual molecule of atmospheric carbon remains in the atmosphere for only a few years on average, the growth limitations of sinks means that the stock will not decline quickly should emissions stop increasing. As a corollary, arguments that 95 percent of annual CO2 emissions are natural rather miss the point. JC comment:  the lifetime of CO2 in the atmosphere is debated, so as a qualitative statement this is ok.
  3. Water vapor primarily acts as a feedback rather than a forcing in the climate system due to its short atmospheric residence time and the limitation to absolute humidity at a given temperature for saturated air. Science of Doomcovers this rather well. Pointing out that water vapor is Earth’s dominant greenhouse gas does not minimize the climate’s sensitivity to carbon dioxide. JC: OK
  4. As a corollary to 3., a warmer world will have an atmosphere with more water vapor. This will tend to enhance the greenhouse effect, though the situation is complicated by the difficulty in both projecting changes in cloud formation and determining the radiative forcing effect of clouds. JC: the coupled water vapor and cloud feedbacks are uncertain, doesnt belong in very likely IMO.
  5. Direct solar forcing has played a relatively minor role in the last four decades, as TSI has been flat-to-modestly-decreasing during that period. JC:  this is still being debated, in terms of calibrations of the satellites, etc.  I would bump this down to likely.

What I think is likely [>66% probability]

  1. Climate sensitivity is somewhere between 1.5 C and 4.5 C for a doubling of carbon dioxide, due to feedbacks (primarily water vapor) in the climate system. This is supported by multiple lines of evidence, including GCMs, paleoclimate evidence (including climate response to forcing during glacial periods as well as millennial proxies), the instrumental record, and the climate response to volcanic forcings among others. That said, this range is large enough that it could mean that climate change will be a moderate issue (1.5 C) or potentially quite dangerous (4.5 C). JC comment: I think we can bound this between 1 and 6C at a likely level, I don’t think we can justify narrowing this further.
  1. Land and ocean temperature measurements over the past century are largely accurate at a global level, though there are some regions that have limited data, especially toward the earlier part of the century. That said, factors like UHI, instrument change, siting issue, and other data quality issues could potentially change the global trend modestly. JC: I’m waiting to see the results of the Berkeley analysis (coming soon) before passing judgment.  I have serious concerns about the ocean data.
  2. Indirect solar forcing is not particularly significant in recent decades. While the role of cosmic rays in cloud formation is interesting and deserving or more study, the lack of a trend and large uncertainty in modalities precludes it being a major player in modern warming. JC:  even the IPCC AR4 did not have confidence on this one; it is at the knowledge frontier, border with ignorance.

What I think is more likely than not [>50% probability]

  1. Intrinsic (unforced) variability plays a relatively large role globally at an intra-decadal scale, but is relatively insignificant at multidecadal scales. In this view, the early 20th century warming was due primarily due to solar forcings and a volcanic lull. JC:  I disagree with this one.
  2. Recent warming is unprecedented over the past millennium. While there are plenty of problems with paleoclimate reconstructions, enough corroborating work has been done to at least elevate this to more likely than not in my personal judgment. Were there reconstructions clearly showing MWP temperatures comparable with, say, the running 50-year mean of the instrumental record I would be less certain. JC:  I don’t think we know; the white part of the Italian flag is very big on this one.

Epistemic levels

When an individual is assessing these, the epistemic level of the assessor is relevant.  I propose the following levels:

1.  Research scientist publishing papers on relevant topics

2.  Individual with a graduate degree in a technical subject that has investigated the relevant topics in detail.

3.  Individual spending a substantial amount of time reading popular books on the subject and hanging out in the climate blogosphere

4.  Individual who gets their climate information from talk radio

Note: personally, I would rate an epistemic level of 1 on some of the topics, and level 2 on others.

Moderation note: this is a technical thread, will be moderated for relevance.

1,120 responses to “Agreeing(?)

  1. As this is directly on topic here, I’d be curious to hear your source for confidence on <2° C climate sensitivity. The lower bound seems much more well-defined than the upper.

    • Judith, would you like all of the above translated into an online survey with demographics and organographics included? It would be fairly easy to do and we could set it to one-time responses only with analysis of IP addresses to avoid duplicate responses.

      I personally would very much like to see what your readers agree with. The disagreements are pretty well documented.

      • well this could definitely be interesting. i think we would want to craft a survey fairly carefully to avoid bias

      • I agree. We should collaborate with people like Bart Verheggen and one of the gentler skeptics and produce an agreed version.

        One key will be segmenting the participants accurately and fairly, not the questions themselves.

        The other key will be structuring the responses so that they are both fair and measurable–two forces in polling that pull against each other.

      • Yep, all very good suggestions Tom, we need to use decent online polling far more in this area, at least so I’ve felt for a while. On how to segment participants, I’ve come to feel the only sensible way, with some precision, is through policy goals, as I tried to explain on William Briggs’ blog last month.

      • I don’t see what you mean by segmenting the participants, unless you mean segmenting the response choices, which requires that the questions be properly segmented. In that case be sure to distinguish “I don’t know” from “we don’t know” which most climate polls fail to do. “We don’t know” is the basic skeptical position. Given the complexity of the issues, with literally thousands of sub-issues, I don’t see useful polling as possible. Still it is always worth a try.

      • David, it is possible to do cross tabulations showing the responses by different population segments. If we ask someone if they like Bart Verheggen’s website and they say yes, we can look at all the answers to all the questions from people who said yes to that question.

        Do you like cream cheese on bagel?

        Bart fans: 68%
        Everybody else: 79%

        That kind of thing.

      • It’s exactly the correlations and contrasts that emerge from such stats that I think could be highly informative. One isn’t trying to put Gallup or Pew out of business with this – but there might be a lot to be learned all the same.

      • David, if you happen to stumble over this, could you email me at thomaswfuller at gmail dot com?

      • This discussion somehow got attached to my question. I’d be curious to hear your answer when time permits.

      • I apologize, PDA. That was my fault, trying to flag our hostess down early.

      • Well, that was my idea too. You succeeded and I failed. So it goes.

    • Who Wove This Web of Certainty ?

      Climategate is only part of an official propaganda-laden, web of certainty that is falsified by experimental observations:

      1. “The Sun is a plasma diffuser that sorts atoms by mass,” Physics of Atomic Nuclei, 69 (2009) pages 1847-1856.

      2. “Earth’s heat source – the Sun,” Energy and Environment, 20 (2009) pages 131-144

      3. “Neutron Repulsion,” The APEIRON Journal, in press (2011) 19 pages.

      Yes, parts of the official propaganda web agree with reality. To be effective, propaganda usually contains some facts. E.g., the surface of the Sun is 91 % hydrogen; global temperatures increased.

      More importantly: b>Who Wove This Web of Certainty ?

      With kind regards,
      Oliver K. Manuel
      Former NASA Principal
      Investigator for Apollo

      • Correction: Who Designed This Tangled Web ?

        Many weavers have been identified working on different parts of the web.

        The question is whether the design came with the public research funds.

      • The threat: Brave New World/1984 tyranny, not AGW

        Climategate exposed an international alliance manipulating and distorting science in the way former President Eisenhower warned might happen one day in his 1961 farewell address.

        The participants include Al Gore and many world leaders, the UN’s IPCC, the US National Academy of Sciences, the International Alliance of National Academies of Science, the UK’s Royal Society, leading research journals (Science, Nature, PNAS, etc.), the Norwegian Nobel Prize Committee, public and private news media, etc.

        There is little or no doubt: This group promoted an international web of deceit about AGW. Leaders of the Western scientific establishment were involved !

        My experience from 50 years of research in a multidisciplinary area (nuclear geo-, cosmo-chemistry, stable isotope mass spectrometry, and space sciences) suggests the same pattern of deceit and data manipulation in many areas of science other than climatology:

        Astronomy, astrophysics, cosmology, nuclear and particle physics, solar and space studies.

        The search for agreement diverts attention away from the central issue that threatens our society – misuse of science as a tool of propaganda – and directed it toward finding the elements of fact in the deceptive AGW story.

        The AGW story contains some factual information, as does deceptive propaganda on the Sun’s origin, composition and source of energy, e.g.,

        Global warming occurred as atmospheric levels of CO2 increased; The top of the Sun’s atmosphere is ~91 % hydrogen; H-fusion occurs in the Sun; etc., etc.

        Instead of trying to identify factual information in the webs of propaganda about AGW, SSM (standard solar model), etc., we need to focus on finding ways to correct the flaws in government science to protect ourselves and future generations from living under the tyrannical Brave New World described by Aldous Huxley or 1984 described by George Orwell.

        That is the real danger!

      • What Controls Earth’s Climate ?

        Professor Curry, I hope you will bear with me and allow me to post our current understanding of what controls Earth’s climate.

        The information posted below is the result of 50+ years (1960-present) of “truthing”: Continuously trying to improve our understanding and knowing that we never have the whole truth. More will always be revealed.

        “Truthing”: Reduces certainty and egoism and increases humility and reverence for Nature.

        Hiding the decline shows the absence of sincere “truthing.”

        1. An image of What controls Earth’s climate.

        2. A manuscript explains How it works.

        3. A video summarizes The experimental evidence.

      • Others who question Is Earth’s heat source really a giant ball of hydrogen described by the SSM (Standard Solar Model) may enjoy a new paper by Vladimir Dzhunushaliev, et al. “A Star Harbouring a Wormhole at its Center.”

        The first two sentences of the abstract: “We consider a configuration consisting of a wormhole filled by a perfect fluid.

        Such a model can be applied to describe stars as well as neutron stars with a nontrivial topology at their center.

      • “Continuous climate change – induced by cyclic changes in gravitational interactions of the Sun’s energetic core with planets – has favored survival by adaptation.” And will continue to do so.

      • Thanks, Faustino, for the quote on Climate change causes:

        “Continuous climate change – induced by cyclic changes in gravitational interactions of the Sun’s energetic core with planets – has favored survival by adaptation.”

    • David L. Hagen

      Climate Sensitivity
      “JC comment: I think we can bound this between 1 and 6C at a likely level, I don’t think we can justify narrowing this further.”

      JC On what basis do you set these upper and lower bounds?

      Spencer & Braswell (2008) found: “we obtain positive cloud feedback biases in the range -0.3 to -0.8Wm^-2 K^-1. . . .our results suggest the possibility of an even larger discrepancy between models and observations than is currently realized”
      See Spencer’s discussion on Foster’s comments
      “As can be seen, most models exhibit large biases – as much as 50 deg. C! — in feedback-inferred climate sensitivity,”
      This up to 50C in models is >> your 6C upper bound.
      Spencer cites: Spencer & Braswell, 2010: “On the Diagnosis of Radiative Feedback in the Presence of Unknown Radiative Forcing” JGR, for his latest work.

      e.g. Lindzen (2009) finds: “…ERBE data appear to demonstrate a climate sensitivity of about 0.5°C which is easily distinguished from sensitivities given by models.”
      Lindzen’s 0.5 C is << your 1 C lower bound.

      When some models give results way above your 6C upper found and several researchers publish sensitivities half your 1 C lower bound, what are we to make of your bounds?

      • That there is a 33% probability that that actual sensitivity could be higher or lower than my bounds. To bound at a 90% level, I would say the bounds need to be 0-10C.

      • As I understand confidence intervals, the 66 percent figure means that if the data used for constructing an interval were sampled multiple times, approximately 66 percent of the intervals constructed in the same way would contain the actual value. However, they would all differ in the actual bounds, so we can’t say that the particular interval between 1 and 6C would include the actual value 66 percent of the time, or that the 1-6 C interval has a 66 percent probability of containing the actual value. (For example, if we resampled the data, we might end up with a 66% interval of 3-7.8 C, which would be neither more nor less likely to contain the actual value than 1-6 C.)

      • In rereading your post, you didn’t specify confidence intervals, but these are what are conventionally used, because estimating the probability that a value lies with a specified range is far more problematic, and requires assumptions about prior probabilities that are more fraught with uncertainty. Typically, therefore, climate sensitivity estimates are expressed in terms of confidence intervals (e.g., 2-4.5 C at 90 percent confidence).

      • One day later, I have some second thoughts about the definition of confidence intervals – e.g., a 95% CI. What I described was a standard definition, which distinguishes between the probability that 95% of samples will include the true value within their CIs (claimed to be true), and a 95% probability that the true value lies within the CI of a given sample (claimed to be false). At the risk of disagreeing with the consensus, I think the two descriptions may say the same thing. Probably no-one is reading this, but I wanted to go on record anyway in case someone wants to discuss further.

      • That statement is incorrect. There is no evidence what so ever of 0 and to insinuate otherwise isn’t taking into account the scientific literature on the subject. Provide me with a reference for evidence that even at the 95% level there is even a speckle of a chance that it is as low as 0.5 even?

      • Robert,
        I will direct you to the climate sensitivity estimate by Stephen Schwartz of Brookhaven National Lab. See

        And his reply to comments in which he modifies his estimate slightly.

        Schwartz gives 1.9 ± 1.0 K as his estimate, although he also quotes Chylek and Scafetta as very low estimates as well.

        But here it the point. Schwartz’s estimate is based on CRU temp data. And if the CRU used unwarranted temperature adjustments to increase the warming trend, as the Climategate emails indicate they may have done, then Schwartz’s estimate is far to high. Reduce his estimate by 1/3 and you have 1.3 ± 1.0 K.

        One of Chylek’s estimates was about half of Schwartz’s estimate. So you see, 0.5C as the low boundary is very reasonable.

      • 0-10C at 90%? I’d say that makes you more of an alarmist than anyone I’ve ever read. Hansen is Pollyanna in comparison. That looks like a 50% chance of the end of civilization.


      • Yes. Quite a howler that was, I must say. Somebody tell Mark Lynas that he’ll need to write several more chapters… ASAP!!!

        10C for a doubling of CO2… my, oh my…

      • 5% at either end? That puts a sensitivity more than 10C inside of 2 StdDev. 2 StdDev is 2.1%

        If you risked the lives of your children at that rate, you’d be put in prison.

        Strange days indeed.

      • Jeffery– please identify what concerns you think would not be manageable? You have raised the concern over a temperature increase, but you seem to acknowledge that as long as the plants have water they will grow find and continue to provide food. If adequate dams and sewer systems are built, what is the great fear? Please try to be specific and not just general BS

      • Seriously. With the fat tail, that’s admitting significant possibility of a P-Tr extinction event.

      • Yes, indeed, it does. If you want 90% confidence, you’re going to get garbage.

      • This is something I’ve argued for fifteen years now. The less you believe in the maturity of climate science, the more you should want to halt CO2 emissions. Any other behavior is inconsistent with that level of doubt.

        The fact that some people who think we have essentially no understanding of climate are not screaming louder than anybody else about a halt to emissions indicates that they are not thinking clearly and consistently.

        To be sure, there are the Lovelock types who believe that very severe climate transitions are imminent, and really do take a consistent attitude toward anthropogenic global forcings. (i.e., terrified) It is fascinating how the “skeptic” crowd do not celebrate such skeptics.

      • Michael,

        The less you believe in the maturity of climate science, the more you should want to halt CO2 emissions. Any other behavior is inconsistent with that level of doubt.

        If you’re on the interstate and drive into a patch of fog, do you slam on the brakes?

      • Vince whirlwind

        No, you take your foot off the accelerator pedal.

        Got any hard ones?

      • David L. Hagen

        Thanks for your clarification. That 90% for 0-10C would include Lindzen’s 0.5C and Spencer’s 0.6C.

      • Assuming these are symmetric, (16.67 % on either side of 1 – 6, 5 % on each side of 0 – 10) this means an 11% chance of 6-10 C sensitivity and 5% above 10 C.

        If, however, we assume a hard clamp at 0, this means a 6.67% chance of 6 – 10 C and 10% above 10 C.

        Either way, it is exactly the odds (1/6) of global Russian roulette with a six-shooter. Who wants to play?

      • WRONG– it is not Russian roulette in any way. Your fear of temperature change does not make it a fact that it would be a disaster for humanity. Climate changes can be managed with proper infrastructure and is not the dire concern that you describe.

      • Vince whirlwind

        The long history of past extinction events proves you wrong in those assertions.

      • Latimer Alder

        So climate change produces asteroids?

        I’m used to some pretty bizarre consequences being predicted if the GAT goes up a tad. But that one takes the biscuit.

        Please produce your evidence that ‘extinction events’ hare reliably linked to ‘climate change’, and in particular to warming.

      • Please describe what type of “extinction event” that you believe climate change will cause that would not be eliminated if infrastructure was built to prepare for the situation.

      • Why should there be a hard clamp at 0?

      • The sensitivity was stipulated positive in the top level article. This might argue for asymmetric tails. IDr. Curry is welcome to specify which it is, but either way we are looking at very high probability of enormous damage.

      • my point was made in this thread
        too uncertain to even put probabilities on this, IMO. the best we can do is try to bound, and I think the IPCC’s likely bound is too narrow.

      • Michael— Your opinion on this is clear, but your have repeatedly failed to identify what the “enormous damage” will be if infrastructure in properly managed over coming decades.

      • Jeffrey Davis

        “if infrastructure in properly managed over coming decades.”

        Thoughts too deep for tears.

      • Climate sensitivity in excess of 6 deg, coupled with a business as usual emissions path would lead to a global warming by 2100 in excess of 10 degrees (and not stopping in 2100 of course). Land warms up more than water; Arctic amplification. And somebody is seriously asking what’s the problem?

      • No, we are looking at a range of possibiliities, a very few of which have theoretical impacts that are wise to insure against. The IPCC doesn’t think that sensitiviy is higher than a maximum of 4.5. Its contributing scientists argue for sensitivity of 3. That does not augur for a ‘very high probability of enonormous damage.’ And to say so is to push this thread into the realms of science fiiction.

      • No Michael,
        A sensitivity range of 0-10C means we don’t really have a clue. It is pure speculation at this point with no empirical evidence to narrow it further.

      • David L. Hagen


        What basis do you give for excluding climate feedback evidence below 1 deg C, by a “climate realist” like Spencer, or by Lindzen based on satellite data, by setting a “lower bound” of 1 deg C?

        To clarify, Spencer’s evaluation of feedback of 0.6 deg. C from satellite transient data is very similar to Lindzen’s 0.5 deg C.

        In fact, even though we expect feedbacks diagnosed from the data to be biased toward zero, here the lines fitted to all the data have slopes actually approaching that value: 6 W m-2 K-1. Translated into a global warming estimate, a feedback of 6 W m-2 K-1 would correspond to a rather trivial 0.6 deg. C of warming in response to a doubling of atmospheric CO2.

      • While I haven’t expended the effort to understand what Spencer is going on about here, it’s also clear that Hagen hasn’t either. The “sensitivity” of which he speaks is specifically NOT the net model response to CO2 forcing.

        This point is clear from a graph in the cited article wherein Spencer compares the latter quantity, which is the one of general interest, to some new quantity which he defines.

        Clearly Spencer thinks this new measure is important, but does not actually confuse it with the actual model response. Hagen is eager to do so.

        I join with rustneversleeps in being astonished at Curry’s ecumenism regarding sensitivity in response to this confused query. Curry has been most obliging to those who claim that climate science is worthless because the understanding generated by the field is negligible. This is unfortunate in many ways, the health of the discipline not greatest among them.

    • Judith pegged her lower bound at 1C — which means no feedbacks. What reasonable study comes up with an estimate for no feedbacks?

      • Sorry. Others have already covered that. Ignore. I wish there were a DELETE button on blogs.

    • As amended by JC I find this a very good summary of what is pretty much known and some other things that might be known. Missing from the picture are the known unknowns.

      Assertions about the effect of CO2 on global mean surface temperature should, I believe, always include a caveat such as “assuming nothing else changes in the climate system”. In other words, if we hold all other known or estimated forcings constant, a change will occur that will fall within a certain range of values. I think that this would be a better way to frame the AGW argument. At least for me, a confirmed CAGW skeptic, this qualification is all that is needed for me to agree with the consensus view expressed above. The physics is sound.

      Aside from questionable research such the MBH Hockey Stick brouhaha, I and many if not most skeptics, are uncomfortable with the “assuming nothing else changes” part. This is, after all, an unusually complex nonlinear dynamical system and it is hard to imagine that its behavior is entirely the result of a single factor. Does increasing the amount of energy in a dissipative chaotic system do nothing more than change the amplitude of measurable phenomena? Or does the climate system, like other dissipative systems, show evidence of the Constructal Law in action?

      The warmist consensus view as far as I understand it is that more CO2 -> increase in GMST -> more energetic everything else. Another way to look at things is more C02 -> increase in GMST -> changes in global climate system. As a skeptic, I will agree to the latter formulation but certainly not to the former. I simply can’t accept a paradigm that simplifies climate change to a mechanical model similar to an internal combustion engine.

      Unfortunately, climate science is based on a pitifully small collection of verifiable observations. Our understanding of climate may be so limited that saying anything useful about its future is at present a fool’s errand. Nevertheless, if you offer enough money to motivate scientists to tackle problems that are for now insoluble, you will find some who offer solutions nonetheless.

      • David L. Hagen

        Ken re
        “an unusually complex nonlinear dynamical system . . . if we hold all other known or estimated forcings constant, (changes) will occur”

        That does NOT mean that climate is static, but that it will continue to exhibit a wide range of natural changes as reflected in the historic/geological record.
        I am not sure we can even determine ” that will fall within a certain range of values.” As in ocean “rogue” waves, combinations of natural forcings can cause extremes that are not commonly seen.

  2. I agree with what is felt to be most likely. Thereafter, I diagree with everything else. Specifically, I disagree with

    “What I think is very likely [>90% probability]

    1.A doubling of carbon dioxide, holding everything else equal, would lead to a global average surface temperature increase of about 1 C. This follows from a basic derivation of forcing from changes to absorption bands, though it is complicated by the inherent difficulty of defining what exactly a no-feedback system is. JC: I have a problem with the way this is formulated, but agree that more CO2 will warm the surface.”

    This is absolutely scientific garbage. The no-feedback climate sensitivity is a completely hypothetical and meaningless number, which not only has never been measured, but almost certainly can never be measured. The degree to which doubling CO2 will warm the surface is completely unknown. From what little observed data we have, the warming is negligible and the signal cannot be detected from the noise.

    • Yes, I agree that the no-feedback sensitivity to a doubling of CO2 is a theoretically calculated parameter that can never be measured in the real world. What I have never understood, though, is how important it is and whether it plays an important role in modelling. ie what if it was 0.5C or 1.5C? How would that affect modelled sensitivity with feedbacks? Marginally or materially?

      • Agreement seconded; question judged a very good one.

      • RobB writes “What I have never understood, though, is how important it is and whether it plays an important role in modelling. ie what if it was 0.5C or 1.5C? How would that affect modelled sensitivity with feedbacks? Marginally or materially?”

        Roughly speaking, the effect of feedbacks is linear. That is, if you double the no-feedback sensitivity, you double the total sensitivity.

      • A beautifully simple answer, which at one level therefore I feel I understand. At another, I have no idea why it should be the case. Don’t we run into spatio-temporal chaos with all of this in the real world, meaning such a nice linear relationship is just another level of moonshine?

      • The whole framing of those simple climate characyerisation in term of forcing, feedbacks and sensitivity suppose that we are working in a linear regime, where all variations are small enough that all relations can be linearised.
        Which makes sense for very small temperature difference. For the considered one, let’s say 3+-2 degree, I am not so sure:
        – for the S-B black body radiation, it probably makes sense, it is in T⁴, but around the current temp it could probably be linearised. There is subtlety here already: T varies around T average with very large amplitudes both temporally and locally, and those variations are large enough to trigger non-linear aspects of S-B. This means that the law should consider both T, and a measure of its variance…
        – For the CO2 forcing, it does makes sense, the forcing difference considered is quite small compared to the total flux at TOA.
        – For the feedbacks (outside from the main S-B negative feedback, which is traditionaly separated from the other feedbacks), I think that the assumption may be not valid, because of water. It seems to me that around the mean T, a difference of a few degree is enough to potentially trigger non-linear response, because some water phase change are very sensitive to temperature.

        But anyway I think that this simple forcing-feedback-sensitivity model is not so useful for the climate system. It is easy in term of derivation because it collapse all possible external influence into an equivalent forcing and make all feedbacks respond only to mean temp, but given that:
        -variation (noise) around mean temp are more than enough to trigger multiple non-linear effects, and T can not in principle be collapsed into a single mean temperature state variable
        -I think that some external influence can not be fitted into a forcing, because they could modify the way the system respond to a mean temperature (feedbacks). It is the case with non-TSI solar influence ( magnetic effect with cosmic ray, variation in solar spectrum instead of total intensity) which are among the competitor to CO2 to explain non chaotic long term climate trends – if they exists.
        -we lack a timescale short enough to consider the forcing as fixed (volcano, CO2 emissions, TSI variations) but long enough to get meaningful climate average (even if such average makes sense, that climate is only weakly chaotic) and certainly too short to reach equilibrium T. Equilibrium climate sensitivity is thus a purely theoretical construct not much more related to reality than the no-feedback sensitivity…

      • A simple precision to what I mean by the sensitivity linked to S-B blackbody radiation should consider both average T, but also the variance of T both spatially and temporally.
        Consider that the average T of the earth is 10°C. It will radiate more if this average comes from a uniform distribution between -5°C and 25°C that if the T distribution is between 5°C and 15°C (*). Climate sensitivity thus makes sense only if one know how T variance change with the average T. If one do not know, it is impossible to give a single climate sensitivity… I think that to alleviate this problem, some propose to work with a “radiative” temperature T⁴ and to define the average temperature as ^(1/4). But then you can have problem with feedbacks which do not depend of the fourth power of local temperature…

        (*)The demonstration is simple but it will not fit in the margin (no, just joking, a simple integral will show it imediately)

      • Kai – Your comment is best addressed by someone who actually constructs climate models for a living. However, based on my knowledge of the process, I would state that the heterogenity you cite is incorporated into the modeling effort. One example, among many, is the derivation of a temperature estimate for CO2 doubling in the absence of feedbacks. If one simply applies SB, assumes a constant linear lapse rate, and a mean radiating temperature of 255 K at a hypothetical mean radiating altitude, the estimate is 1 C. The models, by including heterogenity associated with latitude, seasons, and other variables, arrive at an estimate of about 1.2C. The difference is not trivial, but it is small enough to allow for some confidence in the results.

      • Thanks kai (Pierre de) and Fred. I’d wondered where the 1 and 1.2 deg C came from. Mostly I instinctively agree with kai that the “forcing-feedback-sensitivity model is not so useful for the climate system”. On the GCMs, as a long-term software engineer with an interest in such matters, I assume that both the following statements could be true:

        a. They’re one of the great intellectual achievements of the last fifty years.
        b. They cannot give us any idea of the climate in 50 or 100 years, including such crucial variables as regional precipitation.

        But a is optional.

      • The non-feedback climate sensitivity is one of the concepts, which I do not particularly like as it adds in my opinion one major complication without adding much value.

        The radiative forcing is a necessary measure needed to tell, how CO2 influences the energy balance, when nothing else changes. It can be transferred without any loss of accuracy to a change in the effective radiative temperature leaving troposphere. Including stratosphere adds only little uncertainty, which allows replacing the concept to effective radiative temperature leaving earth to open space, when CO2 concentration is changed, but troposphere and surface otherwise unmodified (the IPCC definition of radiative forcing allows stratosphere to adjust). This change in radiative temperature is about -1C. It is negative and the related positive numbers refer to the warming that has to occur to get back to equilibrium.

        Getting to the related surface warming, assumptions must be made and an artificial definition of “no-feedback” introduced. All this changes the number by around 20%, but this occurs losing at the same time the possibility of having a precise model-independent definition for the concept.

        Whatever is done at this stage gives always just one number that describes a theoretical situation that can never be realized. Real climate sensitivity is something else and making that one step from 1.0 to 1.2 does not help the continuation at all. For the arguments on direct effect of CO2 both values are equally representative, the difference of 20% is insignificant in that connection.

      • Thanks Fred and Pekka.

        I also think that the GCM model incorporate the effects I mention. I think that the sensitivity/feedback description is a remain of the early 1D purely radiative models. At best it could be seen a way to interpret model results, some kind of rough post-processing to fit the model prediction within a mathematical framework that is now traditional in climatology.

        So, model are the real beast to discuss, not the 1D model, that may be used to introduce the subject but are not really useful anymore except as quick sanity check for model outputs.

        I have quite a long experience in modeling PDE with finite elements, finite difference, finite volume, well the usual stuff. This experience do not makes me overly skeptical regarding computer models…but I am not impressed by a pretty color plot animation on a grid either ;-)
        And there is a problem I have no solved to date with GCM, which rings loud alert in my FE-modeler mind:
        -what are exactly the equations solved by the current state-of-the art GCM? Or, probably closer to what is done: What are the equation solved by the submodules, and how are they connected?
        -where can we see a mesh and timestep convergence study?
        I guess (and hope) there is answer to those questions somewhere in the litterature…but they are not in the IPCC reports nor in any blog I have seen to date.

      • Kai,
        I am certainly not the least expert on climate models. The best knowledge I have comes from the book “An Introduction to Three-Dimensional Climate Modeling” by Washington and Parkinson and from a few review type articles. Based on that I can assure only that some effort has been directed to the issues you raise, but I cannot even try to tell, how far the knowledge has proceeded on this line.

        The problems are in many ways difficult for modelers. One difficulty comes from the huge range of timescales and spatial scales that each are important for some part of the solution. Most numerical methods work well only when these ranges are not wide. It may help that the answers are needed only for averages and some distributions, but this is in no means a guarantee that handling some scales in an inaccurate way would not influence the results. And this is only one of the large number of difficulties.

        One issue relates to your question on connecting the submodules. Only part of conservation laws can be satisfied by the basic discretized model equations. Therefore the remaining essential conservation laws must be enforced through additional corrections, which cannot be done locally, but only globally. We need some real experts to tell better, what the situation is.

      • Yes, that’s more or less what I suspected too.
        It is also a kind of deception, like “hiding the decline” did for the perceived solidity of tree ring proxy:
        A numerical model which do not show the equation it solves and the coupling condition at interface or between subphysics is usually inferior to one who does.
        Well, because it means that its results can not really be independently verified. At this point, the only validation are about some global conservation laws (that you mention have to be kludged in sometimes – no good) or experimental validation (that I consider very lacking from what I have seen).
        And it throws out the argument I have seen time and time again in warmist blogs (and, more subtly or more weasely, depending on your goodheart, in the IPCC report) that models are solid because they are based on first principle laws and physics verified in the laboratory. Probably for the radiative subpart. For the rest, I doubt it, and the fact that the solved PDO are not shown explicitely is suspect. I know it can not solved full N-S, this is not feasable at those length and timescales for air or water, and never will be. I hope it is some clean N-S approximation with a model of turbulent viscosity, it looks like météo models do that so probably climate models too, with coarser grids and larger timesteps…
        But I guess that most convective (including evaporation and condensation) phenomenons are sub-grids. Given that they make the bulk of vertical heat transport in the atmosphere, not sure the models are worth more than the expertise of the different groups into building complex subgrid paramterisations, and this is very far from “models implemetning first principles”…
        I think that at this stage, climatology have more to win from progress in filling experimental database than from progress from modelling. So in this sense, paleoclimatology is crucial

      • That’s not what linear means!

        If you double the no-feedback sensitivity and the total sensitivity triples, it is still linear.

      • No it is not. Jim is right.The no feedback sensitivity S_0 gives you how much T varies with the forcing associated to CO2 (wattage at TOA due to an increase in CO2, which I call delta W_CO2).

        delta T = S_0*delta W_CO2 (linear relation)

        S_0 is derived from S-B blackbody radiation and is not what people usually think of CO2 sensitivity. What they want is the quantity per doubling of CO2 concentration. Additional forcing related to a change in concentration is
        delta W_CO2 = C_co2 * log_2(CO2/CO2_0) (log relation)

        so we have the no-feedback CO2 sensitivity as
        delta T = S_0*C_co2 * log_2(CO2/CO2_0) (log relation)
        and the no feedback sensitivity to a doubling of CO2 is given by S_0*C_co2 = SCO2_0

        The feedbacks f tells you how a delta T induce secondary wattage at TOA (additional water vapor, albedo change through clouds, ice,…)

        delta W = f * delta T (linear relation)

        Now further assume that S_0, giving the delta T is valid for any wattage change at TOA, not only from CO2, but from the feedbacks themselves:

        delta T = S_0*(delta W_CO2+ delta W)
        = S_0*(delta W_CO2+f * delta T )
        delta T*(1-S_0*f)=S_0*delta W_CO2
        delta T=S_0/(1-S_0*f)*delta W_CO2
        =S_0/(1-S_0*f)*C_co2 * log_2(CO2/CO2_0)

        The sensitivity with feedback is S_0/(1-S_0*f)*C_co2 = SCO2.

        So the sensitivity to a doubling of CO2 with feedback is linked to the sensitivity without feedback by

        Defining the feedback factor F as S_0*f allows to write

        SCO2=SCO2_0/(1-F) (linear relation)

        Note that the feedback factor F is a property of the climate system not related directly to CO2 (although it can be related indirectly through CO2 degassing of the ocean) but valid for any kind of forcing.
        Doubling the no-feedback sensitivity will double the feedback one, because what climatologist usualy mean when saying what if we change the no-feedback CO2 doubling sensitivity is let’s change C_co2, not S_0…

      • So if I have understood this properly, a small inaccuracy in the no feedback sensitivity can make a significant difference to the modelled sensitivity with feedbacks. ie if you double one, you double the other. It is therefore a relevant parameter even if it can’t be measured in the real world.

      • All I was saying is that y=x is not the only linear function.

        y=2x and 2y=3x

        those are also linear functions

    • Sean Houlihane

      Not being able to observe the no-feedback number does not make it a meaningless concept. It’s value can be debated, but the way it is used here is reasonable as a way of identifying that the basic input to the system of more CO2 is X, where X is fairly small. I think the key point was that it is positive, rather than indistinguishable from zero.

  3. “3. Atmospheric carbon dioxide concentrations are increasing. Folks like Beck notwithstanding, there is no serious challenge to Keeling’s measurements, especially as they have been verified by hundreds of additional methods in the subsequent decades. JC: OK”

    Filtered and averaged concentration is increasing. It might start declining when the temperature starts to plummet. I don’t discard Beck completely. Keeling’s measurements (raw data, code) should be transparent.

    “5. The majority of the increase in carbon dioxide concentrations since pre-industrial times is due to anthropogenic emissions of carbon dioxide. This is confirmed both by the isotopic signature of the carbon and the fact that concentrations rise proportionate to emissions. JC: OK”

    How much is this majority? I am not convinced that concentrations rise is proportional to emissions.

    • Regarding #3, Beck’s work is primarily concerned with pre-Keeling levels, especially 19th century, where there is a lot of evidence for high CO2 levels. Beck assembled something like 90,000 measurements, not to mention stomatal evidence, while AGW is based on ice core data.

      Regarding #5, I have serious doubts that the CO2 increase is due to human emissions. I defer to Howard Hayden on this one.

      • Lots of the historical data were relative accurate (+/- 10 ppmv), but taken at the wrong places: over land, near huge sinks and sources. These are worthless for “background” CO2 levels. The late Ernst Beck averaged everything together.
        E.g. the 80 ppmv 1942 “peak” is mainly based on data from 2 series over land, used for agricultural purposes. The same period gives no peak in high resolution ice cores (8 years averaging), neither in stomata index data or the d13C levels of coralline sponges.

      • Are there any longer term “non-background” measurements? Would annual avearges of non-backgroud concentrations correlate with the backgound CO2 levels?

      • There were sporadic measurements during ships cruises and coastal with wind from the seaside. These data all are around the ice core values for the same period. See:
        Unfortunately, for the 1942 “peak” period there are no seaside data, except from Barrow and Antarctica, both with equipment accurate to +/- 150 ppmv…

        The longest series over land, some 1.5 years, 3 samples per day, shows such a huge variability (66 ppmv – 1 sigma) that one can’t trust the data at all. Modern continuous sampling (30 minute averages) in the same neighbourhood also shows large variability, but the monthly averages more or less follow the MLO measurements with some bias:

        See more background at:

    • 3. raw data: non corrected hourly average data calculated from 2×20 minutes 10-second instrument voltage readings and 3×2 minutes calibration gases are available for 4 stations at:
      The procedures for measuring, calculation, calibration and quality control of the data are here:

      On simple request I received a batch of a few days of the 10-second raw voltage data to compare the results with what was archived in the 1 hour averages database. No differences found.

      5. At least 94 ppmv from the 100 ppmv increase. 6 ppmv from the increase of maximum 0.8°C since the LIA.
      The increase is incredibily fixed in ratio with the emissions at about 53% since 1900:

  4. Sean Houlihane

    As a non-expert, I am currently comfortable agreeing with the 95% group, and have a little more doubt in the 90% group but for the purpose of framing a theory the first 3 of these are a reasonable compromise (debating the detail of CO2 is not productive in the wider context).
    Recent trends in solar parameters, and long term temperature reconstructions seem mostly inconclusive – this does little to help in determining the sensitivity more precisely. Dependence on these trends does not add weight to a theory.
    In my view, everything in the ‘likely’ and below is sufficiently unknown to be plenty to focus on. That implies that I don’t expect much agreement on any of those items in this thread.

  5. Without wishing to sound sycophantic, I agree with Judith’s remarks. To my mind, natural variability (including the role of clouds) is the big uncertainty especially as the alarmist case seems to be based on such a short period of warming.

    This is a useful post as it nicely condenses the areas of debate. When you consider the pages of comments that have been written in the blogosphere one can’t help wondering if this summary is really the extent of the argument. Is that really all there is to it?

    • When you consider the pages of comments that have been written in the blogosphere one can’t help wondering if this summary is really the extent of the argument. Is that really all there is to it?

      I’m sure we can vastly reduce the conciseness in the comments, in case anyone is worried … :) I’m also don’t wish to sound sycophantic but this shows Judy at her best – having the humility to pick up something on the blogosphere that is already good, though far from perfect, and running with it. That way we all gain, we all learn. Go Climate Etc!

    • Well, it is an excellent summary. But there is a lot of debate on the ‘mitigation’ and ‘consequences’ fronts, too. (E.g., is 2-4 C warming on balance bad, or good; would more warming increase or decrease extreme events; we’ve been de-carbonizing for centuries (wood -> coal -> oil -> natural gas) without government intervention; etc.)

      But this comes first – “Are we warming or not from increased CO2, and how much” is primary … the other debates follow from that.

  6. The majority of the increase in carbon dioxide concentrations since pre-industrial times is due to anthropogenic emissions of carbon dioxide.
    Judith, I’m no longer sure about this.
    Paper comes out saying plankton has reduced 40% (I don’t agree with it, but it’s there) if true, it would explain all of the rise of CO2.
    History says CO2 levels have been in the 1000’s, where did it go?
    When CO2 levels were in the thousands, we still had another ice age.
    CO2 levels are the lowest ever, right now. What made CO2 levels drop in the past, and why is that same thing not working now?
    What made CO2 levels rise in the past, and then crash again?
    Oceans have naturally warmed, do we really know how to measure that CO2?
    I have very little faith in being able to tell one CO2 from another….

    I know there’s been a lot of mess trying to explain all of this, but it’s all lacking.
    I honestly do not believe that we even know enough to make this statement………

    • I also feel I know less than I used to on this :)

    • Honestly, with all due respect to the original poster and commenters, I don’t see the value in this kind of post. I have no idea about the qualifications of the commenters to agree or disagree with the findings so I have no idea what value to place on their opinions. So what if joe-blow98 agrees with the 95%, and not any of the other statements? Who is joe-blow98 and why should I give their opinion any weight? Who cares what bloggers in general say about climate sensitivity or attribution or paleoclimate? They are not the people whose opinions count in a science debate. I want to know what climate scientists and those in allied sciences think about the data and theory. Everyone else is just noise.

      • shewonk, it’s a catch 22..
        When people say who they are, they stand the chance of getting attacked for arguing from authority.
        Plus, it’s the internet, anyone can be anyone………

        Best bet is to use your own good judgement.

      • My own good judgement tells me that my own good judgement isn’t enough and that I should listen to scientists in scientific forums rather than anonymous bloggers on the web or non-scientists in self-published books. If scientists in other fields feel comfortable with the consensus view, why should I think I am qualified to dispute it?

        People spend a dozen years in post-secondary education to get a PhD and then years doing research and teaching to gain the expertise necessary to evaluate a science issue. Theirs are the opinions I want to hear, not the opinions of those who passed high school physics or read Discover magazine. So when I want to know the best opinion on the evidence, I seek out scientific peer-reviewed opinion — and the preponderance of evidence, not the one-off paper.

        It is not perfect, but it is all we non-scientist non-experts have to rely on if we want valid opinion. The gut feelings and prejudiced views of the non-specialist have no built in processes and procedures to winnow out the scientific chaff from the scientific wheat. It is all mixed in together. In fact, due to the lack of knowledge and expertise, the non-scientist non-specialist opinion is more likely to be mostly chaff.

        I know this goes against the grain of many people in the blogosphere who want to think they are on the level with scientists on this issue, but I think they are massively deceived, if well-intentioned. Even if you spend 4 years reading in a discipline, as I have since 2007, you aren’t on the same level of expertise. I have a BSc in Biology and have taken physics, astronomy, calculus, stats, botany, geology, chemistry, and biochemistry at the undergrad level and I do not feel competent to evaluate the science and methods nor do I have the time to take the classes to get this competency. That is why we have organizations like the NSF, the national Academies of Science, the IPCC and other science organizations. They are not perfect and can be wrong at times, but I’ll wager that they are right far more often than wrong whereas the reverse is more likely to be true for non-scientists.

      • SheWonk is a bloggery science heretic!

      • So, your belief in CAGW or whatever is based on the length of time a person stayed in academia? While I’m sure people such as Dr. Curry would appreciate this, (maybe?), I have a hard time reconciling this with the contributions of non-scientists in this particular field.

        Shewonk, I’ve seen your comments. You’re a bright person. I can’t help but feel a sense of disappointment that you would acquiesce your judgment to people that may or may not be as intelligent as you based on their length of time in academia. You do a disservice to yourself, but not only that, a disservice to your fellow citizens of this world.

        The wheat and the chaff will be sorted.

      • based on the length of time a person stayed in academia

        Well, she specifically said “a dozen years in post-secondary education to get a PhD and then years doing research and teaching.” In other words, the perspectives of people who have spent a significant amount of time studying and working in a field – particularly a very complex field – have more value than the perspectives of people who have not.

        This seems self-evident.

      • thanks for reminding me, i wanted to add something on epistemic levels, adding that now

      • You left a category out of your list of epistemic levels.

        5. Individual[s] who gets their climate information from main stream media (NY Times, CNN, ABC NBC, CBS, BBC, London Times, CBC…)

      • My own good judgement tells me that my own good judgement isn’t enough and that I should listen to scientists in scientific forums rather than anonymous bloggers on the web or non-scientists in self-published books.

        I have both sympathy and a sense of irony in agreeing with you about anonymous (or pseudonymous) bloggers, shewonk. Indeed my sympathy three days ago led me to suggest why you should depart from your current practice of only listening to those experts who defend Hide the Decline.

        Alarmist climate science is I believe an extraordinary area – just as Eugenics once was – because of the profound social implications of its claims. A journalist like HL Mencken, who was not a scientist, knew Eugenics was a crock, when many US and German ‘scientists’ said it was the real deal. How did he know? By reading outside the official literature. Did it matter people like Mencken took this risk? You betcha.

      • I would agree with that, if each qualified scientist speaks for himself, but not if claims are made that 90% of an unspecified group of scientists agree with AGW!

      • The problem with some scientists (not all) is that they may have spent their entire career in academia, pondering hypotheticals where conclusions need not be empirically verified.
        This seems particularly applicable to climate science. We see statistically contorted models with methodologies unique to the field, where results are deemed more accurate or important than actual observations. To boot, these academics often have highly developed writing skills and exploit ambiguity and uncertainty in their favour.

        On the other hand, many non scientists, or scientists who have worked in industry, have to approach problems with a totally different mindset. Their results will be scrutinized and their solutions must work.
        Having gained an MSc. at Uni after 25 years employed in various problem solving roles, I would certainly have more faith in the opinion of a relevantly qualified and experienced engineer who has studied climate science literature, rather than a career academic in that field.

      • Unfortunately, having advanced degrees does not necessarily mean you are unbiased (Google: “Lies, Damn Lies, and Medical Science” by David H. Friedman, an article previously mentioned in this blog). Our government, and other rich governments around the world, have become huge pots of gold mined by those individuals and organizations who are clever and smart enough to do so. One way is to align with the dominant view of the government on a particular issue. Climate alarmism is one such issue. While politicians come and go, the bureaucracy remains. Because climate alarmism has been around for so long, it has become the dominant view partly because the bureaucracy most likely has self selected for employment those individuals who share the dominant view. Universities, being grant seeking organizations that have become fairly dependent upon government largess of one sort or another, will find it in their interest to give the government what it seeks. This must have an impact on the views of those scientists within these organizations, except for a few who, like Judith, puts personal integrity first. ClimateGate is a good example, in my opinion.

      • Richard Wakefield

        That is why we have organizations like the NSF, the national Academies of Science, the IPCC and other science organizations.

        All hyjacked by people with other motives than science.

      • Bruce Cunningham

        I don’t agree with this line of thinking. It is at best a general rule for evaluating the worth of someone as a possible employee or advisor. The downsides of this type of thinking could be worse than the positive aspects of it. ie.

        I have an engineering education (aerospace), and like many other scientific disciplines, it is comprised of several different ares of study (math, physics, aerodynamics, mechanics, etc). The coursework involved instruction from specialists that had far better knowledge than I about their particular specialty. If I write a paper stating my findings or opinions about a specific subject, and an expert in an area that was used in the paper tells me that I have made an error in a part of the paper that I presented, HE is actually the expert in the field, not me. If I have made a math error in say, solving a differential equation, and a Ph. D in math points it out to me, I should listen to them, and so should you.

        This is what happened with Steve McIntyre . and Ross McKitrick when they pointed out the flawed math in MBH98 in their 2003 paper. Steve is a top shelf mathematician, and Ross a top statistician. yet their critiques were vilified. They were not climate scientists, and shouldn’t be listened to (argument from authority), even though the errors that they pointed out were in their areas of expertise. They were the experts, not the ‘Team”. We should listen to them.

        As a further example (if one is needed), even though I am not qualified to be an accountant at a large corporation since I have not studied accounting, I could however easily point out math errors in adding and subtracting numbers in an accountant’s report. To dismiss my critique of such is not good reasoning.

        Dr. Curry had 4 excellent posts on this very subject. this is one of the best.

      • “…Steve is a top shelf mathematician, and Ross a top statistician…”
        What are you basing this opinion on? Your own judgment, or what someone else told you?

        Would a top statistician confuse degrees and radians?

        If they are both top in their fields, where are their publications?

      • Well, Little Miss Acdemia, not everybody who is good at something chooses to spend their lives in the narrow and confining straitjacket of academic research,. Where the only things of note most will ever achieve will be getting your papers cited and eventually achieving tenured status.

        Plenty of people actually want to create something in their lives so get put from under the suffocating and deeply boring educational establishment as fast as they can and work for themselves or otherwise go and do something else. The academic world is not the only place to do science or maths.

        Part of the problem that many of us with experience outside academe see with ‘climate science’ is exactly that closed little defensive laager like mentality, the absolute conviction that they – with their supposed superior intellects to us mere mortals – are qualified to lecture the rest of us, and that they are immune to any criticism purely because of their exalted status. Some others view many academics as relatively bright people but with few of the skills needed to earn a living in the big bad world. ‘Perpetual student’ is not meant as a compliment.

        I don’t know whether to laugh or cry when I read your comment that so beautifully reinforce this stereotype.

        Please spend time away from academe, then return and let us know if you still see it all through your rose-tinted glasses and with your wide-eyed awe of the climatology gods.

      • Gee, defensive much?

        Where’s your answer to Holly’s question: “What are you basing this opinion on? Your own judgment, or what someone else told you?”

      • @PDA

        If that remark was directed at me, I have no answer. I don’t have any judgment about either individual. But from what I read about his demolition of Mann et al’s Hockey Stick method, he is certainly a better statistician than Mike Mann. No idea whether that qualifies him as top drawer. Looks like that might just mean he’s passed Stats 101 as part of a maths degree. And if he managed to make commercial living as a mathematician for forty odd years – i.e other people thought his work good enough to pay for, then that’s a good start for me.

        My remark was an observation about the implict assumption that the only way to be a good mathematician was via the academic, paper publishing route. Which I find incredibly arrogant and small-minded. But sadly typical of climatologists.

      • My error, the question was directed at Bruce Cunningham.

        The remark was, however, directed at you. In your defensiveness, you rather broadly insulted all those who follow an academic career, which was unfair. No one should (and few, in my opinion, do) denigrate anyone who doesn’t choose a life of research and study. However, anyone who makes their way in the commercial world should have the self-esteem and strength of character to avoid such unkind and prejudicial insults to people who choose a different career.

        To the point: mathematicians are scientists. Not everyone who does mathematics is a mathematician. Someone who works in a challenging engineering career may in fact have superior understanding of certain applied maths than many credentialed mathematicians. However, the title “mathematician” is only applied to people who study mathematics.

        It’s not a value judgment. It’s a job title.

      • @PDA

        Fine. Argue about semantics and your chosen very narrow definition of mathematician if you wish. Others will not agree.

        I don’t denigrate all who follow academic careers. Indeed, as the old saying goes, one of my best friends is a notable academic.

        But I have developed a healthy scepticism about climatologists since starting to try to understand this debate a few years ago. They do not seem to care about following the scientific method with much rigour. Nor do many of them or their vocal supporters feel the need to persuade and explain when hectoring and arrogance once sufficed to make their points.

        So when a climatology supporter wants to judge someone’s abilities purely on academic publications, I am underwhelmed with their persuasiveness. Looks more like defensive tribalism than objectivity to me.

      • Holly be careful. Ross’ radian error is more than matched by Mann’s errors in simple geography. Worse than that, when Ross’ error was found he fixed it and reported the results.

        When one of mann’s geography errors was found out he ignored the correction and published a second paper with the same error. When he finally fixed it he refused to give credit to the man who pointed out the error and he failed to announce the correction and he misrepresented the importance of it.

        Glass houses. Everybody makes mistakes. They should be acknowledged, credited, and fixed.

      • You know, Shewonk, I was going to post something about how you’re not giving yourself enough credit. You said, “If scientists in other fields feel comfortable with the consensus view, why should I think I am qualified to dispute it?” This viewpoint reminds me of that Barbie doll that used to say “Math is hard.” Sure, math takes work. But the more you practice, the more you understand; the more you understand, the more you can do. In that sense, everything is “hard.” Quantum physics is hard. So is painting. Baseball. Whatever.

        But then I read your blog post on this current Hide the decline debate, and I see that you have no interest in critical thinking. You’re right … you are not qualified to dispute it, because you believe you are not qualified to dispute it.

        The deplorable attitude of Barbie saying “Math is hard” is not deplorable because it is a wrong statement … it is deplorable because it is the wrong attitude. Math, or climate science, or engineering, or what-have-you, require knowledge AND creativity. You have to have facts to build your repertoire, but you also have to critically assess how to apply those facts. That’s where the creativity comes in … thinking up potential problems, different angles, pitfalls, etc. You have to uncover and challenge your assumptions, again and again and again.

        Now, there are actually two paths to a PhD: 1) you can act like a scientist and become adept at critical thinking; or 2) you can memorize and trust everything you read, and acquire a large repository of knowledge without full (or any) understanding. If you go the path of (2), your dissertation will likely be more akin to a novel aggregation of previous claims than anything truly useful or deeply tested.

        Now, most people have both (1) and (2), but true scientists will lean very heavily towards (1). This is particularly true in their area of specialty, but this mindset also spills out into other areas. Which is what is happening now, on this blog. Critical thinkers who may or may not be “climate scientists” – and often aren’t PhDs, either – are taking a hard look at the science on a number of issues. Part of that process is to stop and say, Okay – where are we? What are the areas of agreement, disagreement? Where is uncertainty high, and where is it low?

        Speaking for myself, there are areas where I don’t have the expertise to judge, and I don’t plan on acquiring that expertise because I choose not to spend the time. (I’m in IT research, so it’s a bit out of my career path.) But some issues in this debate are still accessible to me, with the amount of effort and attention I’m willing to spend. I focus on those, and perhaps raise naive questions in other areas. The key point is, I question. I wonder. I have curiosity, and a willingness – some would say, the necessary arrogance – to challenge authority.

        I want to know, to my own satisfaction, what’s going on in climate, and my satisfaction threshold is high. You are satisfied with the safety of the consensus view, and that’s fine – that’s your right. But conflating the process of questioning and challenging with some perceived political agenda is simply wrong-headed.

        Saying a chart is wrong should not be construed as an insult on the chart-maker. Saying that a certain presentation of evidence is dishonest is not the same as saying the presenter is dishonest. The true scientists here know that the politics of the situation is a separate issue. And they have no problem being proven wrong on the science, because that is how the science – and our understanding of it – move forward.

        And since I’ve just now realized I’ve gone horribly off topic, let me add: I think the idea of polling the denizens is a great idea. I’d love to see the results of a specific and intelligently designed poll.

      • Ted,

        I’m not sure if Shewonk’s post is about the hardness of math. I’m not sure either that her questioning is about her very self, and not about a more abstract self.

        Shewonk’s interrogation partakes of an ancient line of enquiry: what does warrant knowledge? Searching for this kind of justification is at the core of the theory of knowledge, and therefore has something to do with critical thinking alright.

        I agree with you that to try to work things ourselves (Sapere aude!) or with the help of one’s community is very important. It could even help to be an amateur, as it provides the liberty to look at details at one’s leasure. Benefactors can provide many good insights into many issues.

        I also agree that uncovering assumptions and challenging authorities partake of the way science ought to get done. And when shed under the best of light, we can hope that the critical endeavour of blog research will initiate some constructive dynamics.

        But plain-old skepticism teached us that this only answers indirectly Shewonk’s question. However one approaches skepticism, i.e. whatever answer one comes up with the justification problem, trying to answer that question forces oneself to pause and reflect. If we are to accept your solution, we should only accept contributions that are thought critically, completely worked out, and constructively put forward.

        Readers can judge if this is what’s happening hereunder, amidst the prevalent piling on and the cheerleading. These kinds of comment are so blatant and so brutal that it’s tough to imagine that Shewonk’s question really targets the more constructive dynamics you have underlined. So I’m not sure who’s “conflating the process of questioning and challenging with some perceived political agenda” here.

        I am quite sure that Shewonk understands that questioning and challenging is not the same thing as chumming, blaming and shaming. At the same time, we all can see how the demarcation can get fuzzy. It’s subtle enough to make one step on it from one sentence to another. Take for instance your two important propositions:

        > Saying a chart is wrong should not be construed as an insult on the chart-maker. Saying that a certain presentation of evidence is dishonest is not the same as saying the presenter is dishonest.

        I agree that with the first proposition. I would prefer “bad” to “wrong”, but “wrong” is fair enough for me. The IPCC, and every instances presenting graphical information, should have some guidelines of best practices for graphmanship.

        I disagree with the terms by which the second proposition is formulated. The expression “is dishonest” is commonly used to refer to agents, so the expression “dishonest information” looks a lot like a trick: personifying the information to hide in plain sight the conveyed accusation, i.e. that the presenter was dishonest. Googling “dishonest presentation” should suffice to convince yourself of that intuition.

        (Another trick of the same trade would be to ask a rhetorical question: is the presenter honest?)

        In my humble opinion, this kind of trick seems to me a more central topic to Shewonk’s blog than what we can think of her last skeptical interrogation. But the line of questioning Shewonk proposed is a fruitful one: it should not to be dismissed as a chichi from a Barbie.

        In any case, let’s not forget the main message: Science is Corrupt.

        So let’s get the polls rolling,


      • Shewonk,

        While I agree with you on the limited ability of the general public to understand thecomplexities and nuances of a particular scientific field such as climate science and the value of non-scientists having “opinions” and “views” on specific
        technical arguments such as tree ring proxies, I dont agree that somehow if you are not a scientist in that particular field, you cannot make intelligent arguments or judgements about the science. Neither is it true that if the majority of the scientists in the field agree on something that it has to be true. If that were the case your gastroenterologist will still be treating your ulcerous stomach with stress relief medication and stress control methods instead of a simple anti-bactereal medicine. Let me elaborate below:

        1. Let us first make sure we have some ground rules. Lets assume the person making the “judgement” has the basic logic, mathematical/statistical skills needed. This doesnt require a graduate degree of any kind. It shouldnt even require a bacherlors degree. This constitutes a large chunk of the public, the kind who would pay attention to climate blogs anyway, instead of gravitating to American Idol blogs.
        Im sure there are those who do both. Im not yet talking about scientists in other fields. They obviously have much higher level of skills.

        2. The general public may not have the ability to understand the equations and models in that particular field to provide any worthy opinions about those elements. But what they can and must do is to pay attention to the outcomes of such models
        and equations, particularly if it is bound to affect their and their children’s lives substantially. For example, if a auto engineer says to the public “Boy, haveI got a great idea for the fastest most safest automobile ever built”, public can judge the performance of the automobile along those vectors (safety and speed) without knowing the first thing about the equations that govern the automobile’s engine or the whole system. As long as they can understand simple stats and basic logic, they could do this without the help of experts in automobile. IN fact those
        who critique these things better be independent reviewers who are really not auto experts rather than automobile engineers/experts.

        3.I will admit that it is not that easy in the case of climate science to validate the perf of claims made by scientists, due to the time scale involved. But it can be and must be done nonetheless. Translating the above to climate science,
        if you tell me that in 100 years earth inhabited by your children is going to hell in a handbasket, because our most complicated models built with all those horrendously complicated equestions you can find in math, show that the global temperatures will be 10 deg higher and icecaps will melt, sea will invade land, plant/animal ecosystem will get whacked out of order causing food supply to be badly disrupted, then I, without much
        climate science expertise, can easily ask you the following questions and scrutinize the results:
        a) where can I see that your model’s futuristic predictions about global temp, icecaps, eco system changes in the past have come true, even for much shorter periods of time, like say 20 years, before I take this for granted and make
        radical changes in my life?

        b) Assuming you are able to demonstrate 20 yr predictions with reasonable accuracy, given that these are very complicated systems of planetary scale, how can you inspire confidence in your extended predictions to 100 years, since we
        are unlikely to have 100 year predictions that can be verified?

        c) Let us start with the assumption that humans impact earth’s climate adversely to some degree. I am sure there is disagreement on even these mild statements. But lets put aside those disagreements. Let us also assume we all
        agree to change the human behavior to change the impact on global climate. But, Havent we had ice ages and warmer temps in the past, much before humans could cause any damage to the planet’s environment? If so, how certain are we that these earlier natural occurrences wont repeat irrespective of our impact on the environment?

        d) If such natural occurrences are likely to repeat, how are humans able to control or avert these occurrences by our environmentally friendly actions/policies? If it is not much in our control during one of those natural occurrences, can we
        choose environmental protection policies which are not economically punitive to today’s humans?

        4. Mind you, you dont need an understanding of PDFs, R values, proxies,paleoclimates, ENSOs, PDOs, decadal oscillations and the like to ask these questions. You dont need much of anything but the basic awareness of past climates like Ice ages, warmer periods, basic stat understanding and a little bit of logic.
        These are essentially logical questions

        So I do think you can evaluate or validate the claims of climate scientists and ask additional logical (though experimental) questions without a climate scientist credentials. Much like I evaluate the weather predictions, although admittedly,
        it is much easier to do than climate claim validation.

        Now if you are a scientist like I am in a different field, you can
        certainly scrutinize at a higher level, like how come you believe deleting the post 1960 tree ring data doesnt invalidate the pre-1960 reconstruction when post 1960 measured temp is the only way to quantitatively validate the tree-ring’s ability to be a good proxy for global temp?

        If somebody makes a claim about string theory toda (apparently Stephen Hawking receives a new theory every week by mail), it wouldnt matter to the larger public if there is no experimental proof to validate those claims as yet. But if you claim that I have to make wholesale changes to my lifestyle and sacrifice a chunk
        of my retirement, I want to make sure your predictions actually have credibility based on the validation of your past predictions, before I am ready to take a dent on my lifestyle. I have a justified suspicion given the weather predictions are often a flip of the coin, even while it is claimed that climate predictions are
        much better than weather predictions. The problem is that the climate scientists need to establish that (climate predictions are much better than weather predictions) with verifiable predictions, before we the public can be asked to
        take that for granted. We are brilliant scientists, so trust us, doesnt cut it, particularly since we keep seeing how well weather can be predicted with bright scientists and complicated models and uber expensive paraphernalia.

        In every other scientific field, No one touches your predictions with a barge pole, if your predictions with the same model havent been prevoiusly verified. This is not somwhow a unique standard/burden placed on climate science either. This is the standard expected for every theory/model/claim made in all other scientific fields I know of. So it is unclear to me, why this is any different for climate science.

      • Sorry, some of what I wrote is garbled in terms of spelling and sentence construction. As you can tell, I am having a hard time posting comments on this blog, since it is quite slow to respond. If there are some tricks to posting comments faster, I would appreciate any suggestions

      • Broadband?I am in UK and have no particular response issues with the blog. A little slow to ‘refresh’ perhaps. (1-2 secs).

      • Shiv:
        Right on. Where are the predictions? There aren’t any!

      • Shewonk
        Scientists with good accreditation disagree with each other about every aspect of climate science.
        The only thing that counts is the evidence, cleary and truthfully put .
        We cannot shrink.
        We must evaluate the evidence ourselves.

      • Shewonk. Surely you would agree that everyone is entitled to an opinion, even a mere blogger? Many of the commentators here have read into the subject and whilst they may not have published papers they are reasonably well informed and able to offer a considered view. Your remarks seem to suggest that the purpose of a blog should be to convince a reader. It’s probably a bit more than that really. It’s an opportunity to engage on a subject of interest IMHO…..but what do I know!! :)

      • If the purpose of this blog is to just let everyone express their opinion, educated or otherwise, then fine. It should be understood in that vein. Still, logic demands that we evaluate the worth of the various opinions. There is nothing in the blogosphere general commentary to distinguish the valid opinion from the invalid.

        In sum, if that is the purpose of this blog, it is of no more value than one in which bloggers rate Red Carpet fashions.

      • ….. rather like your own blog then.

      • I won’t defend my own blog because obviously, I am biased and think it has a certain value or else I wouldn’t write it. ;) However, my blog doesn’t claim to be anything but an opinion blog in which I get to indulge in my own brand of commentary including personal observations, satire and sarcasm. Those who find it amusing or engaging are welcome to post. I’ve only ever had to moderate one person, who interestingly, is a frequent poster at this blog.

      • Shewonk, I would certainly recommend that people pay a quick visit to your place. It will help them to understand the context of your comments on this thread.

      • I would advice to evaluate the worth of a particular opinion through the supporting material (logical derivation and/or data backing the opinion, source of data, reference when they are provided, and so on) attached to the opinion, the history of your particular interractions (on this subject, or in general) with the people(s) expressing this opinion, and only as a secondary parameter, far away from the first two, of the formal academic qualification of the opinion giver.
        I have met many PhD whose opinion I would not give a damn, being an advice on how to change a punctured tire or even on their main thesis subject.
        Others have valuable insight on their speciality from having spend a lot of time on it, but are not especially bright and so their opinion on anything broader or speculative is no more valuable than any educated, reasonably intelligent citizen.
        And some are really brilliant and usually have a opinion worth to listen. But they can be wrong too, a PhD is no silver bullet in general, in the field attached to your thesis, or even on the subject of the thesis itself.

        Professors are usually from the brilliant PhD, but can also come from the hard-working, persistant ones… if they have talent for team management and academic politics ;-)

        After all of this, if you are still interested in my formal academic qualification, I have a PhD, now work in the pvte sector but in research on numerical simulations. Still work with professors all day long, and I am one of the advisors for some new PhD students…So I do not speak out of bitterness ;-)

      • You know I read the comments and thought you were a reasonable person. Then the last comment made reference to your blog which is linked in your name.

        I hope anyone else who reads your comments also takes the time to do so because it is both eye opening and appalling at the same time.

        I thought Real Climate was bad enough with the arrogance and name calling but it appears you would fit in well over there. I am also studying as an undergrad – climate science as it where – and I truly hope that other “scientists” that I meet along the way are not as closed minded as your blog appears to be.

        Take from your blog:

        I’ve come up with a term for the trainwreck that is Curry’s blog and similar ventures – Climate Denial Chum.

        I will admit though, I can also use “best judgement” when it comes to blogs and this is one which does nothing to promote scientists in climate science and for someone wanting to claim that blogs are not the best place for science discussion you certainly go a long way in throwing mud at everyone else who tries.

      • yes, there is a certain (low) class of climate blogs, which are identified by their use of the term “denier chum.”

      • I wonder, when the arguments and analysis of those clowns starts to count, will we have attained post-post-normal science? Or is that just the point when we all finally dissolve into a sea of relativism and uncertainty?

      • Once you’ve seen one, you’ve seen them all.

        The usual telltales are links to the other well-known extremist blogs, and for me, e.g. the words “Rebuttal”, “Denier”, “Denialist” usually tell enough to exit the page. This is a shame, that albeit their partizanship and perhaps somewhat immature black&white-type of thinking, people writing those pieces are smart and might have even good points. I bet many of which will regret their writings once they grow up, regardless of what turns out to be “truth”.

      • Well, you can be Very Insulted by the use of such a coarse term, or you can actually read the analysis. Might there be any reason why Lucia’s blog his substantive discussion on topics like this and your blog has Iron Sun Guy, conspiracy ranters and commenters posing as other commenters.

        Is it random, or could it have something to do with the tone set by the host? You don’t have to find the argument compelling, but just pretending there isn’t an argument there doesn’t really bespeak an open mind.

      • @PDA,

        You seem quite sensitive PDA. I am not posing as anyone, or I would have actually called myself “dhogaza”. Mine was nothing more than a satiric post to try to make a point about the silliness of some people who choose to talk down and condescend towards others, regardless of their intent. Those who throw about terms like “denier” towards those for whom it does not apply. I would not, for instance, put you in that group. But there are many who do. I simply chose a similar name to one of those people to make a point. One you apparently missed. It is irrelevant who I am in reality, though I do post from time to time under my own name. But not often.

        I have read more than enough to know how certain people act. They don’t like me having a go at their expense, tough.

        However, for your sake, and the sake of keeping Dr. Curry’s blog civil and not appearing as a farce–something I don’t think it is but many others do and are by no means shy about tossing insults about (a certain bunny comes to mind)–I will cease and desist.

        Again, my deepest apologies to the great dhogaza for any pain I may have caused. For the record, I am neither him nor Mosher.

      • Dehogaza has a point and expresses it with zest and gusto.
        It would not be dishonorable to make that point without a sock puppet.

      • Sock puppet or no sock puppet, the point stands. Would it be better if I used the name John Smith? Or HLM? or “teddy”? Or perhaps “Deeper Climate”? I guess it is the pinnacle of honor to hide behind a pseudonym to make genuine accusations of academic misconduct? You got the balls to accuse someone of something serious and real, you should have the balls to use your real name. John Mashey, for all his disturbing unhinged rants, at least has that going for him.

        No, honor is a trait which is lacking throughout this debate, at many blogs–“warmist”, “lukewarm” and “denailist” alike.

      • > Sock puppet or no sock puppet, the point stands.

        I agree. On the one hand, you have a sock puppet; and on the other, you have no sock puppet. Sock puppetry is then quite unnecessary.

        > Would it be better if I used the name John Smith? Or HLM? or “teddy”? Or perhaps “Deeper Climate”?

        I believe Deeper Climate is already taken. Using Dehogza made your point directly about Dhogaza, as an ad hominem. This kind of trick can be considered offensive after a while; mileage varies from site to site. Using it as a sign of protest can be beneficial. Let’s not slip into netiquette casuistry.

        > I guess it is the pinnacle of honor to hide behind a pseudonym to make genuine accusations of academic misconduct?

        I’m not sure how it relates to what I said except by caricature.

        A commenter reaps what has been sown in the comments under his hame. If a commenter drowns him, her or itself in his, her or its own noise, say by proferring genuine accusation after genuine accusation of academic misconduct, readers might stop recognize him, her or it as a genuine contributor.

        If that behavior acts as a catalyst for that person’s anger, say by preventing that person from child abuse, at least it serves as a genuine outlet.

        > You got the balls to accuse someone of something serious and real, you should have the balls to use your real name.

        Anonymity is a right, whereas identity is a responsibility. It would be inadvisable to confuse the two, like when sock puppets are overused and tolerated by blog curators.

        Accusing someone of something serious without any evidence should not be tolerated by blog curators. But in the end, the policy can never really be stricly enforced, more so when the moral reason for the blog to exist to shame.

        In the end, the reputation of the blog curator is a more important stake than the reputation of commenters.
        If something annoys you here, contact JC.

        If you have a problem with hatred speech, it might be possible to close down a site that promotes (in the technical sense) it, however anonymous it might be.

        If you have a problem with free speech, turn it over to constitutionalists.

        Appealing to pride does you a disservice. Honor is bound to names. My work under my name is my honor.

        > [H]onor is a trait which is lacking throughout this debate, at many blogs–”warmist”, “lukewarm” and “denailist” alike.

        Trying to prevent namecalling is fighting against the wind, and perhaps futile considering that namecalling mainly hurts more the name caller.

        Trying to overplay your hand makes you lose your zest and your gusto.

      • Random Poster Not To be Confused With Anyone Else But Me And Certainly Not Another Antagonistic And Condescending Friend Of The Enviroment--Which I Am As Well


        “dhogaza is a jerk and an idiot”

        That is ad hom.

        Using a “variation” of his moniker to try to convey the actions of that particular side of the climate blogosphere is not. Granted, it’s my opinion of that side. And there are some on the “other” side who are no better. But, I picked on poor dhogaza as an example of the problem as I see it. Complete confidence and hubris are the problem when trying to convince the general public. I may as well have picked another, but he is one prime example. The problem being that any random person, science acumen being irrelevant, who ventures into this world is automatically going to be put off by the reception if they simply don’t buy the party line. They will automatically be put off by arrogance. I have seen it happen, first hand.

        That said, your points are well taken. And as I have said previously, I will let it be. And my apologies to Mr. dhogaza for any pain and suffering..

        Truth be told, Birds of Prey are big in my book. Beaver Creek area especially.

        Good night now and forever…

      • Random Poster Not To be Confused With Anyone Else But Me And Certainly Not Another Antagonistic And Condescending Friend Of The Enviroment–Which I Am As Well,

        When you say that:

        > Complete confidence and hubris are the problem when trying to convince the general public.

        I am in complete agreement with you.



      • Maybe I am an entirely reasonable person and maybe you are wrong about my being closed minded. That’s always possible. :)

      • You’re a political hack. And not a very good one, sorry to say.

      • Well, technically I am not a “political hack”, since that is an unskilled person who works for a political party and does so for personal gain.

        I don’t work for a political party. In fact, if you want something to attack me on, you can call me a “midlevel bureaucrat feeding at the public trough”, since I am a member of “the professional civil service” or “snivel service” as we like to joke. However, I am unionized and so I do not serve at the leisure of the government in power. Neither do I try to appease whatever government I am serving nor do I try to undermine it. I stay where they come and go.

        So, no. Not a political hack.

      • Onlyin your closed mind

      • Harold H Doiron

        The value in the post is in the pertinent questions asked regarding changes in atmospheric levels of CO2 in the past. If we can’t answer these questions, how can we confidently predict anything about the future?

      • Quite so. The theoretical postulated effects must first be evaluated by reference to analogy in natural change in the Phanerozoic geological record prior to the modern era. Until such time as the theoretical CO2 driven temperature relationship can be demonstrated convincingly in terms of quantitative forcing in the natural planetary record, the forcing can not be assigned any confidence value at all.

      • If it comes down to opinion rather than evidence, then I would suggest that while it’s certainly more likely than not that the majority expert opinion is correct, that one should firmly keep in mind that it is opinion, not fact, that one is considering. And it is worth remembering that there have been some spectacular failures of majority expert opinion, even when such experts are in fields – such as medicine – where peoples lives are on the line and standards for evidence are high. Is it a fact or opinion that the GH effect is real? It is a fact. Is it a fact or opinion that humans have had a major impact on climate? An unavoidable and obvious fact, I believe. Is it fact or opinion that the major human impact is CO2? Now we are entering the realm of opinion, in my view.

        As a society, we can, have and do make decisions that impact our future based not only on facts but also on opinions – that’s unavoidable. However, in order to properly assess the evidence – and thus make the best judgement possible given the available evidence – one needs to clearly distinguish between what is fact and what is opinion, because facts clearly carry more weight than opinions (or at least, they should!). We should not act in ways that are likely to be damaging to people (including, but not limited to, economic damage) based purely on opinion, regardless of how expert that opinion is or how many experts we consult – in this respect, we should follow the maxim of the medical profession; to wit, “First, do no harm”.

        I can’t help feeling that we are not following this path – that we are acting in ways that can and do harm people based on the opinion of experts. It may well be that those experts are right (or wrong!), but we do not know they are right (or wrong!) and this makes such actions (those that harm people) morally wrong, in my view. There are many “no regrets” actions that we can take in this area and we should restrict ourselves to those or we risk history judging us very harshly indeed – and rightly so – for our hubris. Yes, rightly so – do we not judge harshly those who act on faith rather than evidence? Surely acting on opinion rather than fact is an act of faith.

      • Trolling again SheWonk? What to do to shut down this unwelcome exchange of facts and viewpoints? You gave it your usual try. Don’t like the thread, STFU. Or better yet, go here for a more sympathetic audience:

      • The fact that you interpret someone disagreeing with you as an attempt “to shut down this unwelcome exchange of facts and viewpoints” says all that needs to be said about your mindset.

      • shewonk,
        People know the smell of bs, even if they do not understand the biology of bovine digestion.
        People see the claims of AGW promoters and while they might not understand radiative physics as much as science of doom know junk claims when they see them.

    • [youtube=]

    • I agree, look at the CO2 tracker. We’ve got so much going on, we don’t know what we don’t know. And people make assumptions on the unknowable.

      • Ever driven in a white-out, suyts? Do you go faster or slower when you can’t see clearly? Using uncertainty as an argument for continuing to barrel ahead blindly makes no sense to me.

      • PDA, the argument cuts both ways. If you have no idea what is going on why would you pursue a very expensive course of action rather than doing nothing until you have a reasonable degree of certainty.

      • It depends on the actual cost of the “really expensive” versus the cost of the catastrophically expensive alternative, which is always sold as a deferred payment plan.

      • There is no such thing as “doing nothing.” Continuing as we are is doing something. This is a facile argument.

      • PDA

        May I rephrase, for my own sake, into a more mathematical framework?

        Your analogy does not reflect doing something vs doing nothing, but doing less that perturbs the Chaos of the climate (going slower) vs poking the hornet’s nest of climate Chaos — or extremities — with a bigger and bigger stick (going faster).

        Jay Currie posits going slower to be very expensive, while Pinko Punko asserts going faster to be a catastrophically expensive deferred payment plan.

        Again, mathematically, I’d like to rephrase:

        Expense of going slower will either be a net loss, or a net dividend. Nigel Lawson proposes that going slower will be a net loss. Free market mechanisms should ensure whatever the expense, the individual choices of buyers and sellers will tend to reduce the impact of said expenses from the maximum numbers Lord Lawson posits to a much lower, marginal, level except where his numbers take on the aspect of pure fantasy, proposing a world that can never be, with an SUV in the driveway for every member of every family on the planet to ensure maximum welfare of the poor.

        Much more reasonably in the alternative with regards to expenses, Ross McKitrick proposes a double dividend to going slower that would be a net gain. This is the very rigourously developed McKitrick Carbon Tax recommendation, though one takes issue with some of the details.

        Also, classic Long Run Cost Analyses show going slower will reduce prices overall in the market and reduce monopolistic pressures, reduce unearned profit and lead to a more efficient economy, encourage new technology and in a Pigouvian sense shift tastes toward positive externalities while decreasing negative externalities.

        Overall, Jay Currie and Nigel Lawson do not reflect the expected expenses one determines from careful examination of their case by the best methods available, but instead grossly inflate the expense without adequately accounting for the likely benefits.

        That’s before we even begin to consider the climate at all.

        Looking at Pinko Punko’s catastrophes, there are many uncertainties and we must take into account what some very advanced thinkers contribute about Chaos, that if we wait long enough, we’ll see the catastrophe anyway, and we can’t say what ‘enough’ means. This, however, _makes_ rather than deprecates Pinko Punko’s argument.

        Insurance places bets on probabilities, not uncertainties or Chaos to minimize risk to each individual by sharing the cost of risk throughout the system so a set of worthwhile ventures may be pursued by all even where the cost of misfortune in that system would be too much for any one to bear alone.

        You cannot insure Chaos. You cannot insure Uncertainty. There are Game Theoretical reasons for this, but it comes down to no one in the long run can afford to bet, or to be the bookmaker, when they can’t know the rules of the game or even how many players there are.

        Reducing Chaos and Uncertainty, therefore — going slower — makes more of human endeavor insurable, which makes more of human endeavor feasible.

        In short: slower is less expensive, has many side benefits, and allows more to be dared by more people; faster is more expensive, has many side detriments, and will hold back more people from more potentially rewarding adventures.

        Did I phrase this correctly?

      • Well Dr. Curry put it differently than I would have, but she captures the sentiment. I would have said something a bit more derisive, something like,

        Well, yes, this obviously means that we should destroy the entire socioeconomic structure of the world and starve developing nations of much needed energy, based on us not knowing something. I’m sure that would fix something.

        I often wonder if people understand the implications of the draconian “remedies” being proposed.

      • I’m often amused that people who claim to be “skeptics,” making judgments solely on evidence, accept without question wild assertions such as the idea that any attempt to limit carbon emissions will “destroy the entire socioeconomic structure of the world and starve developing nations of much needed energy.”

      • PDA, check the numbers. CO2 emissions is a proxy itself. Its a proxy for economic growth. You know, that thing that increases standards of living. As the earth’s population grows, the requirement for energy increases. Already we’ve seen disastrous results from our headlong rush to “fix” something. In the U.S. alone 5 billion bushels of corn/year is changed from food to fuel. The cost of food increases significantly the availability decreases. We’re killing people to save humanity? Sorry, it pegs my fallacy meter. While we’re already OT enough, I’m hoping soon Dr. Curry will do a post on our “solutions” their cost and their effectiveness. That would be in an area of professional expertise for me. But I’ll leave it at this, they don’t work, they’re expensive and they’re killing people.

      • Before the US started making corn ethanol, nobody was buying all of it, it was piling up on the ground.

        Take a look at it from the farmer’s perspective, it’s like it’s my land and I’ll grow what will make me the most money, and that happens to be corn and soybeans. If you want to feed it to the world’s poor, well it’s for sale to the highest bidder.

      • If energy = CO2 emissions, then this of course makes sense. If there were a concerted effort to replace coal-fired power plants with nuclear, for example, your argument pretty much collapses.

      • PDA, I’m all for nuclear energy. Sadly, environmental concerns have basically thwarted any effort made towards that end. Of course, today, from the time of inception and commitment towards building one, it takes about 20years to be built. Instead of, in the finest Quixotic manner, dreaming up whirlygigs and REE sucking solar panels, we should have been building nukes. We said that years ago. Hydro power being even a better option, but again……we’re thwarted. Oddly, by many of the same people advocating a CO2 emission free world. Kinda goes back to the BBC interview, no?

      • suyts,

        it isn’t environmental concerns that have thwarted nuclear energy growth. What has thwarted nuclear is the cost. It’s prohibitively expensive to tie up private capital for the 10-12 years before payback begins.

        In France, nukes are a governmental program.

        So governemt ponies up the money for development and assumes the cost of catastrophic failure. And the people advocating nukes are capitalists who oppose government intrusion in markets?

        Just a few contradictions to resolve.

      • Straw man argument both petty, illogical and irrelevant.

      • Neither does it make sense to blindly change direction.
        We don’t yet even know what we don’t know.

      • Peter -You are correct- we don´t yet even know what we don´t know.

        But we do know what we do know.

        And when we state what we do know, we have a group of people jumping up and down and going “we don´t believe you we don´t believe you” and whatsmore -you are are all crooks with malice aforethought and proper science should be done on blogs by amateurs who know better.

        It is becoming farcical.

        What does `blindly change direction´ mean? Sounds stupid to me- who is suggesting that we blindly do anything?

      • Sarah your description contributes nothing, other than a generalized person against whom you can rail. Yes let’s ignore the “up-down jumpers”. Does that take care of the whole lot?

      • Sarah,
        If there up-and-down jumpers claiming one thing, would you be able to agree that there is another group with opposite views jumping-up-and-down as well?

      • Ok – lets generalize then- one group is saying that there is a significant amount of damage being done to the biosphere through human activity to warrant concern- this group is made up of atmospheric scientists, biologists, physicists, oceanographers, Nasa climate scientists, National Science Academies, WMO etc

        The other group- made up of the odd climate scientist, amateur bloggers, Republicans, retired non accredited weathermen, libertarians, tea partiers, Fox News, Koch Industries, right wing think tanks, conspiracy theorists and cranks who are saying that there isn´t.

        In the middle we have another group-The General Public-many of whom are sufficiently educated to read up the information and decide for themselves. Many of those who do are convinced by the science and thus believe we should address the issue based on what we know. Others are convinced that we do not know what we do not know and we thus shouldn´t `do anything´until we do know what we don´t know. Still others are simply confused.

        There is another important group- the sceptics -who are scientists who specialize in the field of Earth sciences and do research and publish papers to add to the increasing knowledge of how our planet functions- challenging assumptions, putting forth theories which can in turn be challenged and so forth- that is: conducting science in the arena in which science is conducted.

        Blogs- like this one- are useful places to air opinions, even undertake analyses and have arguments. But they are not where science is done- anyone with pretensions of being a sceptic in the real sense of the word should undertake the revelant studies, do research and publish papers which are subjected to review by one´s peers.

        These can then be further assessed by The General Public who take the trouble to keep abreast of scientific developments in this field.

        As someone who is convinced by the science and believes that we should be addressing the problem with some degree of urgency, I am rather more than frustrated by this endless quibbling about what we don´t know about what we don´t know.

        How do you characterize your own position?

      • So no takers on the satellite imagery of our CO2? Can anyone see the obvious respiration?

      • suyts

        It’s not the obvious respiration at issue, rather your obvious misinterpretation.

        Above ( it was claimed CO2 is at its lowest level ever right now. I’m guessing Latitude, who made the claim, is in the 2-5 epistemological category; what I got from reading the level 1-2 epistemological reports is general agreement on (2.3+/-0.5)x10^-4 parts of unity CO2 for the half-million years or more before 1750 AD.

        There’s at least a 40% difference between Lattitude’s claim and the generally agreed, to much higher than 95% certainty, range for ‘lowest ever’ and 180 ppmv (the low end of that range) is so much lower than 390 ppmv as to make that claim silly to see even on a blog.

        Likewise, your graphic is informative, instructive, pretty and somehow leads you to the opposite conclusion of what the best of the work by those in the epistemological level 1-2 (though I think there is more distance between level 1 and than between 2 and 4) says.

        Sure, there’s respiration. There’s also seasonal variation, and day night variation, and regional variation and variation due external forcings like volcanoes.

        There’s also a baseline signal that can be detected, measured, verified and validated within the framework of knowledged and reasoning that forms the science of such matters.

        It’s really good to keep in mind that we don’t know what we don’t know. That’s the beginning of a special wisdom. Yet it ought not prevent us from seeking to know.

        It’s good to know what your graphic presents. It just shouldn’t, except if bias is involved, lead to the interpretation you present, by the methods of reasoning and careful study.

      • lol, ok Bart your appeal to authority is well noted.

        One of your statements seems a bit curious to me.

        “It’s not the obvious respiration at issue, rather your obvious misinterpretation.”

        I asked if others saw a respiration. What, exactly, was the misinterpretation? That’s kinda irksome. I can appreciate you assigning the word pretty to the graphic presented, but it isn’t mine, it’s NOAA’s.

        I don’t think Lat was speaking towards only the last 1/2 million years, but I haven’t read his particular post here, yet.

        One final thought, there is a huge distinction between “seeking to know” and making assertions based on knowledge that is quite obviously incomplete. This is why we’re having this discussion. Because people are expressing certitude about things of which they have no possible way of being certain. My last statement, I put in the = 100% probability range. I’ll note, this is significantly different than saying “we took a vote and most of us are 95% sure this is truth.”

      • suyts

        Technically,we are both inheriting Dr. Curry’s appeal to authority inherent in this thread and its epistemological definition of terms; by your participation in it, one must conclude you too inherit this same quality in what you say here, as you do not explicitly nor until you mention my use of it implicitly dispute it.

        Indeed, by citing Latitude, I certainly was inclusive of non-authority opinion, where you cite by linking to the NOAA video only level 1 of the epistemology.

        If you’re going to take note of arguments from authority.

        How can you not have read Latitude’s particular post here? It’s the one you replied to with the post starting “I agree..”

        Small wonder you don’t know what you don’t know if you don’t read what you agree with first, and then compose world-spanning economic theories about baselessly.

        What exactly was the misinterpretation? Michael Tobis says it well below, but to be exact, if you can look at a scale of 365-390 ppmv and thence draw the conclusions on it to agree to and further produce assertions on CO2 moving from as low as 180 ppmv, and not before holding a baseline above 280 ppmv until this quarter millennium on a timespan comparable to the age of our species, then you are clearly misinterpreting.

      • Sorry Bart, I’ve been on several different blogs simultaneously, and sometimes I lose track of the particular threads of a post I’m conversing on. (It is more stimulating this way.) Of course, you’re right, I did state, “I agree.” I apologize for my confusion. So, let me clear up what I was agreeing with,

        “I honestly do not believe that we even know enough to make this statement………

        I also agree, that by our presence here, “we are both inheriting Dr. Curry’s appeal to authority inherent in this thread and its epistemological definition of terms;” But, I should point out, that it was by this very premise, that gave rise to the skeptical community.

        All give a pass on your snarky comments (because it was me that caused them) except to say, limiting global CO2 emissions by its very nature would have “world-spanning economic” consequences. I find it profoundly telling that we could create some very complex assumptions as to CO2 levels and tree rings and the like to the point of minutia and trivia, but have little to say about the subsequent effects of our actions beyond temp and CO2 levels. It is folly.

      • suyts

        Very well-spoken, thank you.

        Appeal to authority is a very great danger.

        It can take a small child to say the emperor has no clothes.

        It may take a condemned criminal to recognize an injustice done to another.

        We ought not dismiss any voice in all this.

        Further, the power of authority undetected to bias perception and preempt logic is great, we know from countless historical cases.

        Still, once an authority has been validated by logic and observation and so many tests and checks as can be made by an ordinary skeptic, the attraction of referring to the works of authorities as a short-hand for reproducing their works.

        I admit, as Dr. Curry often looks for gentle and fair ways to encourage we too-frequent and under-credentialed posters to read and learn instead of post and rant, I was using her method to see how the fit felt. I’m new to the form, as I generally avoid it for reasons above.

        For myself, about your conclusion, I say this: the temperature record is to me of at best tertiary importance. All this effort on such a little piece of the puzzle reminds us how huge the problem we have to solve.

        Knowing the regular and solvable patches of the problem are disjointed by Chaos, which trumps all, we are picking our way through a turbulent river of unknowables by stepping stones where logic and knowledge may be firm enough to uphold some conclusions.

        I favor relying on the CO2 data, and the mathematical certainty that CO2 emission as a perturbation is going to upset some of the stability of the climate, and we can perhaps say little more than that, except with less perturbation there may be more stability.

        And I’ll work on my snark.

      • BTW, Lats. epistemological category is probably 2. If we’re going to lend any meaning to such. I only say that because I’m very familiar with his posits and we’ve had several discourses throughout our time in the blogosphere.

      • Note that the absolute difference between the blue colors and the red colors is small. The patterns are easily understood in terms of sources and prevailing winds.

        It is good to get this kind of resolution, because it will help enforcement in the apparently unlikely event of a remotely adequate international agreement. But I don’t understand why you find this animation mysterious. It is pretty much what you’d expect, isn’t it?

        People really ought to distinguish between “not understood” and “I don’t understand it”. It’s a very important distinction.

      • Well, ok, small……..april – aug a drop in CO2 15-20 ppm prevalent all across the NH. Where did it go? Conversely a 15-20 ppm increase starting during the winter. Where did it come from? It isn’t the factories and coal plants, they don’t emit that much CO2 to raise it that short period of time.

        5. The majority of the increase in carbon dioxide concentrations since pre-industrial times is due to anthropogenic emissions of carbon dioxide. …….

        The only way #5 can be true is if the respiration witnessed was entirely symmetrical. In other words, the mechanism that takes out the CO2 during the summer is equal and opposite of the mechanism that puts it back in during the winter. Then the increases could be attributable to mankind. You ever see it work like that in nature?

        There is no way a person can state with any certitude that we know the increase isn’t the difference occurring in the stated mechanisms.

        I’d say I’m breathlessly awaiting your next wonderfully snarky insights, but I’m not.

        Maybe you should break out the old calculator and pop in some assumptions and see if I’m correct instead of blathering about understand and understood. BTW, ain’t gonna happen, sis.

      • suyts

        I don’t mean to step on Michael Tobis’ toes, but the level of CO2 has always so far as the various ice core and like data strongly suggest (above 99.5% with consilience) been seasonally variable over land due to interaction of plants and temperature as proven by NH/SH trends, just as it is diurnally variable due to photosynthesis.

        CO2 levels have also always been, by the best interpretation of this ice core record dating 650,000 years or so, up to 1750 AD, selecting out cores and like data that show a signal of some external factor like volcanic activity or ‘dead air’, been varying gradually up and down from 180 ppm to 280 ppm with no particular periodicity and very few exceptions into the low 310 ppm range.

        To account for attribution, given this variability, analysts used a number of techniques. They looked for the signature of fossil carbon’s distinct isotope ratio. They looked at gross tons burned. They used standard techniques of describing dynamic equilibrium of gases in air, and had long, intricate debates in the peer reviewed literature. They refine this iteratively, as more data comes available and better interpretations are offered, tested and accepted.

        It’s possible they’re all wrong, of course.. but even so, what they say makes rational sense and is reflected in the data.

        Which they have all over the phrase, “entirely symmetrical.”

        Fill a half dozen large buckets with water and label them ‘MAN’. Set the drain and tap in your sink to the point the water level remains constant. Label that level ‘Nature’. You’ll note ripples in the sink make this level vary a bit.

        Now dump in a bucket of MAN.

        The level goes up.

        Immediately dump in the next bucket. And the next. And the next. And the next. Look for a mop.

        Every decade MAN adds as much new CO2 to the air for every square inch of sky as equals the mass of graphite in the clay core of a standard 8″ pencil.

      • Well, I was a bit OTT, but dayem, he’s stating I didn’t understand what I was seeing, when he had no idea of what I was stating.

        I accept your explanation as a general position of consensus thought. The way I read the explanation, and, correct me if I’m interpreting wrong, is that we can accurately measure the various intakes and out-gassing of CO2 to where it remains relatively static except for man’s contribution. In fact, in your own response, “…..been varying gradually up and down from 180 ppm to 280 ppm with no particular periodicity and very few exceptions into the low 310 ppm range.”…implies the variance is as great as what we’re all up and in arms about…….(and that’s if you agree with the precision of the ice cores samples. I’m still working my head around that and withhold judgment as to their validity.)

        Not to beat a dead horse, but this strikes me as Briffa’s method. They cut off the last 50 years because of a divergence….this implies they know it never happened before.

        Again, leaning on the validity of ice cores, …..the last 650,000 years…….ok, that would work with me, except, many believe earth’s history is much longer than that. What of periods of time before? Did the past equilibrium seeking mechanism die? It is stated that CO2 levels varied much more back then.

        The thing that bothers me, is the level of certitude attached to #5. I agree, it makes sense. This is probably the case. To state that we know this to be the case is impossible to state. Again, I submit, we haven’t accounted for the ppm change seen. And here’s the thing that bothers me the most. Other than ice core samples, is there anything else that has advanced this part of the theory in the last 30 years of ever increasing funding for climate research? I haven’t seen any. It was posited and accepted, in spite of howls of protest. But, to my knowledge, that’s been about it. We repeat the same arguments and there is rarely any new insights to the theory……..after over 30 years?

      • suyts

        Again well-spoken, thank you.

        I really doubt anyone familiar with me or the consensi calls me a consensus anything. Anything kind, at any rate.

        And yes, you are wrongish, to quibble, unless we’ve seen a different 30 years of science.

        There’s a voice in my head I always hear shouting, “No! No! That’s NOT the way it really works!” about practically every explanation I ever see or read or hear. My own included.

        It takes every fibre of discipline I have to restrain that compulsion down to mere skepticism by effort of logic and reason, analyses and mathematics, and it does make me snarky, but I often come to quell my objections by selecting of the various alternatives the one that does best answer logic and mathematics, analyses and reason, and a framework of knowledge and general principles.

        If you call that consensus, guilty as charged, and I pity the poor world of people in this maddened consensus class they share with me.

        I don’t know Briffa.

        I’ve seen and read the discussions of his method in some depth, and see no great similarity.

        Comparing and characterizing all of science by the tree-ring debacle is perhaps unproductive.

        In this case, however, it holds up well as an example of opposites.

        Ice cores are a different sort of observation than tree rings, as ice is not subject to the same vagueries as living plants.

        The statistics are entirely different.

        The selection criteria is objective (meaning not self-referential) and based on a better-known and less assailable mechanism.

        The rate of rejection of ice core samples within that mechanism is far lower, and the number of ice cores and length of the ice core record are substantiallty greater.

        Most of the objections to Briffa simply do not apply, and where they do apply, they apply in a much less plausible light or as a luminous opposite.

        A variance from 180-280 (and in a vanishingly small number of instances up to 310) much does mean Natural variation is on the same absolute scale as the human variation to date. Except the curve has always turned downward by 310 ppm on the ice core record (of which, unlike anything in the thermal record, we are perhaps more confident than any other measurement in all of Climate Science, at least so far as I have seen proposed, exceeding many of the standards of certainty of Physics, Chemistry and Astronomy) for over half a million years.

        Until now, since 1750, when the Industrial Revolution happened.

        We’d be idiots as a species to not suspect something was up.

        We can broadly measure or estimate present day emissions (to a couple of significant digits) and work out our contribution to CO2 that way. This method agrees with that method and adds precision.

        We can measure like isotope concentrations, too, an entirely different basis for deciding the contribution. This method agrees with that method and adds precision, and tends to confirm the related but distinct isotope methods used in ice cores to boot.

        We can measure optical properties in the range of CO2’s absorbtion spectrum, again an entirely different basis. Again, agreement.

        We have seen many alternative proposals howled, which were experimentally shown to not agree with what really happens, by the above methods and other measures over and over again.

        This is the observational index other science only wishes it could touch in increasing Probability and also diminishing Uncertainty.

        So, sure, what you call consensus, the work done by people devoting years of their lives to this and acknowledged to be brilliant at it, and that I tried to knock down by looking at other sources and using my own reasoning and always failed to find sufficient fault with to overturn, might be wrong about this one thing.

        If they are wrong in this gold standard of reasoning, then we really can know nothing at all.

        If ‘know’ means nothing, why bother have a word for it?

        No. We KNOW this, within our definition of Uncertainty.

      • Bart,

        Thanks for the response. I’d like to clear some things up about what I said, ….. I wasn’t calling you a consensus anything, but your explanation was consistent. There are quite a few things I agree with, also. When I referenced Briffa’s paper, it wasn’t really to disparage, rather to show, that many things in climate science are based upon the opinion that an occurrence never happened before. (I assume, the reasoning behind throwing out the most recent tree rings.) While there certainly is much else to say about the study, I was limiting it to that observation.

        Towards ice core samplings. I’ve truly haven’t looked into the methods employed. The problem I have with them, is how they can time-sequence material that may have thawed and re-froze a few times and the fact that particulate can move through ice. But again, I haven’t looked at it, so I withhold judgment.

        Towards the isotopes, I assume you’re referencing the 12/13 CO2 isotopes. I’ve got a few links and a couple of papers that I haven’t got to yet, I’ll probably give them a go as soon as I find some time. Have you any to suggest?

        When you stated, “We’d be idiots as a species to not suspect something was up.” I entirely agree. My logic, my reasoning, is that we simply don’t know enough about the system to make assertions. Not so much as to the isolated specifics, but rather knowing all of the dynamics involved. In fact, we can be pretty sure we’re woefully lacking in our knowledge. We don’t know what we don’t know.

        Bart, I’ve enjoyed our little colloquy. Thanks.


      • Suyts,
        The scientists working in a particular field are supposed to know a lot more than others. Their scientific publications tell about their knowledge, but very seldom for outsiders to the research area to really judge. Thus the observation that I or you doesn’t know about the certainty of the conclusions is not a proof in either direction.

        Very much skepticism has been directed towards climate science. Certainly some of it is well justified, some totally unjustified and very much in the range, where it is difficult to say. By the third group I mean skepticism that cannot be removed from, what outsiders may really judge. They cannot pinpoint correctly anything improper, but they may have some generic reasons to doubt, whether the scientists have really presented a fully objective picture or whether the scientists have been able to avoid all significant pitfalls.

        We should somehow find the right balance between trusting scientists fully and having no trust to anything that we cannot check ourselves. If there would be time to wait until the science has settled on the issues, there would be little problem, but with climate issues many want to have answers faster than normal scientific processes can confirm them.

      • Suyts,

        I am quite skeptical to anything said by anyone (at both sides of the fence), whatever his/hers degree and tend to check it myself (as far as possible) before agreeing or disagreeing with an opinion.

        In the case of CO2 increase and human emissions, there is extremely little doubt that humans are the cause. Every observation agrees with it and all possible alternatives fail one or more observations. See:

        In short, oceans are not the source, as their d13C level is too high (thus should increase the d13C level of the atmosphere, while we observe a decrease) and vegetation is neither, as we observe that there is a net production of O2, thus vegetation as a net sink for CO2. All other possible sources for CO2 are minor and/or much too slow.

        There is a lot of recent research showing the distribution of human CO2 in the oceans, the partitioning of CO2 sinks between oceans and vegetation, etc.

        About the reliability of ice cores, the main objections are from Jaworowski, here what I make of his objections:

        And direct chemical measurements of CO2 in the atmosphere during the pre-Mauna Loa era had their problems too:

      • Pekka, thanks for the input, the trust/skepticism problem is one of our own making. The old adage, “fool me once…….”, applies. While, I find it entirely likely that most engaged in climate science are very intelligent, sincere and honest people, there have been a few cases of blatant hyperbole that caused the general public to believe certain things that I believe are highly unlikely. For instance, the pinpointing of places where prolonged droughts will occur if climate change continues on its death spiral.(this is only one of many examples) While I’ve yet to find someone that can give me a justification for such a prognostication, I’ve yet to see a refutation or even a clarification of such hyperbole. Trust is much easier kept than recovered. So, some of the skepticism may subside, but only if a consistent self-policing mechanism is visible. Else, people will continue taking their word with a grain of salt.

      • Ferdinand, thanks for the links, I promise to give them a good read when time permits!

      • suyts

        Had a long reply praising yourself and Ferdinand and others with links and boring stories, but computer crash ate it.

        In brief, anyone can start with wiki on ice cores and explore for themselves, so long as they are skeptical and widely read without falling prey to traps and deception.

        Given your attitude and energy, I have faith you will find what you seek, whether it agrees with what I found or not.

        Good luck.

      • “april – aug a drop in CO2 15-20 ppm prevalent all across the NH. Where did it go? Conversely a 15-20 ppm increase starting during the winter. Where did it come from?”

        The biota, of course.

        “In other words, the mechanism that takes out the CO2 during the summer is equal and opposite of the mechanism that puts it back in during the winter. ”

        In the long term average with steady state biota, yes, certainly.

        Are the biota not steady-state? No, they aren’t exactly. That is a well-known term in the anthropogenic CO2 forcing. But a familiarity with the Keeling curve will reveal that the two main features at the global scale are a nearly constant amplitude annual cycle and a persistent year-over-year increase. This is all well-understood.

        The exact details of the biotic sinks are essentially a minor correction on this picture, and pretty much invisible on the animation. What’s interesting about it is the visibility of the large anthropogenic point sources. You can focus in on details and do lots of good science. But to my eye the movie holds no big picture surprises or anything that would rise to the level of unexpected or mysterious.

        If you personally find it confusing, so be it. If you find an explicit controversy with the literature, so much the better – these are opportunities to expand our understanding.

        If you find a contradiction with the major high likelihood IPCC consensus conclusions, then your original posting would make sense, but then you really ought to tell us what they are.

        The important point is that there may be things you don’t know, or that Judith Curry doesn’t know, or that I don’t know. That deosn’t mean they are unknown.

        The purpose of IPCC is to gather the relevant known information and state it in a balanced way. You and Curry have very little faith in the consensus process. Mine is rather higher. But even if you don’t accept IPCC you have not shown that a particular piece of knowledge is unknown, just because you yourself do not know it.

        “I don’t know”, “it is unknown” and “it is unknowable” are drastically different epistemic claims. Their persistent confusion is the key to our policy dysfunction.

      • Michael, I didn’t find it confusing. I simply presented a changing graphic and asked for thoughts. I’m not the least bit confused about what it is stating. But, please, expand my knowledge base. Without speaking to the epistemology, explain to me how it is we “know” this isn’t the mechanism that is increasing the atmospheric CO2 levels rather than the relative insignificant anthropological contributions. Accumulating? Perhaps, but the respiration viewed seems to contradict that thought. You may think 15-20 ppm swing over the majority of half the earth in a period of 1/4 of a year isn’t much, but we’re all excited about an increase of 100 ppm in about a century. Yeh, ok, knowing, unknowable, etc…. if the out-gassing were just slightly more than the sinking, over the same time period, then it could explain the majority of the increase in atmospheric CO2, but we “know” that’s not happening ’cause some really smart guys had looked into it and came up with a different explanation. And, because they are really smart guys, their explanation is more valid. Even though, neither has been proven nor disproved. (I know the answer to that one.) God, I love climate science.

        BTW, I’ve never seen it, but perhaps I missed it, has anyone ever credibly refuted Jaworski?

      • Suyts,

        If something else is increasing the CO2 in the atmosphere more than the human activities, then where has all this extra CO2 gone. There are some difficulties in figuring out, where the other half of the human contribution has gone, explaining the disappearance an large additional contribution is beyond all ideas anybody has presented.

        The question is really about the amounts of CO2 in different reservoirs, not about the whereabouts of some particular molecule.

      • The question is really about the amounts of CO2 in different reservoirs, not about the whereabouts of some particular molecule.”

        Yes, and the duration in the various reservoirs. And the variants of the cycles, both within, and external to, the reservoirs.

      • But there really are no signs of anything that could be even close to the human influence. All other contributions seem to be only some percents of it over periods of ten years or more. Up to one or two years the fluctuations of natural sources may be more significant.

        The carbon cycle is reasonably well understood and the conclusion is totally clear: The only significant factor that has caused the increase in CO2 level during the period of good measurements (i.e. since the beginning of the Mauna Loa time series) is the anthropogenic influence. Everything else is just minor corrections.

      • “But there really are no signs of anything that could be even close to the human influence. All other contributions seem to be only some percents of it over periods of ten years or more.”

        I don’t think we’re looking for another explanation. I think someone postulated through various observations and it was accepted because it fit a narrative. Specifically, G.S. Callendar.

      • Jaworowski was refuted in a review article which was (as of 2004) his only meaningful citation on glaciology.


        The refutation is in

        The Ice Record of Greenhouse Gases.
        Raynaud, D.; Jouzel, J.; Barnola, J. M.; Chappellaz, J.; Delmas, R. J.; Lorius, C. Science Volume 259(5097)

        When I searched in 2004, I could find no answer to Raynaud in the literature or elsewhere.

  7. Zeke’s “extremely likely” 1-4 absolutely, yes.
    But 5 is No – there is serious scientific evidence that the majority of the CO2 increase is NOT anthropogenic. This viewpoint must be included albeit it being a minority. This is exactly the kind of point where the present gerfuffle started, where serious minority viewpoints were simply excluded or shouted down. Personally I think that the minority viewpoint here is scientifically more sound. I think this situation happens frequently, that the “correct” science is held by a minority.

    What is needed is open discussion, with graphics, ordinary language, as little technics/maths as possible (though some may be essential), sources, and without accusations, so that the evidence itself becomes accessible to a larger number of people.

    I would like to see science-by-wiki in such situations. Not a la Wikipedia, but a modification to allow exploration of hypotheses, in a dedicated wiki.

    Then it would be easier to discern the true brilliance and good science from the charlatans and showmen who can look very similar – the hardest is when they overlap as happened I think with Tesla.

    Going down Zeke’s list, I personally find steadily less and less agreement, and conversely, more and more need for the above – clear exposition of “minority” hypotheses.

    • Lucy, you say things so much better than I do…
      Here’s a thought
      Knowing that adding iron and phosphorus to the oceans would make them take up more CO2…..

      ….there’s a distinct possibility the oceans have become too clean

      We know that plants grow better at higher CO2 which would include plankton, etc

      • Latitude

        “We know that plants grow better at higher CO2,” is an overly simplified and grossly inaccurate Idsoism, and “which would include plankton,” simply ignores the problems of acid-base balance in the oceans, as well as the evidence you yourself cite ( though say you disagree with.. why?) that plankton levels are reported down by 40%.

        CO2 is a plant hormone inhibitor, not a fertilizer. Tiny shifts in CO2 levels have dramatic and varied effects on different plants differently in different circumstances. Having faith in CO2 to benefit the plants of the world would be like having faith injecting testosterone daily into every mammal in the world from fetus to corpse would benefit the mammals of the world. It’s unstudied, and it’s probably at least a little dangerous.

        Also, we already add iron and phosphorus to the oceans in extreme amounts. All this seems to do is promote coastal and river delta dead zones.

      • Bart R, there is no evidence of negative effects of CO2 on land plants, up to 1,000 ppmv even beneficial for all sorts of plants. Sea organisms have already more than enough CO2 from the surrounding waters, but the effect of a 100% increase of CO2 in the atmosphere is only a 10% increase in total CO2 in the surface waters. The effect of that on ocean pH until now is practically unmeasurable in the pH noise and is calculated from the other constituents. pH (and temperature) differences between the equator and the poles are enormous, compared to the tiny change that is at work.

      • Ferdinand Engelbeen

        “..there is no evidence of negative effects of CO2 on land plants, up to 1,000 ppmv ..”

        One does not wish to sound rude or unfair, but we’ve seen the “there is no evidence of harm,” argument before in tobacco and thalidomide, drunk driving and performing surgery without handwashing.

        It is a generally disparaged assertion, and though in the way you may mean it you are doubtless correct so far as that narrow definition goes, you do make a statement one suspects you may have done too little research to credibly claim on its face value.

        Do you mean one does not produce lethal doses in plants with CO2 at 1000 ppmv, or toxic doses?

        What is the lethal dose of testosterone, or the toxic dose of estrogen?

        If all the plants in the world were only plants in greenhouses, your claim would absolutely be the end of the matter, and I could not disagree with it, as toxicity would be all that we might need consider, and the benefits to productivity at little cost to viability in such sheltered and controlled conditions would be an exciting opportunity for us.

        However, a vanishingly small fraction of plant life grows in greenhouses.

        Plants are affected differentially by this very powerful hormone inhibitor, and plants in the wild compete with one another.

        Horticulturalists usually raise CO2 levels for plants during the hours of light, when uptake diminishes hormonal side effects, and their plants enjoy so many protections from stress as can be engineered, and so much addition of nutrient too in observance of Liebig’s Law of the Minimum as is prudent.

        In the wilds, plants are subject to every stress, have no supplemental nutrients, and have no relief from these elevated CO2 levels at night

        In the chaos of the wilderness, or even of outdoor gardens and farms, one would neeed go very far to support the claim of no harm, given the complexities and uncertainties involved.

        When you speak of other constituents being used to calculate pH changes, you again remind us of the complexity and chaos of the chemistry of our oceans.

        Certainly there is large natural variability across the globe in sea temperature and pH. Does this make the oceans more predictable, or less, with regard to small changes in key fractions?

        One submits there is a shared common resource in the wild plants and seas of the world, that these resources are not without practical limit when held up against unstudied changes of global scale, and the democratic principle does not in such cases call for proof of harm before stopping, but proof of consent prior to continuing, and compensation for the stakeholders for the risk of adding to the perturbation of a chaotic system, payed directly by those who benefit from the emissions.

      • So rather than having evidence or a “peer reviewed study”, you’d rather people just take you at your word that it *could* be toxic. You’d think that this would be one of the topics that the warmists would be screaming about if it were the case, but strangely, it’s not. Ever looked at the historical chart for atmospheric CO2? Below 400ppm CO2 is a *very* rare occurrence for this planet. I’ll be very interested if anyone takes up your “Plants are OK with 1000ppm CO2 in a green house, but are poisoned outside of it” theory up for study.

      • Eric Barnes

        You’re arguing something that was never claimed.


        Why would toxic matter?

        Why do you construct this toxic straw man?

        Let me repeat: toxic doesn’t matter.

        Chaos does.

        Unstudied does.

        Consent matters.

      • Eric Barnes –
        BartR often argues “by assertion”. For example, he talks about “wilderness” but I seriously doubt he knows what it is, or how it operates or the changes that have occurred over the last 20 years. If he did he wouldn’t be singing the same song.

        IOW – he’s wrong.

      • Jim Owen

        You mean ?

        Let’s look at the case:

        Do I restate my case regardless of contradiction?

        Did I?

        I expanded my case when it was called too short. How is this argument by assertion?

        I corrected straw man contradictions that put words in my mouth.

        That straw man contradictions come up repeatedly does not make my case the repeated exercise. It makes the practice of furnishing straw man a common fallacy.

        Have I amended my understanding through the course of the discussion? Absolutely.

        The case I would make now would by no means be the case I made when I began.

        My case would be far stronger, more evolved, more complete and more elegant.

        Do I see in my repetition proof of the truth of what I say? Where do I claim that by repetition I make my case better?

        It’s by the changes, the additional research others lead me to undertake, the growth in my understanding their challenges give, that makes my case better, and I’d be a moron to only repeat without making use of the more informed position I am now in.

        Here’s where I began:

        “We know that plants grow better at higher CO2,” is an overly simplified and grossly inaccurate Idsoism, and “which would include plankton,” simply ignores the problems of acid-base balance in the oceans.. CO2 is a plant hormone inhibitor, not a fertilizer. Tiny shifts in CO2 levels have dramatic and varied effects on different plants differently in different circumstances. Having faith in CO2 to benefit the plants of the world would be like having faith injecting testosterone daily into every mammal in the world from fetus to corpse would benefit the mammals of the world. It’s unstudied, and it’s probably at least a little dangerous.

        Here’s where I am now:

        “We know that plants grow better at higher CO2,” is a Big Lie, meant to be repeated until people believe it is true but clearly not anything like the whole truth; and, “which would include plankton,” simply ignores that marine diatoms, 40% by fraction of photosynthesis of the single-cell water plants, evolved in the period of reduced CO2 levels (180-280 ppm). You don’t need to claim CO2 is a poison, or toxic, or detrimental to any one plant at a particular level to object to increasing its levels without control across all plants. Nothing done in greenhouses applies to this or proves much applicable outside greenhouses. CO2 is a plant hormone inhibitor/promotor, not a fertilizer or nutrient. Tiny shifts in CO2 levels have dramatic and varied effects on different plants differently in different circumstances. Having faith in CO2 to benefit the plants of the world would be like having faith injecting progesterone daily into every mammal in the world from fetus to corpse would benefit the mammals of the world. It’s being studied with confirmed disruptive effects, and it’s demonstrably at least a little dangerous while the claims of benefits about this waste dumping are grossly exaggerated.

        Now, as for ‘wilderness’, I can’t make heads or tails of what Jim intends. Am I too Environmentalist, nor not Environmentalist enough?

        So, I might be wrong, but I learn when I’m wrong, and admit it, and look for opportunities for correction and improvement.

        I leave it to you to decide.

      • Bart R,

        I have my paycheck from the pension fund of my former work (chemical concern, not Big Oil or Big Coal for that matter).

        I was not talking about greenhouses only. There are a lot of open air experiments under way (in forests, pasture,…) , where nothing else is changed than supplying some additional CO2. As far as I know, no adverse results are reported until now. See e.g.:
        Indeed, CO2 only supplied during daytime. But I have figures of the CO2 levels at night in the same neighbourhood in summer:
        Much of the extra nightly CO2 comes from plant respiration… Of course, if the background CO2 increases, CO2 levels will increase at night too. But plants are not “poisoned” by CO2 at night, they are one of the causes of the increased levels…

        Neither do your references show negative outcomes, except if you go up to 5,000 ppmv, which is 5 times more than the limit I proposed.

        I am aware that some (C3) plants will profit more than other (C4) plants from enhanced CO2 levels, which can lead to changes in relative abundance and distribution of these species. That only will reverse (in part) the opposite evolution.
        And I am aware of the latest report that reduced evaporation in an increased CO2 atmosphere may influence climate. But that is mainly beneficial for growing plants in deserts (as an Israelian study found)…

        Most wild plants we now have did evolve in CO2 atmospheres of 1,000 ppmv and more. I don’t see why these should be harmed by the same CO2 levels again. Only C4 plants evolved because of lowering CO2 levels. That may be a disadvantage.

      • I’ve never seen CO2 complained about directly. Climate change is primarily a water problem. Over-abundance in some places and less than relied on in others. The problem isn’t what CO2 does to plants: the chief problem is what the temperature increases will do to the distribution of water.

        Changes in the distribution of water and a change in the pH of oceans.

      • Ferdinand Engelbeen

        Uh.. I’m glad you have an income?

        It’s not my concern. I have worked as a consultant to some corporations I now criticize. I’m not into the whole ad hom paranoid conspiracy thing. People can be wrong without being paid to be wrong.

        For instance, you failed to mention that most of the conclusions of your first link support all I say. Look at for Kammann, C., Müller, C., Grünhage, L. & Jäger, H.-J. (2008): Elevated CO2 stimulates N2O emissions in permanent grassland. Soil Biology & Biochemistry 40, 2194-2205 and in one Google search find which shows CO2 rise causes plants to produce more N2O (a bad thing).

        Over and over this GiFACE research shows shifts in speciation and microbial composition, we agree, which is my point, and which ‘opposite evolution’ is a gloss for radical uncontrolled forced redistribution of all the plants we know.

        You haven’t attacked my argument, you’ve armed it.

        Also, for instance, you keep talking about poison, which I do not. (Well, not until the N2O revelation you provided.) How can I avoid being target of this type of straw man?

        Would you be so kind as to provide a link or reference to this reduced evaporation CO2 climate study? If it is as opposite in conclusion to your assertion as this exchange leads us to believe, one would prefer judge for himself.
        The last time we’re fairly sure CO2 regularly topped 1,000 ppmv was on the order of 100,000,000 years ago, and we have SWAG putting the current sub-300 ppmv concentration at about 20 million years old.

        Sure, the photosynthesis pathways evolved before the current era, but no plant alive today is likely to be within 50,000 generations of those higher CO2 levels. 50,000 generations is a lot of evolution, even for plants.

        C4 and CAM plants.. like maize, sugar cane, sorghum, pineapple, orchids, cacti, sedums, marine diatoms (about 40% of plankton by contribution to photosynthesis).. That may be a disadvantage indeed.

        I hope you like barley and potatoes.

      • Jeffrey Davis

        You make excellent sense.

        But I can’t prove water or temperature to a level that satisfies my skeptical mathematics, and see no need to.

        The direct CO2 cases in and of themselves are enough to decide for myself that I do not wish to consent to further rise in CO2 level.

      • The “reply” was off, because of too many responses I suppose….
        This is in response to

        Your original claim was that more CO2 would be detremential to lots of plants. But the references you gave only did show that up to 1,000 ppmv lots of plants grow better. Only a few didn’t benefit, but absense of benefits is not the same as proof of harm…
        Only at 5,000 ppmv there is proven harm for people and plants.

        The same for the N2O releases: I have not found any evidence that N2O harms plants (N2O is not NOx!), but it is a potent greenhouse gas.

        As all C3 plants tested show growing benefits by up to 1,000 ppmv, I am pretty sure that the biological reactions established over 100 million years ago still are working fine…
        Of course, there will be loosers and and winners, but a changing world is not necessary worse or better than a static world (which never existed). Or is a change only bad if it is introduced by humans?
        BWT, I think that land use changes have been far more damaging than more CO2 for biodiversity…

        About water vapour, here a good summary:
        Although there may be negative points (more runoff), for desert plants , that is by far beneficial:

      • Ferdinand Englebeen

        Please allow me to demonstrate your straw man. I’m sure it is unintended, but straw man it remains.

        You say, “Your original claim was that more CO2 would be detremential to lots of plants.”

        I said, “We know that plants grow better at higher CO2,” is an overly simplified and grossly inaccurate Idsoism, and “which would include plankton,” simply ignores the problems of acid-base balance in the oceans.. CO2 is a plant hormone inhibitor, not a fertilizer. Tiny shifts in CO2 levels have dramatic and varied effects on different plants differently in different circumstances. Having faith in CO2 to benefit the plants of the world would be like having faith injecting testosterone daily into every mammal in the world from fetus to corpse would benefit the mammals of the world. It’s unstudied, and it’s probably at least a little dangerous.”

        I look for equivalences between what you say I said, and what I actually said, and see exactly none.

        How can you be hearing me claim detriment for lots of plants in my original statement?

        Sure, later I expand — and in a full third of my expansions try to disambiguate this ‘poison’ or ‘toxic’ or ‘detriment’ framework you and others keep repeatingly trying to put into my mouth — and it’s probably true that there is a lot of detriment to many plants even already.

        But that wasn’t my original claim.

        My claim is that the claim of benefits is a lie.

        Can you imagine after all of this why I might feel that claim is only strengthened?

      • Your claim seems to have a lot of hand waving involved. On balance, it would seem that higher CO2 is better for most plants is a pretty conservative statement that is easily demonstrated. Your claims that additional CO2 on the scale that is occurring on earth needs seems very wanting.

      • Eric Barnes

        You’re certainly correct, so far as it you apprehended my points.

        To handwave less, one refers to a document ( that discusses the plant hormone topic (CO2 is an ethylene inhibitor) and a contrary report (though paywalled) in its abstract touches on some of the questions hot in botany today and at least tangential to what I am suggesting be considered:

        In short, it isn’t even known yet which plant hormone interactions could be considered complex, and how many if any would be considered important, and that there is a long way to go in this disputed area, which itself is only a small part of our issue.

        I don’t pretend to be a botanist, but if leading edge publications are still disputing so preliminary of a question, it is to me unstudied.

        And that’s just inside single pea plants in a greenhouse.

        Let’s look at “better for most” in the context of past experience.

        In Australia, it was agreed importing rabbits would be better for most for hunting.

        The epidemic of rabbits that overwhelmed Australia proved most were better without rabbits ( despite the few benefits.

        See also for another benefit to most, except run amok it is now a pest to most.

        One mammal, one anuran; how do these compare to all plants everywhere under the unstudied pervasive influence of a hormone?

        To handwave less.

      • Thanks for the refernces

      • Bart R:

        Let’s look at “better for most” in the context of past experience.

        What if we go back a bit further, like to the onset of a glaciation period. There would have been a large reduction of plant biomass, and consequently a large increase in CO2 levels, over a relatively short period. If increased CO2 levels are mostly bad for plant life, this would have reduced the plant biomass still further, and so on.
        The mere fact that we’re around to be having this discussion is evidence that this positive feedback probably didn’t occur.

      • Peter317

        Or that it had some singular and powerful external forcing at some point that reversed it?

        Or that the feedbacks you introduce are not long-run at equilibrium?

        And it’s also irrelevant, and a straw man.

        See, I don’t suggest, or hope I don’t suggest, and keep repeating in every way I know how to, that I’m not talking about bad for all plants.

        I’m talking about bad for us through the plants we are used to.

        Kudzu sure doesn’t reduce rural biomass, but I know of many who curse the idiot who introduced it to their life.

      • Bart I have read the references you did give for the following quote:

        CO2 is a plant hormone inhibitor, not a fertilizer. Tiny shifts in CO2 levels have dramatic and varied effects on different plants differently in different circumstances.

        The first reference does mention the word CO2 once, in the references. Looking at the reference only shows that that article is about closing the stomata under influence of CO2.
        The second article is behind a paywall and may show that plant hormone interactions are complicated. Of course I agree with that.

        That doesn’t imply that CO2 is a hormone inhibitor of any kind. Not that I have read anywhere. Please can you give a direct quote that more CO2 inhibits anything?

      • Is anyone aware of greenhouses that artificially removal co2 from within their environment? There are many which add co2.

      • Bob Koss

        Excellent question; here’s a slightly dated reference:

        Scroll to the second section from the bottom for:

        bPlant Damage As A Result Of Co2 Supplementation
        Do not allow excessive CO2 levels in greenhouses. Levels of 5,000 ppm can cause dizziness or lack of co-ordination to humans. Higher than recommended levels* can cause necrosis of old tomato and cucumber leaves. African violet leaves become very hard and brittle, show a very dark greenish-grey colour and often malformed flower petals, which do not fully expand. A similar symptom with freesia flowers has been observed where the CO2 burner was used to provide the majority of the heat requirements of the greenhouse, and thereby generating excessive amounts of CO2. Except in emergencies, do not use CO2 burners as the prime heating system.

        *While some recommendations for some plants are as high as 1,300 ppmv, the article elsewhere notes A lower level (800–1,000 ppm) is recommended for raising seedlings (tomatoes, cucumbers and peppers) as well as for lettuce production. Even lower levels (500–800 ppm) are recommended for African violets and some Gerbera varieties.

        Looking at Figure 1. you may observe that at around 400 ppmv, the net rate of photosynthesis in ideal greenhouse conditions begins to gain much less per additional unit of CO2; we’ve already hit the point of diminishing returns and by Liebig’s Law of the Minimum can say with some confidence that experiments could find that additional CO2 on plants in the wild may be net detrimental right now.

        Be nice if someone did those experiments.

      • Thanks for the link Bart.

        So, no one artificially reduces co2 in greenhouses to improve plant growth.

        The take-away from the article seems to be; plants will benefit from increased co2 at least until we are above 800 ppm.

        It seems like plants have been on a starvation diet for centuries.

      • Bob Koss

        We must have read different articles.

        The take-away is pretty much the opposite of what you say.

        One, your centuries amount to at least 650 centuries, and probably much more; this is not a starvation diet, but a hormone-free one that all plants worldwide have evolved and adapted to. Unless you also think we should start injecting testosterone into our diets, you’re simply being misleading.

        Two, the article flatly discusses artificially limiting CO2 levels. Did you mean do any greenhouses reduce CO2 below ambient outdoor levels? The point of a greenhouse is to grow plants for profit, not build a biosphere for long run stability. (The failed Biosphere 2 had such extreme CO2 concentration issues that they do discuss CO2 limiting strategies, and settled on cooling their plants — though it meant lower crop yields and thus caused them to fall short of a critical goal.)

        Three, 800 ppm refers to productive container plants in greenhouses, not to all plants everywhere, so saying “until we are above 800 ppm,” assumes we can generalize from greenhouses to the wild, and from domestic plants to all plants, which we know we cannot do. (Also, in some rare ‘dead air prone’ margins, a 40%+ rise in CO2 concentration in the last quarter millennium does take these marginal zones above 800 ppm already.)

        Four, Liebig’s Law of the Minimum says there is a vertical line we must draw through Figure 1. in the link, that line determined by the least plentiful nutrient or condition for that wild plant or farm crop. Past that line of generally unknowable position, all benefit of additional CO2 is lost. For many plants, we have plentiful cause to suspect we’re past that line in the wild and even in some farms.

        Zero benefit. Powerful plant hormone.

        Do you want larger lettuce, kale, spinach and cabbage leaves? Larger, brittler, shorter-lived, brown leaves. Sounds yummy.

        Do you want weeds (who favor shorter lives and make due on fewer nutrients by robbing their neighbors anyway) with longer, more invasive stems and roots?

        Flowers are the sex organs of plants. Do you want to eat something with deformed sex organs?

        How well do you suppose these overstimulated, short-lived, disproportionate, sexually deformed plants survive in the wild? Have you not seen

      • Huh, lost a zero. 650,000 years is 6,500 centuries.

      • It seems co2 is the limiting factor, otherwise co2 wouldn’t improve growth.

      • Bob Koss

        Now you get it.

        CO2 isn’t the limiting factor in greenhouses, as when well-fertilized, containerized, well-watered, humidity-controlled, climate-controlled, pest-free hand-reared plants get it while photosynthesizing they grow more.

        Outside greenhouses, at some point, other factors limit faster than CO2 does.

        If that were all there were to it, that would be enough on its own. But it’s much worse; different plants respond diferently, and usually weeds and undesirable plants benefit more than desirable ones almost by definition. What characteristics the observed hormone changes cause, weeds compete best under.

        Which, I’m repeating myself as somehow you missed it, and apologize if this seems patronizing or snarky; it isn’t intended that way.

        How can I more clearly say you are talking only about greenhouses and I am talking about everything else?

      • Bart, the problem I find in your specific argument in this specific post (not to single you out, I sense this in all posts engaged in back and forth, and also my own argumentation – though I am a recovering addict) is how easily we traverse levels. We summarize chaos and look for signals. When someone else summarizes we want to look under the hood because we do not agree with the summarization, and lo and behold we find such variability and use its presence to negate the “opponents” summarization. Do not know whether Latitude is correct but pointing out the magnificence of plant biology does not necessarily negate his argument. Is his summarization about planktons correct or not?

      • DEEBEE

        “Is his summarization about planktons correct or not?”

        If not decomposed into its false parts, the only answer to a summary is a pointless he-said, she-said.

        Latitude is wrong.

        Yes, Latitude says pretty much nothing that is correct here:

        Knowing that adding iron and phosphorus to the oceans would make them take up more CO2..

        We do add iron to the oceans.

        We add it by the shipload, literally, when we dispose of ships to form artificial reefs.

        While the reefs are generally beneficial, they provide also plentiful proof that adding iron to the oceans is not a plausible remediation.

        More, we add both iron and phosphorus in staggering amounts through our rivers and outflows to the seas. This we see in the coastal and river delta dead zones that account for much of the plankton die off ( by anoxia.

        IE, we’d have to pump the oceans full of more oxygen in these places to get sea life back.

        ..there’s a distinct possibility the oceans have become too clean..

        Some of the dead zone phenomenon itself is within the range of natural variability; sometimes rivers do flood with natural nutrients and cause some natural die back. However, the evidence is pretty overwhelming that it’s human activity causing most of that phenomenon too.

        That phenomenon is likely the major significant ocean life stressor, along with some fishing techniques, overfishing, maritime traffic noise, and a list too long to easily sum up.

        You can’t call any of this ‘clean’ by any definition, unless by clean you mean sterile, and by sterile you mean dead or dying.

        CO2 change, however, remains a plausible chief suspect in the global plankton die off outside ocean dead zones, and certainly plays some role.

        You can’t phosphorus it out. You can’t iron it out.

        ..We know that plants grow better at higher CO2 which would include plankton, etc.

        See the rest of the thread for discussion of the distinction between the false benign-toxic framework Latitude introduces here, and what the real thing looks like under the hood with regard to plant hormones (orders of magnitude lower concentration) and the chaos of competing and naturally stressed wild plant systems and Liebig’s Law of the Minimum.

        We can’t know what Latitude saw when he looked under the hood, as he doesn’t show his work, link to sources, or use detail at all. We can know he came to an unsupported and probably false conclusion even leaving out chaos. We can know it might be possible to design experiments to model wilderness conditions for wide varieties of plants to test this. We don’t know if anyone has, or what those outcomes would be.

        So where Latitude says “We know,” he is flat out incorrect, and where he says “plants grow better at higher CO2,” he is leaving out too much from his summary to do anything but mislead, and where he says “which would include plankton,” there too he is flat out ignorant.

        And I’d like to take an opportunity to whine and complain here, to support your generous spirit of questioning but ask perhaps for some balance of all of us.

        Often on this blog we Goldilocks. Either one Argues From Authority, or one doesn’t cite sources. There’s no fine balance that appeases all. Either one is too verbose (me! me! me!) or one summarizes too much. I get engineers accusing me of not having read their elementary engineering math textbooks because I try to speak plainly. (Yes, this is me trying to speak plainly.) I see people criticized for being inaccessible or wrong for using apt and proper scientific techniques.

        Maybe instead of saying the porridge is too hot, we can ask who the porridge is for, when we challenge one another?

        In Latitude’s case, his porridge is not right for anyone.

      • “IE, we’d have to pump the oceans full of more oxygen in these places to get sea life back.”

        This is not true. From my experience sailing offshore for almost 20 years, the mid oceans are generally pretty empty of life, while near land life is much more abundant. This is reflected in the clarity of the water, which is clear mid ocean and murky near land, even where there are no people. The difference is nutrient run-off from the land through erosion as wall as human sources. Mid ocean life has used up the nutrients and has a lot tougher time of it, as much of the nutient falls as a rain of dead organisms to the bottom, which can be miles below.

        The idea that river run off kills life is misguided. What happens is that the nutrients can lead to population explosions of life, which use up all the available oxygen leading to local die off. In shallow water the now dead organisms are not wasted, their energy and nutrients are recycled by the survivors and transient species.

      • ferd berple

        You’re quite right, my summary is not ‘true’ if you mean there are other ways to say the same thing.

        Nothing you say isn’t in the link to NASA’s discussion, or is even missing from mine except focus is different; I gloss what you say as phenomena within natural variability.

        In the wash, it all comes out the same: in the past quarter millennium, we have good cause to believe plankton levels have shifted dramatically and overall lower in ways CO2 rise must be a major suspect.

      • The missing nutrients mid ocean are not gasses. What is missing is minerals such as phosphates. These arrive in limited supply, carried from the land by river run-off, and are quickly consumed. Low phosphate soap is used in houses because it leads to an explosion of plant life in rivers and lakes, which can kill competing species.

        Fresh water (river) run off is fatal to coral, which is why you often find a pass though coral reef and atols on the lee side of islands, which are exploited by sailors. Passes are not found on the windward side because salt water is continually blown onto the coral promoting growth. Even with heavy wave action, winward coral is typically healthier than leeward corals.

        CO2 obsession blinds many to the simple facts of life on the planet.

      • ferd berple

        I guess I’m a little confused by what you’re claiming.

        Are you saying the mid-ocean plankton level drops are because people shifted to low-phosphate soap?!

        All the other factors you attribute are ages old and so far as one can tell, have not significantly altered in any way correlated with this plankton clearing.

        Have rivers begun to flow uphill?

        If the delta and coastal blooms are increasing (which is pretty certain, well-documented) then what’s using up these nutrients and keeping them from getting mid-ocean? Shouldn’t the opposite effect happen, under your hypothesis?

        Sweetwater channels in coral aside, other things appear to be killing coral than can be attributed to rivers, too.

        I’m thinking that before you call others blind, you have to inspect the beam in your own eye here.

      • You are making stuff up at best. There have been thousands of studies of plant growth response to CO2. Not one of them has shown an adverse effect to higher CO2 levels. That includes all three photosynthetic pathways. There is an incredible wealth of information available to you. Read absolutely everything at Don’t make stuff up or parrot something you might have read at an environmentalist blog. Read the pertinent original research.

      • Polly Lydell

        You think because I don’t parrot Idsos, I’m parroting?

        I don’t go to environmentalist blogs; or is Climate Etc. now environmentalist?

        Show the cite at CO2science that addresses my argument, and I’ll give you a cracker.

        If you get over the distinction between TOXIC (adverse effect) and HORMONAL (physiological response), I’ll give you another cracker.

        If there have been thousands of hormone physiological response natural condition simulating studies, or hundreds, or dozens, they must be unpublished, because they don’t especially pop up when I look for them, and I’m not really convinced Idsos prominently feature science contrary to their agenda, except to excerpt and mischaracterize.

      • I stand corrected.

        Ferdinand Englebeen has kindly provided a link supporting my case.

      • I read this a few years back. I fell it might be relevant to the discussion.

      • Sorry, I meant to say I feel it might be relevant.

      • Bart,

        I don’t see the problem. If the response to more CO2 is largely beneficial in growth and water use, why do you object to any hormonal changes (like N2O increase) which have no negative effect on growth or health of the plants at all?

      • Ferdinand Engelbeen

        The problem.

        1. Poleconomically – any assertion that forced, unconsented change to any resource we all share, is unacceptable and of itself odious, regardless of claims of benefit.

        Men make more money than women, women live longer than men, one of these is a benefit to anyone but I’m fairly certain that global forced sex-change operations would be resisted regardless of claims of benefit.

        It’s the same thing, poleconomically, as forcing CO2 levels to rise, in this sense.

        2. The claim of benefit itself is overblown and dubious.

        It amounts at best to about 0.7% increase in growth rate for those select plant species susceptible to this change under optimal conditions, cutting off when the limiting factor is encountered.

        3. The claim ignores how much is unknown about the details of how the benefits themselves operate;

        Many people call CO2 a fertilizer, which is clearly ludicrous; at 390 ppmv in atmosphere, its effects are hormonal/inhibitor, not nutrient. This is a very underdeveloped field of botany itself.

        4. The claim ignores much of what is known too about the limits of the benefits;

        Liebig’s law of the minimum (often not capitalized for various epistemological reasons), the cut off in various plants for gain to photosynthesis (maximum of 1300 ppm, but lower for many plants), the point of diminishing returns (about 400 ppm, but lower for many plants) of photosynthesis gains from CO2, all are ignored in this claim.

        5. The claim utterly ignores the side effects;

        CO2 is a plant hormone, analogous to testosterone in mammals; it’s known to affect gross sex traits in plants, among other changes. How can we judge a claim like this, when the people making it refuse to honestly evaluate even the obvious detriments of side effects?

        6. The benefits accrue only to select plants, the side effects to all plants;

        Some gain the benefit, all pay the price. Sound familiar?

        7. The claim overlooks that the biosphere is chaotic.

        This is not in chaos terms a ‘benefit’ (there is no such thing in chaos), but an external forcing acting as a perturbation; such perturbations destability systems, they are whacking the hornet’s nest with a stick.

        What good enough reason do we know to perturb the biosphere in such a way for a maximum net 0.7% per year growth increase in some plants if all conditions favor them otherwise?

        8. The claim itself is dishonest;

        There is too much of this waste. It’s cheap to dispose of it everywhere without caring about consequence. It’s a sham and pretense to cover this real reason for the action as a benefit.

        This is exactly the same claim one would make if one spread manure not just on one’s own farm fields, or only those fields of others willing to accept one’s waste, but also if one spread the manure everywhere, all the time.

        It’s a waste product.

        Pretending a benefit is simply a lie.

      • As ALL field trials show as worst case no benefit of a CO2 doubling, best case a 100% growth increase over the same time span, you are telling nonsense that CO2 is not a fertiliser.

        Of course one must be careful with any negative effect that such a common fertiliser effect can have. But until now, even with 100 ppmv more, I haven’t seen any (a change in plant community composition is not negative or positive in itself). Including a net increase of 1.5 GtC per year in vegetation, the “Greening Earth”, seen in satellite images.

        Again, give a direct quote of the effect of CO2 as hormone inhibitor (or promotor…).

        Anything humans does have its effects on nature. From building houses, roads and bridges to dams and especially land use changes and the introduction of allien species where they don’t belong. But the last thing I should object to are the CO2 emissions…

        That doesn’t imply that we shouldn’t look for cheap, affordable alternatives for an ever more energy hungry population. But sorry, I am tired of the daily alarmist stories…

      • “ are telling nonsense that CO2 is not a fertiliser..”

        Try looking for the typical applied concentration ranges of fertilizers like N, P, K, Ca, and Mg (all orders of magnitude higher than 400 ppmv), and the sensitivity of response of plants to changes in these fertilizer levels, compared to a change in 100 ppmv. The label on a bag of fertilizer or plant food at your local garden shop should suffice.

        Compare with the concentrations of plant hormones (all the same level more or less as CO2 for comparable effect).

        CO2 is a plant hormone, not a fertilizer.

        “Again, give a direct quote of the effect of CO2 as hormone inhibitor (or promotor…).”

        Again? I must’ve missed the first time you asked it.

        Try Google Scholar with the search term “plant hormone inhibitor CO2” if you seek quotes.

        Straw men and red herrings, wild geese and irrelevancies, these do not pertain and I will not stoop again to try to meet you at that level.

        Using your tiredness as an excuse for lying, what is the logic of that?

      • Bart, I have used Google Scholar. Their are no quotes that CO2 is a hormone inhibitor or promotor. All I can find is that it competes with ethylene (which is a growth inhibitor and a ripening promotor), probably because both follow in part the same biochemical pathways.
        see e.g.:

        Even more for N2O production : Extra growth of plants under extra CO2 produces more food for bacteria around the roots, promoting N2O production from nitrates in the soil. Nothing to do with plant hormones.

        “This property of Ag(I) surpasses that of the well known ethylene antagonist, CO2..”
        “If inhibitors of ethylene formation or action (Co2+,.. “

        “Carbon dioxide and 1-MCP inhibit ethylene production and respiration of pear fruit by different mechanisms

        Whether hormone, hormone antagonist, hormone controller, hormone inhibitor, hormone precursor, hormone promotor, or hormone regulator for plants in the wider literature, it all amounts to the same for our purposes: distinct from fertilizers or nutrients, more impact from smaller changes, changes that affect physiology and gross anatomy.

        CO2 is not plant food, but plant drug.

        It is not part of the plant’s diet, but of its hormone system.

        The analogy is not giving plants more milk, but putting them on steroids from conception to death.

        Then, after death, it affects the microbes that feed on plant decay, as it affected partner microbes during plant life.

        These plant sex, size, conformation, and ripening affecting shifts form a continuum from detrimental to beneficial, if by benefit all you mean is first generation mass.

        This continuum descends as CO2 level rises, detriment growing at some rate (though it is arguably minor as a first generation direct effect) and benefit cutting off and dropping quickly, and has a different shape, for different plants and different conditions, mostly as yet not well-studied.

        Thus it is a differential perturbation across species, and will shift populations over time. We can expect a millennial scale of CO2 elevation. A millennium is long enough for such shifts to extinguish many gene pools and reduce biodiversity.

        Heck a human lifetime is 70 odd generations for many plants, also more than enough.

        As may be 30 years.

        20? Can we say that without alarmism?

        CO2 is a waste product.

      • Bart,

        If you don’t know the difference between competing for the same enzymatic reactions and (in)direct influence on hormone levels, then you have no idea where you are talking about. None of the references you gave is about hormones, all about competing levels.

        To give an example: people who were poisoned by methylalcohol can be helped by giving them a high dose of normal (ethyl)alcohol. Both follow the same enzymatic route of oxydation, leading to resp. formic acid and acetic acid. Formic acid is a strong nerve toxin, acetic acid is not. By adding a high dosis of ethylalcohol, the amount of formic acid formed over time is suppressed and may stay below the harmful level, if there is sufficient removal out of the body.

        CO2 doesn’t influence plant hormones. It may suppres the formation and actions of ethylene, which is a strong growth inhibitor (and a plant poison in elevated dosis) and a ripening gas (reason that you need a lot of ventilation on banana ships). All what may happen with elevated CO2 levels is that fruits are ripening somewhat slower.

      • Ferdinand Engelbeen

        We can agree, if you don’t want to go blind drinking wood alcohol, chase it with vodka. It needn’t be the same amount, it can be less, or more, but not two orders of magnitude more.

        Which is the difference between CO2 levels and fertilizer levels, and again strongly argues for considering CO2 a plant hormone, or at the very least hormone-like, especially when taken with the types of anatomical and physiological changes seen in various of the studies and sources cited, that are typical of hormonal shifts, not of diet changes.

        However you sugar-coat it, this shifting all over our plants and us that your CO2 is doing is just another reminder that CO2 is a waste product, and you’re trying to dress it up as something else to pull the shift over our eyes.

      • Bart,

        As a long time organic gardener myself as one of my hobbies, I do apply some 10 kg organic fertilizer per year per 100 m2 in my garden, of which some 5% is nitrogen (as nitrate). That is 0.5 kg nitrogen fertilizer per year per 100 m2.

        The net yield of a certain type of forest is a sequestering of some 4.5 ton carbon per acre per year (*). That is the difference between yearly uptake and release from decay. Converted to 100 m2, that is about 40 kg net sequestering of carbon per year per 100 m2. Taking into account that growing vegetables has a lower sequestering potential than trees, the net yield may be halve of that, thus some 20 kg sequestered per 100 m2. In fact, a multitude of that is sequestered during the growing season. Simply said, the amounts of CO2 sequestered are a few orders of magnitude larger than the amounts of nitrogen fertilizer used.

        Thus CO2 is not a hormone disruptor, in many cases it is the limiting factor, even at low fertilizer availability, and it simply is the necessary building block for photosynthesis which, at current levels, is in short supply.

        (*) page 10

      • Ferdinand Engelbeen


        First, CO2 in the air is on the order of grams per square meter from ground to top of sky, so we are between four and ten orders of magnitude below your 40 kg per square meter already.

        Second, N2 in the air is >70%, so we’re many orders of magnitude below the N2 available.

        Third, as you must well know, N2 fixing microbes form an intense beneficial relationship with most plants, again orders of magnitude different.

        I know you’re better at math than this.

        Please, drop the blinders and look with unbiased eyes at this question.

        I know you are capable of fair-minded, even-handed conclusions about matters of science.

        Why cling so hard on this one point?

        The literature is rife with references to CO2 interactions with plant hormones in the same concentrations and with many of the same types of outcomes.

        If CO2 isn’t the testosterone of plants, it is certainly the estrogen or if not that, the norprogesterone or the clomifene or femarelle or lasofoxifene or most definitely fulvestrant.

        You’re simply moving the debate away from the point to the quibble. From the subject you are refusing to argue to the straw man you believe you have a case about.

        Why would an earnest and sincere gentleman of your credentials and stature do such a thing?

      • You misinterpreted what I said. I was talking about what plants use to grow. That is minerals and fertilizers, water and CO2 and of course sunlight. Without CO2, no plants based on chlorophyll synthesis can exist.
        In the plants (dry matter) the C:N ratio varies between 13:1 and 120:1, depending of the type of plant. No matter where it is taken from (air, water, soil), how it is taken, or what the quantities or ratios are of the building blocks in the different media to make the plant.
        Thus a plant needs 1-2 orders more carbon (from CO2) than nitrogen (from nitrate or ammonia added or synthesized by bacteria).

        You may call CO2 what you want, I don’t think this debate makes any further sense. If you think that a molecule, directly necessary to build up the structure of a plant is a hormone disruptor of the same, then that is your good right. I only think that not many will follow you in that reasoning.

      • Ferdinand Engelbeen

        What you say seems to make good sense from a certain perspective, leaving off a few salient observations.

        We can agree that practically every atom of carbon (the backbone of all organic molecules) in plants comes from CO2 in air or water (else whither marine plants?).

        In this sense, building block.

        But if true of C, why not of Cr?

        That’s a building block, too.

        If Cr, then too Cu, Se, Mo, I.

        We’re at almost 70% above the median level of CO2 of the last 20 million years (by best extrapolation, and confidently for the past half million years and more), and had in all that time never been more than 22% above that average until the past 250 years.

        Can you think of no building block you would not wish to ingest above 70% over the median intake? Sodium? Cholesterol? Fats? Carbohydrates?

        Even in your framework, which falls apart as none of these causes gross physiological and anatomical changes other than morbid obesity and high blood pressure, is morbid obesity considered healthy?

        And let’s not forget, if commercial handlers need food to ripen, they artificially add ethylene. How will that happen in Nature?

        Unripe vegetation feeds nothing well.

      • We’re at almost 70% above the median level of CO2 of the last 20 million years (by best extrapolation, and confidently for the past half million years and more), and had in all that time never been more than 22% above that average until the past 250 years.

        One last remark:
        How was the terrestrial vegetation doing at 180 ppmv and how at 280 ppmv? And how is it doing at the current 390 ppmv? As far as I know, pretty well, according to satellites chlorophyll imaging: the earth is greening. And it stores some 2 GtC more carbon away (underground and above ground) than a few decades ago.

        Ethylene production is increased, not inhibited up to 3,900 ppmv. Thus ripening is slowed down only at extreme levels of CO2. See:

      • Ferdinand Engelbeen

        You have been a most scholarly, patient, informative and challenging correspondent, and I thank you sincerely.

        How was the terrestrial vegetation doing at 180 ppmv and how at 280 ppmv?

        A fascinating question, and I wonder at the puzzle it must pose scholars in those fields able to approach that research.

        And how is it doing at the current 390 ppmv? As far as I know, pretty well, according to satellites chlorophyll imaging: the earth is greening.

        Are we really judging Nature by the same standards as Pamela Anderson, Heidi Montag and Anna Nicole Smith?

        By how big we can pump up her tomatoes by dumping artificial levels of hormones into her?

        And it stores some 2 GtC more carbon away (underground and above ground) than a few decades ago.

        And if true.. producing even higher levels of methane? And still lapsing further and further behind the increasing CO2 levels? Why is this point even brought up, except to mislead and obfuscate? You certainly can’t be so silly as to believe it a benefit, or think any skeptic should.

        Ethylene production is increased, not inhibited up to 3,900 ppmv. Thus ripening is slowed down only at extreme levels of CO2.


        You get there on your own without making me repeat it.

        CO2 stress forces Ethylene production to increase.

        Ethylene, the powerful plant hormone, is increased by CO2 wastes dumped into the air.

    • Lucy,

      It’s good to see you commenting here – I’ve long been a silent reader of both your site and your periodic comments on WUWT.

      As far as Zeke’s list is concerned, I start to ‘drop out’ at points 4 and 5 of the 90% list. I think solar and cloud albedo with greater water vapour are still much more open to uncertainty than 90%.

      I love your idea of a science wiki: with the caveat that it avoids the kind of censorship that occurred with Connelly and Wikipedia.

      I agree that exposition of minority hypotheses is absolutely vital. This is science we’re talking about. Evolution and free exchange of ideas, methodologies, data, code, mainstream and minority, are what this process should surely be about
      For a scientist to be proved wrong but, in the process, to have advanced the understanding of her chosen field, is the ultimate accolade, IMO.

      • “I love your idea of a science wiki: with the caveat that it avoids the kind of censorship that occurred with Connelly and Wikipedia.”

        That a single person can take over Wikipedia and delete a weath of knowledge provided by others to support his own agenda and limited point of view is a major loss to all of humanity. It reminds me of the burning of the lighthouse at Alexandria. It is a fundamental design flaw in Wikipedia.

    • “there is serious scientific evidence that the majority of the CO2 increase is NOT anthropogenic.” of course there is dear. So what is it this week? Volcanos?

      • deltaT

      • NAH! that was last week. Wake up Rumpelstiltskin!. Its Martian CO2 this week

      • Your patronizing reply misses my underlying point, namely that wherever there is serious minority hypothesis with evidence, it needs to be made visible in its best form, alongside the “consensus” hypothesis – and that this is a very important example of a general scientific principle which the pursuit of single “consensus” statements has undermined.

        This is not the place for me to spell out or argue the details. If you can do so without being driven by desire simply to mock viewpoints different from yours, look at the ultra-slow effect of the thermohaline current, in addition to questionable ice-core CO2 measurements; the evidence is in different sensitive comparisons of delta CO2 levels with delta emissions levels, as well as isotope studies; nothing watertight proven but a lot of highly suggestive coherent evidence that it’s bad science to neglect.

      • “A serious minority hypothesis”, no there isnt, there is just a bunch of internet cranks with some pretty screwy science.
        No one of any substance in the debate questions the source of the increase of CO2.

      • And delta T as Edim says.

    • Hi Lucy, good to see you here.

      You know, I strongly disagree with you on this point. All available evidence points to the emissions as main cause of the increase in the atmosphere. Moreover, all alternatives I have heard of fail one or more observations. Thus are rejected by the facts.

      For other readers here:
      My stance can be read in a comprehensive overview here:

      The same topic was elaborated in four contributions at WUWT, which generated some 1000 responses all together (that was a lot of work to react on, poor Judith with over 3,000 responses now, you have my compassion!):

      • Nice narrative. Whenever I see graphs and numbers without error bars and no understanding of how they impact the core numbers, I put such narratives in my pending bin. What I do not have a sense of is how when the errors bars are added (please no > 50% or 67% or some other substitute for the traditional 95%). Otherwise by magnifying the y-axis can produce all kinds of trends. Not saying that is the case here, but as long as that analysis is not part of your narrative – my pending bin. Also your comfort with throwing away samples makes me wonder the bias this introduces.

      • 1. In the case of modern measurements, the error band is +/- 0.2 ppmv. About the width of the datapoint pixels used…

        2. The full scale y-axis does show the trend over the 45 years:
        Still the same 60 ppmv increase, or about 20% of the initial value.

        3. The reasons for deselection of data is to exclude data which show local contamination. After all we are interested in background data, not the local volcano or downhill vegetation depletion of CO2. If one is interested in these items, do measure near the volcanic vents or within the vegetation (which is done too). The criteria for deselection and all procedures at stake are outlined here:

        But for your assurance, I have calculated the average and trend for the year 2004, with and without outliers: no difference found, only the stdev is better, as is the look of the graph without outliers.
        According to Pieter Tans, the difference is maximum two tenths of a ppmv over a year (as also indicated on my page). Any deviation in one year would be compensated in the next year(s) anyway.

      • Ferdinand, I’m very happy for you to disagree with me. All I ask for is for the other viewpoint(s) to be given hearing alongside yours, using the best available evidence.

      • Quite right Lucy. But the best available evidence is virtually no evidence, and what little we have is contradictory. Ferdinand’s argument always comes back to arithmetic = causation, that is, our emissions exceed the increase so they must cause the increase. It is a simple fallacy. The fact is we have no idea at this point.

      • David,

        You have a small bussiness. You start the day with adding 100 dollar of your personal money into the cash register. After a lot of bussiness transactions that day, you count the cash register at evening and see that you have a gain of 50 dollar over the previous evening. You have the same scenario day after day for 50 days long. Total own money added: 5,000 dollar, gain in the cash register: 2,500 dollar. Do you still think that your bussiness is going fine?

      • If in that period you have bought assets to the value of $50,000 you are doing great. If you have invested the money in equipment needed to expand your business, you are still probably doing great. If you’ve spent the $50 dollars each day in the bookies and consistently lost or in the local bar and got p….d up every lunchtime, you aren’t doing great.

        It all depends on how the money has been used. Just looking at the cash drawer tells you about cash. In isolation it doesn’t tell you anything about the ‘health’ of the business.

        Accountants have developed a standard technique called a ‘balance sheet’ that begins to give a broader view.

        (Please God tell me that there aren’t really any grownup humans posting on this blog whose knowledge of the fundamentals of business are really so limited? If so, it might explain a lot about the different mindsets between the committed and the sceptical).

      • OK,

        It was a bad example, as bad as every example one can think of. Make it better and replace cash register with “balance sheet” and the 100 dollar at the start of the day with 100 million dollars investments at the start of every year for the next 50 years. The balance sheet at the end of each year shows a net gain of 50 million dollars in cash and bank accounts, but a net loss (including investments and fixed assets) of 50 million dollars in the total balance each year. What did cause the increase in cash and bank deposits? What will the shareholders think of their investment?

      • @ferdinand

        What caused the change? Sale of assets.

        Is this good or bad? Depends. If the shareholders decided that they want to get out of widget manufacturing and retire, this may be great news and shows fine resource management. Or maybe they want to buy some big expensive new equipment that will give them the leap on the competition. Other reasons might not be such good ones.

        But you illustrate an interesting point. Nothing is inherently ‘good’ or ‘bad’ unless you understand the context of an observation and make your judgment against that.

        But all AGW scarists automatically assume that all change is bad bty its very nature and to be avoided/prevented. As such they are extremely conservative in their outlook.

        Personally, I think a warmer world, will, on average, be a better world. And I haven’t seen any compelling evidence to show why I am wrong.

        Lots of people running around and making a lot of noise about how the End of the World is Nigh. But no actual evidence. If you have some, please show me.

        PS – climate models are not evidence unless proven to have consistent and reliable track record of accurate prediction of the real climate over a number of years. AFAIK none have done this

      • Ferdinand, not only is it a bad analogy it is the wrong analogy. Suppose my cash register is linked to a bunch of others. The total cash flow is not determined by me alone. My transactions may even be irrelevant. We need to understand the system before we can know why the system is changing.

      • David and Latomer ( the reply is off again…)

        I am as critical about the climate models as you, I suppose.
        I have some experience with models, be it for chemical processes, not climate. I know how difficult it is to have such a model working even for the simplest physical processes, where all physical parameters were known. And had some bad experiences where one (chemical) parameter was unknown.

        That said, I have not the slightest confidence in current climate models, they are missing too many real values of parameters. Especially the one-sensitivity-fits-all sounds to me as horror. It simply is impossible that all kinds of different forcings (SW, LW) have the same (+/- 10%) impact on temperature / climate.

        But at the other side, I am pretty sure that we are responsible for the increase of CO2 in the atmosphere. My strength in practical problem solving in the past was by eleminating the impossibilities rather than looking at the possibilities.
        In the case of CO2 increase, there are two relative fast natural sources: oceans and vegetation. All other possible sources are too small (volcanoes) or too slow (rock weathering).

        Oceans have a too high d13C (d13C in the atmosphere and upper oceans is observed in going down), and vegetation is a net O2 producer (observed), thus a net CO2 sink, as the oceans are (observed). Ergo, human emissions are the sole cause of the increase.

        Even without the above lack of alternatives, the mass balance still holds: as long as the increase in the atmosphere is less than what humans emit, then nature as a whole is a net sink for CO2, doesn’t add anything to the total mass of CO2 in the atmosphere, even if it circulates 10, 100 or 1,000 times more CO2 over the seasons. At the end of the year, only the difference between ins and outs counts.

    • Just because you seriously believe something does not make it serious.

  8. Regarding solar influence on climate changes, there is still a lot of uncertainty and some correlations have been discarded too early by the consensus science. There are some striking correlations, solar cycle length for example.

    Short cycle -> warm
    Long cycle -> cold
    Which could be interpreted as:
    More RPM -> more power (whatever is rotating or cycling)

    See Fig. 4 in this paper:

    Another divergence post ~70s

  9. Yes, I’m very interested in cutting down the possibility for irrational ‘none-hitters’ but, I think, again, putting this down to what we can ‘agree’ upon (what can I, as a none scientist, not agree upon?) may not quite hit the point? I, as a none scientist, have a ‘gut’ feeling (based, however, on a lot of reading and even more ‘thinking’) that much of this is slapdash and bogus. For instance, let us just take the first ‘>90% certainty’ that the greenhouse affect is well attested – this is true, despite the irrationality of certain ‘Dragon slayers’ – but the question is, as a lay person I ask, how does this play out in a stochastic system? ‘Stochasticism’ is partly a proportionate expression of the multiplicity of unaccounted for variables?
    But, putting the science aside, what disturbs is the ‘ought’ and ‘must’ that seems to come as an inevitable corrally. Let me put it this way. Let us say, the world and human beings as a species had five days to live, unless they did such and such. What if they decided not to? Isn’t that valid? Isn’t human choice valid?

    • Again, I ask why we should take your view into consideration? As a non-scientist, why do you feel qualified to evaluate the validity of the science? Do you have any basis to do so other than a gut feeling? Should we do a simple poll of the citizenry and see how many people’s gut feelings are pro or con and base our policy decisions on that?

      Might as well write off science in that case and go with the old standby — superstition, religion, tradition and plain old wive’s tales and guesses.

      • That’s very weak, she-wonk, very weak!

      • Shewonk, what about going with ‘a considered view’? See my response to you further upthread.

      • shewonk,

        I don’t think it’s a case of “writing off science”, or ignoring the views of citizenry. Science, like every discipline, has a duty to its patrons, in the case of most climate science, the taxpayer. IMO this necessarily gives the citizenry the right to examine and question the presentations of science that they have patronised, especially when it informs public policy that will have a material impact on their lives. It’s not good enough for scientists to say that people aren’t capable of understanding – if this is actually the case then why on earth even try to produce an assessment report for politicians?

        I’m sure that quantum physics doesn’t currently experience this level of scrutiny; if, however, quantum physicists were advocating taxes and costly artificial trading schemes to outlaw rogue particles, you can be sure that they too would be subjected to a similar level of scrutiny…..and quite right too I reckon. It happens in my profession every day, as a fact of life.

      • Saad, Quantum Physics isn’t advocating anything nor is climate science. The quantum physics may have findings and implications for humanity – fission and radioactivity and the bomb, for example. Climate science has findings and implications for humanity — the GHE and global warming, for example. Humanity may choose to explore those findings and implications or not. That is political. I agree that science used in the formulation of policy must be the best we have at the time, but it’s the scientists who are best able to evaluate what is “best at the time” not the blogosphere.

      • Shewonk, don’t talk about something you know nothing about, please –

        The quantum physics may have findings and implications for humanity – fission and radioactivity and the bomb, for example

        Oh dear.

      • It’s an example, Lewis, come on. She should have said “quantum cryptography” or something. It doesn’t detract from the point.

      • PDA, I was merely giving an ironic counter-pointer to her dismissal of me. Of course, she has every right to talk about whatever she doesn’t and whatever she does know, but she better get that moat out of her eye first!

      • “mote”

      • Beam.

      • I should have written “nuclear physics” or “physics” in general.

        Which just goes to prove my own point about laypeople opining on science matters. ;)

      • Shewonk, climate scientists have actually been advocating things. The interference of advocacy and science is indeed at the root of many efforts by climate scientists to transmit a “clear message”, that is not “diluted” by divergent data or “weakened” by wide uncertainties. To that effect some of them have gone to great lengths, as documented in recent episodes like the CRU mails, to keep data secret, to hinder publication of opposite views, and the like. That is precisely the whole point of Dr Curry preoccupations that led her to open this blog: ordinary methods of telling what is science and what is not, essentially peer-reviewed publication, is not sufficient in this case. Some think a transformation is ongoing about the way science is being assessed and disseminated, a transformation in which the surge in Internet content has a big role.
        In this particular area of climate change, many of the assertions made by respectable scientists in peer reviewed literature are not backed up by archived data, code and other materials, and long legal battles have been fought to get those essential pieces of information put out for scrutiny. Much of those battles have been fought in blogs at through FOIA requests, since much of the specialist peer-reviewed journals conspired to keep dissension out. It is indeed an interesting historical process in the development of science, and you should pay attention to it. It is not something to be easily dismissed.

        Besides, as you see at the end of Dr Curry’s post starting this thread, this is a rather technical thread that is moderated to avoid excessive “noise”.

      • (Major premise) Climate scientists have actually been advocating things.

        (Minor premise) Judith Curry is a climate scientist.

        The conclusion is left as an exercise to the reader.

      • Willard, you little syllogistic tyke! :-)

      • That’s about the same implied logic as, “all dogs are animals, all cats are animals, therefore all dogs are cats”

      • Peter317,

        Your syllogism is a Barbara,
        Whilst mine would be a Darii,
        If it were a syllogism.

        But it is not, as its conclusion,
        As always must be that
        Science is Corrupt


      • shewonk:

        …..Quantum Physics isn’t advocating anything nor is climate science.”

        In a purely semantic sense you are right, so I would like to tighten my argument a little. Some prominent climate scientists are most certainly advocating their preferred policy outcomes, in addition to presenting the results of their various experiments.

        To return to my quantum physics example, I don’t think Oppenheimer’s personal opinion on the morality of using the atomic bomb was ever considered by those that decided to use it. If he expressed an opinion, it would have been weighed only in terms of the science and certainly not in terms of ethics.

        I believe that the same should be true of climate science. Another blogger here, asked me if I would rather a heart surgeon was advising the government on climate change policy than a climate scientist. I answered that, in view of the number of hypothermia deaths recently in the UK due to the elderly economising on their heating, the advice of a heart surgeon may have been rather more useful in quantifying the effects of “low carbon” energy policies.

        I guess, in the end, it’s people like us who have to try and come together on this issue and find a way forward. There is a way, somewhere, I’m sure. What do you think?

      • simon abingdon

        Not “the advice of a heart surgeon may have been rather more useful” but “the advice of a heart surgeon might have been rather more useful”.

      • In a purely semantic sense you are right, so I would like to tighten my argument a little. Some prominent climate scientists are most certainly advocating their preferred policy outcomes, in addition to presenting the results of their various experiments.

        Yes, and they are entirely able to do so, in a democracy. As long as their science is sound and is published in the peer reviewed literature, I am not concerned if they speak out.

        A scientist’s opinion on non-science matters is no better or worse than a layperson’s. It is up to us to weigh the opinions of scientists on non-science issues. A scientist may be right to express an opinion on the science they are expert in. It is another for them to opine on which policy option best addresses the threat. Unless they are an expert in the outcomes of policy decisions, their opinion, as Feynman said, is just a bad or good as any other laypersons.

        Relevant expertise is what counts here.

        I guess, in the end, it’s people like us who have to try and come together on this issue and find a way forward. There is a way, somewhere, I’m sure. What do you think?

        I fully support people becoming as educated as they can about these matters. I don’t want to sound as if I am against curiosity. I think it is a shame that we don’t have a better education in the process and history and logic of science. There is a great deal of scientific information out there but one has to have judgement to evaluate what is sound and what is dreck or snake oil. Having that judgement is what is key. Sometimes, you have to defer to experts.

        I know it goes against the grain of some people to do so, but as the saying goes, a little knowledge is dangerous. It gives you the illusion that you are competent when you are not.

      • Shewonk,

        I agree that the position you are advocating (generally ‘trust well-qualified scientific experts’) would usually be the best course, and has previously been the one I’ve followed. However, in CAGW we seem to have an exceptional case where something else is called for. Why? The accusation has been leveled that several leading climatologists have distorted the peer-reviewed science by:

        – Overstating alarming scenarios
        – Understating uncertainty
        – Suppressing legitimate minority viewpoints
        – Suppressing legitimate criticism of their work
        – Subverting the peer-review process
        – Not reporting known adverse data in their publications
        – Cherry-picking data to show a desired result
        – Not taking steps to counter media and political exaggerations based on but unsupported by their work
        – Using new and poorly characterized statistical methods without which their results would change substantially

        There is at least some solid evidence supporting many, if not all, of these accusations. This situation is thankfully rare but certainly not unprecedented in the history of science (Piltdown Man etc).

        On top of this there is a veritable perfect storm of situational drivers that indicate this particular field at this time deserves increased scrutiny.

        – The well-documented funding incentives
        – Much of climate science being a new field
        – The small number of practitioners in the field
        – The well-documented close-knit professional relationships in the field (see: Wegman et al)
        – The fact that likely policy outcomes support actions also generally desired by the majority political viewpoint held in academia

        In light of all this I think increased skepticism and scrutiny of ‘consensus’ climate science is not only justified but the only prudent course for reasonable non-experts to take. This doesn’t mean that the consensus viewpoint is entirely wrong or can never be proven correct. It just means that the bar is higher, the scrutiny deeper and the actions cautiously slower.

        I’ll add that one of my own personal tripwires has also been tripped by this CAGW situation. Based on past life experience, anytime anyone comes to me and says:

        – There is certain cataclysmic catastrophe ahead (not right now but soon).
        – We absolutely must take drastic action now, Now, NOW!
        – This action will be extremely costly.
        – Unfortunately, evidence that would conclusively prove this extreme action was immediately necessary won’t be clear for quite some time.

        There have been many, many examples from Y2K to domestic terrorism, acid rain, ozone depletion, global cooling, over-population, internment of all Japanese-Americans, peak oil, etc, etc, etc. I am old enough to vividly remember the shrill panic in the media and the seemingly conclusive, reputable science-based support for all of these (except Japanese internment – I’m not quite that old but my parents remember the hysteria in detail). In every single case drastic immediate action was eventually proven to be alarmist and unnecessary. Why does this keep happening? I don’t know. There have been interesting studies that tie it to human psychology. I would ask why, after being driven to needless over-reaction so many times, aren’t we far, far more skeptical of any claimed catastrophe that fits the ‘signature’ above?

      • Surely a scientist is one who actually practices the scientific method in a scientfic field.

        It is not enough to loudly proclaim that one is a scientist. The walk must be walked as well as the talk talked.

        Climatology seems to have a great many participants who are ‘world class’ at the latter, but pay scant attention to the former.

      • Mark, steps WERE taken to curtail acid rain and CFCs that were causing ozone depletion. They both ceased to be emergenices BECAUSE governments took action on them, despite industry wailing about how such actions would destroy the economy. The economic alarmists were wrong then and they are wrong now.
        If the governments had refused to act then, we would be in more trouble now.

      • Actually, ‘shewonk’ (I get very irritated with pseudo-nyms ) why don’t we just take the medieval perspective of Beddington and proscribe ‘contrary’ opinion? As a ‘none scientist’ I meant, of course, I am not a professional, doctored and acknowledged expert. Which does not mean I, and many others, could not have a very well informed opinion on the science. In your world, we would give up the ability to decide for ourselves and defer to a scientocracy? And, pray, what are your qualifications? If you have none, you better back out but carefully but avoiding the elephant!

      • Well, you see, Lewis Dane, the internet is still a realm of freedom, and we are free to use our real names or not. I get irritated with people who like to pontificate about the use of real names on the net and who like to reveal them when the people prefer to remain anonymous.

        As to the rest of your post, you may think and argue that you have a well-informed opinion on science, but how can I tell? If I am not well-informed, how can I tell if your opinion is? Only the expert can really evaluate non-expert opinion as to whether it is well-informed. So again, I am left with the conclusion that yes, your opinion may be well-informed but unless I am equally well-informed, how can I or those less well-informed tell?

        I prefer to read scientific opinion rather than lay precisely because at least there is some objective basis for thinking they know what they are talking about.

      • Then what’s your beef? Read ‘scientific opinion’ and don’t plague us with your very ‘unscientific’ judgements? How can I tell, you being anonymous, if your not completely crazy? I’ll tell you one way – by addressing the substance of what you write and refraining from making, admittedly fun, cheap shots?

      • I’m sorry, shewonk, I lost my temper with you and I didn’t mean to. It was only because what you said has become somewhat typical of a very antisocial discourse. I will, and nor will you, I’m sure, never defer to ‘authority’, in whatever form. I’m sure, in your heart of hearts, you agree. Now, can we get back to the subject at hand?

      • I will, and nor will you, I’m sure, never defer to ‘authority’, in whatever form.

        I take it you are joking.

        I do defer to authority when it makes sense and when it involves an area of expertise for which I can’t be expected to judge. For example, when I go to the emergency ward and am told that my aging grandmother needs a nebulizer for her COPD, I am not going to refuse to accept the authority of the respirology specialist and check out the blogs to see what the lay public has to say about it.

        Likewise, when I am asked to vote for a politician or a political party’s platform in an election, I check out whether they support the consensus view on global warming. Because the consensus view is based on the preponderance of scientific peer-reviewed evidence.

        Even McIntyre says that the prudent politician would do so.

      • shewonk: “I do defer to authority when it makes sense and when it involves an area of expertise for which I can’t be expected to judge”

        Judith is an expert. So do you accept Judith’s doubts about the certainty of the IPCC or are you selective about which experts you believe? If the latter, there must be a debate to be had and you are no different to any other blogger.

      • Judith is an expert. So do you accept Judith’s doubts about the certainty of the IPCC

        Read it again: “the preponderance of evidence, not the one-off paper.”

      • Rob, Judith is one scientist. She may be right but I can’t tell.

        Therefore, I look to the preponderance of evidence in the peer reviewed literature. It may be wrong, but until there is a replacement that is just as prolific, I have to go with it instead of the opinion of one expert.

      • Now it’s “nulla non verba”. Why is this site such a good source of garbled latin?

        Here’s the source material:

        ” Nullius addictus iurare in verba magistri,
        quo me cumque rapit tempestas,
        deferor hospes”

        Horace Epistulae

        “I am not bound to swear allegiance
        to the word of any master.
        Where the storm carries me,
        I put into port and make myself at home.”

        The intended meaning is that science is not subject to nonscientific dogma despite powerful interests, not that scientists are lying to you and you should listen to the people with money on the line!

      • Michael, your interpretation of a misquote from my favourite poet, Horace, is not really helpful. So I misspelt my latin? Grow up.

      • Yes, what Shewonk said has become quite typical of an antisocial discourse, according to Lewis Deane.

        So what Shewonk said made Lewis Deane do it.

        Bad Shewonk.

      • O what weally foolish fool.
        Shewonk, even when I go to the Doctor, being a relatively sensible fella (I believe) I think about what he’s saying and weigh it up. Nulla non verba is obviously not your motto, but it is mine.

      • Since I can’t respond to Lewis due to threading, I will say here that I am not talking about a general visit to a doctor. I am taking about the ER where grandma is unable to breathe and is blue in the lips. I listen to the respirology specialist and when he says that she has COPD and needs a nebulizer to open up her airways, do I doubt him and take out my iPhone and google COPD and check out the website “” to see if the majority of bloggers think nebulizers are harmful or helpful? Say I do have time to have a second opinion, do I ask MrsDoubter87 if COPD requires frequent nebulizer treatments? Or do I get another respirology specialist to take a look at grandma?

        Back in the day, before civilization, we might have had to be experts in everything and could rely on our own best judgement to decide issues but we’ve progressed since then. We have bona fide experts today and the amount of sheer knowledge and technical skill needed to arbitrate some matters is well beyond the average layperson.

        Common sense in this case is the ability to know your own limits and to know what authorities to go to when deciding matters.

      • People always bring this up, shewonk, and it’s always very foolish. If your ‘grandma’ (why do people have to make this thing personal, I wonder?) were blue in the lips and near to death and you happened to be a sub saharan african, would you not have to defer to the ‘authority’ of the only ‘medical’ person around, ie the witch doctor? Think.

      • Lewis Deane is right: sapere aude!

        Sapere aude.
        Quite Easily Done.
        By anywho, anyhow, about anything.
        Science is corrupt.

      • And, also, I note, and this seems somewhat typical, you do not address one substantive point I attempt to raise – most of my comment was addressed as questions – why not answer them, instead of attempting ad hominem dismissals?

      • Lewis,
        Shewonk is complaining about people arguing from authority…

        ….by arguing from authority

        Since there are some of us that would rather not put our name out there, shewonk says we should go away and shut up..

        Ever notice or pay attention to which group of people are always telling people they don’t agree with to do that?

      • Shewonk is complaining about people arguing from authority

        Really? Where does she do that?

        Since there are some of us that would rather not put our name out there, shewonk says we should go away and shut up.

        Really? Where does she do that?

      • you do not address one substantive point I attempt to raise

        Because maybe there were none?

        why not answer them, instead of attempting ad hominem dismissals?

        An ad hominem in this case would be for me to say that you are an idiot and therefore, we should ignore you. I did not argue that. I don’t know that you are an idiot.

        It is not an ad hominem to say that the peer reviewed literature is the most likely source of the most valid science and that we should rely on it instead of blogs for our science knowledge…

        Which is what I was arguing.

        That may, by implication, suggest that your opinion is not as valid a that of the peer-review literature, and sorry if that hurts your feelings, but I can live with that.

        I am not arguing from authority as I have none. I am arguing that the actual authority — peer reviewed science — is more likely than the blogosphere to be valid.

        It is possible that you are right and that your opinion is valid. I have no way of knowing if it is because I am not an expert.

      • O my God, you are polite!

      • Firstly, what right have you to talk about ‘peer’ reviewed science? Taking your logic at it’s face value, only an ‘authoritative’ person could determine whether this or that ‘authority’ was ‘authoritative’ (understand logic, eh?)?

        ‘It is possible that you are right and that your opinion is valid. I have no way of knowing if it is because I am not an expert.’

        Indeed, so stop pontificating, especially if it involves being needlessly rude.

      • Am I needlessly rude? When is rudeness needful?

        I think I’ve been the model of politeness. I think you don’t like the implications of what I have written and are taking personal offence from a general statement.

      • Speaking of common sense, common sense would seem to dictate that a non-scientist is not as authoritative on science issues as a scientist. Only those filled with hubris would think otherwise. As Feynman said, “I believe that a scientist looking at nonscientific problems is just as dumb as the next guy.” The opposite is also true.

        I would think that even a person with only high school science would recognize that peer reviewed science is the most likely authority when it comes to questions of science, not lay opinion.

        It doesn’t take a PhD in science to know that. Or so one might think…

        As I said, it’s entirely possible for a layperson to be absolutely right about a science question, but the rest of us are far better served listening to the peer review science over the opinion of a blogger on a blog.

      • You didn’t answer me, of course. To repeat:

        Firstly, what right have you to talk about ‘peer’ reviewed science? Taking your logic at it’s face value, only an ‘authoritative’ person could determine whether this or that ‘authority’ was ‘authoritative’?

      • Lewis,

        Surely politeness is to be encouraged – at least that way we might respond to each others’ views rather than each others’ insults.

      • Exactly.

      • Shewonk,

        Why have blind faith in peer reviewed papers? One out of ten ground breaking peer reviewed papers may stand up over time. The major scrutiny happens after publishing. Blog review has a lot of noise, but speeds up the process. Instead of snail mail letters or published critics that take years, things get hashed out in a shorter time with email and blog posts.

        19th and early 20th century mudslinging was more eloquent, but the results are the same.

      • It’s not blind faith. Blind faith involves believing in something that has no basis in reality. There is a sound basis for trust in the peer review process over time.

        Any one paper in the literature may be off or fraudulent. Bad reviewers, bad editors, bad researchers — they all may get through and lead to bad science. There is no alternative. Certainly blogs are not the answer.

        While there are errors in the peer reviewed literature, there are at least some processes and procedures and values in place that are agreed to by those who participate and oversee it that can act to minimize them. We certainly shouldn’t leave matters of such importance to blogs because there is absolutely nothing to prevent charlatans with no scruples from using lies and masterful rhetoric to mislead people. And as we have learned lately, there is nothing in the blogosphere keeping corporations or governments from using social media like blogs, twitter, facebook and the like from trying to create a false sense of consensus (like climate skepticism) on matters of public concern or interest — or lack thereof.

      • Masterful charlatans are a problem. Almost as much of a problem as ill informed followers of agenda driven activists. This particular post is novel in that it can give one a little insight as to what we are dealing with. There is a lot that is agreed and some points of disagreement. While there are a few bloggers that are way out there, a major appears to be reasonable. Well, as reasonable as people can be.

        I don’t have a degree. I took a semester off to make some cash but kept getting raises every time I tried to go back to college. So I have nearly thirty years of engineering experience, but had to hire fresh out engineers to stamp my work.

        I really would not be bothered with climate change had I not seen a tree ring based temperature reconstruction claiming an accuracy of +/- 0.5 degree with a 95% confidence interval for global past temperature. That sounded a little over optimistic to me. Almost to good to be true? Set my BS detector off. Seems to have set a bunch of other BS detectors off too.

        Without the internet, we may be all sitting around fat, dumb and happy waiting to see if we get our ration of electricity today.

      • Almost as much of a problem as ill informed followers of agenda driven activists.

        To be sure, there are followers on both sides of this divide who are there not because they understand the science but because they are attracted to the potential policy implications which fit with their worldview.

        It is true that there may be the moralistic environmentalist luddite types who have a rather apocalyptic view of the future and thus they are attracted to AGW the way that Christian evangelicals are attracted to the idea of war between Israel and the Arab world as the hopeful harbinger of Armageddon. I’ve encountered them. They have their spiritual bags packed and are waiting for the rapture.

        The same applies for some “skeptic” followers. They are anti-government anti-regulation libertarians who are attracted to the skeptic side because it fits with their political ideology. These are the kind who think that if you don’t have a gun in your hand, the government will take your house and brainwash your kid in one world order communism. I’ve met a few of them as well.

        It has nothing to do with the science but the policy implications.

        I just reject the premise of this whole post. It’s just mental w*&^ing. Self-pleasure is fine and dandy. Just don’t fool yourself that it’s a big romance. ;)

      • What? Difficulty in answering? On what, let me ask, in a democratic society (something you perhaps think is ‘unnecessary’? Just when the whole world is demanding this?) can we base policies? An ‘informed’ public opinion was what the 19 Centuary said, because they had faith in the basic rationality of the people. But you know better. Better to use ‘hide the decline’ graphs in front of that dumb herd, eh? Because ‘human beings’ are basically base?
        I’m sorry, Dr Curry, for losing my temper here but this just seems kind of typical of a very un-rational approach.

      • You’re probably closer to truth than you realize.

        Perhaps you’ve seen this quote, “If I could instantly produce a genie with a magic wand to stand here before you today. And if, that genie could wave his magic wand and wall-la….carbon dioxide would no longer be a greenhouse gas that produced uncontrollable global warming….How many in this room would be happy, satisfied and pleased?” Two people out of two hundred hesitatingly raised their hands. Of the others, some smirked, some laughed and some yelled out, “No, no. Hell no.”

      • Wall-la.

        “I cannot testify that this event actually occurred. But, I heard it as though it was a truthful report. ”

        This is rather to the point of what to believe and why. Should an understanding of the world be purely anecdotal, subjective, “post-normal,” whatever accords with your preconceptions? Or should it be based in fact?

      • lol, PDA you’re a hoot, only one look at WUWT? Go back into the archives. I believe you’ll find the source of the story. Or are you going to be one of those that insist I provide a link to every thing that is of general common knowledge?

        Oh what the heck, I’ll indulge…..give me a few….

      • This story rings true.
        This related one too:

        Ok, the chit-chat pause is up.
        Science is Corrupt.


        Second para.

        So, to answer your question, of course, it should be based on fact, but I think it important to note, to some, as this experience shows, some don’t really care about the facts. Their dogma is entrenched. Once we as a society, finally dismiss this CO2 alarmism, another issue of alarm will be brought up. Some simply believe that man is an aberration of nature and not part of nature.

      • “General common knowledge?” Again, you’re assuming what Solitaire Townsend told the interviewer actually happened. You don’t know and neither do I. Merely the act of asserting something on BBC does not, you may be surprised to learn, convey any truth value.

      • The Carbon Fairy story is absolutely true..

        The organiser herself who asked the question, repeated it, on a BBC Radio 4 program above.. I’ll dig out the link on bbc iplayer.

        I don’t think many realise the significance of WHO the person is that told the story..

        It is Solitaire Townsend – the co-founder of Futerra. (Rules of The Game, Sell the Sizzle, Branding Biodiversity, New Rules New Game, etc)

        Futerra who were behind the advice to the UN Environment program and the UK government, with respect to communicating climate change to ACT like it is real and now..

        If you look at that BBC transcript. MR IPCC himself Mike Hulme of UEA absolutely confirms the environmentalists agenda..

        Me-thinks a little follow up for John Coleman at WUWT is due.. ;)

        Ed Gillespie, the co-founder of Futerra, his good mate (according to him twittering) Bryony Worthington, just becme Baroness Worthington in the House of Lords, where the former Minsiter for Energy and Climate Change (Ed Milliband) who is the now the Labour Party Leader, said she was instrumental in writing the UK Climate Change Act.)

        So Futerra’s connections are deep into the political/media establishment of the UK… Ed and BRyony are on the board of SANDBAG, campaigning for emission trading in Europe….

        And Baronnes now Bryony, ever the activist is also a board member of the 10:10 Campaign, which was behind the ‘No Pressure’ blowing up sceptics, including children in a classroom, by their teacher, PR disaster..

        So if Solitaire Townsend says.. that a deep green environmentalist element want social economic, de-industralisation on the back of climate change.. well why would anybody doubt her, her AGW consensus credentials are impeccable..

        Unlike their scientific credentials…

        Bryony studied English, Solitare English and she also has a Masters in Shakespeare Studies..

        These people have been driving policy in the UK, NOT scientists.

        A fatanstic quote from the next big scare – Futerra, Branding Biodiversity.

        “Our audiences are emotional, NOT rational”


        All the above info freely available from the Futerra, Sandbag and Guardian websites…..

      • Suyts – I’m glad you gave the link, because to me, it shows that WUWT misrepresented what happened. Here is the relevant part of the interview:

        “TOWNSEND: I was making a speech to nearly 200
        really hard core, deep environmentalists and I played
        a little thought game on them. I said imagine I am the
        carbon fairy and I wave a magic wand. We can get rid
        of all the carbon in the atmosphere, take it down to
        two hundred fifty parts per million and I will ensure
        with my little magic wand that we do not go above
        two degrees of global warming. However, by waving
        my magic wand I will be interfering with the laws of
        physics not with people – they will be as selfish, they
        will be as desiring of status. The cars will get bigger,
        the houses will get bigger, the planes will fly all over
        the place but there will be no climate change. And I
        asked them, would you ask the fairy to wave its
        magic wand? And about 2 people of the 200 raised
        their hands.”

        If I had been in that audience, I probably would not have raised my hand, because the question was complicated. It involved not only anthropogenic warming, but also the laws of physics and the persistence of human selfishness as an important force in society. Before responding, therefore, I would probably have wanted to take several minutes to disentangle the separate themes before deciding how to respond, even though I would be happy to see CO2 reduced to pre-industrial levels by magic or otherwise.

      • Sigh, yes, I suppose we could assume Mr. Townsend is being untruthful. But then, PDA, if that is to be your standard, you’ll have to replicate every bit of climate science to believe it.

        But then, the question is provocative, is it not?

      • Fred, I like your response. It is to your credit that you’d understand some of the caveats carried some implications. However, it is very possible that you are reading into the questions that the speaker didn’t mean to convey. His comments about selfishness and physics, meant that people wouldn’t change. Simply the laws of CO2 would. But that is the question. Ostensibly, we’re just working on the warming aspect, right? We’re not trying to change the nature of people are we?

        BTW, WUWT, carried it in more detail prior than today. The one today is a different person’s take of the event.

      • On what, let me ask, in a democratic society… can we base policies?

        Well, in her post above, she says “scientific peer-reviewed opinion — and the preponderance of evidence, not the one-off paper.”

        Is it perfect? No, and Shewonk acknowledges that. Is it possible that “the preponderance of evidence” is completely off-base? Abso-frickin-lutely.

        What I don’t get – and what I suppose Shewonk doesn’t get – is what you propose to put in its place.

      • PDA:

        “What I don’t get – and what I suppose Shewonk doesn’t get – is what you propose to put in its place.”

        I think it’s sensible to evaluate policy on the preponderance of evidence, whilst accepting that this evidence may change over time.

        This should also apply at a policy level ie: the preponderance of evidence suggests that we will not succeed in reducing CO2 outputs in the next 50 – 100 years , whatever the environmental outcomes.

        Thus it makes pragmatic sense to me to focus our attention on a medium term adaption policy, whilst investing heavily in cleaner cheap sources of baseload energy, such as thorium fission and gen4 fission reactors and, in the slightly longer term, nuclear fusion reactors. In the meantime let’s focus on the massive amount of unnecessary pollution and bad land management practices which affect our environment on a daily basis. This we can definitely do something about.

        What do you think?

      • Any response, PDA?

      • I don’t necessarily agree that “we will not succeed in reducing CO2 outputs in the next 50 – 100 years,” and I can’t comment on a “medium term adaption policy” without details.

        Other than that, yes, we should definitely be working on cleaner cheap sources of baseload energy. Like yesterday. Nuclear presents its whole own set of challenges, but I’m afraid there’s no equivalent option at the present time.

      • “What I don’t get – and what I suppose Shewonk doesn’t get – is what you propose to put in its place.”
        Why do you think it necessary to have something replace it?

      • “Why do you think it necessary to have something replace it?”

        So PDA can do the same thing he/she is now criticizing/dismissing others for. So he/she can criticize/dismiss it.


      • My statement was in response to Lewis Deane’s question “On what, let me ask, in a democratic society… can we base policies?” If it’s not the preponderance of scientific evidence, then what do you suggest?

      • PDA,

        As free people with a stake in our own destinies, it should be based on our -judgement- of the evidence.

        Didn’t anyone ever tell you this, in all your years of education?


      • I don’t think they teach much of that stuff any more. What philosophy and logic? Baa. My daughter, soon to graduate, working towards a doctorate, is telling me she’ll never have to take an economics course. I’m shocked at this.

      • We’re talking, precisely, about how to judge the evidence. You reject the preponderance of expert opinion as a yardstick. How do you suggest citizens evaluate evidence in fields where they don’t have complete understanding?

      • PDA, it is here that there will always be an impasse. So, we should base our laws and policy on the consensus of a very small group of people………..I think humanity has already been down that road. I should think we’d be much chagrin to revisit it.

      • No, I don’t think we should “we should base our laws and policy on the consensus of a very small group of people.” Laws and policy should be determined through the democratic process.

        Citizens, as I think we’d both agree, should be informed voters and incorporate the best possible information (as well as personal values, ideology etc.) to their decisions. In the case of science, if they’re not to be guided by the preponderance of evidence, then what do you suggest?

      • PDA, I don’t propose to put anything in the place of the ‘democratic will’ of the people – how could I, this weak of all weaks? The point, therefore, is, is that ‘will’ ‘rational’? I believe it is. You and shewonk, maybe not?

      • Neither do I propose to do away with democracy. Neither has anyone in this thread, as far as I can see.

        I don’t know how you can evaluate the “rationality” of an abstract like “democratic will.” Individuals can reason, but can one speak of groups exercising cognition? It’s an interesting philosophical question, but probably out of scope for this discussion.

        The matter of how individuals can best use practical reason to make optimal decision is a bit more bounded. How does one make judgments in areas where one’s understanding is limited?

      • “A democracy is nothing more than mob rule, where fifty-one percent of the people may take away the rights of the other forty-nine.” Thomas Jefferson

        “The best argument against democracy is a five-minute conversation with the average voter.” Winston Churchill

        “Democracy is two wolves and a lamb arguing on what to have for dinner.” Benjamin Franklin

        The problem is that the 51% are not necessarily smart enough to make the right decisions. The other problem is that there is no better system.

      • No one pretends that democracy is perfect or all-wise. Indeed, it has been said that democracy is the worst form of government except all those other forms that have been tried from time to time.
        — Churchill

        Democracy is only helpful if optimal knowledge is allowed to be disseminated to the most voters. But free-speech can be used to drown out what is the best known human knowledge. This still does not mean that the policy options are obvious, even without the garbage science, but at least we would have moved onto the point of discussing what we value and how we should protect it.

      • Democracy is certainly messy, just like this thread. Which reminds me

        1. Climate Etc. isn’t a democracy
        2. Moderation note: this is a technical thread, will be moderated for relevance.

        I wonder if this comment and many above it will here tomorrow. I’m hoping not.

      • shewonk,

        This is why we’ve a representative form of governance. Consensus seems to work the same way as simple democracy.

        “The problem is that the 51% are not necessarily smart enough to make the right decisions.”

        That isn’t the problem, the problem is there are some that would take their right to be wrong away. What a sad, generic, sterile society it would be if we all were forced always make correct decisions. It would insure existence but end living.

      • PDA, read shewonk

        ‘“A democracy is nothing more than mob rule, where fifty-one percent of the people may take away the rights of the other forty-nine.” Thomas Jefferson

        “The best argument against democracy is a five-minute conversation with the average voter.” Winston Churchill

        “Democracy is two wolves and a lamb arguing on what to have for dinner.” Benjamin Franklin

        The problem is that the 51% are not necessarily smart enough to make the right decisions. The other problem is that there is no better system.’

        Nothing here suggests much faith in the people. As for the supposed abstractness of the so called ‘democratic will’, it’s all we have!

      • Shewonk, in many cases the “science” is not well understood by the scientists. For example, the various iconic papers, (Mann98, Jones90, Steig 10) are statistically very doubtful.

        And, in fact, a good deal of the modeling is more closely related to econometrics than it is to say, resource ecology or biology. The analysis of time series can and is competently performed by non-scientists on a regular basis.

        As well, basic logic, the creation of intelligible null hypotheses, the qualitative examination of data and many other elements of the “science” can be handled by non-official experts.

        Importantly, those unofficial experts are not parti pris; that is they do not have careers which will be influence by their willingness to go where the science takes them rather than in the direction of a pre-determined agenda.

        Frankly, given the mess revealed by Climategate, it is difficult to take much of what the Team puts out without a rigorous audit. Which, happily, it gets.

      • Shewonk, in many cases the “science” is not well understood by the scientists.

        That may be the case because often science is about pushing the boundaries of knowledge and that will alway involve uncertainty. It suggests that it is even more precarious for me to think I can understand it at a level that is necessary to judge.

        For example, the various iconic papers, (Mann98, Jones90, Steig 10) are statistically very doubtful.

        I accept the NAS report on the hockey stick paper. As to Jones 90 and Steig 10, they may be based on doubtful statistics. Individual papers can be erroneous. Future work in the peer review literature will either condemn them to obscurity or will correct them or improve them or validate them.

        As a non-statistician, I have no way of telling if those papers are based on valid or invalid stats. Hence, the best strategy for me as a layperson is to look to the long term peer review science to sort these papers and these areas out.

        You see the problem we laypeople face — we don’t know enough to know which papers to trust or doubt. Instead of falling into cynicism, in which I doubt all scientists and their motives, thus losing any ability to benefit from science, I think it is best to trust the process and methods of science to produce the best science on which to base our decisions.

        Frauds do occur. Bad science does take place and erroneous findings are published. They are usually found out in short order, and if not, eventually are overturned.

        And, in fact, a good deal of the modeling is more closely related to econometrics than it is to say, resource ecology or biology. The analysis of time series can and is competently performed by non-scientists on a regular basis.

        Even I analyze time series on a regular basis. :) I agree that statistical methods can be appraised by those who have an expertise in statistics. Hence, I initially gave McIntyre and McKitrick a lot of weight when considering criticisms of the MBH reconstructions. But I soon realized that even the technical experts can get it wrong, on blogs or in papers. These are complicated methods being discussed and a lot of it is more than just proper method; it involves proper interpretation of what methods are applicable, how to apply them, and what conclusions can be drawn about the analysis drawn from them.

        Again, my common sense tells me it is far better to rely on the peer reviewed literature to sort out which experts have it right and which have it less right and which are just flat out wrong rather than the opinion of bloggers.

        As to models, I agree that the kind of and complexity of the modelling of the climate is a different kettle of fish from the usual models in biology, which is the area in which I have most knowledge (although not expert). While biological systems are complex, the models of the climate are, from what I understand, much more complex and require huge supercomputers to run. There is a difference between understanding the basic principles of modelling at a lay level and being able to evaluate the specific model, its validity and its output.

        When people on blogs write off the models out of hand, I have to ask myself — who are they and on what basis do they write off the models? I have no means of telling the expert from layperson on the blogs and so can’t tell whose opinion is informed and valid and whose is just a repetition of something that appealed to the person for political or personal value-based reasons.

        As well, basic logic, the creation of intelligible null hypotheses, the qualitative examination of data and many other elements of the “science” can be handled by non-official experts.

        But how do I know that? In the absence of some kind of process or procedure or agreed-upon terms to ensure that these non-official experts have the ability to handle the data, create null hypotheses, and other elements of science, how do I know they are up to it? It’s entirely true that there are non-official experts out there who can opine on a blog and be absolutely correct in their evaluation of the methods of science and its findings. There are also a great many very persuasive blog commenters who claim that they know what is valid and correct, and through sheer force of rhetoric, they appear to be very authoritative.

        My problem, and the problem facing laypeople, is that we are not able to tell one from the other in blog land. At least when we go to the peer review literature, we know that other experts have done a vetting of the work and its contribution to the science. It’s not perfect but at least it is a process that has, in the long run, worked. At least when we go to the science organizations, we know that the opinions coming from them are informed and expert.

        Importantly, those unofficial experts are not parti pris; that is they do not have careers which will be influence by their willingness to go where the science takes them rather than in the direction of a pre-determined agenda.

        They may not have a particular bias, but they will have their own set of issues that may bias them to take the science in a particular direction — political ideology (no government intervention in the market) or economic (an interest in the fossil fuel industry’s health). We all have those issues. Every one of us. At least the scientific method and peer review process have procedures to try to minimize those influences and come up with the most objective knowledge possible.

        There are no such constraints in the blogosphere.

        Frankly, given the mess revealed by Climategate, it is difficult to take much of what the Team puts out without a rigorous audit. Which, happily, it gets.

        Again, this is a matter of judgement and I think that one requires a knowledge of how science works and how peer review works to be able to judge if what was revealed in the illegal release of the CRU emails showed anything that undermined the science or process.

        To a layperson unfamiliar with science as a process or peer review as a process or the specific science itself, it may look at first glance to be of concern. I am not so sure it does after a deeper examination. So far, there have been several inquiries into the matter and none have found any grounds for that conclusion.

        That people refuse to accept the findings of these inquiries suggests that they have already formed a conclusion and will accept no other answer.

      • Shewonk, in many cases the “science” is not well understood by the scientists. For example, the various iconic papers, (Mann98, Jones90, Steig 10) are statistically very doubtful.

        That is not at all proof that the authors have not understood “science”. Rather that may be stated as an indication that the papers are perhaps not very good science. It is not a proof of that either, but certainly an indicator.

        New creative work can seldom be done without errors. It is good for the science that new results are published reasonable rapidly. They will be accepted for publication based on their virtues, not based on their faultlessness. Errors that the referees spot and that can be corrected, shall of course be corrected, but no proof can be required that no errors remain. Further research by the same authors and by others is suppose to correct in time, what remains to be corrected.

      • “Should we do a simple poll of the citizenry and see how many people’s gut feelings are pro or con and base our policy decisions on that? ”

        Hell no! The citizenry making policy decisions? That would be a democracy. Perish the thought.

        Boy I hope more CAGW proponents are as honest about their contempt for voters over the next 21 months.

      • In our democratic systems the citizens do not make most policy decisions; we elect representatives who make these decisions on our behalf. The idea is that they will educate themselves on the issues, which of course includes consulting the experts.

        This can go wrong in many ways, of course, but governments do not govern by individual voters voting on every issue, nor by what blogs and bloggers decide.

      • At least he is trying to understand, haltingly as it might be. You seem smug in you ignorance and use that as a weapon to knock down any one trying. If you find what he is saying incorrect,, then correct or just go away. If all you want to do is smirk then just lurk.

      • SheWonk, still trying to shut down an unwelcome exchange of ideas? This isn’t a college campus where sophomoric ignoramuses get to do that. Agitate elsewhere.

      • Why don’t you engage with the ideas she is discussing instead of insulting her?

      • Holly Stick, we are discussing the science. Shewonk thinks the NAS panel supported Mann over McIntyre. It doesn’t. It supported McIntyre on all the disputed points of science. It was polite to Mann, far different from the Wegman Report, but North testified before Congress that he and his panel agreed with Wegman. Does that matter to Shewonk? Not at all. She is here to flog the disinformation put out by RealClimate that the NAS report was bad for McIntyre.

  10. witness the whole Sky Dragon debacle over at Judy’s blog

    This comment of Zeke’s is a little puzzling to me. I followed the original Sky Dragon thread pretty closely and it appeared that Claes came out looking very bad. Fred, Pekka and others very convincingly refuted what he had to say…in what way was that a debacle?

    • It was a debacle because Judith wasn’t so afraid of debate that she felt she had to ban the topic, because she trusted the people here to discuss it and judge it with hardly any input from her, because she treats people with whom she disagrees with deep respect as human beings. This is not how it works in climate, Gene. If we didn’t demonise our enemies, where would we be today?

      Worth reading Steve McIntyre for a truly toe-curling example from 2006 on Bishop Hill earlier. All hail Dr Curry for being so different from these ‘community norms’. (It is hard not to effuse a little. Sorry.)

  11. Is my view this frame, as adjusted by JC, closely reflects the dinner party and water cooler consensus amongst the scientifically literate population who have no financial or reputational dogs in the fight. Thank you for bringing this forward for consideration.


    • It takes more than watercooler scientifically literacy to evaluate this, IMO.

      How much literacy does a non-climate science scientist need to evaluate the validity of climate science? A PhD in another allied field such as particle physics? How about biochemistry? Genetics? Will a MSc do? How about a BSc? A subscription to Discover or SciAm? Watching the National Geographic Channel?

      • Are those your qualifications? Glad to know. It isn’t a question of the science that agitates you (and me) and to pretend otherwise is just typical disingenuousness!

      • You still don’t get it do you?

        I have no qualifications that count when it comes to evaluating the scientific literature. Hence, I see the most valid authority to be the peer-reviewed literature and the scientific opinion of the experts who publish in it.

        Not commenters in the blogosphere, named or anonymous.

        And if I told you that my name was Susan N Lund, from Alberta Canada, would that make my opinion any more relevant or valid?

      • :I have no qualifications that count when it comes to evaluating the scientific literature. Hence, I see the most valid authority to be the peer-reviewed literature and the scientific opinion of the experts who publish in it.”

        A thecnical analyst is qualified

      • To repeat, and as a little exercise in thinking perhaps you could work up an answer?

        Taking your logic at it’s face value, only an ‘authoritative’ person could determine whether this or that ‘authority’ was ‘authoritative’?

      • No, you’d use exactly the same test: the preponderance of evidence. What is the evidence that the National Academy of Sciences is authoritative, and what is the evidence that it is not?

      • PDA. Yes. So you’ve set yourself up as an ‘authority’ on this ‘preponderance of evidence’ – should I defer to you, rather than the NOAA? For I, as a’non scientist’, cannot determine their ‘authority’? But, no, rather, I should defer to any ‘demagogue’ and chap standing upon a tin toilet who tells me he knows what is ‘authoritative’? You see where this is going?

        Let me put this way. However ill-informed we, the ‘public’, are, we will not do what you want. Like them potatoes?

      • Indeed, let me put another way. What has this weak told us? That the public will always inform itself and that you must, at your peril, respect the ability of that public to inform itself? More potatoes.

      • Lewis, use your own judgment. What is the evidence that the National Academy is authoritative, in your opinion, and what is the evidence that it is not?

      • That is plain old silly. Whatever NAS says, one can evaluate whether it makes sense. If it does not why not, would be the criteria for me. Then you are at liberty to accept or reject the counter for logical, appeals to authority etc. reasons. Using you apparent criteria even NAS is not entitled to make any judgments, it is not a climate scientist.

      • No.

      • simon abingdon

        Sorry you’re still feeling weak.

      • How much literacy does a non-climate science scientist need to evaluate the validity of climate science?

        Quite a bit of the needed evaluation today requires nothing more than a good solid high school math and science background, and some basic common sense. (This is actually sad: there is no excuse for errors easily visible to a person with only a high school education!)

        Such a person can evaluate whether the scientific method has been followed, whether methods, data and analysis are presented or hidden, whether data is being honestly presented (at a basic level), whether uncertainties are carried through, etc etc etc.

        Even more important: climate science is a multidisciplinary field. Climate scientists have often claimed exclusive ownership over the field, while unwilling to recognize their own crucial weaknesses in dimensions of import to their work.

        * A professional statistician can easily assess the statistics in climate science — better than most climate scientists.
        * A computer data/software professional may well be able to assess the computations involved.
        * A field biologist may know quite a lot about biological response to climate. (Even a trained Master Gardener may have better insight than a desk-bound scientist, into how proxies respond to climate change.)

      • That’s sure to win you friends among those who frequent the climate contrarian and skeptic blogs, MrPete but I think you’re being too generous. There are of course, those who do not have higher education who may hold the right opinion on any given subject, but like a person who can’t show their work in maths, I can’t trust that they know what they’re talking about.

        I don’t think that anyone with a high school course in maths or physics or biology is on the level with PhDs who are engaged in field work and peer-reviewed science. That’s pure hubris.

        That may make a lot of people feel inadequate but hey, that’s the nature of our society.

      • I think you missed my point. I am in no way suggesting equivalent ability of HS and college grads to evaluate the entire situation.

        I am suggesting that
        a) many aspects of this are not graduate-level issues, and
        b) many aspects of this are graduate-level issues for which experts outside of climate science may have equal if not more expertise.

        This is not to preclude or minimize the aspects for which climate scientists do hold special expertise.

        The point is, there is no reason to presume that we must in all ways defer to the climate scientists’ understanding.

      • In what ways would you think that you or I are qualified to not defer? Over what issues? What areas?

      • I provided a sample list in my replies above. Two examples:

        At one extreme, of the basics, I would offer that anyone with a decent high school science education should be qualified to observe whether a graph is presented with uncertainty bars or not, and to notice the same. That should not be above your pay grade, particularly since you work in the medical field in some way.

        At the other end, consider my case as one who is not a scientist, nor have I even completed a graduate degree (long story — the timing was bad.) So in the scale provided above I count only as a “3” although I would claim expertise for some things easily at the “2” level and some things at the “1” level. Even though it can’t be proven by academic credentials. As a professional with decades of real-world experience in various areas of computer and information science, I had better be qualified to assess many aspects of data collection, management, and algorithmic calculations–in any scientific field, climate science or not. Why? Because if I’m not qualified, then you should not be trusting the tools, methods and calculations used by climate scientists and others to do their work, nor the results of that work… because I had a role in developing and refining some of the very fundamental tools they (and you) use!
        In a way, I’m not at all unique or special in this. There are millions of professionals with vast experience in using sophisticated methods and tools that are also used in science. Lucia Liljegren is a well-known example: she’s not a scientist, yet her professional experience easily qualifies her to comment in many arenas. Same with many others whose names are frequently mentioned.
        At the same time, just because a professional (or scientist) is qualified to weigh in on one aspect, does not mean they are qualified to assess every aspect. That’s already been noted in this thread. Probably nobody is qualified to assess every aspect of climate science! This is where we all need to nurture a high level of personal humility. All of us.

        And that highlights another aspect which any mature adult can assess: as soon as we see a so-called expert who imagines they are qualified to weigh in on every aspect of climate science… we know it is time to be very cautious about what they say.

      • And then there is I;
        Capable, not qualified
        To peer everywhere.

      • You just don’t get it, Policy Lass. In general you are still right about expertise and authority. But in climate science a coterie at the core became enslaved to forces way beyond their control. We should all hope they may be allowed to be free enough to observe an even more powerful force than enslaved them, and that will be Nature.

      • Sorry MrPete but as a layperson, I have no way to judge your abilities. You may have all the qualities you describe, but without some recognized scientific credentials, a publication record and/or membership in a learned society, I have no way of knowing if your opinions deserve my attention or whether you are just another blogger with a viewpoint that is self-serving. You may say you are at a level 3, 2, or 1 but how can I tell? By how convincing you sound? I’d be self-deceived if I thought I could judge between someone who is a talented lay expert and a talented BS artist blowing smoke. I’d like to think I can, but on a blog, there is no way to tell — unless I am an expert and can judge based on my knowledge of the field and literature and methods.

      • There are (at least) angles to this:
        a) Self-assessment: am I qualified to assess XYZ or should I defer to “authority”?
        b) Other-assessment: is the “authority” qualified to assess XYZ?

        I was answering (a). You appear (now) to be asking (b).

        What I am saying is: there are aspects of climate science which any person with basic science understanding can personally assess. And there are other aspects which many non-science professionals can personally assess. It doesn’t actually matter what others think. We can do this ourselves.

        And beyond that: without any appeal to authority, our assessments can be shared with others, and can stand or fall on their own merits, because many others are qualified to make the same assessments.

        You appear to be searching for authorities who simply ought to be believed… because they are The Experts. My response: everyone makes mistakes. So I can only truly have confidence in the quality of my own assessment, and in my ability to evaluate certain aspects of what others discover, and finally whether others have a solid track record (for whatever that is worth.)

        Yet (especially in science!) we Really Ought Not to simply believe the Authorities, and even moreso not believe The Consensus. Because consensus is not science. Science is not even a little bit democratic. A minority of one can falsify what millions believe to be true.

        This is why in some ways the current post has very limited scientific utility. Agreeing on “settled science” is very pragmatic and probably a Good Thing… yet is not itself scientific. What we are really doing here is determining which questions will Not Be Asked and which (non-scientific) assumptions will be made.

      • @ MrPete.

        I think the following quote from Steve Connor’s email exchange with Freeman Dyson is relevant to your comment above about consensus:

        The point I want to make is that it may well have been right for the scientific “establishment” of the 1930s to be sceptical of Wegener’s theory [about plate tectonics] until more convincing evidence emerged, which it eventually did. The experts, rather than the public, could see the flaws in Wegener’s argument which is why there was a scientific consensus against him. You are saying that the situation today with global warming is similar. However, surely an important difference this time is that it is the scientific consensus that is warning us of the dangers of continuing emissions of carbon dioxide, and that this consensus is saying quite categorically that if we wait until utterly definitive evidence emerges of dangerous climate change it will be too late to do anything about it.

        Generalizing about science and consensus is a bit broad to be of much use. There are specific aspects of this debate that don’t generalize easily.

      • Sorry MrPete but due to threading I can’t reply directly to your post.

        Consensus is not science but it is the only way that any kind of summary of the field can be made that is useful to both practitioners and the rest of us. As the Wiki entry says, “Consensus is normally achieved through communication at conferences, the publication process, replication (reproducible results by others) and peer review. These lead to a situation in which those within the discipline can often recognize such a consensus where it exists, but communicating to outsiders that consensus has been reached can be difficult, because the ‘normal’ debates through which science progresses may seem to outsiders as contestation.”

        The consensus can be wrong of course, but it is much more likely to be on the right path than the outliers. For laypeople, the consensus is the best bet, not the opinion of bloggers or contrarian scientists. For example, do I accept the scientific consensus that the AIDS is primarily caused by HIV infection or do I accept the skeptics who claim it is cause by some other yet-to-be-discovered source or that HIV is a big hoax?

        I’m not saying that anyone should blindly follow an expert just because he or she has credentials. Like I say preponderance of evidence based on the peer reviewed literature.

        I am saying that laypersons should be skeptical of self-proclaimed experts in blogland and the anonymous opinions or eponymous opinions of those without or without credentials.

        Perhaps the hardest thing is to be honest with yourself and admit your own degree of trustworthyness. Should you believe your own arguments for accepting some position? Do you hold them because they are the most scientifically sound positions or because they fit with your worldview and prejudices? Your gut feeling is not the best judge of scientific matters. There are no processes or methods in place to prevent your biases from influencing which positions you take.

        Most of the time when a layperson with no background wants to understand some science question, they are far better served going to the science authorities such as the NAS, IPCC, and others than blogland or your “gut feeling” because here there be dragons.

      • @Shewonk, I agree that most of the time it is reasonable to weigh the consensus and the most-published experts quite heavily.

        What Judith (and many others) have pointed out is that in this case we’re dealing with an issue where there are significant non-scientific influences on the consensus/experts. There is no level playing field.

        Those influences (e.g. politics, finances, etc) may or may not cause the consensus/experts to be incorrect. What they undeniably accomplish is this: related important questions are not being equally investigated, if they don’t align with the majority or the politically acceptable view.

        The result: larger uncertainty than necessary, almost all of it in the direction opposite to the consensus view. This does not make it “more likely” that the consensus is incorrect but rather it is more likely that they don’t actually know as much as they think they do, either about the problem or about solutions.

        This also does not imply that (as some say) if we’re so uncertain then that means it is more likely worse than what is being proposed. The bias is already in the “worse” direction.

        One realistic implication is that I cannot trust the experts as much as I would like, because it is more likely in this case that they know less than they want to admit.

        That’s probably the major reason I have put so much effort into personally digging in to various aspects of this question.


        …surely an important difference this time is that it is the scientific consensus…is saying quite categorically that if we wait until utterly definitive evidence emerges of dangerous climate change it will be too late to do anything about it.

        Unfortunately, this consensus is blind in one eye: it is only looking at half of the problem. And long experience with interventionism in nature says that we frequently act in haste with awful unintended consequences. If there ever was a case where it is important to at least be “pretty close”, this is it.
        We’re still adjusting our understanding of sources of GHG by huge amounts; adjusting our understanding of forcings and feedbacks by huge amounts; adjusting our understanding of the most important question (is today’s climate unusual) by huge amounts. The cost of wasting a few trillion is humongous. The cost of investing in the exact wrong thing is also humongous.
        The few things already advocated by experts haven’t worked out so well in the last decade. So their track record is quite weak in my book. But that’s another topic (unless JC wants to add voting on not only scientific assessment of the problem but also on assessment of past/present/proposed solutions.)

      • @MrPete,

        Unfortunately, this user interface makes it difficult, indeed, to respond.

        From where I sit, your determination that the consensus, such as it is, is only looking at one side of problem is highly speculative. It is based on the blanket assumption that, as you stated in an earlier thread, (I’m paraphrasing) that no research with skeptical findings gets funded. That notion is based on a mechanism whereby all climate research is funded on an a priori determination of what it’s findings will be. This does not jibe with my understanding of research funding. It does seem plausible to me that there could be influences whereby established experts exert influence on what theories are considered valid enough to get published in high impact journals – but to categorize the research funding processes as categorically as you do, IMO, I’m sorry to say, borders on a conspiracy theory. While I have read of accounts by skeptical scientists of how they are selectively funneled out of the funding process, the level of coordination it would take to virtually eliminate any funding for good research scientists who might reach findings that diverge with what we are calling “consensus” here seems far too complicated logistically to be doable – particularly when you consider those very same scientists are frequently characterized by the the folks who make such claims about inequities in research funding as being so incompetent they are unable to see “obvious” flaws in their scientific reasoning.

        But all that said, I think that is a side issue – in the same sense that it was a side issue when Judith brought it up in response to my critique that her observations regarding “tribalism” are problematically one-sided.

        On point, I am arguing that you were treating the questions over the value of consensus in the process of science, anc secondarily policy development based on science, as a one-size-fits-all type of situation. With theories about AGW, the questions related to the role of consensus takes on a idiosyncratic and specific character, and it doesn’t seem to that the role of consensus in the AGW debate is significantly advanced by referencing the relationship between science and consensus in a more general sense.

        As was suggested in the excerpt I quoted – scientific consensus in all issues is not equally of importance.

        Your comment regarding the pros and cons of policies that have already, and could in the future, result from a consensus which is short of proof is of interest, and I hope to visit this blog again in the future on a thread where we might exchange perspectives on those questions.

      • Judging whom to believe or how much weight should be given on each argument is always difficult. Certain biases are known to exists and skeptically minded emphasis them, but do they overemphasize or not – or do I overemphasize them or not? I have written about the biases in many places both on this site and elsewhere and I’m continuously pondering are the biases really so bad or am I throwing aside perfectly valid evidence.

        Concerning various claims presented in public I have found one good question to be:

        Would this claim to be presented even, if it is false?

        If my answer is that almost certainly it would be and by one of those people who indeed presented it, then the statement has no value. What is the value of a statement that will be presented in the same way whether it is true or not?

        (I apply my rule most commonly to politicians and well known issue advocates, but it is equally applicable to all strongly controversial issues.)

      • Shewonk,
        Interesting. I’m guessing that you are assuming all those people who graduated and went to work in the real world stopped thinking and learning. I also guessing you are assuming that they would never work in fields similar to those studied by Climate Scientists. Also, I guess, you assume they would never bother reading any of the papers written by Climate Scientists and those in related fields.

        Sorry, but you are wrong on all accounts. In fact, when you examine the time line, a the information fellow who received his PHD 20 years ago in a field currently associated with climate science is in many cases obsolete. Even fields of “pure physics” such as radiation physics have seen changes. A good case could be made for essentially anyone with a scientific bent closely monitoring climate science could easily be as well educated on the subject as one of the senior climate science folks.

        My later career years before retirement were spent in computer engineering. More than once I demonstrated software to visiting university professors who responded with something like: “That was an interesting presentation but it would never work if you actually attempted to build it.” Interestingly, the response was anger when I explained that the demo was of a fully operational system and in use 24 hours a day by hundreds of operators, technicians, and engineers.

        There are lots of people out there who are fully qualified to evaluate climate science presentations without PHDs in “Climate Science.”

      • A good case could be made for essentially anyone with a scientific bent closely monitoring climate science could easily be as well educated on the subject as one of the senior climate science folks.

        That’s even ridiculous by the standards of this site.

      • PDA,
        I guessing you have not interacted much with senior folks in the academic community. Some are darlings, some just honest people doing an honest job, and some are political wonks who ‘administer’ science in their field. Their claim to fame is sometimes simply having their name placed as co-author on work their post grads have done. Having a PHD and holding a senior position at a university is not universal sign of sound knowledge or even judgment. So yes, folks not part of the official climate science circle can certainly be as well educated on that subject.

      • Welcome to the real world. In industry, there are people who have the title of analyst, as well as people who act as analysts as part of their job duties. This can be anything from competitive analysis to analysis of potential new technologies, research, patents, etc. The approach of an analyst is typically different from what you see here, and no, they are experts at doing the analysis, not necessarily conducting the research itsself.

        There’s quite a few perfectly good wheels lying around, but everybody seems to invent their own. Why is that?

      • It’s pure hubris.

      • Ms. Wonk,
        Peer reviewed citation for that?

      • None needed for that is pure opinion. ;)

      • 1. People who graduate and get jobs (like me and presumably you) tend to go out into the world and learn their own areas of expertise. They are busy and unless they have reading climate science as a hobby, they are unlikely to know much about it. Some of us have taken reading the climate science literature up as a hobby. I know I have. :) People where I live think I’m nuts, but whatever. Still, while my 4 years of reading climate science may have given me some knowledge, it doesn’t mean I am able to arbitrate scientific questions.

        What it should mean is that I am now much more aware of how little I know about climate science, since I have spent 4 years and only know a bit more about one small area.

        2. A PhD from 20 years ago is presumably busy doing field work and/or research and teaching and has to keep up with the field or become irrelevant. In the contemporary academic world, its publish or perish baby unless you are solely an adjunct lecturer and only teach. So it is possible but not very common or likely that most PhDs in a field do not keep up with the literature in their field – even ones who got their doctorates two decades ago. There may be talented amateurs who are as up to speed with the literature as experts, and can offer a valuable bit of insight, but those of us without said expertise have no way of telling if they are spot on or merely parroting something they have read on a blog.

        My point is not that everyone who is not a PhD (Climate Science) is an idiot, but that I can’t tell whose opinion is or isn’t worth consideration in the blogosphere and whose argument is scientifically valid or who is just plain bonkers. Credentials aren’t perfect but they are far better than internet monikers and bald assertions.

      • Ahh, thanx Ms. Wonk, I understand now. This is your personnal way to wade through this complex science. Understood. Yet for others, they do have the ability to run with the big dogs, such as O’donnel et al . Lay people by your description, yet helping to further the understanding. For a while there I thought you were stating that only PhD’s who were in CS for many years could actually understand our climate system. Whew, you had me worried there for a bit :)

      • If a non-science expert can publish in the scientific literature and their work stand up to scientific scrutiny, I would consider their opinion on a level with science experts, yes. However, I still take the preponderance of evidence as the proper guide, not a one-off paper in the peer reviewed literature. As I have repeated, one paper can be a fraud or bad and slip through peer review so it is not wise to just accept the claims of any given paper. That’s not healthy skepticism.

        What a layperson really needs is a summary of the science produced by expert scientists who have the ability to comprehend and evaluate the science and report it in a comprehensible way — kinda like the NAS, the various learned societies, why, even the IPCC, the WMO and others. Do they ever make errors? Of course they do. Only a fool will expect perfection and only a denier with anti-science motives would use the existence of specific errors as justification for doubting the whole endeavour.

      • One of can be a fraud. Nobody expects perfection.
        You professedly cannot tell these situations apart, so how would you judge. Change you handle to sheknownot

      • “What a layperson really needs is a summary of the science produced by expert scientists who have the ability to comprehend and evaluate the science and report it in a comprehensible way — kinda like the NAS, the various learned societies, why, even the IPCC, the WMO and others.”

        I’ll take any analysis team with a track record that’s less than 1 erronoeus report in 10.

      • Having a long background in science, but somewhat new interests after retiring, I have noticed it painfully true that the gap is indeed wide between an active scientist in some field and an outsider with good background, but not active research level participation in the field. This becomes apparent, when I think my own writing.

        It is relatively easy to write short messages to discussion threads like this one. In these comments missing some important work is perfectly admissible. That allows me to express with confidence my thoughts, in which I have fairly strong trust, but when I think, how I could proceed to the level of a scientific publication that would fulfill those criteria that I set for publications of experienced scientists, I notice that I would have to do really much additional ground work – and here I do not talk about going to a field that would be totally alien to me to start with.

        Active participation in research brings with it a more up-to-date knowledge of the state of science. It brings with it also additional knowledge about the trustworthiness of other scientists. Sometimes it may present also an one-sided and biased view, when different schools of thought are unable to understand each other or when a faulty paradigm has too much influence, but not at all as often than outsiders tend to think.

      • Pekka,
        I’d just like to make sure my comments were not construed to refer to all science research. I was responding to claims that those outside the ‘climate science’ community are not qualified to judge the validity of statements made by ‘climate scientists.’ As I read what I wrote, I can see that my statement was could be taken to mean something other than what I intended. I apologize for that.

        My thoughts in making that statement were about specific things. That is when forest biologists warning that the growth rings of specific trees do not provide accurate temperature indications were ignored. The biologist might not be a ‘climate scientist’ but could certainly have been following the science associated with tree biology quite closely.

        Another example would be claims about hurricane intensity. It would be exceedingly unlikely that those folks who spend their careers tracking, studying, and predicting hurricanes would simply ignore published academic papers on the subject. Certainly they are themselves researchers, though not considered insiders in the climate science community, and are qualified to judge the validity or utility those papers.

        Research and study does exist outside the academic world.

      • Looking at climate science, there are many issues that can be explained to well educated outsiders well and whose justifications can be assessed by these outsiders, but there are also areas of research which require detailed and wide knowledge to assess with any certainty. Much of the controversy about uncertainties comes from these areas, most notably from climate modeling.

        Modeling systems that are as complex as the Earth system is extremely difficult. Many people (myself included) have doubts on the quality of the models. We know that modelers of systems in many ways similar, but usually simpler than the Earth system, have great difficulties in getting reliable results. We know that the errors are often subtle and difficult to observe. We know also that there are certain general limitations on, what can be modeled successfully and what not. All these issues lead us to have doubts on the climate models and also on the capability of the climate modelers themselves to assess the accuracy of their models. All this without any need to judge the capabilities of individual scientists.

        Even, if the climate modelers have been successful in building the models to give valuable results and even if they have good reasons to believe that they have succeeded, it may still be impossible to convince outsiders. Any set of tests may be of little real value, and the success in it misleading. As outsiders, we cannot judge it. But we cannot judge either whether the modelers are really competent in giving a correct judgment on their own work, and I mean “competent” not “willing”. It’s most likely that they don’t know it either as well as they would like to know. Some of the modelers themselves have expressed assessments of that nature.

        Still the modelers, or at least the most competent among them, have a much better understanding on the capabilities of the models than we outsiders.

        There are some similar issues in any difficult research problem. I am pretty sure that the paleoclimatologists who create the reconstructions have much valuable knowledge overlooked by the statisticians, who criticize their work for deviating from standard practices. The issues are not at all that clearcut that a deviation would automatically be an error. The standard practices are useful and following them provides great advantages, but they are not the most powerful methods, when the problem to be analyzed deviates from the standard settings. This is a fact overlooked in much of criticism. The extra power is unfortunately often obtained losing at the same time on the possibility of estimating the accuracy of the analysis.

        Looking at the research from outside on the basis of special knowledge of some related field (like statistical analysis) may bring valuable extra value to the research. It may also point out errors, but it may also be misguided, and it is that in particular, when there is a strong desire to condemn as soon as some deviation from expectations is observed.

      • Pekka,

        Being retired, I agree with most of your commentary. Nonetheless, I don’t think that our age or employment status precludes us from being objective about what current scientists have to say about any specific subject.

      • You don’t know enough science or math to judge whether others know enough. Discover? National Geographic? SciAm? Does anyone with their wits about them read any of them? Your attempts to support the usual warmist arguments from authority are pathetic.

  12. Even though I probably agree the forcings will end up from 1C to 6C, I don’t believe there is any valid mathematical path to that number….i.e. this calculation has unbounded error.

    The models are the weakest point of climate science, and until they are validated this estimate of temperature rise is not possible (and using hindcasting with tuned models doesn’t have any credibility in my book)

    This result is simply not knowable at this time.

    You can calculate future probabilities from past records, but this temperature estimate is stating confidences on the effect of carbon above and beyond theoretical effects primarily as a result of simulations that have unbounded errors on the inputs and outputs.

    The confidence level stated appears to be a gut feel assessment and belongs in the “we don’t know enough to make an assessment yet” category. Certainly there is political pressure to do it anyway, I’m only saying this number is very likely to have no traceability and thus needs demoted to at least <50% based on this alone.

    • Tom, I’m responding here to Pekka above you due to indenting making Pekka’s post non-reply-able.

      Pekka, when you say

      Still the modelers, or at least the most competent among them, have a much better understanding on the capabilities of the models than we outsiders

      I agree but would like to point out that there is a difference between knowing all the complexities of how something works and understanding what that thing can’t do. For instance, I do not know how to fly an airplane nor can I tell from looking what its flight characteristics are (climb rate, max altitude etc). However, I do feel able to determine from a general examination some things it cannot do such as whether this airplane can land on water.

      In the same vein as Einstein who famously said something to the effect “a thousand cannot prove me right but one can prove me wrong”. I don’t need to know all of the subtle characteristics and interactions in a climate model to understand that it doesn’t account for water vapor forming additional clouds which act as a negative feedback on warming. A thorough and honest modeler will make these sorts of limitations clear “on the label” as it where. If such limitations aren’t clearly and fully disclosed (bad modeler!) then helpful critics may point them out. Short of a response saying “oh yes my model does account for that right here”, I now know something definitive about what that model cannot do. All without having to be an expert modeler myself.

      • Mark,
        We are not looking at a new theory as in the case of Einstein, we are looking at the capability of calculating useful results based on a variety of knowledge. Our problem can never be answered precisely, but it is possible that it can be answered well enough for practical purposes. This hypothesis can be proven wrong only by showing that the results are worthless.

        Of cause also simple errors in what has been done, make the results worthless, but typical weaknesses in the methodology only add to the uncertainty without proving failure. This is precisely an area where expertize is valuable in the same way as it is valuable in nonscientific professional activities. This is an area, where wide knowledge of earlier related research that goes beyond publications is essential. Only through really working with the models and following closely, what others have achieved, can one make the best possible judgment on the value of the calculations.

        Here we have the dilemma: To be able to judge the status of the models fully one has to get involved. That means unavoidably that one loses part of impartiality and gets influenced by biases of the research field. The best experts cannot judge, how much bias they themselves have, even less can they convince others that their bias is of little significance.

        We shall not have naive trust, but we should not either throw the baby with the bath water.

  13. Judy – As I commented at Lucia’s, I think we can actually accept 1-5 of the extremely likely group as true facts. With everything else (except perhaps no. 1 of the very likely), I think the degree of certainty needs to be knocked down at least one notch (in other words, I pretty much agree with you).

    As to No. 1 (~1C from CO2 doubly with no feedbacks), I think it is ok as far as it goes based on radiative physics. However, it is a theoretical number only and, as such represents a starting point only; It doesn’t have real world application though.

    On the paleoclimate reconstructions, I think perhaps that the focus on global reconstructions as to whether the entire globe was warmer of cooler in the past isn’t particularly relevant and more focus should be place on regional scale reconstructions. Also, I don’t think Zeke gives enough weight to the inherent uncertainties with many of the different temperature proxies.

  14. LOL,

    I agree with most but the things I disagree with snowball down the list.

    First, Solar variation is most likely limited to 0.1 C for the past two centuries which implies that the first half of the 20th century had a significant (0.1 to 0.2 C) natural variation since reduced volcanic is unlikely to be 0.3 C for that period.

    Paleo reconstructions tend to suppress variation, so past temperature change is likely underestimated by 0.1 to 0.5 C.

    The surface temperature average is likely overestimated slightly, approximately 0.1 C, mainly due to ocean and polar coverage.

    Feedback of convective clouds is likely negative not neutral.

    The range of sensitivity then would be closer to 1.3 to 4 C. The lower end due to natural variability of cloud feedback.

  15. Putting the major propositions on the table to discuss likelihood or uncertainty is quite a good thing. Helps to put order in the debate too.

    The fact that the no-feedback CO2 sensitivity can not be directly measured (it is a theoretical concept) does not mean it is not useful. It can be calculated from basic physics, and thence separated from the feedback issue, which is more hotly debated.

    Zeke’s interval for sensitivity (cum feedbacks) from 1.5° to 4.5° comes from the IPCC AR4, and to that Judy adds a more generous upper bound of 6°. It might be so, but I do not think it can be established with reasonable certitude or likelihood with our present knowledge (or lack thereof), especially about clouds (and considering saturation bounds for atmospheric humidity). It is quite possible that clouds’ cooling effect with higher CO2 is larger than thought, and vapour warming feedback is lower, AFAWK.

    So far, an increase of nearly 40% in CO2 has caused (if we believe the existing figures, another big issue) a temperature raise significantly lower than 1°C (closer to ~0.5°-0.7°), with feedbacks and all. If sensitivity were, say, 4° then a 40% increase of CO2 would have caused a rise of 1.6° at least, which does not seem to be the case. Much more so if sensitivity is 6°C. If direct CO2 effect is about 1.1°, net total feedbacks could be much lower than thought.

    Judith caution regarding historical instrumental temperatures series is well founded. Even the modest temp increase recorded in the global temp series is likely to be overstated (and very unlikely to be understated) due to various factors such as UHI (in its broader definition of stations getting increasingly in close vicinity of concrete, bricks, asphalt, metal and engines, even in rural areas) and also problems with the choice of stations, and other problems with infilling and averaging of gridcells without due consideration of spatial autocorrelation and other similar problems (cf e.g. the Steig-O’Donnell debate).

    • Hector M writes “The fact that the no-feedback CO2 sensitivity can not be directly measured (it is a theoretical concept) does not mean it is not useful. It can be calculated from basic physics, and thence separated from the feedback issue, which is more hotly debated. ”

      To pick a nit; no-feedback sensitivity cannot be calculated; i.e there is no exact formula. It can only be estimated. If you believe Tomas Milancovic, which I do, it cannot even be estimated.

      • In fact, Jim, I meant “estimated”. Sorry for the use of “calculated”. I’m not sure whether I agree with Milancovic, so I’ll let it here at the moment.

  16. The questions seem to ask ‘how confident are we of the scientific basis of AGW?’ (roughly). Which is fine. There’s also the question of ‘How confident are we that recent temperature variations have all been adequately explained, and that all future variations can be explained?’. (Rephrased in some way that’s acceptable to both sides of the debate). In the end, this debate is all about understanding and predicting temperature (climate) changes. If we can’t do that to a useful level of confidence, none of the rest makes any damn’ difference.

  17. Dr. Curry:

    I am not convinced about the impact of doubling. I had a discussion at scienceofdoom about this and though we agreed to disagree, he did not find a compelling reason to dump my argument. (Scienceofdoom is an excellent site for lay people to get an understanding of CO2’s heat absorption properties, or more accurately electromagnetic radiation absorption) I’ve summarized things on my blog under a post called “The path length approximation”. It is the method used by engineers to calculate heat absorption of intervening CO2 and water between a hot surface and a cold surface. It is a method I have used professionally with success in achieving a functional design. Steve M. and Willis can confirm that the “forcing” curve generated is relatively similar to what is generated using modtran. I have plotted 5.35 ln [CO2] on the same graph and there is a very close fit. The difference is the method used in all other fields to calculate CO2’s absorbance produces a maximum impact, beyond which further increases in CO2 concentration have no impact. It is only in climate science that there is this hypothesis of a continuous increase in impacts as concentration increases. That is, I would say that the logarithmic approximation could be supplanted with an hyperbolic approximation with an asymptote at about 200 ppm CO2.

    I hope I’m wrong. Because if I’m right, that is a pretty spectacular fail on THE fundamental premise. As I’ve said elsewhere, “Science” will be catastrophically injured, if I’m right.

  18. I accept almost none of these claims at the ridiculous probability levels they are expressed in. That was easy. On with the debate.

  19. Zekes sees the following as “more likely than not (>50%)”: “Recent warming is unprecedented over the past millennium.”
    Literally, recent WARMING (i.e. recent CHANGE in temperature) is more or less the same observed in the warming period up to 1940. So not unprecedented even within the same century.
    If “warming” here is used to mean “absolute temperature” the debate is quite open. Efforts to demonstrate it, mainly through the Hockey Stick and its derivates, have encountered fierce opposition and been the object of criticisms on methodological grounds. Also, “recent” peaks in temperature are clearly associated with El Niño events (such as 1998) and there is no perceptible causal link in the literature between El Niño amplitude and global warming, as least in AR4 and subsequent literature on the subject (so far, the stronger El Niño period on record is 1885-1915). If one defines “climate” in WMO terms (30 year averages) any of the latest 30-year periods including 1970-99 (i.e. smoothing over individual year peaks) has been warmer than the preceding one, but not by much. All in all, this does not bestow 50% confidence (or more) on the proposition that “recent warming is unprecedented in a millennium”.

  20. I agree with all of the extremely likely, but question most of the others in one small way or another. I only have time to comment on one. Said to be “likely:”

    1. “Climate sensitivity is somewhere between 1.5 C and 4.5 C for a doubling of carbon dioxide, due to feedbacks (primarily water vapor) in the climate system. This is supported by multiple lines of evidence, including GCMs, paleoclimate evidence (including climate response to forcing during glacial periods as well as millennial proxies), the instrumental record, and the climate response to volcanic forcings among others. That said, this range is large enough that it could mean that climate change will be a moderate issue (1.5 C) or potentially quite dangerous (4.5 C). JC comment: I think we can bound this between 1 and 6C at a likely level, I don’t think we can justify narrowing this further.”

    I think it is more likely the range is 0.5C to 1C. It appears to me that a majority of 20th century warming was natural (overstated at that because of unwarranted adjustments to the data) and that the net feedback to rising atmospheric CO2 is negative. We are simply not seeing anything like dangerous warming. An estimate of 6C is astronomical. I don’t know of any real world observations or math that can support it.

    • Look at the graph presented in Zeke’s post at Lucia. Scientific evidence shows that your estimates are very unlikely. You asked for observations for a 6C number, but missed to asked yourself how earth should have escaped snowball earth. Or that with your estimate the faint young sun paradoxon would be a real paradoxon.
      As Shewonk would say, your numbers are a lay opinion.

      • CO2 cannot be the answer to the faint sun paradox because of the low 180 ppm concentration during the non glacial first half of the carbonaceous period. The combination of a fainter sun, higher temperatures, and lowest ever CO2 concentration argues for a very low sensitivity.

      • swift,
        do you have a source for 180 ppm? Sounds like a scientific sensation: proxy data from billions years ago ;-)
        What about another example: Little Ice Age. If you explain LIA by a weaker sun, so a forcing of about -0.5 W/m^2 and a climate sensitivity of 1C would lead to a decrease of global temperature of about 0.1-0.2°C.
        Up to now I’ve never heard a sceptic claiming LIA being less cold than most reconstructions show.

      • Andrea,
        The problem is that we do not know all of the forcings involved. You often hear people claim we do, but we have to be careful of unknown unknowns. If we knew everything about forcings, then we would not have the issue of missing heat that Kevin Trenberth became famous for.

        We don’t understand clouds. The LIA could have been a very cloudy time.

        Also, the hypothesis of solar amplification is still up in the air. If the climate is particularly sensitive to changes in solar output, the LIA could be particularly cold from solar changes.

        Then there are the things we don’t know we don’t know. Can anyone explain why ocean heat content has not increased since 2003? Not that I know of. Instead of grappling with what is going on, researchers want to pretend it is instrument error.

        The climate sensitivity estimate by Stephen Schwartz was based on the CRU temperature record. His estimate was on the very low end of the IPCC range. But if the CRU temp record has a warming bias from unwarranted adjustments, then the Schwartz estimate is actually too way too high possibly 33% too high. This puts the climate sensitivity pretty close to the numbers I provided.

      • I have lost the reference from four or five years ago (Computer death) and could not find it again. However I have found another with a CO2 level in the range we have experienced since the 1940’s At 379 ppm within 35 ppm, the start of the Namurian period, 330 million years ago, should be deep in an glacial period if CO2 was the answer to the faint sun paradox. Instead it saw the beginning of an ice age.

        If a quiet sun during the Maunder Minimum cased the LIA,then the variation of the total solar irradiance was not enough to cause the probable cooling even at a higher sensitivity. There have been two indirect methods proposed that could magnify the effect. The well known galactic cosmic ray hypothesis is one. The other is a more recent proposal that UV radiation has a significant effect on the amount of ice crystals in the stratosphere. My estimate of the temperature rise from doubling CO2, is about .7 or .8 degrees C.

  21. “I have serious concerns about the ocean data.”

    Dr Curry, as the ocean data is crucial to the “global datasets” I would very interested to learn what your “serious concerns” are. However as you say probably best left until the Berkeley analysis is available especially if it is imminent.

  22. The skeptical community should consider adopting the term “Sustainable Energy” as it solution to AGW, as an alternative to “Green Energy”

    The term “Sustainable” energy is politically very powerful because it implies both green energy and affordable energy, for the long term. It is difficult to see how anyone can argue against it, and it provides a means to unite people from both sides of the argument.

    Dr McKitrick made two very powerful points in his report:

    1) The satellite records is the most accurate records and it is trending below the best case IPCC projections. Things are not as bad as forecast, showing that there is time to implement alternative policies.

    2) That if the projections are correct, that a shift to “green energy” will save money and create jobs, why does it require a large UN regulatory structure with carbon taxes, credits and penalties? Wouldn’t companies make the switch to improve their bottom line without regulation if the policies were economical?

    Given that there is time, and companies will switch if it is economical, would it not make more sense for the skeptical community to adopt “Sustainable Energy” as a more reasoned solution to “Green Energy”? The point being that people need ” Sustainable Energy” to survive and prosper, and thus solve poverty on a global scale, as is happening today in India and China.

    “Green Energy” is not a solution if it is not economically sustainable. If it was economically sustainable, why does it require such a large degree of UN regulation, taxes and penalties?

    • Well, maybe the labeling would work, it seems to work for other things, but I don’t see us having a energy problem other than the self-imposed sort. The energy issue is a self-fixing one. Man progresses, the assumption what we would continue to use coal and oil for infinity is just strange to me. Things change as do our sources of energy. We’ve no way of know what we’ll be using in 100 years. I think its best just to let it happen.

    • “Wouldn’t companies make the switch to improve their bottom line without regulation if the policies were economical?”

      Are you sure there’s even an informed decision being made?

      * “Real Price Of Gasoline” Report Reveals Actual Cost of Gas to Consumers Is as High as $15.14 per Gallon
      * That full report as a PDF

      * Real Cost of a Gallon of Gas: $11.35 plus

      * IEA reveals fossil fuel subsidies top $550bn

      • Out of the 550, Iranian dictators are subsidizing 101 to keep their population happy That should be included in the discussion?
        But let’s stipulate the number and assume that all of it applied to oil and not fossil fuel as indicated.. US consumption is about 20 million barrels per day. I think that is about a third of world consumption. So the world is consuming about 60 million barrels per day. That is about 22 billion barrels per year. That makes the “subsidy” about $25 per barrel. A barrel is 42 US gallons. That is about 60 cents per gallon of oil. In rounded numbers you can get 20 gallons of gasoline from a barrel of oil. So the subsidy is 3 cents. If all is applied to that part of the barrel.

  23. You forgot to include a category of “Extremely Unlikely,” which is where THIS nonsense would belong :

    “Recent warming is unprecedented over the past millennium. While there are plenty of problems with paleoclimate reconstructions, enough corroborating work has been done to at least elevate this to more likely than not in my personal judgment. Were there reconstructions clearly showing MWP temperatures comparable with, say, the running 50-year mean of the instrumental record I would be less certain. ”

    See the hundreds of studies under “Medieval Warm Period,” and “Roman Warm Period” here:

    Please don’t tell me we still have folks that accept the spaghetti graphs! :-)

  24. Well, there you have it! Dr. Curry, it a consensus, skeptics don’t think point number 5. has near the certainty as stated and alarmists don’t believe that’s a valid opinion because we don’t have enough letters in front of our names.

  25. “I think we can bound this between 1 and 6C at a likely level, I don’t think we can justify narrowing this further.”

    I wonder if we can be this certain. Weather is chaotic. Climate is weather over time. A chaotic time series. Unpredictable, nonlinear responses should be expected.

    For example, the paleo record of earth’s average temperature for the past 600 million years appears to have an upper bound of 22C and a lower bound of 12C, regardless of CO2 levels. Until and unless climate science can explain why these bounds exist, any projections of temperature dependency on CO2 are fraught with uncertainty.

    For example, Earth’s temperature is something like 14.5C right now. Based on the paleo records, no amount of CO2 is likely to raise the temperature more than 7.5C. This suggests that simple projections based on doubling CO2 are very uncertain.

    Whether this will be harmful to life is questionable. Tree’s maintain their temperature at 21.5C, regardless if they live in cold or warm climates, and they grow better with increased CO2, so it would appear they are well adapted to a warmer, CO2 rich planet.

    There is no reason to expect other life forms on the planet are any less well adapted. Human beings routinely heat and cool their houses to 72F (22C). Is it a coincidence?

    Why are humans creating so much CO2? Mostly to heat things up. Very little energy goes for cooling, because evaporation is a much more cost effective means of cooling. We do not have a similar, low cost means to heat things up. This simple fact of physics is why cold is much more a threat to humans and human civilization than is heat.

    The bottom of the oceans contain an enormous reservoir of cold water. It is very simple to pump this to the surface and cool the planet for centuries to come, and generate net energy at the same time. This was demonstrated off Hawaii 30 years ago.

    The principle uses the temperature difference between the surface water and deep sea water to drive a sterling or similar engine. A pipe run deep into the ocean to draw up the cold water, and once the engine is primed it will continue pumping indefinitely. Any excess energy can be used to generate electricity.

    As a bonus, the upwelling cold water carries nutrients, which are beneficial to sea live in the area and can be used as a basis for aquiculture. In theory we could create enormous floating cities using this technology, with food and energy created by the pumps, and cool the planet at the same time.

    • Fred – trees maintain 21.5C? That would make the subarctic forests a huge source of heat, and tree-hugging a life-sustaining activity, instead of a disparaging metaphor. Are you sure about this? Last time I felt a tree trunk in cold weather it was – well, cold…

      • From Canada To The Caribbean: Tree Leaves Control Their Own Temperature, Study Reveals
        Tree leaves hold a constant 21.4C when photosynthesizing
        ScienceDaily (Jun. 11, 2008) — The temperature inside a healthy, photosynthesizing tree leaf is affected less by outside environmental temperature than originally believed, according to new research from biologists at the University of Pennsylvania.

        Surveying 39 tree species ranging in location from subtropical to boreal climates, researchers found a nearly constant temperature in tree leaves. These findings provide new understanding of how tree branches and leaves maintain a homeostatic temperature considered ideal for photosynthesis and suggests that plant physiology and ecology are important factors to consider as biologists tap trees to investigate climate change.

      • Fred, I have had a chance to read the commentary on the paper you referenced. The tagline

        “From Canada To The Caribbean: Tree Leaves Control Their Own Temperature, Study Reveals
        Tree leaves hold a constant 21.4C when photosynthesizing”,

        is simply incorrect – the commenter writes:

        “They aren’t however suggesting that a tree’s leaves stay at the same temperature all-day or all-season long. Instead, 21C is more of a long-term target that the tree achieves on average over the course of a year.”

        This is far less jaw-dropping finding. I imagine, however, that the mechanism suggested by their findings may have some implications for dendrochronology.

  26. 4.As a corollary to 3., a warmer world will have an atmosphere with more water vapor. This will tend to enhance the greenhouse effect, though the situation is complicated by the difficulty in both projecting changes in cloud formation and determining the radiative forcing effect of clouds. JC: the coupled water vapor and cloud feedbacks are uncertain, doesnt belong in very likely IMO.
    Climate sensitivity is somewhere between 1.5 C and 4.5 C for a doubling of carbon dioxide, due to feedbacks (primarily water vapor) in the climate system.

    If ” a warmer world will have an atmosphere with more water vapor,” why has atmospheric water vapor declined since satellite measurements began in 1983, and why has tropospheric relative and specific humidity declined since 1948?

  27. Dr. Curry, it appears your replication of another blog may have been a bit ambitious. Personally, I got stopped on #5. It doesn’t stand to reason. Because we’re only measuring atmospheric CO2, that isn’t all of the earth’s CO2. The ocean sinks and out-gases CO2 at different rates at different times at different places. As does the flora of the biosphere.

    The rate of increase of atmospheric CO2 has diminished in the last decade. Now that in itself doesn’t mean a whole lot, but I don’t believe we’ve quit increasing our CO2 output.

    I’ve posted a video atmospheric CO2. (satellites are cool!!!) While I’m usually a numbers guy, in that I’m not much for graphical representations, sometimes they’re necessary to get the whole picture… it where.
    Please watch it and then try to list the many inferences one can take from it. Many directly relating to this post.

  28. 2 Zeke statements, Judy’s Comment and my comment.

    Water vapor primarily acts as a feedback rather than a forcing in the climate system due to its short atmospheric residence time and the limitation to absolute humidity at a given temperature for saturated air. Science of Doomcovers this rather well. Pointing out that water vapor is Earth’s dominant greenhouse gas does not minimize the climate’s sensitivity to carbon dioxide. JC: OK
    HAP:The atmosphere can hold much more water than 100% humidity in the form of water drops in clouds and fog.

    Recent warming is unprecedented over the past millennium. While there are plenty of problems with paleoclimate reconstructions, enough corroborating work has been done to at least elevate this to more likely than not in my personal judgment. Were there reconstructions clearly showing MWP temperatures comparable with, say, the running 50-year mean of the instrumental record I would be less certain.
    JC: I don’t think we know; the white part of the Italian flag is very big on this one.
    HAP:They are not currently growing grapes in Greenland. We are not near as warm as then.

  29. Judy – I believe this thread will confirm what we have already observed from the Sky Dragon thread and the Radiative Transfer threads – attempts to arrive at a minimum point of agreement will degenerate into squabbles about even those minimum items. I find your post interesting for its insight into your thinking, but I doubt that the exchange of comments that follows will often let you get much further. Rather than discussing how best to constrain climate sensitivity estimates, for example, we will see arguments that most CO2 increases are not anthropogenic, or that further increases in
    CO2 will have no impact, and so on.

    I hope I’m wrong, and if fruitful areas of discussion emerge, I’d like to participate, but I’ve grown somewhat pessimistic.

    I do tend to agree with much of your assessment, although as you know, I assign somewhat higher probabilities to many of the items. As one example, I find the probability of a climate sensitivity less than 2C to be small, and less than 1.5C to be very small, but that has already been a topic for a different post. Rather than belabor that point, which in any case is only a personal opinion rather than a “fact”, I would only suggest that interested readers visit AR4, WG1, chapters 8 and 9, read the text, and more importantly visit the most salient references as well as any references a reader believes were not in that report but are relevant.

    • Fred, my point is that when there is disagreement by people with high epistemic levels that have investigated the issue, then the confidence level is probably lower than assumed by each.

      • Agreed 100%. The parties are way too confident in their results and their proposed solutions. None have stood the test of time, which tells us we should not have confidence in the results.

        Cancer research was set back many years as a result of a similar battle, with radical surgery emerging as the treatment of choice in spite of the evidence, based mostly on the status of surgeons. Many died before their time as a result. Experts can be and often are wrong, especially when it affects their livelihood.

        You are doing a great job! Thanks for taking the time to read and reply.

      • Are you sure about the 100%? :)

      • Judy – Who do you have in mind when you refer to people with high epistemic levels? How much disagreement by a minority do you need to reduce the confidence held by the majority? If the balance is very lopsided, does this raise confidence instead, or is unanimity required? How important is consilience of opinion as opposed to consilience of evidence, a topic I addressed in an earlier thread?

    • I would add a mixed version to assigning the likelihoods.

      As an personal assessment I agree with the list of Zeke (although I have issues with the concepts, some of which are poorly defined).

      As my view of what has been justified convincingly by science, I would move close to Judith’s assessment. The difference comes from lack of evidence on the accuracy of the estimates and from many biases, which certainly exist, but whose strength is difficult to determine. In particular the uncertainty related to potential bias is strengthened by the attitude of many climate scientists, which has created pressure of uniformity for the whole community. This uncertainty can be lessened only by well demonstrated openness, which would also tell, how the risk of bias is countered in scientific practices. Here it is not enough that procedures are correct, their correctness must in addition be demonstrated.

  30. Judith wrote, “I have serious concerns about the ocean data.”

    Me, too, but my concerns are for the long-term datasets, which is why I spend most of my time evaluating satellite-era SST data.

    Is Berkeley addressing SST data? That wasn’t clear at their website.

  31. In addition to clouds and fog, air can be supersaturated.

  32. “This is confirmed both by the isotopic signature of the carbon and the fact that concentrations rise proportionate to emissions”

    The isotopic signatures have alternative explanations, and correlation is not causation. If the extra CO2 is a result of out-gassing as a result of natural warming, then the correlation could be entirely coincidental.

    Given that human CO2 production is such a small percentage of the total production, even a small error in measuring natural effects could be the cause of the observed increase.

  33. It is great to get back to the main point of the AGW discussion.
    I have a few comments.
    a) 1 C from CO2 doubling. Yes, this is a number that you can arrive at with some assumptions. The more easily defendable number is 3.7 W/m2 forcing at the top of the troposphere from CO2 doubling which comes straight from radiative transfer models that are trusted and verified. Unfortunately the average joe-public won’t know what this number means without context such as the 0.2 W/m2 from the 11-year solar cycle, or estimated 0.5 W/m2 from the LIA solar reduction. I have always thought this 3.7 W/m2 should have more prominence in the debate.
    b) I agree water vapor feedback should be in the very likely category, but clouds should be separated out from this. Clouds could go either way in my opinion.
    c) Solar forcing changes in recent decades don’t look to be significant, even compared to the 11-year cycle, so I agree with the original categorization as very likely.
    d) Sensitivity. I am inclined to agree with 2-4.5 C. Richard Alley has a very nice lecture supporting this from paleoclimate. I could provide a link if interested.
    e) Surface temperature record. I believe Roy Spencer in his last Heartland Insititute talk, re-did the land data from the raw records himself, and checked against UAH, and found CRU was basically correct. I don’t expect Berkeley’s data to do much else.
    f) Natural variability on decadal scales. Maybe at a stretch 0.5 C, which is the amplitude of the ENSO cycle, could show up at decadal scales too, but given how strong a signal that has to be (look at ENSO), it would be somewhat amazing if such a thing showed up and had a physical explanation with ocean conveyor belts. I am very skeptical of multi-decadal ocean cycles of any significant amplitude. Obviously something like the Gulf Stream halting would be a significant impact, but is non-cyclic, and AGW has not ruled out such events.
    g) OK, we can bring up MWP, but that could have been solar, while this one obviously isn’t. It don’t know why MWP is supposed to raise any doubt about AGW. There may be solar warming mechanisms too, certainly consistent with AGW that accounts for solar forcing changes.

    • Jim, love Prof Alley. If we could harness his giddy energy, we would be off the cabaceous cycle in a mili-second!

  34. A small question that I have not yet managed to answer and have not seen a satisfactory explanation anywhere. All the points by Zeke is theory and based on this theory climate models are programmed and so on. I’m pretty certain that the pure physics part should be right as it’s old established knowledge. But isn’t there somewhere still too big an abyss of uncertainty as definitely for ten years, since 2001, maybe even since 1997 or 1998 the temperatures have not risen (and this year, at least now, is not shaping up as a hot year) while CO2 levels have grown with business as usual. What if this would continue for another, say 5 to 6 years, making the no-growth strip to 20 years? Will the theory be falsified?

    • According to the NOAA State of the Climate 2008 report, “Near-zero and even negative trends are common for intervals of a decade or less in the simulations, due to the model’s internal climate variability. The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate.”

      According to Phil Jones, there has been no statistically significant warming since 1995. Ergo, the models have already been falsified at the 95% level. Fun with statistics, but no worse than the confidence levels assigned in this post and by the IPCC.

      • This is a critical point.

        The current temperature plateau is not consistent with any of the General Circulation models. If this plateau continues (as, in my view, it is likely to given the switch in PDO) at what point do the modelers concede that their specifications are in error?

        In other words, when do we revert to the null hypothesis that man made CO2 is not causing warming? If we go by the NOAA report we are already there.

      • Jay

        They do admit it NOW, but in PRIVATE:

        1) I think we have been too readily explaining the slow changes over past decade as a result of variability–that explanation is wearing thin. I would just suggest, as a backup to your prediction, that you also do some checking on the sulfate issue, just so you might have a quantified explanation in case the prediction is wrong. Otherwise, the Skeptics will be all over us–the world is really cooling, the models are no good, etc. And all this just as the US is about ready to get serious on the issue.
We all, and you all in particular, need to be prepared.

        2) Yeah, it wasn’t so much 1998 and all that that I was concerned about, used to dealing with that, but the possibility that we might be going through a longer – 10 year – period [IT IS 13 YEARS NOW!] of relatively stable temperatures beyond what you might expect from La Nina etc. Speculation, but if I see this as a possibility then others might also. Anyway, I’ll maybe cut the last few points off the filtered curve before I give the talk again as that’s trending down as a result of the end effects and the recent cold-ish years.

        3) The scientific community would come down on me in no uncertain terms if I said the world had cooled from 1998. OK it has but it is only 7 years of data and it isn’t statistically significant.

        That was no warming for 7 years.

        Now, it is no warming for 13 years.!

      • Where on earth are you geting the idea that there has been no global warming since 1998? Sorry, the land and ocean are both still warming:

        If you do not like my link, then go back to the top of this page and readthe 95% certain statements. Read number 1 & 2 until you understand them.

      • @Holly

        You’ll forgive me a small guffaw. You link to ‘skeptical science’ as being ‘experts’.

        Yet even their own ‘about’ page admits that they are not. John Cook, who wrote the cited article, studied physics. He states – and credit to him for this – ‘I am not a climate scientist’.

        Beware of all self-proclaimed ‘experts’. But be specially aware of treating as experts people who don’t even make that claim for themselves.

      • False, Sven. 2000, 2007, 2008, 2009 all show warming for Hadcrut. Read this until you understand it:

      • Sorry Holly. I looked at Sven’s graph.

        What is wrong with it in your opinion? Has he hidden something? Does it not show what it seems to show? It is a graph that anyone can plot with as good basic data as can be found…I gues sthe maths behind it is right, What, exactly, is your problem?

        Brusquely (I am being charitable) demanding that he goes away and reads another article ‘until he understands it’ has two effects for me

        1. It shows that you have no actual answer to his point. Or that if you do you are incapable of articulating it

        2. It suggests that you have learnt your rhetorical skills elsewhere in the blogosphere where arrogance, rudeness and unpleasantness are perceived to be symbols of expertise. Here, however, they merely betray a weakness of argument and suggest a shallowness of understanding.

      • Holly Stick, I think that the main difference in our approach is that you are trying to prove your point while I’m just trying to find out. I’m not repeating any “deniers” claims but am rather following the temperature data and have done that for years already. The only data that shows warming from 1998 is GISS. None of the others does. As I said, that is something for what I don not have and have not seen any satisfactory answers. Yours definitely has not helped me forward.

      • If you were honestly “just trying to find out”, you would not cherry pick your years so carefully. Anyone who posts that graph starting in 1998 without including some caveats is dishonest.

        The scientists say 10 years is too short a time for a meaningful trendline. It should be at least 15:

      • The proper way to plot your data is this :

        The way you plotted it is a prime example of cherry picking. And of bad chartsmanship. As well as being misleading.

        What you did there was to generate a linear plot through an inflection point. The inflection point is obvious by visual inspection and cannot be ignored just because it’s “inconvenient”. If you play with the WFT software, you can nail the inflecton point to the tenth of a year. I did exactly that several yearsa ago And even the GISS data showed the inflection point – although somewhat later than the others.

        If someone (ANYONE) is telling you that it needs 10 years or 15 or 3o, then they’re lying, scientist or not. Neither nature nor climate operates on their schedule.

      • I don’t see any good reason for you to split them like that. And obviously a longer term trend is going to be more accurate than a piddling little 10 year trend.

        Look what happens when you switch from Hadcrut to Gistemp:

      • Holly, your reply is exactly the kind of “proving your point” that I was refering to. Please read, what my point was. I never claimed that there is not or has not been any global warming. My point was that from 1998 (or at least 2001) there has been no warming (or in other words, there’s a plateau or even cooling) even though CO2 has continued to rise (and that’s what Jim Owen’s graph is also showing). That’s why I’m using 1998 0r 2001 as a starting point. 10 years or 13 years is quite a long time for this. And it’s not cherry picking. Since 1998 there’s only one year that will give significant positive trend – 1999. And I said already above that GISS is the only exception. If you have a good enough reason for that, I’m more than willing to listen. I’m truly interested to find out what’s the reason for that but sorry, that answer is not convincing.

      • The specialists that you are refering to are trying to prove that nothing is wrong. Come on, these specialists are speaking about 15 year long cycles of El Nino and La Nina years! If you ever have followed the ENSO graphs you would know what rubbish this is. It would be cherry picking if I would use 1998 starting point to prove that there is no global warming. If I use it to show that there is a plateau for the LAST 13 years it is not cherry picking. In 2007 there was the same discussion after an article by David Whitehouse and Tamino was trying to convince everybody that 7 years means nothing we should look at 10 years. Well, now it’s even 13 years. And since 2001 (again, except GISS) there’s even a cooling trend. At the same time CO2 is rising. It’s still something I can’t convincingly explain to myself. I have no idea how it’s gonna continue, but what I see now needs explanation (to me at least it seems it does).

      • Oh, and one more point. It would be cherry picking if 1998 would be the only year that would give a flat or negative trend, but since 1998, 1999 is the ONLY starting point that gives a warming trend, after that it’s all either flat or negative (exception – GISS)

      • False, Sven. 2000, 2007, 2008, 2009 all show warming for Hadcrut. For the GISS explanation read this until you understand it:

      • Ok, sorry, I was not quite correct in the preciseness of my claim. To be more precise, 2000 is a positive trend but so small that it could pretty much be called flat. 2007, 2008 and 2009, on the other hand is really so short a period that it’s pretty much just year to year variation. 1998-2010 or 2001 to 2010 is not. Still, I’m not trying to prove anything but if this plateau is not a problem, even a question to you, then be it. For me it is.

      • You are manipulating yourself a line that shows cooling. When you choose the unusually warm year 1998 as the start of a line, you are cherry picking. And yes the shorter lines are less trustworthy, which means that the longer your trendline, the more accurate it should be. 30 years long is much better than 10 years long.

        And as the link I gave you explained, Hadcrut does not include Arctic temperatures, and the Arctic is where amplified warming is taking place, so Hadcrut temperatures are too low. As warming in the Arctic has been increasing as predicted by the climate scientists, I presume the HadCRUT temperatures are getting less accurate.

      • Holly –
        I don’t see any good reason for you to split them like that. And obviously a longer term trend is going to be more accurate than a piddling little 10 year trend.

        Let’s start with the second point – less than 10 years ago the climate folks were using 5 year trends. Were they wrong?

        Then, due to some “inconvenient data” they changed to 8 year trends. Were they wrong?

        Unfortunately, the climate didn’t cooperate and they were forced to change to 10 year – and then 15 year trends. Now we’re approaching the end of that 15 years. And you want to change to 30 years trends? Moving the goalposts is one way of being dishonest.

        Note – that “piddling” 10 year trend was once the gold standard. It wasn’t changed because it was wrong, but because the data stopped cooperating with the desired storyline. The extension of the trend times became a “convenient” way to maintain a fictitious storyline. Which is one of the dangers of the longer timelines you seem to favor.

        Actually, there’s nothing wrong with 30 year trends – IF AND ONLY IF – the data is actually linear. OR if you’re using a polynomial for your fit.

        However, generating a linear trend for obviously non-linear data is, at the very least, ignorant. And can be dishonest if you have the background to know better.

        Climate is not a linear function. And when you have 10 years (or even 5 years) of data that clearly indicate a “break point” then it behooves you to pay attention and not make dogmatic statements about how that “break point” does not exist.

        The argument has been made on another thread on this blog – that “eyeball data analysis” is not a valid methodology. And that’s ignorant nonsense. I spent 20 years doing “real-time eyeball analysis” on strip chart recorder data for spacecraft operations. It works extremely well – IF you know what you’re doing.

        As for Skepticalscience – They’re neither sceptical – nor, in my opinion – science. I stated so and met their challenge on a previous thread. You need a different source. But that’s your problem, not mine.

      • Jim Owen Do you have citations for the use of 5 year and 8 year and 10 year trends?

        Sorry, I doubt that eyeballing a chart is a useful way of addressing climate change, which is not a spacecraft operation. It looks to me like you just cherry picked your end dates to get a result you wanted.

      • Holly, what do you mean I’m manipulating data? What I have observed is that we have a lack of warming for 13 years. Not 14 or 15 or 16 or 30 (yet at least?). If we have a flat, as good as flat or cooling trend until 2010 with starting points at 97, 98, 00, 01, 02, 03, 04, 05, and 06, it would be choosing 99 that would be cherry picking I guess. Or 07, 08 or 09 where drawing a trend (of 1 to 3 years!) would just be nonsense. In other words – flat or cooling 13, 12, 10, 9, 8, 7, 6, 5 and 4 year trends. N’est-ce pas? Think with your own head and do not just try to “shoot down” the “denialists” (the sole purpose of sceptical science).

      • Sven, go read my links again. You do not seem to understand what they say.

      • But I’ll stop here, there’s no sense in this discussion

      • Sven,

        First of all, you should be using 2011 as your end point rather than 2010 in order to get the most up to date data. This still given a negative trend for HadCrut but a positive one for GISS, RSS and UAH. As Holly Stick pointed out if you start in 2000 you get a positive trend for all four records.
        Of course there is no “correct” period to look at, just the general rule that longer trends are more meaningful than shorter ones, but 1998 is a particularly bad starting point (in the context of a debate on GW anyway) due to it being exceptionally warm largely for reasons other than GW. Having said that, for the period 1998 – 2011 all four records actually show a warming trend.

      • No worse indeed.

        Can we go home now?


    JC: “…but agree that more CO2 will warm the surface.

    There is no evidence for this statement according to the following data:

    1) In the period from 1910 to 1940, the globe was warming at a rate of 0.15 deg C per decade.

    2) After 30 years of human emission of CO2, in the period from 1940 to 1970, the globe slightly cooled.

    3) After further 30 years of human emission of CO2, in the period from 1970 to 2000, the globe warmed at a rate of 0.16 deg C per decade, similar to the period from 1910 to 1940.

    4) With further 10 years of human emission of CO2, since 2000, there was little warming with average global mean temperature anomaly flat at about 0.4 deg C as shown in the following chart.

    At no 30-year period in the temperature record has the natural warming rate of about 0.15 deg C per decade for the period from 1910 to 1940 has been exceeded. As a result, there is no evidence of accelerated warming due to human emission of CO2.

    Change in global mean temperature pattern may give evidence of man-made global warming, and it may be confirmed if we don’t see global cooling from 2000 to 2030 similar to past cooling in the period from 1880 to 1910 or in the period from 1940 to 1970 shown in the following chart.

  36. Zeke says:

    # Water vapor primarily acts as a feedback rather than a forcing in the climate system due to its short atmospheric residence time and the limitation to absolute humidity at a given temperature for saturated air. Science of Doomcovers this rather well. Pointing out that water vapor is Earth’s dominant greenhouse gas does not minimize the climate’s sensitivity to carbon dioxide. JC: OK

    The statement is wrong as it stands. Even if we ignore clouds and also ignore water vapor’s role in transporting heat, water vapor is still the major absorber of longwave infrared energy. If we remove water vapor from the atmosphere, the world will quickly become much cooler.

    If we restrict our discussion to the greenhouse effect, water vapor still predominates because it absorbs energy over a much broader band of wavelengths, and more strongly than carbon dioxide. In addition, some of the absorption bands overlap. Increasing carbon dioxide would have no effect on atmospheric absorption of far infrared in those bands because it is already being absorbed by water vapor.

    If one argues that water vapor acts primarily as a feedback, you are also arguing that carbon dioxide is truly inconsequential.

    Water vapor absorbs much more energy than carbon dioxide.
    So, if absorption is not water vapor’s major effect
    We can pretty much ignore the effect of carbon dioxide

    I’m pretty sure Zeke doesn’t want to make that argument. ;-)

    The Science of Doom article conflates a bunch of issues and is particularly unhelpful for understanding the nature of CO2 and water vapor as greenhouse gases per se.

    A reasonable starting point for understanding atmospheric absorption of longwave infrared is thiswiki article. Note that the graph in the article is for transmittance rather than absorption. You can get an idea of absorption by turning the graph upside down. The blue areas represent wavelengths where less energy is absorbed.

    As you are well aware (but some readers may not be) the wavelength a surface radiates is determined by its temperature. Warmer surfaces radiate shorter wavelengths. Normal terrestrial surface temperatures occur in the blue region of the graph around 10 um.

    (As always, follow the references rather than taking the wiki article itself as gospel.)

  37. Judith,

    Just for the record, I rate a no3 on your epistomological list. I part company with the confidence list at nos 4 and 5 of the 90% band.

    I guess this confirms me as a lukewarmer!

  38. Just for the record, she wonk, here’s your post and my reply:

    shewonk | February 26, 2011 at 12:10 pm |
    Since I can’t respond to Lewis due to threading, I will say here that I am not talking about a general visit to a doctor. I am taking about the ER where grandma is unable to breathe and is blue in the lips. I listen to the respirology specialist and when he says that she has COPD and needs a nebulizer to open up her airways, do I doubt him and take out my iPhone and google COPD and check out the website “” to see if the majority of bloggers think nebulizers are harmful or helpful? Say I do have time to have a second opinion, do I ask MrsDoubter87 if COPD requires frequent nebulizer treatments? Or do I get another respirology specialist to take a look at grandma?

    Back in the day, before civilization, we might have had to be experts in everything and could rely on our own best judgement to decide issues but we’ve progressed since then. We have bona fide experts today and the amount of sheer knowledge and technical skill needed to arbitrate some matters is well beyond the average layperson.

    Common sense in this case is the ability to know your own limits and to know what authorities to go to when deciding matters.

    Lewis Deane | February 26, 2011 at 12:21 pm |
    People always bring this up, shewonk, and it’s always very foolish. If your ‘grandma’ (why do people have to make this thing personal, I wonder?) were blue in the lips and near to death and you happened to be a sub saharan african, would you not have to defer to the ‘authority’ of the only ‘medical’ person around, ie the witch doctor? Think.

    • reminds me of the advertisements you see on TV…

      Take this new wonderful drug or your brain will explode…

      Immediately followed by the ad from the law firm saying:

      …if you took this drug and your brain exploded, call us, we can help

      We are very advanced………..

      • LOL!

        Sorry. I’ll try to write something substantive but that just tickled my fancy. :)

        There is a reasonable degree of skepticism we should all carry around with us and use when faced with claims from experts. I work in the health care field and frequently deal with what are called “critical incidents” so I am well-aware that even the experts can make mistakes and errors and that it is far wiser to be well-educated and thoughtful than blindly follow what people claim and order. I am pro-skepticism when it is merited.

        The “trick” is to figure out when it is merited and when it is not. Unwarranted skepticism slides into cynicism and that is what I fear from this attack on climate science and science in general.

      • shewonk, I think you need to be careful about asserting an “attack on climate science and science in general”.

        Most of the skeptics who are worth reading are actually defending climate science and science in general from what appears to be an attempt to assert greater certainty than is warranted.

        The fact is that climate science got off to a bad start when it was used by people like Al Gore, David Suzuki, Greenpeace and the WWF to push a political agenda. Worse, what should have been an objective appraisal of the state of the science was turned into a political football in the various IPCC reports.

        The reputation of the climate scientists – at least the Team – was not enhanced by their refusal to release their data and their code. And it was pounded by the release of the Climategate emails and code. (And, I note, that not a single one of the “investigations” you cite above would pass even the most basic tests of objectivity or throughness.) And this reputational damage was compounded by the Team’s tin eared website which, frankly, often seems like it is run by a bunch of snickering frat boys rather than distinguished scientists.

        The politicization of climate constructed a very tall edifice on necessarily weak foundations. There is no shame in scientists admitting uncertainty. Unfortunately, in climate science there has been a huge pressure to create a “consensus” position to bolster a particular policy agenda. And part of that consensus has been to claim that both the basic science and its implications are “settled”. Which, in its turn means that the important caveats going to uncertainty, the incompleteness of the data, the unverified nature of some of the statistical methods and the tentative nature of the models has tended to be suppressed, either directly or by way of a sense of professional prior restraint.

        Noticing all of this and bringing it to public attention is, in fact, a defence of the seriousness of climate science and an attempt to enforce the general ethical norms of science on a very young discipline. In my own experience, the leading skeptics take science very seriously indeed.

      • I agree with you Jay that there are many in this debate on both sides who are taking part because of what they perceive to be a threat to science. That is how I feel and what motivates me. I love science. I revere it, but I am not sanguine that it is safe from political interference and manipulation by those who seek to dispute its findings. Those who claim to be upholding “sound science” appear to be doing it more of a disservice than a service, especially in light of recent budget cuts that are plainly motivated by politics rather than financial exigencies.

        The whole meme of “sound science” is one I am interested in. It has been used before to undermine the actual sound science being used to inform public policy, which is my area of study. I figure you look at the results of these claims, and don’t take them at face value. I see no value in the skeptic blogs who smear climate science and scientists and raise unfounded or unwarranted doubt about both.

        It’s one thing, and quite easy, to claim the high moral ground and assert that you are all about sound science. It’s motherhood and apple pie. It’s another thing to actually do something that promotes sound science.

        I don’t see a lot of that in the skeptic blogosphere. And even efforts that I do see that improve science such as clear climate code, and the work of Ron Broberg, Zeke Hausfather and others, may only serve to allay the unfounded fears and overturn the unsubstantiated claims of the skeptics. In other words, we could have trusted the scientists in the first place and would have if certain “skeptics” and deniers — yes, I will use that word for those disputed science for political or economic interests — hadn’t raised unfounded doubt.

      • And from what you have learned in your field, more than in most I would imagine, do you not see that this is “normal” human behavior, behavior that cannot be issolated? Were not “those who disputed science for political or economic interests”, your “skeptics” and deniers, about as vocal to those who supported “science” for political and economic interests, the “warmers” and supporters? Is it not the “choices” we have regarding the solutions to the Problems that divide us more than the science? And when it comes to “choices” I think you’ll agree that there is nothing very scientific about the way people choose.

      • HMMM !Finally something I can agree with. Are there two people with the same handle. Just when I had decided to blow off anything you wrote, you had to go and do this. SHAME :-)
        My only nit would be that one has to evaluate every “attack” and see for what it is. Yes there are groupies on each side but that is the price to be paid for being in the blogosphere.

      • No one is attacking climate science or science in general. Your generalization is sophomoric. What is being questioned is questionable science.

  39. From Jim D’s comment:

    “1 C from CO2 doubling. Yes, this is a number that you can arrive at with some assumptions. The more easily defendable number is 3.7 W/m2 forcing at the top of the troposphere from CO2 doubling which comes straight from radiative transfer models that are trusted and verified. ”

    This is exactly the problem. Assuming that you can extrapolate theory to reality. Radiative transfer models may be trusted and verified but “forcing” is not just radiative transfer. I do not believe in CO2 forcing, or this 3.7W/m2, because it is meaningless unless backed up with a characterised experiment. It could be 0.37w/m2 or 37W/m2 if typical order of magnitude variations that you commonly get in models apply.

    For me the whole issue with AGW is that no-one has bothered to test forcing in a lab. No-one is characterising the effect using a gas and vapour mix, and using solar simulators, to get a handle on the magnitude of the effect and of other processes that may go on.

    Now we know that CO2 re-radiates at certain wavelengths and also that it absorbs and thermalises at others. So it both gets hotter and it acts like a “reflector” if you will of a certain part of the spectrum. But how this translates into the physical change of surface temperature under the presence of convection with a vapour providing a means to transfer heat from the surface to the atmosphere, is a much more complicated and nuanced process. And not a fully known process.

    Some people on here might say that either you can’t do an experiment, it’s too hard or that or you don’t need to. Well, all I can say is LHC?

    I’m an experimenter and 3 times in my career to date, physical testing and evidence have turned theory and assumptions on their head. If you don’t test and get evidence, for or against, it isn’t science. It’s just theory. I’m sorry if that ruffles peoples feathers but this is the hard reality of science. If you aren’t attacking the heart of your theory with test then you haven’t shown anything.

    No amount of MODTRAN and radiative transfer, or water feedback and all that is going to count. You need to test.

    Lastly, if you look at how people have become polarised with issues, the psychological effect of commitment and consistency, then really a reconciliation is impossible. What’s needed is a straight Occam’s Razor. Weed out anything that is conjecture and just work on the facts.

    Measure CO2 forcing, Characterise it. Repeat and repeat until everything you say is backed up by a test result with your errors shown. Then talk about what you do.

    • Radiative transfer models can explain the current radiative fluxes, so we can be confident in their results if you take today’s atmosphere and double CO2 in it. This is what 3.7 W/m2 comes from as a global and annual average. It does not depend on feedbacks or atmospheric changes other than doubling its CO2 gas content. This is why it is such a clean result, and not under dispute.

    • “For me the whole issue with AGW is that no-one has bothered to test forcing in a lab.”

      I’m a non-scientist – are you serious about this? Can you give an example of the sort of lab experiment you have in mind?

      • Hi TomFP

        Yes I am serious. I’ve been looking for a paper for years on the characterisation of CO2 forcing with a representative atmosphere.

        The kind of place you would start is this (and I’m not saying it’s easy but you have to try):

        Take a large laboratory, ideally thermally and humidity controlled, and construct a large tank made with all but one side NaCl Glass (rocksalt), and one side as it is transparent to IR radiation.
        Have a side that is blacked out and with some sort of absorbing surface on it to act as the sink
        Get solar simulator lamps, the kind used to test satellites and place them so that they shine onto the surface from the outside of the tank. Fill the tank initially to atmospheric pressure with a given starting humidity and initial CO2 content (ppm). Turn on the lamps and let the temperatures stabilise.

        You would have arrays of thermocouples on the surface, on the sides of the tank, on the floor around. You would also have humidity sensors, spectral analysers (for the lamp power output). Basically you want to characterise an initial condition as best as possible. In this case it is a “greenhouse” with no convection. Remember a greenhouse doesn’t heat up because of reflected IR (that was shown in the 1920s); it heats up because of lack of convection. So you would start with a condition, then you add in more CO2 and let the temperature stabilise.

        Now this is just the start. You need change the set-up to be more like an atmosphere if you can, and you need to account for conduction in the tank walls, convection (if introduced); also you need to use other gases with similar molecular configuration to CO2 but without the IR absorptivity.
        You try and characterise everything, so that you get as close to a basic atmosphere as you can. And then see what your results are.

        The reason being, as many are trying to point out, CO2 forcing is a phenomenological effect. As in it doesn’t require you to have an Earth’s atmosphere to see it working. You should see something even with a basic set-up.

        Yes it takes time and patience but is it not worth doing? I mean if it is science then there is no argument. You are debating the logistics not the logic.

        Also, off the top of my head, a very tall tank may allow for a small lapse rate like effect, with warm air rising.

        Why do I believe this?
        My background is material science and ion thrusters. As an example, over a year ago we did a test with a probe taking electrical traces inside a running thruster, to confirm plasma parameters that we had been using in modelling for 10 years to predict lifetime. Turned out we were wrong not only about the values, but the assumptions behind the values themselves. And we wouldn’t have found this out unless we tested it.

      • Micky, all you say makes sense, but as I say I’m not a scientist. I have been persuaded by the Proxymorons that lab experiments cannot provide this sort of study, there is only one earth, etc. While I reject most of what they say, I had hitherto accepted this. But you contradict it, saying, in effect, that they have leapt to model-based conclusions while neglecting lab work that was indeed feasible.

        Anyone else care to comment? Judith?