Appraising Marvel et al.: Implications of forcing efficacies for climate sensitivity estimates

by Nicholas Lewis

Different agents may have effects on global temperature (GMST) different to those which would be expected simply by reference to the radiative forcing they exert. This difference is encapsulated in the term “forcing efficacy”.

In their recent paper, Marvel et al. estimate efficacies for various forcings from climate simulations of the GISS-E2-model over the period from 1850 to 2005 (the historical period). They then use data pertaining to three recent observational climate sensitivity studies, incorporating the efficacy figures and calculating new estimates for the transient climate response (TCR) and effective climate sensitivity (a proxy for equilibrium climate sensitivity: both are designated ECS). Taking the average for the three studies, these new estimates imply an increase in TCR from 1.3°C to 1.8°C and in ECS from 1.9°C to 3.0°C. The increases are due to the efficacy-adjusted sum of forcings over the historical period being substantially less than the unadjusted sum of forcings.

Marvel et al. conclude that “GISS ModelE2 is more sensitive to CO2 alone than it is to the sum of the forcings that were important over the past century” and that “Climate sensitivities estimated from recent observations will therefore be biased low in comparison with CO2-only simulations owing to an accident of history: when the efficacies of the forcings in the recent historical record are properly taken into account, estimates of TCR and ECS must be revised upwards.” The second statement would not be scientifically valid even if Marvel et al.’s findings were correct. Results from any single-model model study reflect the characteristics of the particular model involved, which may well behave differently from the real climate system – and from other models. Moreover, due to multiple methodological, data and computational errors and deficiencies in their study, Marvel et al. fail to establish that their first assertion is true either. When these problems are corrected, GISS ModelE2 does not appear to be materially, if at all, more sensitive to CO2 alone than it is to the sum of the forcings acting over the historical period.

Marvel et al.’s revised observationally-based TCR and ECS figures substantially exceed the GISS-E2-R model’s TCR of 1.4°C and effective climate sensitivity of 1.9–2.0°C.[1] However, GISS-E2-R already exhibits warming that is greater than in the real climate system: the simulated GMST increase and ocean heat uptake rate are both higher than observations at the end of the historical period, which implies that its TCR and effective climate sensitivity are probably excessive. That their new estimates of TCR and ECS are higher still is therefore paradoxical and suggests that there is something seriously wrong with their work.

The transient efficacy estimates in the paper disagree with estimates from more detailed work by James Hansen using the earlier GISS Model E, and with other work using different models. The equilibrium efficacy estimates use the same GISS-E2-R forcing data as do the transient estimates, and are therefore also very questionable. Moreover, Marvel et al.’s use of ocean heat uptake values rather than radiative imbalance data, which is what should have been used, biases down its estimates of equilibrium efficacies and of ECS.

Marvel et al. estimate forcing efficacies from simulations in which the climate is forced by just a single forcing at a time. Efficacies that are derived in this way may be different to those that apply when all forcings are applied simultaneously in the same model. The forcing produced by a forcing agent may vary substantially with climate state. Previous studies show that to be the case in GISS-E2-R for both aerosol and ozone forcing. Moreover, efficacies estimated from a climate simulation may be substantially different to those that apply in the real climate system.

The efficacy estimates Marvel et al. made using instantaneous radiative forcing (iRF) are largely irrelevant, since few if any observational studies use that measure of forcing. IPCC AR5 does not provide estimates of iRF either, preferring the effective radiative forcing (ERF) measure. Moreover, Marvel et al.’s iRF efficacy estimates use a regression model under which a zero forcing may, unphysically, have a materially non-zero effect on temperature. In some cases, requiring zero forcing to have no effect on GMST radically changes the estimated efficacies.

The efficacy estimates scale with the forcing arising from a doubling of CO2 concentration (F2xCO2). Marvel et al. use the RF value of F2xCO2, 4.1 W/m2, as its iRF value and hence in calculating iRF efficacies, and they imply that they use the same value for the ERF F2xCO2 and for ERF efficacies. No value appears to have been published for either iRF or ERF F2xCO2 in GISS-E2. In GISS-E, iRF F2xCO2 was 10% higher than the RF F2xCO2 value. Were the same true in GISS-E2, all the iRF efficacy, TCR and ECS estimates calculated from Marvel et al.’s data would need to be increased pro rata. Likewise, there are grounds for thinking that the true ERF F2xCO2 value is ~10% higher than the one they used. Without accurately established iRF and ERF values for F2xCO2, efficacy estimates can have little credibility.

On the basis of the indicated ERF F2xCO2 of 4.1 W/m2, all ERF efficacy estimates given in the Marvel et al. paper disagree with those I calculate using their data. Moreover, the climate sensitivity (TCR and ECS) estimates that they give using ERF appear to be inconsistent with both their data and their ERF efficacy estimates.

Using better justified estimation methods, and the GISS-E2-R effective rather than equilibrium climate sensitivity, the Historical iRF and ERF data are both found to produce efficacies within 10% or so of unity, both when using Marvel et al.’s estimates of the forcing from a doubling of CO2 and with them adjusted up by 10%. This indicates no material bias in climate sensitivity estimation as a result of forcings that were important over the last 100–150 years having differing efficacies from CO2.

Marvel et al.’s calculations of TCR and ECS estimates for the three observational studies cited contain multiple errors. They are also conceptually wrong in the case of Otto et al. 2013, since the underlying forcing estimates used in that study already reflect efficacies.

The methodological deficiencies in and multiple errors made by Marvel et al., the disagreements of some of its forcing estimates with those given elsewhere for the same model, and the conflicts between the Marvel et al. findings and those by others – most notably by James Hansen using the previous GISS model, mean that its conclusions have no credibility.

[1] The ECS estimate also substantially exceeds the GISS-E2-R model’s equilibrium climate sensitivity figure of 2.3°C.

A more comprehensive and technically detailed analysis can be found in a post at ClimateAudit.

JC note:  As with all guest posts, please keep your comments civil and relevant. In discussing this paper, you may also wish to refer to two posts at RealClimate:

265 responses to “Appraising Marvel et al.: Implications of forcing efficacies for climate sensitivity estimates

  1. Pingback: Appraising Marvel et al.: Implications of forcing efficacies for climate sensitivity estimates | Enjeux énergies et environnement

  2. Thank you for your patience, Professor Curry, in trying to find some element of scientific veracity in policy-driven AGW.

  3. The methodological deficiencies in and multiple errors made by Marvel et al., the disagreements of some of its forcing estimates with those given elsewhere for the same model, and the conflicts between the Marvel et al. findings and those by others – most notably by James Hansen using the previous GISS model, mean that its conclusions have no credibility.

    One problem with appearing absolutely certain is that it makes it very difficult to walk it back if it turns out you’re mistaken, or have over-reached somewhat. Feature rather than a bug?

    • good point. you should call yourself …and then there’s politics

      Next, perhaps you can explain to the great unwashed ” Auditing isn’t really part of the standard scientific method. ”

      I already have the answer: I don’t have time… I couldn’t convince anyone because their minds are already made up… the quote is out of context.

      My answer is that the correct version is ” Auditing isn’t really part of the academic scientific method. ” This is why academic science never builds anything for use by the general public, industry or the military. The academic contributions have to be filtered through an auditing process before that can happen.

      Since the consensus of climate science is solid, it’s time for the academy to give way and let the responsible professionals decide how best to respond.

    • “mean that its conclusions have no credibility.”

      I think this goes a bit to far.

      It may seem quaint but in science folks generally let the results speak for themselves and they refrain from commentary on others.

      Marvel presents their case
      Lewis presents his case
      Generally one should avoid claiming victory especially in such certain terms.
      unless the science is settled. hehe

      • “Generally one should avoid claiming victory especially in such certain terms.”

        Perhaps Nic feels that it is his duty to make dramatic statements while making little mention of any doubts he may have – after all, that’s how you get media and public attention on important issues, right? If in doing so, he is remaining honest, then perhaps there is not even a double ethical bind for him.

        Or perhaps you feel that claiming victory prematurely is itself dishonest – even if you can manufacture 97% agreement.

        Or perhaps you feel that it’s wrong to denigrate those who disagree with you instead of politely pointing out their mistakes.

        Or perhaps the politics is now so dominant in this issue that like so many, you are removing the mote from your brothers eye, while ignoring the beam in your own?

        Who knows?

      • Steve Mosher, This should be about the science and not about “optics.” I hope Schmidt responds and there can be an honest exchange of facts and data. You should know Mosher that there is a long history of Real Climate obfuscating and denying real problems with Mann’s work for example. Schmidt was all in on that too. But perhaps now that Schmidt is an institute director, he will be more responsible. In any case, you of all people should understand why people would be skeptical of a paper that seems to contradict a large body of work by a large number of top notch scientists including apparently Hansen and AR5. I can understand Ken Rice’s science free political response, but we need to get to the bottom of this.

        If one wanted to argue for low sensitivity, one could note that the latest GISS model has an ECS of 2.3, considerably below earlier versions of the same model. It fits a pattern of recent results finding lower ECS than most previous work.

      • > It may seem quaint but in science folks generally let the results speak for themselves and they refrain from commentary on others.

        This one can go up to 11:

        Numerous studies have revealed biases within the scientific communication system and across all scientific fields. For example, already prominent researchers receive disproportional credit compared to their (almost) equally qualified colleagues — because of their prominence. However, none of those studies has offered a solution as to how to decrease the incidence of these biases. In this paper I argue that by publishing anonymously, we can decrease the incidence of inaccurate heuristics in the current scientific communication system. Specific suggestions are made as to how to implement the changes.

        http://arxiv.org/abs/1512.05382

      • I had a similar reaction to Nic saying ‘their conclusions have no credibility’. Perhaps saying that their conclusions were different than his, given the results of the analysis or stating that the analysis was flawed, so no conclusions should be drawn would have felt better to me.

    • Horst,

      This is why academic science never builds anything for use by the general public, industry or the military. The academic contributions have to be filtered through an auditing process before that can happen.

      Maybe a but simplistic but, yes, probably a fair description of how things work in general.

      Since the consensus of climate science is solid, it’s time for the academy to give way and let the responsible professionals decide how best to respond.

      Well, apart from the slightly derogatory “responsible professionals” I, again, largely agree. Do you really think that climate scientists are actively trying to be the ones who decide how best to respond? I realise that there are some who express their opinions as to how we should respond, but they seem to be in the minority (for example, Hansen and others advocating for nuclear, others who seem to promote renewables). Do you really think that somehow doing climate science is preventing others from making decisions as to how best to respond?

      Steven,

      Marvel presents their case
      Lewis presents his case
      Generally one should avoid claiming victory especially in such certain terms.

      Yup, pretty much my view on this.

      • The funny thing is that I cringed at that sentence. My thought was
        “Dang Nic, let your readers say that your opponent lacks credibility”

        But now we are off in a discussion of rhetorics rather than the paper.

        There is a lot to digest in Nic’s latest work.

        It sure would be nice to be able to go through it point by point without
        personalities and other crap..

        Gavin too looks like he will not shirk from harsh language..

        Then too you have to consider that some of outsiders are not fully upto speed with the peculiar civilities required of working scientists.

        “He is wrong” is usually phrased… “the conclusions do not appear to be fully supported “

      • But now we are off in a discussion of rhetorics rather than the paper.

        Indeed, but if someone has indicated that they have established what they believe to be absolute truth, a discussion seems rather pointless.

        There is a lot to digest in Nic’s latest work.

        And in Marvel et al.

        It sure would be nice to be able to go through it point by point without
        personalities and other crap..

        Absolutely, would be a lovely change.

        Gavin too looks like he will not shirk from harsh language..

        I’ve no idea why he should.

        Then too you have to consider that some of outsiders are not fully upto speed with the peculiar civilities required of working scientists.

        Possibly, but it’s not all that complicated. Even in day-to-day life you don’t typically tell someone that what they’ve done has no credibility and then expect them to say “okay, thanks, I shall immediately change what I have done ….”. Of course, if you see it as some kind of marketing exercise where you hope your produce succeeds and the other fails, maybe you do, but that’s not really ow science should work.

      • Mosher, Perhaps your best post ever !!

        ATTP; “Possibly, but it’s not all that complicated. Even in day-to-day life you don’t typically tell someone that what they’ve done has no credibility and then expect them to say “okay, thanks, I shall immediately change what I have done ….”.

        Well actually I would say:’ ok thanks’ because it would be true. The second place where I might say that is if Gavin took a hard look and admitted he made a mistake. So that is two possible cases where you could tell someone that.

      • Well actually I would say:’ ok thanks’ because it would be true. The second place where I might say that is if Gavin took a hard look and admitted he made a mistake. So that is two possible cases where you could tell someone that.

        So the only possibility that you can envisage is one where the person claiming that the other persons work has no credibility is the one who is correct? No possibility that the person making the strong claim might be wrong? Have I misunderstood you?

      • ATTP.

        Actually No!
        In fact I suspect that Gavin is correct, I would not expect him to make a silly mistake. Now as to how the assertions made by Nic vs those by Gavin I would say it’s a 50/50 chance. Since Nic is responding I would give the house (Gavin) the odds. However back to my previous point, In was only giving you two possibilities of why someone would say that.

      • ATTP:Well, apart from the slightly derogatory “responsible professionals”
        This is a legal term used in the US that codifies the potential civil and criminal liability for the licensed practice of science and engineering that effects the environment and public safety.

        As far as climate actions or inactions, we have had enough research from IPCC and it’s time to have proper risk assessments and economic analyses using folks whom do this in the real world. The USEPA should take this on with a Superfund type of approach because they have the most experience managing professional environmental contractors and the US benefit the most and are responsible for the largest share of energy and industrial production.

    • Appropriate comment from the guy who has had to do more back pedaling and change of direction than your average cornerback.

  4. Thank you. Will you be publishing this rebuttal somewhere? Do you encourage Marvel et al. to withdraw their paper?

    What does this episode say about the state of peer-review in Climate science?

  5. Read the more detailed critique at CA. Can only conclude that as the wheels come off the CAGW bandwagon, increasing desperation leads warmunists to produce ever shlockier and easier to rubbish papers claiming it aint so. This one appears so bad it should be retracted.
    It is tough when Mother Nature herself evidently disagrees with warmunism.

  6. stevefitzpatrick

    Hi Judith,

    I’ll ask you the same questions I asked Nic at Climate Audit:

    1) Since you were one of the co-authors of one of the three papers Marvel et al claimed produce inaccurate sensitivity estimates, you are a logical candidate to act as a reviewer. Were you asked to review Marvel et al? (Nic was not.)

    2) Ar you and/or others planning to submit a comment on Marvel et al to the journal?

    • Nope, I was not asked to review this paper

      • > Nope, I was not asked to review this paper

        There was a second question, Judy.

      • Willard (and then there’s linguistics): Playing the role of the scolding nag because that’s all he’s go. What a sad, vain little fellow.

      • I’m actually interested by Judy’s answer to SteveF’s question, O Grouching Tiger.

      • Willard, Perhaps she didn’t answer the second question is that it wasn’t important enough to even have thought about what she might do.

      • > Perhaps […]

        Thank you, Judy.

      • willy, willy
        You should thank ordvic for kindly giving you a plausible face-saving reason for Judith ignoring you.

      • Judith apparently only talks to those who listen, not demand.

      • Would that explain why she ignored one of SteveF’s questions, RLH?

      • Willard:Would that explain why she ignored one of SteveF’s questions, RLH?
        I think not. Dr. Curry is likely terrified of answering that question once she found out you were interested in the answer. My God, man. Have you no decency. You really need to take a time-out the next time you feel the need to throw your considerable intellectual gravitas at inferiors.

      • “Would that explain why she ignored one of SteveF’s questions, RLH?”

        Ask her, not me

      • > Ask her, not me.

        Why would I need to ask her about your explanation, RLH?

      • “There was a second question, Judy.” Climateball. A question about whether she was asked to review can be answered in a second. A question about future plans about a publication may not be answerable at all right now, and may take months for that kind of decision. Ridiculous.
        This kind of stuff makes you look low.

      • “Why would I need to ask her about your explanation, RLH?”

        Because only she would know the answer to the question that was asked.
        Offering an opinion when it is plain I do not know the facts is not sensible IMHO,

      • > A question about future plans about a publication may not be answerable at all right now […]

        (1) “I don’t know.”

        (2) “I haven’t considered.”

        (3) “I’m not that interested.”

        (4) “I’d rather grab some popcorn right now.”

        (5) “Maybe, I’m waiting to see what Nic can write up.”

        (6) “No.”

      • 5 out of 6 (go ahead and pick which 5 you prefer)

      • > Offering an opinion when it is plain I do not know the facts is not sensible IMHO.

        Of course you could, RLH, and in fact you “apparently” just did, by attributing to me a question that was asked by SteveF. MikeR did the same, and now “apparently” needs to face the implication of accusing SteveF of playing ClimateBall.

        Here’s what MikeR said about when people don’t answer:

        The result: Marvel and Schmidt can fight it out now, or people like me will assume that they have no good answers.

        https://andthentheresphysics.wordpress.com/2016/01/09/what-a-surprise-not/#comment-70616

        Apparently, “fighting it out” now takes less time than answering a simple question.

        Apparently, MikeR considers Judy “from the world’s foremost experts in estimating sensitivity to CO2.”

      • Are you happy with Dr. Curry’s answer, little willy? She didn’t exactly tell you to talk to the hand. That’s something.

      • Woah, Don Don. I need to think about that one. Please give me a few months. Have you noticed that only one possible response is incompatible with the others? I hope you like popcorn as much as I do.

        On behalf of SteveF and myself, thank you for your candid answer, Judy.

      • The only response not compatible with the others is “no”, little willy.

        You should be happy that she bothered with you. Judith apparently finds you less disrespectful and annoying than your little moderated friend, whose name we can’t mention.

      • “5 out of 6 (go ahead and pick which 5 you prefer)”

        Is that a statistical answer?

      • “You should be happy that she bothered with you. Judith apparently finds you less disrespectful and annoying than your little moderated friend, whose name we can’t mention.”

        Do tell.

      • Please keep your chips for another round, RLH. Meanwhile:

        https://twitter.com/nevaudit/status/686617411211100160

      • Little willy is showing that he is not the linguistic leviathan that he thinks he is. Read harder-think harder, little willy.

      • “Please keep your chips for another round, RLH. ”

        Can I go all in? That will make things much shorter. (and probably less words all round)

      • > Can I go all in?

        Of course you can, RLH. You can even go all in with more than your own stack of chips.

        Since you’re new here, let me tell you a little secret. To get the answer you already know:

        First, you’ll have to own the tricks you pulled in this subthread against me, including your last rhetorical question.

        Second, you’ll have to tell me if you consider Judy “from the world’s foremost experts in estimating sensitivity to CO2,” and why.

        I suggest not to wait before our Grouchy Tiger resurfaces, to let Don Don handle the protection services, and to grab a bag of popcorn.

        Thank you for your concerns.

      • Willard runs out of squirrels and has to create imaginary ones.

        Judith sends him to the laundry room for being a bad puppy.

      • Little willy has probably had enough on this one. Scurried back to the safety of kenny’s lonely little blog. Little kenny had a lot more traffic when he was focused on stalking Anthony and a lot people stumbled in there thinking they were going to the legitimate WUWT.

      • curryja: 5 out of 6 (go ahead and pick which 5 you prefer)

        Well said.

      • “Of course you can, RLH”

        OK. I think I’ll settle for whatever VP thinks of what I have done with his work. He is credited in the R as a contributing source. Go check if you like.
        There is a post over on WUWT from that work. Did you forget that or just not know?

      • Willard:

        Of course you can, RLH. You can even go all in with more than your own stack of chips.

        Since you’re new here, let me tell you a little secret. To get the answer you already know:

        First, you’ll have to own the tricks you pulled in this subthread against me, including your last rhetorical question.

        Second, you’ll have to tell me if you consider Judy “from the world’s foremost experts in estimating sensitivity to CO2,” and why.

        I suggest not to wait before our Grouchy Tiger resurfaces, to let Don Don handle the protection services, and to grab a bag of popcorn.

        Thank you for your concerns.

        This is pure desperation, Willard. I was under the impression you were better than this, but I’m just now starting to appreciate the Koans of Don Don. I’ve been giving you far to much credit. I’ll give you a hint. The trifecta is a house of cards, a mere word or thought, ie. not real. The universe only recognizes tetrahedron to sustain a stand: 1+1=4

      • > The trifecta is a house of cards, a mere word or thought, ie. not real.

        Yet a part of you is moving into it, Grouchy.

        A trifecta’s a bit realler than the Trinity. Not that Trinity’s unreal to Neo. Do you think there’s a connection between the Matrix and the Oregon Standoff? Both have guns and are surreal.

        There’s man all over for you, blaming on his boots the faults of his feet. (He takes off his hat again, peers inside it, feels about inside it, knocks on the crown, blows into it, puts it on again.) This is getting alarming. (Silence. One deep in thought, The other pulling at his toes.) One of the thieves was saved. (Pause.) It’s a reasonable percentage. (Pause.) Gogo.

      • I believe we live in a natural world, RLH, and that humans do things with words. I also believe in honor. How about you?

      • …the type of honor found among thieves and anonymous propagandists.

    • On the contrary, I cannot imagine an Editor picking someone criticised in a paper to review that paper. Review is not the place for hashing out disagreements. That should be done in the literature.

      • i agree that is how it should work, but this situation is very asymmetrical for consensus scientists versus those who challenge the consensus. If I were an editor, i would solicit a review from those being criticized (they are the ones most likely to have something meaningful to say about the paper), but I would weight their review that considered their arguments, rather than their conclusions.

      • Exactly, they only accept review by those who are known to agree.
        Their review is only a place for consensus agreement.

        Review is not the place for hashing out disagreements. That should be done in the literature.

        So, review is not to determine if something is correct, review is needed to support whatever has been published.

        We have observed that, it is the way it is. Many do disagree with doing that. I do disagree with doing that.

      • David W:

        I believe Steig was allowed to review the O’Donnell paper (with Nic Lewis as one co-author) that was critical of his paper’s statistical methods. And ClimateGate revealed a lot about the deficiencies of peer review in climate science.

        http://climateaudit.org/2010/12/02/odonnell-et-al-2010-refutes-steig-et-al-2009/

      • “i agree that is how it should work, but this situation is very asymmetrical for consensus scientists versus those who challenge the consensus.”

        Judith if I may:

        Politics is closer to the word consensus than Science IMHO.

      • I don’t get this. If they _don’t_ solicit disagreement, then by definition peer review is useless for determining whether a paper makes an effective response in a disagreement. So why does everyone keep pointing out that Marvel’s paper was peer reviewed and Lewis’s response is not?

      • Peer review basically says a paper is worthy of exposure to the wider audience of scientists… publication, which is where the real review should take place. And that is what Nic Lewis has done. He is one person. They, the wider audience of scientists, may find it substantive or they may find it complete hooey. They haven’t spoken, nor have the authors other than Gavin’s statement that he thinks some of what Lewis has said on Climate Audit is confused. Maybe it is; maybe it’s not.

      • JCH is correct. The primary purpose of peer review is to cast votes on whether or not the paper should be published. Where there are perceived weaknesses in a likely candidate, the reviewer may ask for changes, addition work, etc., as well as suggesting improvements. Negative reviews need to say why the paper is not right for, or not worthy of, publication in this journal. In no case is this the place to debate the science, because reviews are secret while debate should be public. When an editor sees a debate springing up they may well replace the reviewer, since debate has no end, it does not serve the purpose of review.

      • Somewhat off topic, but I have in interesting peer review drill going on. There is an experimental online journal called F1000Research that first publishes your paper then gets and publicly posts the peer reviews. So I sent them: Wojick D and Michaels P. “A Taxonomy to Support the Statistical Study of Funding-induced Biases in Science.”

        One review so far, from an outfit called Retraction Watch, which you would think would like our work, because they are all about scientific misconduct. But they hated it, perhaps because they are journalists, not scientists, so probably lefties who hate Cato. They never addressed our actual findings — the taxonomy and the potential for bias cascades. They just attacked minor points in our discussions.

        So I wrote a response saying I see no reason from this to change our paper. This is all availble at http://f1000research.com/articles/4-886/v1

      • stevefitzpatrick

        David W,
        I think it is not terribly uncommon for editors to ask soneone who’s previous work is being criticized to be a reviewer (Eric Steig rather harshly reviewing O’Donnell et at, for example). The important question is if the Editor is smart enought to take any such review with a grain (or many grains!) of salt. Ultimately, Editor Broccoli published O’Donnell et al over Steig’s objections. I expect that the process was somewhat educational for all involved, including Steig. An interesting side note to the O’Donnell/Steig conflict is the recent paper (highlighted by Judith) showing that rising CO2 is in fact expected to have a net cooling inflience on East Antarctica, at least at higher elevations…. adding support to the O’Donnell et al conclusion that East Antarctical really is not warming much.

    • There is no honor in kicking and tormenting the feeble, Willard.
      Farewell to Trinity
      Spend the years of learning squandering
      Courage for the years of wandering
      Through a world politely turning
      From the loutishness of learning

      • There’s even less honor in estimating the strength of those with whom you exchange, or worse to adjust your manners accordingly. The best way not to pull your punches is never to throw any. Love and light all circles, any minarchy.

      • We are under a pernicious form of minarchy, today, willito. The apparatus and onerousness of government is barry big, but those with the ultimate executive power are minimally equipped with ability and integrity.

      • Words of wisdom, Don Don. Words of wisdom.

      • “Love and Light” …that’s what everyone thinks of whenever Willard posts. My dear boy confuses the rules of cricket with honor.

  7. The Marvel et al. paper argues that simplistic approaches like Lewis’s with one aerosol forcing number representing the globe are too simple. There are global pattern correlations that affect how effective these aerosols are, and these correlations are completely missed by the one-dimensional models that Lewis still seems to favor. He needs to address his own assumptions in the light of these criticisms rather than criticize people who criticize his simplification of the problem. There are reasons that Lewis’s 1d approach is flawed for ECS estimations. Marvel identifies one, and Armour identified another a few years ago. There are no shortcuts. You can’t consider the globe to be a homogeneous billiard ball when you use a so-called observational approach. It just isn’t, and it matters that it isn’t.

    • Jim D, there is a large flaw in your defense of Marvel. If effective forcing requires ‘a 3D ‘ model rather than ‘a spherical cow’ (both your terms and your thesis), then the 3D GCM should do a reasonable job at major 3D climate features being effectively forced. Things like regional clouds, tropical precipitation, regional downscaling… They do not. Therefore, as NL points out in more detail at CA (which indicated upthread you had not read), it is just a GIGO exercise. Especially when the warmunist team had previously looked at effectivity and concluded effective forcing was not a lot different than forcing.
      Using models that don’t do what you need to say sensitivity is even higher than models estimate, so that warmunists can ignore all the observational effective sensitivity estimates, smacks of illogical desperation.

    • “You can’t consider the globe to be a homogeneous billiard ball when you use a so-called observational approach. It just isn’t, and it matters that it isn’t.”

      So HADCRUt, BEST etc are, what? Pointless? Useless? Wrong?

      And the disparagement RPSr got for suggesting exactly what you just have over a decade ago was what? The chatter of the ignorant? The mutterings of those too slow or stupid to understand? The shrill denial of those stuck in an outdated paradigm?

      Or didn’t you notice that you didn’t just shoot yourself in the foot, you fired a machine gun at the legs of the entire regiment?

      • Did you notice that global temperature series are not the same thing as deriving an ECS with simplifying assumptions from a limited time series of that temperature? What are you talking about?

      • “What are you talking about?”
        This: “You can’t consider the globe to be a homogeneous billiard ball ” – Isn’t a GMST, however estimated, doing just that? Isn’t average insolation, as used in many studies, assuming just that? I’m not saying that such simplifying assumptions shouldn’t be made – we can certainly gain insights from doing so. I’m saying that if you want to criticise people for reading too much into results that do use such simplifications, then it’s certainly reasonable to suggest you apply the same reasoning to all the others that do so as well. If you did, then claims like GMST accuracy to 0.01C would be, well, silly, right?

      • GMST doesn’t assume anything of the sort. It’s what you do with it, like when you calculate ECS assuming every part has been changing the same way over time and will continue to, which is patently false. This is the core of Armour’s criticism of those methods.

      • “GMST doesn’t assume anything of the sort.”
        Perhaps not, but it does make several equally “wrong” (as in: “can be inferred from existing data without a reference to the literature that demonstrates there’s a robust and physically plausible explanation”) assumptions – things like (but not limited to):
        the relationship between two measurement sites in terms of trend is consistent over multi-decadal to millenial timescales;
        a random sample of a convenience sample has the same statistical properties as a random sample of the entire system would have;
        adjustments based on statistical properties of the data itself do not increase the width of the confidence interval by the size of the adjustment because the law of large numbers can reduce it more than the adjustment increases it

        Don’t get me wrong – I’m sure that there is valuable information and insight to be gained from even sloppy and mismanaged data and its manipulation, but you need an honest and transparent system so that everyone understands the limitations of what you present. And you also need people who are willing to say “I was wrong” and “I didn’t think of that” rather than defend sloppy work just because it’s “on message”.
        But that’s not how large swathes of climate science present, is it? Maybe that’s just bad presentation, but it’s not confidence inspiring to those of us that are outside looking in – most especially those who have worked in other areas of research and/or done engineering work (I’ve done both, BTW)

        My message to concerned climate scientists is simple: if you are convinced there’s a problem that requires significant changes to the way society sources and uses such a basic requirement as energy, then thank you for the insight and warning. Please now stand aside and let experts in every sub-field you rely on go over this with a fine toothed comb – metrology, statistics, geology, biology, economics and many more disciplines can confirm (or overturn as the case may be) your data, methods and conclusions and present a much more compelling case to the politicians than your field can do on its own. And check your ad-hom with your coat – no matter if it’s deserved or not, it makes your argument look weak.

    • Is it a Marvel of Science or a Marvel Comic?

    • Maks, could have but chose not to make your nonlinear dynamics (chaos) argument. There are simple reasons why other simpler to understand approaches may be more powerful for the general public.
      Like, you said X would, but Y happened.
      Since the science is ‘settled’, it is mostly about the political messages.
      I want to win this debate, no matter how, so long as honest.

    • “You can’t consider the globe to be a homogeneous billiard ball when you use a so-called observational approach.”

      That appears to depend on how far off you are looking from to start with. Things get clearer at first as you approach but then way too much detail takes over and makes things difficult to see well.

  8. stevefitzpatrick

    Jim D,
    Did you read and understand Nic’s longer post on Marvel et al at Climate Audit?

    • No, perhaps you can explain how he defends his simplification. I don’t think he went there. You need a more complex model than his to get at this issue. Marvel et al. can use a model to shows the flaws of his simplification. Efficacy is a real issue.

      • Hahaha!
        “Did you read the details, jimd?”
        “No, but it is all wrong, I am just sure of it.”

        Priceless! What an oaf.

      • The paper introduces the concept of efficacy. It uses a model to demonstrate it. As Gavin says at Realclimate “The claim is not being made that the GCM is exactly a match to the real world, but rather that if a simplifying assumption made about the real world doesn’t hold up in a GCM, it probably won’t hold up in the real world either.” Getting into the weeds of a particular GCM is missing the point. It can be illustrated with any GCM, and that was the one they had to hand. It’s about efficacy, a real effect missed by the likes of Lewis in his one-dimensional way of thinking. He can’t dismiss that with handwaving. He has to use a GCM to counter that.

      • You would find that you get the same sort results when you use an Etch-a-Sketch. Think of the money saved.

      • The paper is founded on unverifiable speculation. The gravamen of the underlying thinking is that you can have two things — the nature of which seems obvious — but when you put the two things together, something unthinkable may happen –e.g., you have a terrier and your friend has a sheepdog. The terrier wags his tail, loves attention and wags its tail. The sheepdog is slow and easy and loves children. But, you put the two together and all hell breaks out. Who knew?

      • Curious George

        How come efficacy – a real issue – was missing from a settled science?

      • GCMs are used all the time and they include this effect implicitly. Lewis represents a step backwards with a method that excludes it. The paper isolates an important difference between what Lewis does and GCMs and that also helps explain their divergent sensitivities. This realization of added complexity discredits low sensitivity efforts with simple models, so you can see how some people may be upset. As someone said, you can simplify things, but not too much.

      • The Marvel paper criticizes Lewis and others for using a “spherical cow” type of model to represent a complex system. Using a GCM model which at least has 4 legs and a head, you can show how wrong a spherical cow is. This is the point being missed. Skeptics often say that the climate is too complicated to model but give a pass to Lewis and his methods, and now they criticize people who say it is more complex than Lewis said. It is completely contradictory. Choose a lane, people.

      • Efficacy wasn’t missed by climate scientists. It was first investigated by James Hansen, then director of GISS, in a very thorough 2005 paper, using GISS model E (whereas Marvel, Schmidt et al use the updated, but not necessarily superior, Model E2). Hansen, unlike Marvel et al., found that efficacies for essentially all forcings were close to one when effective radiative forcing (ERF, estimated by fixed SST GCM simulations) was used as the measure, as in AR5 and Lewis and Curry 2014.

        Armour’s findings were about time-varying climate sensitivity and have nothing at all to do with forcing efficacies. Moreover, Armour used a single AOGCM with an unusual latitudinal feedback structure in his study. It is possible that effective climate sensitivity increases over time (ignoring, as for equilibrium sensitivity, ice sheet and other slow feedbacks), but there is currently no model-independent reason to think that it does so.

      • stevefitzpatrick

        Jim D,
        “No,…”
        I suspected as much. Do you think it is OK to always ignore the technical substance? Seems that way to me.

        Nic’s longer post was about Marvel et al (NOT about Lewis and Curry, Otto et al, or other empirical estimates). He discusses the apparent inconsistencies of Marvel et al with other published work, as well as some of the strange (and dubious) choices they made in their analysis. Marvel et al completely ignores (and does not refer to) an earlier paper that did a similar analysis, but came to a different conclusion… which was that most man-made forcings are not very far from unity in “efficacy”.

        Surprising that you don’t want to actually read and understand something before spouting off.

      • Don’t assume little yimmy tells the truth, steve. He read it but the little hoffpo drone ignores the parts he doesn’t like.

      • stevefitzpatrick

        Nic Lewis,
        “Armour’s findings were about time-varying climate sensitivity ”

        Maybe there could be an ‘apparently’ added before ‘time-varying’. If I understood Armour’s paper correctly, he claimed that all feed-backs were close to linear in response to temperature over time, but that different regional warming rates (specifically, slow warming at high latitudes) could make the feed-backs and sensitivity appear to increase with time. FWIW, I didn’t find Armour’s paper very convincing, because the actual pattern of warming seems the exact opposite of what Armour’s mechanism would require. Of course, I may have missed something in the paper…. and it was a couple of years ago that I read it.

      • stevefitzpatrick

        Don,
        What is a ‘hoffpo drone’?

        Honest question.

      • You can also check Gavin’s post on this at Realclimate. This looks more convincing to me, and they say they have compared methods used by Otto et al. with GCMs, and, yes, you need to correct Otto’s results for efficacy. Lewis says he can’t get their numbers but that doesn’t stop him from spouting anyway, so this is for them to sort out. It’s possibly just a misunderstanding of the work, and Lewis jumped the gun before he had all the relevant facts.

      • Typo. Huffington Post drone. Mindless talking points from political journalists. Buzzfeed, “churnolist” type nonsense.

      • stevefitzpatrick

        Aaron,
        “Mindless talking points from political journalists.”

        Thanks. Is Jim D a journalist? The lack of technical content (and understanding) in his comments seems consistent with that being true.

      • No, Jim D is not a journalist. If you want me to explain any physics to you, let me know.

      • stevefitzpatrick
        Don,
        What is a ‘hoffpo drone’?

        http://media-cache-ak0.pinimg.com/736x/fe/c6/68/fec66832ef14889d714382b28e8a2f9c.jpg

      • HuffPo has a whole climate change section.
        http://www.huffingtonpost.com/news/climate-change/

      • Also, regarding your using Hansen in your defense, his efficacy near one applies to 100 years after the forcing was applied only when equilibrium is already achieved. At the end of the current data we are still in a highly transient state with 75% of the forcing having been applied in less than 70 years, and 50% since just 1980, so its apples and oranges to raise Hansen in the context of the current forcing change rate.

      • You can spot the drones easily. They incessantly preach by rote the party-line and never admit to any flaws or uncertainty in their positions. They also have little antennae sticking out of their little heads for receiving their marching orders from huffpo HQ. Little yimmy always wears a beanie, but you can still see the bumps.

      • stevenreincarnated

        The paper didn’t introduce the issue of efficacy. It has been around a long time. You used to argue vehemently that it wasn’t an issue. Glad to see your views are maturing.

      • The paper quantified the effect of efficacy on the simplifying assumptions used in one-dimensional approaches. I don’t think that had been done before, mainly because no one was using those 1-d approaches for ECS until recently, so this is a study that was needed to evaluate their biases.

      • JimD, I believe this dispute is about how to calculate and use “effective” forcings. Nic it seems to me makes a good case that AR5 and Hansen 2005 support his position.

      • It’s about the spatial variability of forcing and warming patterns and their correlation effects, which the Otto and Lewis models have to neglect due to their simplicity.

      • JimD, if all about the spacial variability.

        “NASA’s “GISS-E2-H” model appears to replicate overall warming best, but is among the worst models at replicating regional trends. China’s “FGOALS-g2″ appears to be the best performer at replicating regional trends, but still over/under-predicts the warming trend by about 0.5C per century almost everywhere.”

        http://berkeleyearth.org/graphics/model-performance-against-berkeley-earth-data-set/

        Part of that is the questionable usefulness of a GMST especially when GMST includes warming that is indicative of little energy and less energy being retained.

      • It has more spatial variability than Lewis’s model which has exactly zero, not even land-water-ice, so it is much better than what they are comparing it with.

      • JimD, Lewis’ model uses the definitions of sensitivity which are simplistic to begin with, but them are the conventions. Using more complex models that are spatially inaccurate to estimate a “global” trend of a not very thermodynamic relevant average temperature anomaly isn’t exactly a slam dunk improvement.

      • OK, but he can’t claim to be using “observations” when an observable fact is the variation across the earth’s surface that he assumes is zero. You should make things as simple as you can, but there is such a thing as too simple.

      • Anything that improves the accuracy of any the estimations involved is to be welcomed IMHO.

      • Efforts to improve forecasting the future are laudable. And anything that gives JimD more chances to be wrong can’t be all bad. But just like watching Lennie and Guido working on their latest system to pick the ponies, I’m not hopeful for success.

      • You can watch people work. Not polite to laugh though.

      • It was a similar thing when Steinman et al. criticized the Wyatt paper for using a flawed AMO representation, and the response was not to own up that, yes, it was simple, but to sidetrack into other details. Here we see the same with Lewis not owning up to the simplifications of his approach, pointed out by Marvel et al., and its flaws as a result of it, but just sidetracking. That’s a common pattern. It only plays to their base, but is not impressive to those criticizing the approaches because it doesn’t answer their main points.

    • stevefitzpatrick

      Jim D,

      Do you understand that the Real Climate post on Marvel et al came BEFORE Nic Lewis posted at Climate Audit? Gavin could not have responded to the issues Nic raised, because he had not seen Nic’s post.

  9. In other words, the more we learn the more we see that everything is unusual compared to what the global warming alarmists predict. What is normal is that we cannot predict the weather and by extension, the climate. Nothing is as simple in the real world as it is in the digital world of the climate models that the Left uses to blame humanity and modernity for heating up the globe (the AGW hypothesis).

    • “we cannot predict the weather and by extension, the climate”. That is certainly true now, because we are using weather models to try to predict climate. We do not yet have a climate model. When we do, no matter how good the climate model is it will not be able to overcome deficiencies in our ability to predict the things that affect climate – solar activity, ocean cycles, etc – and it will not be able to overcome deficiencies in our understanding of how things that affect climate actually work – solar activity, Earth orbital changes, etc. It is about time that we started putting some real effort into finding out how the climate actually works instead of wasting time and money on models that can never work.

      • MJ, tend to agree. A sufficiently granular climate model to even befin to to yhe job properly is computationally intractable. Essay Models all the way Down. Guest post last year at WUWT. So have to parameterize without knowing natural/anthro attribution. As the pause shows, ignoring natural variation is a fundamental error.
        But models are all the warmunists got. Observational temperatures, SLR, effective sensitivity all say whatever AGW might be, it is not a big problem needing immediate decarbonizarion. Only models that do not work make that projection.

    • Clocks ‘n clouds,
      one linear, th’ other
      diabolical-dynamical.

  10. If we lived on a cool, dry, inert rock with no cloud, climate scientists could do some fab work. They could really get in touch with their inner modelling child.

    – ATTC

  11. nobodysknowledge

    Much of the fanatism started with the first GISS model,with a sensitivity of 4,4 or 4,3, and runaway scenarios and tipping points. It heated some brains to a point of no return. Now we have the Marvel speculations, hidden behind new models. I think they could say it in more plain english, that planet earth has warmed more than can be measured. Ocean and gases have stolen the heat. The only way to find it is by using models and letters as TCR and ECS. And then it is the land use. More CO2 leads to catastrophes of vegetation and nature that bring the greatest warming. How it is understood is a mysterium, but Marvel et co have the hidden insights.

  12. “A narrative of a scientific establishment thrown into [chaos] mild confusion by outlier results that leads a band of plucky computer modellers to take up a lot of supercomputer time to investigate and who then come up with a perfectly reasonable explanation that reinforces the consensus, can occasionally get written about.” – Gavin Schmidt.

    Ha! Whatever would we do without this plucky little band of adorable rapscallions? Models! Supercomputers, even!

    Let’s invent some new sciencey words – forcing efficacy. Surely that will get our names in the papers!

    Not working too well these days. Nobody seems to care all that much.

    What a pity.

    Cheers.

  13. Curious George

    Merriam-Webster: Simple Definition of efficacy: the power to produce a desired result or effect. I like Dr. Hansen’s taste in words.

  14. ENSO ONI for the OND reporting period is 2.3.

    In 1997 the same number was reach in the OND reporting period.

  15. Discussing “climate sensitivity to CO2” is kind of like deliberating on the number of unicorns in the world, and whether it’s growing larger or smaller over time. What I mean is simply that we have as much actual empirical evidence for the existence of even one unicorn in this world as we have for the basic AGW claim that more CO2 in the atmosphere can, will and does cause a net rise in Earth’s average global surface temperature, i.e. NONE whatsoever!
    https://okulaer.wordpress.com/2016/01/10/the-climate-sensitivity-folly/

    • The temperature has risen. The instruments say so. The question is as always, why and from what cause and for how long.

      • RichardLH, you ask:
        “And you expanded on my observation how?”

        The link? The data?

      • Richard,

        You left off “Why should we be worried?”

        Everything else is an exercise in science. Useful for expanding our understanding of our planet and perhaps someday leading to useful tools to help us better plan and manage our activities, but certainly not worthy of front page attention.

      • How would I know that as a fact? Do you?

      • Know what as fact? That we
        shouldn’t be worried?

        I guess that depends on what sort of individual you are. If you are the type who needs proof they are “safe” from unproven or speculative dangers, then then we don’t know for a fact there is nothing to worry about.

        If on the other hand you are rational and require some sort of evidence to back up claims of threat and danger, then the absence of any is usually sufficient to subsitute.

        Perhaps a better way to have stated it is there is no evidence of there being anything we have to worry about.

    • RichardLH,

      Yes, the temperatures have risen. That in itself, however, does NOT tell us WHY the temps have risen. The “climate sensitivity” folly is to simply ASSUME that rising atmospheric CO2 is the cause without even a single piece of empirical evidence from the real Earth system to support such an assumption. It is purely theoretical.

      Since 1950 global temps only went up between 1976 and 2001, in three distinct steps, one in 1979, one in 1988 and one in 1998. The ENTIRE warming is to be found within those three steps, explained in full by natural (ocean) processes. There is absolutely NO room for CO2 or the hypothetical entity that is “radiative forcing”:
      https://okulaer.wordpress.com/2014/07/30/modern-global-warming-in-three-steps-the-fairly-short-version/

      • And you expanded on my observation how? By adding details instead and making possibly unverifiable assumptions.

      • RichardLH, you ask:
        “And you expanded on my observation how?”

        The link? The data?

      • The Context?

      • okulaer: The “climate sensitivity” folly is to simply ASSUME that rising atmospheric CO2 is the cause without even a single piece of empirical evidence from the real Earth system to support such an assumption.

        That is only 1 of the follies. Another is to assume that the accumulating CO2 necessarily has no effect. Yet another is to conclude that exactly 50% of warming since 1880 is due to anthropogenic CO2. All of the arguments for particular quantitative effects of CO2 have liabilities.

    • Well….

      UCB did do a study for 11 years that gave us the 0.2 W = 22 PPM number at two locations (Alaska and Oklahoma).

      Presumably they used a calibrated radiometer that they pointed at the sky. The sky is a large target so they probably pointed it in the right direction.

      Now this is significantly less than the IPCC and any sort of gung ho global warmer claims for the near-TSR forcing level.

      However it is significantly more than nothing.

      About 2/3rds of the forcing out there is looking for a home or attribution. From rough computation I like to think 1/3 of the forcing (1/2 of the non-GHG forcing) is ALW.

  16. if modelers knew the climate dynamics they could have incorporated them but they don’t. since temperatures are no more rising for 15 years and are begining to drop, be prepared for quite a drop. since my climatic model is the only model in planet that projects droping temperatures and since I have developed this theory on the solar activity, sun spots and solar wind, I am glad to see everything come true and verified.
    NEW JAN 2016 a PRESENTATION to sumarize the solar wind, sunspot cycles and solar driven climate mechanisms is available on my blog dimispoulos.wix.com/dimis

  17. Pingback: The blindspot of Computing and Science? | Climate Data and Summaries of the data

  18. Which do you think is greater?

    The number of times that Josh sees things which aren’t there or the number of times Joseph doesn’t see things which are?

    • You counting? Seems like a very train spotter thing to do (with apologies to train spotters).

      • Were I counting I wouldn’t have had to ask the question. I thought you are supposed to be intelligent. Or maybe I just heard that from you.

  19. Nicholas Lewis, thank you for the essay. Is there a pdf available for downloading?

  20. Pingback: All is not at it seems | Climate Data and Summaries of the data

    • Let’s see, that decade would have the most uncertainty, I would guess at least +/- 0.5 C and the first huge model miss is around 1915 where they underestimate ocean inertia and the influence of some possibly unknowable function. Then there appears to be some difference in the rate of ocean heat lost and the rate of ocean heat uptake but absolutely no way of determining either because of limits of data. Then if you had unlimited data, you still aren’t really going to know what is “normal” i.e. the correct initial conditions for a model that pretty much should include some degree of non-linearity.

      Now if you strip away all that false precision, you have A fairly well known forcing that should produce SOME warming with SOME indeterminate degree of variation related to two or more competing semi-linear internal responses to all forcings, some of which aren’t very well balanced.

      You end up with about 0.8 to 2 C worth of “sensitivity” and about 1.2 C of completely unpredictable uncertainty. If you pick a modern ear baseline where you have more data and a better handle on forcings you end up with about 0.8 C – 2.0 C “sensitivity” and an uncertainty range of about +/-0.3 C degrees. With the modern era baseline you can at least somewhat exclude negative sensitivity values which could be a good thing.

      https://lh3.googleusercontent.com/-c0pfLjbKCEU/VP3rswWDfRI/AAAAAAAANGo/rEIY7HakJCg/s839-Ic42/simple%252520linear%252520regression%25252013mma%252520and%252520oppo.png

    • I still demand prosecution of those responsible for the temp rise beginning around 1910, the obvious beginning of all our woes. (Global temp may be an ineffably silly notion, but I still can’t help trembling before any sciency looking graph. Several decades of junk education have not been in vain.)

      Big Paraffin, you are under suspicion! First you supplant naturally harvested organic whale oil, then you spike the climate! I also note the spread of the tango dance craze after 1910. Just saying.

      – ATTC

  21. http://www.bbc.co.uk/news/uk-england-cambridgeshire-35280290
    Bronze Age houses uncovered in Cambridgeshire ‘best ever’

    That is in the ‘Fens’. At probably the closest to sea level you are going to find.

    “The circular wooden houses, built on stilts, form part of a settlement at Must Farm quarry, in Cambridgeshire, and date to about 1000-800 BC.”

    So that’s 300 years or so of no sea level size. :-)

    • Richard Linsley Hood ‏@RichardLinsleyH · 2 mins2 minutes ago
      #AreSeaLevelsRising http://bit.ly/1RjE3bM 3000 years in Cambridgeshire UK of nearly level

      • No intervention by infrastructure? IQ level dropped west of Holland?

      • And try paddling a boat into Ostia or Ephesus. It seems that even a bit of siltation or a mound can stop all this catastrophic sea level rise – for centuries! Though in the case of the Roman era ports you’d be hard pressed to dredge them clear. Like the landing place of the Claudian invasion in 43 AD, it’s too long a trudge. Just use the newer, lower sea levels. Or wait for more warming.

      • ” IQ level dropped west of Holland?” If you knew the Fens you wouldn’t say that. They do take offense rather easily.

      • http://www.mustfarm.com/
        Bronze Age Timber Platform

        Thanks to funding from Historic England and Forterra, in September 2015 we began a new project – Bronze Age Timber Platform. This is an 8 month excavation of a settlement at the site that was destroyed by fire, causing it to collapse into a river channel, preserving the contents in situ. Information on our progress and discoveries can be found in Bronze Age Timber Platform.

        Bronze Age River

        In 2011 the Cambridge Archaeological Unit, University of Cambridge, in collaboration with Forterra, began to unearth a series of extraordinary finds. What we found, what we learnt and what we know about the history, geology and archaeology of the area, can be explored in Bronze Age River.

      • P.S. For the Americans amongst you that is like saying “you f……g b…k guys down the road need to go to school again” or something close. I would recommended not visiting if you get over here.

      • ” IQ level dropped west of Holland?” If you knew the Fens you wouldn’t say that. They do take offense rather easily.

        They have a history of rioting against water pumping… probably lots of pubs as well!

      • “probably lots of pubs as well!” Well if you but knew that was one of the epithets always thrown at the Fens. Think a rural, flat, landscape, which the Dutch helped ‘recover’. Actually there is very little in the way of dams and walls etc. Just some big, slow (they used to be steam) pumping engines moving the river to the sea. Like the Somerset levels but inhabited earlier.

      • “They have a history of rioting against water pumping…”

        It you want me to dig out the list of rioting as regards, rivers, locks, weirs, mills, in England alone it might take up a bit of space.

      • “…then in 1417 or 1418 the collectors of a subsidy distrained the abbot for a tenth of his moiety of Castle mills, and fighting broke out between townsmen and the abbey servants. The abbot complained that men led by the mayor, bailiffs, and two aldermen, had broken his weirs, fished his fishery, assaulted and imprisoned his men, and carried off his goods; a bailiff and a subsidy collector alleged that the abbot and canons had assaulted them, one attack having taken place in St. Mary Magdalen’s church during mass. (fn. 230) A settlement was not reached until 1419. (fn. 231) ”

        http://www.british-history.ac.uk/vch/oxon/vol4/pp3-73

      • https://en.wikipedia.org/wiki/Stretham_Old_Engine

        Please do your research first. Too easy otherwise.

      • https://en.wikipedia.org/wiki/The_Fens
        The Fens are very low-lying compared with the chalk and limestone uplands that surround them – in most places no more than 10 m above sea level. Indeed, as a result of drainage and the subsequent shrinkage of the peat fens, many parts of the Fens now lie below mean sea level. Although one writer in the 17th century described the Fenland as entirely above sea level (in contrast to the Netherlands),[5] the area now includes the lowest land in the United Kingdom, Holme Fen in Cambridgeshire, at around 2.75 metres below sea level.[6] Within the Fens there are a few hills, which have historically been called “islands” as they remained dry when the low-lying fens around them were flooded. The largest of the fen-islands is the Isle of Ely, on which the cathedral city of Ely was built: its highest point is 39 m above mean sea level.[7]

      • Lol, my point was there has been significant infrastructure change during the 3,000 years. So, whatever… why the bronze-age site is about to dry out is an interesting question. On SLR you are not up against me; you are up against Mitrovica and his team at Harvard, and you have already lost.

      • “Indeed, as a result of drainage and the subsequent shrinkage of the peat fens, many parts of the Fens now lie below mean sea level. ”

        Read closer. So which infrastructure are you talking about. The one that dropped the river levels in the first place or the one that kept it there afterwards?

      • Sorry, can’t do miracles.

      • The question is, given that datum point (the bronze age river) and being able to estimate from river flows, etc. the likely distance to the sea, what sea level rise would you propose for the Bronze Age in the Eastern UK?

  22. 3000 years – fingers never could type

  23. Pingback: Must Farm (details) | Climate Data and Summaries of the data

  24. David Springer

    Amazing. Got around to reading this and I find not a single mention of efficacy for different wavelengths of light and different surfaces absorbing them.

    No difference in efficacy between solar UVB and near IR? Or between near IR and visible light? Or between shortwave from the sun and longwave from the atmosphere?

    Really?

    http://cdn.meme.am/instances/500x/51417663.jpg

  25. Paper by Rajaratnam et al, ‘Debunking the climate hiatus.’
    at the Bish. Seems R et al mistakenly downloaded and
    worked on the wrong GISS data set. Ah well, mistakes
    happen, who can forget upside down Tiljander.

    http://bishophill.squarespace.com/blog/2016/1/12/nothing-in-it-is-correct.html

  26. Until you can all agree on whether changes in soil moisture are due to lower solar, or due to higher CO2, use solely sea surface temperatures for global mean surface T change.
    And always with respect to AMO phase.

  27. I’m amazed at how such high ranking scientists miss such simple things. I don’t have a fancy PhD, but any undergraduate can understand the Stefan Boltzmann Law + Taylor approximations. If you have a black body of area A and some temperature distribution, then the first order Taylor approximation says that the amount of radiation this black body will radiate to space is

    σAmean(T)^4, where σ is the Stefan Boltzmann constant and mean(T) is the average temperature of Earth. This approximation is basically what Nic Lewis does for his estimates and what James Hansen does for his Paleoclimate estimates (actually pretty much all Paleoclimate estimates use this approximation).

    But how valid is the first order approximation? Well one way to see how reasonable the first order approximation is to perform the second order approximation, which is

    σAmean(T)^4 + 4σAmean(T)^3*std(T), where std(T) is the standard deviation of the temperature. This means that the global mean temperature gets corrected by approximately -4std(T), that is the higher the variance in the global temperature distribution, the lower the global temperature given the same total forcing.

    But why are different parts of the Earth of a different temperature than others in the first place? Well the main reason is that forcing is not even across the Earth’s surface. If we assume that the Earth has roughly a constant heat transfer coefficient, then std(T) will be roughly proportional to std(F), where std(F) is the standard deviation of the forcing distribution across the Earth. Thus in the second order approximation, the Earth’s global temperature depends linearly on both the mean radiative forcing and the standard deviation of radiative forcing.

    The above result means that a change in radiative forcing will have a stronger effect on global temperatures if it occurs in a polar region compared to an equatorial region. Changes in solar irradiance change the radiative forcing in equatorial regions more than polar regions, changes in GHG concentrations give a roughly even change in radiative forcing across the Earth’s surface, and changes in Milankovitch cycles and changes in ice caps are more strongly concentrated in polar regions. This means that approaches that use the first order approximation to estimate climate sensitivity from the instrumental period (such as Lewis) will underestimate climate sensitivity and approaches that use the first order to estimate climate sensitivity using paleoclimate data (Hansen and others) will overestimate climate sensitivity.

    I’ve done a fair amount of calculations trying to estimate this bias, and in the case of paleoclimate 3C estimates, an upward of at least 0.5 C due to this bias is not unreasonable, especially when the ‘consensus’ position is to basically ignore milankovitch cycles when explaining temperature changes over the pleistocene, even though milankovitch cycles are the ultimate causes of those temperature changes. Also, if one uses a simple grey earth model one finds that not taking into account the distribution of radiative forcing of changes in solar irradiance overestimates its strength by a factor of 2-3 compared to greenhouse gas forcing.

    So the way I see it, either one can take the insane position of Lewis & Hansen, that distribution of radiative forcing doesn’t matter (which I will call the Stefan-Boltzmann law denier position), in which case ECS is simultaneously ~1.5 C according to instrumental data and ~3 C according to paleoclimate. Or one can take the more sane position that distribution of radiative forcing does matter and this explains a fair amount of the discrepancy between instrumental estimates and paleoclimate estimates. Probably the reason Lewis and Hansen cling to their positions so strongly is laziness, if you can pretend distribution of radiative forcing doesn’t matter then calculations are much easier.

    As for Gavin Schmidt, he’s right that distribution of radiative forcing does matter, but he’s deluded and inconsistent if he doesn’t think this causes a significant upward bias in Paleoclimate estimates (which, if we go by his blog post where he said Marvel et al. reinforces the 3 C ECS concensus position, he does so). However, in one of Gavin Schmidt’s recent blog posts, he mentioned an ATTP blog post, where at the top of the comments I pointed out this fact quite strongly, so maybe he saw my comments and will eventually change his mind about Paleoclimate estimates (there might be hope).

    • Would you mind putting some numbers and calculations together with your Taylor expansion of the Stefan Law and posting the results? That is pretty strong language to use without providing a semblance of evidence.

  28. The problem in most cases is that to get from the numbers we have to the projected numbers we are offered I the future is that it is a very long gap to plug.

    I am not sure some of the constructions made so far are that sound, architecturally speaking.

  29. Pingback: Huge efficacy of land use forcing in one GISS-E2-R simulation: is an ocean model error involved? | Climate Etc.

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