Scientific American article: “How to Misinterpret Climate Change Research”

A Scientific American article concerning Bjorn Stevens’ recent paper “Rethinking the lower bound on aerosol radiative forcing” has led to some confusion. The article states, referring to a blog post of mine at Climate Audit, “The misinterpretation of Stevens’ paper began with Nic Lewis, an independent climate scientist.”. My blog post showed how climate sensitivity estimates given in Lewis and Curry (2014) (LC14) would change if the estimate for aerosol forcing from Stevens’ recent paper were used instead of the estimate thereof given in the IPCC 5th Assessment Working Group 1 report (AR5 WG1). To clarify, Bjorn Stevens has never suggested that my blog post misinterpreted or misrepresented his paper.

The article also states, paraphrasing rather than quoting, “Lewis had used an extremely rudimentary, some would even say flawed, climate model to derive his estimates, Stevens said.” LC14 used a simple energy budget climate model, described in AR5 WG1, to estimate equilibrium climate sensitivity (ECS) from estimates of climate system changes over the last 150 years or so. An essentially identical method was used to estimate ECS in Otto et al (2013), a paper of which Bjorn Stevens was an author, along with thirteen other AR5 WG1 lead authors (and myself). Energy budget models actually estimate an approximation to ECS, effective climate sensitivity, not ECS itself, which some people may regard as a flaw. AR5 WG1 states that “In some climate models ECS tends to be higher than the effective climate sensitivity”; this is certainly true. Since the climate system takes many centuries to equilibrate, it is not known whether or not this is the case in the real climate system. LC14 discussed the issues involved in some detail, and my Climate Audit blog post referred to estimating “equilibrium/effective climate sensitivity”.

I sent Bjorn Stevens a copy of the above wording and he has responded, saying the following:

“Dear Nic,

because I have reservations about estimates of ocean heat uptake used in the ‘energy-balance approaches’, and because of a number of issues (which you allude to) regarding differences between effective climate sensitivity estimates from the historical record and ECS, I am not ready to draw the inference from my study that ECS is low. That said, I do think what you write in the two paragraphs above is a fair characterization of the situation and of your important contributions to the scientific debate. The Ringberg meeting also made me confident that the open issues are ones we can resolve in the next few years.

Feel free to quote me on this.

Best wishes, Bjorn”

Update 26 April 2015

Gayathri Vaidyanathan tells me that the article has  been changed at ClimateWire .  Certainly, the title has been changed, and I presume the text has been amended per the version she sent me, which no longer suggests misinterpretation. But Scientific American is still showing the original version, so the situation is not very satisfactory.

Update 28 April 2015

The text of the article has now been changed at Scientific American, although the title is unaltered. The sentence referring to misinterpretation now reads “Stevens’ paper was analyzed by Nic Lewis, an independent climate scientist.*” At the foot of the article is the note:

Correction: A previous version of this story did not accurately reflect Lewis’ work. Lewis used Stevens’ study in an analysis that was used by some media outlets to throw doubt on global warming.


  1. Gary
    Posted Apr 24, 2015 at 7:39 AM | Permalink

    Are you seeking a correction from Gayathri Vaidyanathan?

    • Posted Apr 24, 2015 at 12:34 PM | Permalink

      Yes, I am asking for it to be made clear that I did not misinterpret Stevens’ aerosol forcing paper in my Climate Audit blog post.

      • kim
        Posted Apr 24, 2015 at 1:43 PM | Permalink

        Who is that whispering in my ear,
        Can I believe what I do hear?
        Let me be desperately, cowardly, clear;
        Fear is all that we have to fear.

      • Don Monfort
        Posted Apr 25, 2015 at 7:23 PM | Permalink

        Here’s what I expect from the author and the publications:

        They simply say that they did not claim that Nic Lewis misinterpreted the paper. Nic’s ECS estimate based on the paper prompted others to misinterpret the paper:

        “The misinterpretation of Stevens’ paper began with Nic Lewis, an independent climate scientist. In a blog post for Climate Audit…………………………………..
        Lewis’ blog post prompted conservative publications to crow that global warming is not a major threat.”

        That last part is the misinterpretation of the paper.

        • Ron Graf
          Posted Apr 25, 2015 at 8:39 PM | Permalink

          Don, I agree with you, they will try, but I wouldn’t want to have to make their case because they have a clarifying sentences to follow: “In a blog post for Climate Audit, a prominent climate skeptic blog, he used Stevens’ study to suggest that as CO2 levels double in the atmosphere, global temperatures would rise by only 1.2 to 1.8 degrees Celsius. The measure is called “climate sensitivity.”

          It’s emphasized the implication Nic is a skeptic and is the one who is interpreting “only 1.2 to 1.8 degrees…”

        • Don Monfort
          Posted Apr 25, 2015 at 11:04 PM | Permalink

          Why was my comment put in moderation?

        • john321s
          Posted May 30, 2015 at 3:27 PM | Permalink

          Don: Because you’re not part of the in-crowd!

  2. Posted Apr 24, 2015 at 7:57 AM | Permalink

    The full SciAm article states:

    Soon after, he [Stevens] took the unusual step, for a climate scientist, of issuing a press release to correct the misconceptions. Lewis had used an extremely rudimentary, some would even say flawed, climate model to derive his estimates, Stevens said.

    This is not even paraphrasing the actual press release. There is no mention of Lewis and nothing close to “extremely rudimentary, some would even say flawed” language in the release. Was the statement issued elsewhere by Stevens?

    • Posted Apr 24, 2015 at 8:04 AM | Permalink

      Was the statement issued elsewhere by Stevens?

      Not if his email to Nic is anywhere near genuine. And we have that verbatim.

      • Don Monfort
        Posted Apr 24, 2015 at 1:25 PM | Permalink

        Stevens didn’t deny he said something like:

        “Lewis had used an extremely rudimentary, some would even say flawed, climate model to derive his estimates.”

        That’s a separate issue from the accusation of Nic misrepresenting the paper.

        If Stevens didn’t say it,he should make that clear and ask SciAm for a correction.

    • Follow the Money
      Posted Apr 24, 2015 at 3:24 PM | Permalink

      “some would even say..”

      This rhetoric is often best translated in the singular: “I think…”

      But in the Climatescientology context it may more likely be, “My bankster-funded p.r.firm/NGO contact says…”

    • MikeN
      Posted Apr 25, 2015 at 8:08 AM | Permalink

      There was an interview as well, and presumably this came from the interview. However, the quote had nothing to do with the press release. This is similar to what Brandon was saying about National Post and Andrew Weaver.

  3. bernie1815
    Posted Apr 24, 2015 at 8:11 AM | Permalink

    The article’s author, Gayathri Vaidyanathan, seems to be completely out of her depth. Has she been in contact with you? Surely she tried to get your perspective on this issue. Is ClimateWire so unprofessional?

    • AntonyIndia
      Posted Apr 24, 2015 at 9:28 AM | Permalink

      Feather light.
      She was born in India and raised in the U.A.E. and Canada. She has a M.S. in Journalism from Columbia University’s Graduate School of Journalism, and a B.Sc. in Biochemistry from McMaster University in Canada.

    • Posted Apr 24, 2015 at 12:38 PM | Permalink


      I knew nothing of the Scientific American article before it was published.

      • patmcguinness
        Posted Apr 27, 2015 at 11:43 PM | Permalink

        “I knew nothing of the Scientific American article before it was published.”

        That sentence alone condemns it. Any fair journalist would interview the target of the piece, and when they don’t, it’s a ‘hit piece’.

    • Posted Apr 24, 2015 at 1:13 PM | Permalink

      Writers trying to operate beyond their depth is a common problem.

      One Monique Kieran of the Times ClimateAlarmist (well, Times Colonist legally) blathered about solar cell energy as a great thing for the Victoria BC area.

      When I challenged her on that she referred me to a video of a municipal government operation called Solar Colwood.

      But the video very clearly stated that solar cells are not viable there, whereas the organization promotes solar hot water heating which is very different and may be viable.

      And she was challenged by someone else about a good article.

      It’s another case of a long time editor who is very biased and not very good at being an editor.

  4. Ian Blanchard
    Posted Apr 24, 2015 at 8:39 AM | Permalink

    To me it looks like Nic and Bjorn Stevens are not all that far apart only the sort of difference between two scientists who are looking at the same data using different tools. Indeed, this response reads to me as though Dr Stevens could be persuaded that ECS is relatively low (i.e. less than 2 deg C) if further data pointed in that direction. Exactly what a scientist should do.

    I can though understand why Dr Stevens could consider his work to have been mis-interpreted, as some blogs did over-play the conclusion that ECS was low – yes, the implication of the revision to the aerosol forcing data is to lower the climate sensitivity, but not by a particularly large amount, and if you start from the premise that the GCM-based estimates of warming (2-4.5deg C) are reasonable, this revision does not eliminate the risk of dangerous warming (whatever that means…)

    As for the Sci AAm article, this seems to be a curious jumble of half truths, mis-quotes and wishful thinking on the part of the author, and I think merits a correction, perhaps through publishing a joint letter authored by Nic and Bjorn clarifying their positions and areas of agreement and disagreement.

  5. Don Monfort
    Posted Apr 24, 2015 at 9:08 AM | Permalink

    Does Stevens’ reply mean that the author of the SciAm article made this up:

    “Lewis had used an extremely rudimentary, some would even say flawed, climate model to derive his estimates, Stevens said.”

    Does anyone believe that Stevens was prompted to put out the press release because he was inundated with emails from schoolteachers?

    • Carrick
      Posted Apr 24, 2015 at 9:48 AM | Permalink

      As I said on Judith’s blog, it would be interesting to get a direct response from Stevens regarding that supposed paraphrase of Steven’s remarks. A statement from Stevens whether or not Vaidyanathan even interviewed him might be enlightening too.

      • Don Monfort
        Posted Apr 24, 2015 at 10:33 AM | Permalink

        She quoted him several times in the article, including:

        “I was touched that they’d write me and double-check that my study was being interpreted correctly,” Stevens said, speaking on a train en route to the Netherlands.

        I don’t see any reason to think she would be so bold as to write an article based largely on a non-existent interview. Maybe if she wants to get into a different line of work.

        It seems to me that Stevens was deliberately vague in his email to Nic on exactly what he might have told the SciAm “journalist”. He seems to be walking a fine line, trying to stay out of trouble with the consensus goons, while avoiding disrespecting Nic. Poor guy.

        • tomdesabla
          Posted Apr 24, 2015 at 10:56 AM | Permalink

          I wonder if Prof. Stevens will end up walking the same path as Judith Curry. When we speak of “walking a fine line” etc the parallels do seem evident. By his response to Nic, it appears that his personal conduct and integrity are important to him. On the other hand, by his statements regarding the “risks” of a 2 degree temperature increase, and by linking to RealClimate in his press release, it appears he still gives much credence to The Team.

          One can get a sore real end from sitting on the fence. It’ll be interesting to see which side he ultimately hops off on. I do agree with Don though – in that I highly doubt that it was letters from schoolteachers that has led the good Prof to issue his press release.

        • kim
          Posted Apr 24, 2015 at 11:27 AM | Permalink

          Fear and tremblin’
          In the children’s
          Been a buildin’,
          That’s the burden.

        • mpainter
          Posted Apr 24, 2015 at 12:02 PM | Permalink

          Yes, poor guy who probably did not consider that his statements and motives would wind up being carefully parsed on Climate Audit.

        • Follow the Money
          Posted Apr 24, 2015 at 3:47 PM | Permalink

          “speaking on a train en route to the Netherlands.”

          Ha! I reserve comment. What??

        • Eric Barnes
          Posted Apr 24, 2015 at 7:42 PM | Permalink

          I’m sure the checks cash just fine and Stevens definitely wants to keep it that way. Janus would be proud of Stevens, I can only regard him as a spineless coward who is paid to say what his benefactors desire be said.

        • kim
          Posted Apr 24, 2015 at 8:04 PM | Permalink

          The God of Gates, threshold to the new.

      • Posted Apr 25, 2015 at 10:04 AM | Permalink

        Eric Barnes

        “Janus would be proud of Stevens, I can only regard him as a spineless coward who is paid to say what his benefactors desire be said.”

        I think you have Bjorn Stevens completely wrong there.

        • Eric Barnes
          Posted Apr 25, 2015 at 4:02 PM | Permalink

          IMO, it’s not just Stevens, but a theme with most climate scientists. Say just enough to keep the cause alive and keep the gravy flowing. Do you honestly think there is a dangerous tipping point? I’m convinced there isn’t one and the IPCC is corrupt. It’s my opinion. Thanks for letting me express it. Steve isn’t so tolerant.

        • Sven
          Posted Apr 25, 2015 at 4:27 PM | Permalink

          I think that if Eric Barnes has Bjorn Stevens completely wrong then it should be up to Stevens and not Nic to demand a correction to the article.

  6. Posted Apr 24, 2015 at 9:12 AM | Permalink

    The Scientific American article also clumsily compares [Lewis’] sensitivity value with “the assumed 2 C threshold for catastrophic [sic] climatic change in parts of the world.”

  7. John Archer
    Posted Apr 24, 2015 at 11:29 AM | Permalink

    Perhaps some kind person with a subscription to SciScam could post a comment under that pile of … foam … with a link to Nic Lewis’s take on it here. I’d have done it myself but I cancelled my subscription to the kommic many years ago at the same time as I dumped its sisters, Nature and NewPsyantist, for the same reasons — their all being riddled with that hideously alien peecee agenda being only the half of it. Aerosols, the lot of them! Or something like that.

  8. Kenneth Fritsch
    Posted Apr 24, 2015 at 12:04 PM | Permalink

    I would suppose that using someone’s research results and obtaining some further results, and at least tentative conclusions, with which the original author may not be comfortable is nothing new in the world of science. I would pay not so much attention to what that original author may imply in some rather vague rejoinders but rather to any detailed criticism of the use of the original research that author might provide.

    I believe what I have not seen in this discussion is reference to Nic Lewis’ main point that using the newer aerosol estimates leads his method results to greatly truncate the higher end of TCR and ECS and not so much lower the median values. As a rational policy consideration for drastic and immediate government mitigation of AGW this has major implications – and obviously not unnoticed by those advocates for action.

    Interesting that if one makes the effort to take the proxy data used in Mann 2008 and applies it to a temperature reconstruction without the infilling, many truncation, use of instrumental data and upside down proxies that the original author does, the results provide a very different conclusion – even with the given error of selecting proxies after the fact.

    • David Young
      Posted Apr 24, 2015 at 2:00 PM | Permalink

      Nic is doing a tremendous favor for climate science that perhaps only a financially independent scientist can do. It is funny however to watch the response of the “experts” to a fresh perspective. It illustrates I think the prevalence of bias in the current way money, career, and peer pressure interact in science.

    • stevefitzpatrick
      Posted Apr 26, 2015 at 7:39 AM | Permalink

      You are absolutely correct; the key result is the large reduction in the area fraction under the PDF curve for ECS above ~2.5C. If the probability of ‘catastrophic’ warming is shown to be minuscule, then the demands for draconian public action to reduce fossil fuel use become rather silly. I can only imagine the pressure Bjorn Stevens is under for ‘giving ammunition to the den!ers’. I predict this will not turn out well for him.

  9. hdhuffman
    Posted Apr 24, 2015 at 12:04 PM | Permalink

    Still Obsessing On Climate Sensitivity

  10. Frank
    Posted Apr 24, 2015 at 12:22 PM | Permalink

    Nic, I saw your name in the acknowledgments of the Stevens (2015)- paper about aerosols. For what help? It would make me wonder if Stevens was surprised by the conclusions for ECS/TCR because of former discussions as one would await when you are in the acknowledgements??

    • Posted Apr 24, 2015 at 12:43 PM | Permalink


      You have sharp eyes! I simply gave Bjorn my comments on an earlier version of his paper. They had nothing to do with ECS/TCR, as I recall.

  11. kim
    Posted Apr 24, 2015 at 1:35 PM | Permalink

    This is a marvelous, nearly unprecedented, opportunity for Bjorn Stevens to ‘stop the hysteria’, but ugh, the timing. Can’t we wait a year?

  12. patmcguinness
    Posted Apr 24, 2015 at 5:48 PM | Permalink

    So Effective Climate Sensitivity may be quite a bit less that Equilibrium Climate Sensitivity?

    This makes sense and may resolve the conflict between the instrumental and paleo records: The equilibrium, given the ocean heat uptake data, takes centuries to reach, and there be some number of added factors that are not in the instrumental record or beyond precision of measurements in a 150 year record, but are captured if you look at the full 1000+ year responses to paleo events.

    Lewis-Curry+F-aer update TCR of 1.2C, Effective-ECS of 1.45C (that measures ~150 years) is on the low end of ECS values, and there is a consistent patter of paleo records estimating ECS, which coincidently are not time-constrained. Taking both data sets as valid suggests that the delta is due to timeframes and that cutting off at 150 years lowers estimates versus a run to 1000 years. So we may still have an equilibrium-ECS of 2.0-2.5C or so, but one that takes ~1000 years to reach equilibrium. Deep ocean heating reaches equilirium on that timescale.

    This leads to a question regarding IPCC timeframes for warming projections: Is the IPCC mistranslating Equilibrium CS numbers that are suitable for 500-1000 years into projections of temperature ranges for this century ie 50-100 years? Are paleo-reconstructions being used to influence TCR estimates upwards, for which they have no skill/utility?

    IPC RCP 8.5 projections show 4C+ warming, “doubling CO2 means 3C, which means lots of warming by 2090”. Even if you accept a high long-term ECS number, like 4C, it’s almost impossible to translate that into 4C of warming in the next 50 years – and yet the IPCC projections do that.

    The deep ocean is a great temperature moderator, one that moderates a warming impulse over centuries. The correct projection for warming by 2090 would be closely related to TCR, and the best estimates for TCR will be instrumental based, ie based on prior 70-130 years of natural variability and AGW. umber for 2090, which is 75 years from now, should be the TCR. Effective-ECS will be the 2150 value and Equilibrium-ECS wont get hit until 2500.

    • RayG
      Posted Apr 24, 2015 at 6:01 PM | Permalink

      I wonder if you are placing too more of a load on the quality of the paleo records than is warranted. I believe that our host and his colleague, Ross McKittrick have raised sufficient question about our understanding of paleo reconstructions to consider the validity of the existing reconstructions as not yet established.

      • richardswarthout
        Posted Apr 24, 2015 at 9:01 PM | Permalink

        As I read SM on paleo reconstructions, some are reliable and some are not, depending on type and geographical location. I think he would say it is a mistake to lump them together.


      • patmcguinness
        Posted Apr 24, 2015 at 11:00 PM | Permalink

        The quality and precision of the proxy records is yet another gating concern. What I am saying that there is an issue of short-term vs long-term response, and that records that lack time precision cant say much about short-term response, ie TCR. They may be useful to indicate something about longterm responses. I am thinking in particular about records regarding prior ice ages.

    • Posted Apr 25, 2015 at 10:00 AM | Permalink


      “Lewis-Curry+F-aer update TCR of 1.2C, Effective-ECS of 1.45C (that measures ~150 years)”

      Note that the Effective-ECS here is not the transient response over ~150 years, which would take no account of ongoing absorption of heat by the ocean at the end of the 150 year period. Effective-ECS does take account of ocean heat absorption. It assumes that the fraction of the forcing increase dF that has not been offset by the increase in surface temperature (dT) at the end of the 150 year (or whatever) period, which equals the ocean heat uptake dQ, causes a proportionate subsequent rise in GMST equal to dT * dQ / (dF – dQ). That is, it assumes that climate feedback strength remains constant.

      “So we may still have an equilibrium-ECS of 2.0-2.5C or so, but one that takes ~1000 years to reach equilibrium.”

      Yes, but if the Lewis & Curry range for effective climate sensitivty is correct then that would almost certainly require climate feedback strength to decline over time – which it may do – not remain constant.

      • patmcguinness
        Posted Apr 30, 2015 at 1:22 PM | Permalink

        Thanks for the clarification and education. If it would take non-linearities in climate feedback to to reconcile paleo and instrumental records, I don’t see how that bridges a large gap (eg 1.5C to 3C). I was trying reconcile the two, but I guess we are back to postulating that the ECS numbers are not inconsistent because paleo reconstructions have wide error bars with most low estimates under 2C and many under 1.5C.

        Scafetta used evaluation of astronomical cycle to calculate a closer approximation of the instrumental record and coincidently derived an ECS in the 1.5C (1.0-2.3C) range, cutting the IPCC estimates in half.

        Click to access scafetta_ee_2013.pdf

        It seems to supply some of the explanation for how the ‘simplistic’ derivation aligns with physical reality.

  13. RayG
    Posted Apr 24, 2015 at 6:02 PM | Permalink

    Oops, the “too” in the first sentence should be struck.

  14. Michael Jankowski
    Posted Apr 24, 2015 at 7:24 PM | Permalink

    So the SciAm complains that Lewis’ model is “extremely rudimentary” (attributing that claim to Stevens) while passing on the fact that Stevens’ own model is self-admittedly “simple” according to the abstract.

    • patmcguinness
      Posted Apr 30, 2015 at 1:23 PM | Permalink

      The skeptics’ models are ‘simplistic’, the warmists’ (similar) models are ‘elegant’. 🙂

      • Posted Apr 30, 2015 at 2:15 PM | Permalink

        I feel a revision of Einstein coming on.

        Models should as simple as possible (well done warmists) but no simpler (you skeptics disgust me)

        I’m sure the great man wouldn’t mind.

  15. Frank2
    Posted Apr 24, 2015 at 11:50 PM | Permalink

    With fewer revenues, all publications have to produce stories using fewer resources. In the meantime, a variety of advocacy organizations have developed which provide new stories to Scientific American and other publications (including the NYT). SA is loaded with articles from Propublica on fracking and ClimateWire and Climate Daily on climate change. It isn’t clear how much SA has to pay for these stories. Some of SA regular writers do a reasonable job of presenting all sides of a story, but the stories originating outside SA are invariably one-sided and misleading. (See SA’s story on Otto (2013):

    I would be surprised if all of these sizable pseudo-journalist organizations were supporting themselves from the revenue they get from selling stories. ( A law firm specializing in representing clients who may have suffered suffered damage from fracking, for example, might be interested interested in supporting Propublica’s crusade against fracking. IMO, normal journalistic ethics seem to have been abandoned by these organizations, possibly to keep funding and paychecks flowing. E&E Publishing (the owner of ClimateWire) began by collecting and distributing newspaper stories and summaries of select scientific papers to Congressional staffers interested in GHG legislation around the time of the Kyoto protocol was being negotiated.

    • Navy Bob
      Posted Apr 25, 2015 at 8:34 AM | Permalink

      Frank – Thanks for the info on E&E Publishing’s origin. I too have wondered how they manage to pay their massive staff. I’ve been on their mailing list for the last few years, and, while they’re definitely greenie activists, the sheer volume and breadth of their coverage of energy and environmental issues is unequalled. If you keep in mind their left-wing bias while reading, their pubs can be a valuable resource.

  16. MikeN
    Posted Apr 25, 2015 at 8:12 AM | Permalink

    I suspect that there is a third party who has provided talking points for this article. The ‘flawed model’ probably comes from there, while Stevens perhaps just mentioned they used a simple model.

    • mpainter
      Posted Apr 25, 2015 at 2:06 PM | Permalink

      The term “flawed model” is unambiguously attributed to Stevens, although one wonders about the lack quotation marks. If Stevens did not use such an expression, one would expect that he would issue some sort of denial. If he does not, what else can be concluded but that he used those words.

      • Posted Apr 25, 2015 at 4:14 PM | Permalink

        I find Mike’s model helpful because while multiplying entities it reduces temptation to grandstand. Judith’s made plain (or at least made credible) that Stevens is walking a fine line with the release of these two papers and the ongoing debates with Lewis. Nic’s in a far better position to judge how to proceed.

        The Ringberg meeting also made me confident that the open issues are ones we can resolve in the next few years.

        I’m very glad to know that’s what Stevens thinks is happening and it sure doesn’t sound bad.

        • mpainter
          Posted Apr 27, 2015 at 7:38 PM | Permalink

          Really, what is not an open issue in this climate sensitivity? I would not expect any resolution, that opinion based on what I have seen in climate scientists.Resolution of issues does not seem to be in the cards.

        • Posted Apr 27, 2015 at 7:38 PM | Permalink

          I think you’re right that a faint note of optimism crept into my final sentence. I’ll try and ensure it never happens again.

        • Eric Barnes
          Posted Apr 27, 2015 at 8:29 PM | Permalink

          Also, not wanting to be one who is exclusively negative, I’d like to thank Nic and Steve for their tireless effort and near infinite patience with the issues they have taken up. I do appreciate it.

        • mpainter
          Posted Apr 27, 2015 at 10:35 PM | Permalink

          Upon reflection, if the “pause” maintains for a few more years and then the AMO turns blue, we could see these issues become like old soldiers who ” never die, but simply fade away”. How’s that for optimism?

      • mpainter
        Posted Apr 25, 2015 at 4:29 PM | Permalink

        Such a state that science is in, that one needs to resort to a protective smokescreen.

      • Posted Apr 26, 2015 at 4:48 AM | Permalink

        The piece doesn’t say that Bjorn Stevens himself thinks the simple model involved is flawed. I don’t doubt that there are some climate scientists who think it is flawed, which is what the article implies Stevens said. That doesn’t mean that the model actually is flawed, of course.

        • MikeN
          Posted Apr 26, 2015 at 9:26 AM | Permalink

          Exactly. Someone else said it is a flawed model, perhaps Gavin. Reporter brings up the talking points, and Stevens just says the model was used.

  17. Posted Apr 25, 2015 at 2:28 PM | Permalink


    A reasonable closure to this controversy would require the SciAm article’s author Gayathri Vaidyanathan to issue a clarification.

    Have you asked her to do so?


    • Posted Apr 25, 2015 at 4:01 PM | Permalink


      • kim
        Posted Apr 26, 2015 at 10:57 AM | Permalink

        Glowing like the metal on the edge of a knife.

        H/t JJSteinman.

    • Cortlandt
      Posted Apr 26, 2015 at 2:06 PM | Permalink

      To the list of criticisms suggesting a clarification add:

      1) The very one sided explanation of the implications of higher or lower aerosol levels. There is no clear “explainer” about the implications of lower levels of aerosols to balance this:
      “So scientists have long harbored a fear: Perhaps aerosols are cooling the planet so much that in their absence, global temperatures will rise rapidly. ”

      2) The very sympathetic, ad hominem, almost hagiographical spin given to Stevens:
      – “it was not the type of attention that the study author, Bjorn Stevens … was seeking”
      -“the normally reticent scientist, who says his aim is not to convince anyone of anything”

      3) Of course, to hold a personal interview with Stevens, to quote Dessler but not attempt to get a comment from Nic Lewis is journalistic malpractice.

      4) Highly misleading (potentially libelous by some standards):
      – “Stevens said his study is something to be mulled over, but it does not call into question man-made global warming.”
      In the same vein neither does Nic Lewis’s paper or That is probable grounds for clarification in itself.

      5) Same quote regarding man-made global warming as above:
      It glosses over the difference between man-made global warming as a binary state as opposed to questions of degree. IMO this is not critical journalism.

      6) This one I would put to others but I question the accuracy of describing a press release as an “unusual step” in:

      – “Soon after, he took the unusual step, for a climate scientist, of issuing a press release to correct the misconceptions.”

      If we consider blog posts and statements made to interviewers as the roughly equivalence to issuing a press release I suggest that most fact checkers and editors would rule the statement above misleading.

  18. Danley Wolfe
    Posted Apr 27, 2015 at 8:25 AM | Permalink

    My question. I would like to have someone clarify on the use of the term equilibrium as used in the field of climate change. If inputs are constantly changing equilibrium to the transient input change is never achieved. Can’t we find a better word to describe this situation. As said, the equilibrium refers to the transient response to a given set of inputs and not a state of balance in a state variable.

    • Posted Apr 27, 2015 at 10:09 AM | Permalink

      Danley Wolfe –
      Equilibrium climate sensitivity is defined as the “change in global mean temperature, T2x, that results when the climate system, or a climate model, attains a new equilibrium with the forcing change F2x resulting from a doubling of the atmospheric CO2 concentration.” Climate models typically require upwards of 1000 years. For CMIP5, the method used was to quadruple pCO2 in a step change, then run the models until the temperature stopped changing. ECS was set at half the change, to scale it per doubling.

      I think “steady-state” is a better term than “equilibrium”, but then nobody asked me. 😉

      • Posted Apr 27, 2015 at 3:55 PM | Permalink

        If they’d asked me I’d have said to ask you 🙂

  19. Danley Wolfe
    Posted Apr 27, 2015 at 11:21 AM | Permalink

    Harold W –
    I agree completely. My background in chemical reaction/catalysis and thermodynamics makes this confusing and misleading. It is based on models and therefore is a hypothetical number based only distantly on data (i.e., modeled data). More like a bathtub w/ leaky drain and faucet –> you can change the input resulting in a new equilibrium … oops, steady state.

    • mpainter
      Posted Apr 27, 2015 at 11:52 AM | Permalink

      There used to be such a term used occasionally years ago: dynamic equilibrium. This is a contradiction in terms but useful for indicating a system that moves toward an equilibrium without achieving it because of the dynamics of the system.
      You will find a lot of imprecision in climate science in terms, language and thoughts; I call this “fuzzy language” and fuzzy language–> fuzzy thoughts, in my view.

  20. Derek H
    Posted Apr 27, 2015 at 4:54 PM | Permalink

    Sadly, this incident doesn’t surprise me anymore. I stopped paying a lot of attention to Sci Am years ago when they jumped the shark and went full-force into pushing the CAGW agenda. The magazine also started accepting articles on soft science subjects which were (IMO) sketchy at best about the same time frame. I was very reluctant to drop my subscription as it had been a favored lunchtime read for roughly 2 decades but the magazine seemed more like Omni or Pop Sci than the Sci Am I had grown to love.

  21. Posted Apr 27, 2015 at 7:29 PM | Permalink

    Reblogged this on I Didn't Ask To Be a Blog.

  22. MikeN
    Posted Apr 28, 2015 at 8:30 AM | Permalink

    Nic is it a fair summary of the situation to say
    1) Using AR4 methods and AR5 numbers, Nic calculated the best estimate of global warming to be 1.64C, down from 3.0C in AR4.

    2) Using Stevens’s aerosol calculations, Nic lowered the estimate even further to 1.45C.

    • Posted Apr 28, 2015 at 10:13 AM | Permalink


      1) I used a method described in AR5 and used in a 2013 study of which 14 AR5 WG1 lead authors were authors. The best estimate of 1.64 C was of equilibrium/effective climate sensitivity, and compares with 3 C in AR4.
      2) Correct

      The 1.64 C and 1.45 C values are median estimates; there is significant uncertainty attached to them, particularly the 1.64 C estimate. There is also a possibility that effective climate sensitivity, which my method estimates, may be a biased-low approximation to equilibrium climate sensitivity. The average behaviour of current climate models suggests that it is biased low, but not greatly (maybe by 10%-15%). But climate models are not the real world.

      • MikeN
        Posted Apr 28, 2015 at 11:20 AM | Permalink

        OK, thanks. Is the 3.0C, ad hoc, or did they use a method to calculate it(other than min + max /2)?

        • Posted Apr 28, 2015 at 2:50 PM | Permalink

          It was “expert judgement”. The ‘likely’ range was 2 – 4.5 C. The best estimate is rightly closer to the lower bound than the upper bound, as nonlinear relationships between ECS and what can be observed implies a probability distribution that is skewed to the right.

  23. mpainter
    Posted Apr 28, 2015 at 3:55 PM | Permalink

    So the editors at SciAm have admitted the error and corrected it. Climatewire, too. I must say that I am mildly surprised.

    • Posted Apr 28, 2015 at 5:32 PM | Permalink

      Great result Nic. The headline being corrected would be nice.

  24. mpainter
    Posted Apr 28, 2015 at 4:09 PM | Permalink

    Also, having read the Steven’s press release again, I note that, after the CAGW obligatto, his last sentence quenches it with a little cool water by admitting that his last study does indeed dock the tail of the ecs estimates. Such is climate science.

  25. Ron Graf
    Posted Apr 28, 2015 at 7:14 PM | Permalink

    Besides the obvious slant of the article I noticed a subtle self censorship by the writer on voicing facts having a negative implication to the models and trend on warming theory.

    There is no silver bullet for understanding aerosols fully since research is an accretive process. Consider clouds, for example, which are the other great unknowns in climate science. About 10 years ago, scientists did not know whether clouds were warming or cooling the planet. Now, they have more insights into their behavior.

    Thanks to the writer one is left guessing what insights. From the tone of the article one would guess wrong.

    • mpainter
      Posted Apr 29, 2015 at 12:43 AM | Permalink

      Vaidyanathan now understands that it was she who misinterpreted and that Nic Lewis got it right, we can conclude. And now she should also understand that if Stevens is right, then Nic is right and that she has only erected another screen to shield the faithful against the ugly truth. I wonder if she is content with that.
      I still marvel a bit at their speedy correction of the error, so uncharateristic of those who uphold the faith.This low aerosol threatens the very knees of AGW .

      • Posted Apr 29, 2015 at 2:32 AM | Permalink

        Cognitive dissonance. Long may it continue.

      • Don Monfort
        Posted Apr 29, 2015 at 11:41 AM | Permalink

        It is surprising that they made the correction. However, this remains:

        “Lewis had used an extremely rudimentary, some would even say flawed, climate model to derive his estimates, Stevens said.”

        If Stevens didn’t say that, it’s more egregious than what they corrected.

        • Posted Apr 30, 2015 at 7:02 AM | Permalink

          It was a dreadful article and all one can say is that it’s now less dreadful. But the speed with which a correction was made, in the right direction, in a form that is highly embarrassing to consensus central as it desperately tries to keep the ‘evil den1ers’ narrative going, is surely fruit of Stevens no longer being willing to play the patsy. Perfection there is not. But Nic Lewis is playing a blinder, to use a phrase we like to encourage people with in the UK.

    • MikeN
      Posted Apr 29, 2015 at 2:37 PM | Permalink

      The mind should develop a blind spot whenever a dangerous thought presented itself. The process should be automatic, instinctive. Crimestop, they called it in Newspeak.

      He set to work to exercise himself in crimestop. He presented himself with propositions—’the Party says the earth is flat’, ‘the party says that ice is heavier than water’—and trained himself in not seeing or not understanding the arguments that contradicted them.

    • Cortlandt
      Posted Apr 30, 2015 at 12:05 PM | Permalink

      Re: Don Graf’s comment.

      Add this to my prior list of problems suggesting a correction.

      – “About 10 years ago, scientists did not know whether clouds were warming or cooling the planet. Now, they have more insights into their behavior.”

      I believe that for the most part the situation from 10 years ago still holds today. I believe that a competent fact checker would so find.

      RE: Don Monford, et. al.
      “Lewis had used an extremely rudimentary, some would even say flawed, climate model to derive his estimates, Stevens said.”

      FACT: An essentially identical method was used to estimate ECS in a 2013 paper authored by Bjorn Stevens, Nic Lewis and a number of other IPCC lead authors. This is uncontested as evidenced by a email from Stevens to Lewis in which Stevens acknowledged Lewis for his “important contributions to the scientific debate”.

  26. Cortlandt
    Posted Apr 30, 2015 at 1:13 PM | Permalink

    The scientificamerican piece is as much or more a editorial about politics and society as it is about the science of Steven’s and Lewis’s papers. That is clear from the title and key points in the editorial about how the story was commented upon by blogs. Of interest here then is this
    blog from
    which traces the influence of the phrase “death blow to global warming hysteria” from a Cato blog to other blogs. (See the link above for links to Cato and other blogs)

    The Cato blog quotes Nic Lewis then comments:

    [quoting Lewis from] — “But perhaps even more important than the best estimate is the estimate of the upper end of the range, which drops from the IPCC’s 4.5°C down to 1.8°C.”

    “This basically eliminates the possibly of catastrophic climate change—that is, climate change that proceeds at a rate that exceeds our ability to keep up. Such a result will also necessarily drive down estimates of social cost of carbon thereby undermining a key argument use by federal agencies to support increasingly burdensome regulations which seek to reduce greenhouse gas emissions.”

    “If this Stevens/Lewis result holds up, it is the death blow to global warming hysteria.”

    The “basically eliminates” phrase may overstate the case; I’d prefer to say that is “greatly reduces the estimated probability of higher levels of global warming”.

    At the same time the partisan mediamatters makes at least two major blunders. First, The “death blow” comment was not made in reference to Stevens paper as mediamatters insists upon more than once. As the quote above shows the Cato blogs clearly relates it’s “death blow” comments to the implications of Lewis’s work. Second, Mediamatters forces all the emphasis on the “death blow” phrase and ignores milder and uncontested characterizations of Steven’s paper such as:

    “The new Stevens’ result—that the magnitude of the aerosol forcing is less—means the amount of greenhouse gas-induced warming must also be less; which means that going forward we should expect less warming from future greenhouse gas emissions than climate models are projecting.”
    – from Cato blog

    Finally, similar points can be raised about other blogs criticised by mediamatters, in particular see the first blog listed from

  27. admkoz
    Posted May 4, 2015 at 2:11 PM | Permalink

    I have a fairly dumb question: I always hear about heat being “taken up” by the ocean. What about the land? Is the amount of heat absorbed by the land so low that it can be ignored even in models that run for 1000 years?

    • Posted May 4, 2015 at 5:51 PM | Permalink

      I don’t find the question dumb whatsoever. I find it is completely ignored. Think about the heat rain carries into the rock. In my opinion, this may be the ‘missing heat’, climate modelers are allegedly looking for.

      Of course the heat capacity is so large they don’t really want to find it.

      • bill_c
        Posted May 8, 2015 at 2:17 PM | Permalink

        Hm. Church et al estimated this. But I don’t know on what parameters. Still found it to be a lot less than the ocean – so while possibly misparameterized, not *completely* ignored.

      • Geoff Sherrington
        Posted May 13, 2015 at 10:37 AM | Permalink

        Hi Jeff,
        Is it too semantic to note that the heat is not taken up by the land so much as reconfiguring the continuous heat flow from the earth’s interior in a classical hot conductive bodies in contact scenario? This mechanism is invoked e.g. at Michigan for creating borehole temperature profiles that are supposed to reflect how hot it was for how long at the rock/air surface uf to a few 00 years ago. There are several publications with theory diagrams showing boundary cases for down hole T logging.
        (Personally, I am highly sceptical of the stability of the method of T reconstruction by inversion, but let us put that aside for the reason that I’ve actually been involved in drilling large numbers of holes into rocks).
        I’ve been pretty sick and have not thought through just here what the consequences might be for global heat balance if work was done to slow the release of geothermal heat, a la work supposed to be done to slow the flow of greenhouse heat. I might be barked up a wrong tree.
        Magnitudes are different in these 2 cases.
        Cheers Geoff.

        • admkoz
          Posted May 18, 2015 at 9:44 AM | Permalink

          Right. It seems clear that ‘equilibrium’ can’t be reached until that process is complete – a few billion years maybe?

          But whether you call it ‘uptake’ or ‘slowing down of heat outflow’ it seems like a permanent heating of the air and water above it has to have some impact on the process.

    • Posted May 5, 2015 at 8:31 AM | Permalink

      According to Figure 1, Box 3.1 of the IPCC AR5 WG1 report, heat uptake by land over 1991-2011 was only about 2.4% of that taken up by the ocean.

      • Posted May 6, 2015 at 6:21 AM | Permalink

        Nic, there must still be things in AR5 WG1 on which you don’t have a settled view and others (like assumptions about carbon-cycle feedbacks) where you would definitely seek to question the status quo. Where would this 2.4% heat uptake by land 1991-2011 sit on the spectrum?

        • Posted May 6, 2015 at 1:51 PM | Permalink

          Land uptake estimates would have to be several times too low for the error to be of any significance, so I don’t see any point questioning it.

        • Posted May 8, 2015 at 5:43 AM | Permalink

          Your focus is a lesson to us all.

      • Follow the Money
        Posted May 6, 2015 at 3:30 PM | Permalink

        I see the box. Land is based on a single borehole study published way back in 2002. Hm..

      • admkoz
        Posted May 7, 2015 at 4:17 PM | Permalink

        OK, but if the air and ocean warmed, would not the temperature gradient between them and the land change in a way that resulted in the land taking up heat faster?

        I mean, any ‘equilibrium’ calculation has to mean the whole thing is in equilibrium with the huge solid it’s sitting on. Maybe that equilibrium takes so much longer to reach that it is not significant within a 1000 year time frame, but it still seems weird to never hear about it.

      • bill_c
        Posted May 8, 2015 at 2:18 PM | Permalink

        ahh I should read down first.

    • patmcguinness
      Posted May 21, 2015 at 12:02 PM | Permalink

      Water is an amazing heat transport and storage molecule. iI’s heat capacity is high, it conducts heat well, and the processes of evaporation, melting, precipitation etc. that operate in natural conditions on earth, can unlock a lot of heat. It’s so good we used in steam engines, Rankin power generators and in nuclear power plants. Our oceans are on average several km deep, but ocean circulation can drive hot or cold water in or out of the deep ocean to the surface and back again. Rocks otoh dont move nor melt at earth’s surface temperature nor conduct heat as well. In EE terms, the oceans are a huge capacitor, while land is a low capacitance high resistance. It’s not surprising that almost all the subsurface to atmosphere heat interactions are with bodies of water.

      • Posted May 22, 2015 at 7:10 AM | Permalink


      • admkoz
        Posted May 22, 2015 at 3:33 PM | Permalink

        I realize that heat exchange is *faster* with water. But if we’re talking about *equilibrium*, then doesn’t that get evened out to some extent?

        I keep hearing that enormous amounts of heat are ‘hiding in the deep ocean’. Well, there must be some sort of equilibrium between the ocean and its floor, and if enormous new heat is added to the deep ocean, then at “equilibrium” hasn’t some of that bled out into the ocean floor?

        Or does that “equilibrium” take so long to reach that it is irrelevant?

  28. Cortlandt
    Posted May 8, 2015 at 8:47 PM | Permalink

    Yet one more fault with the “How to Misinterpret” piece, this one going directly to the allegation of misinterpretation.

    (9) The scientific american piece is as much or more a editorial about politics and society as it is about the science of Steven’s and Lewis’s papers. That is clear from the title and key points in the editorial, a central point of which is the allegation that

    “His [Steven’s] work has been portrayed by conservative news outlets and blogs as undermining the theory of human-caused global warming. Red lights lit up. “New Climate Paper Gives Global Warming Alarmists ‘One Helluva Beating,'” Fox News declared.”

    Although this alleged misinterpretation is arguably the central point of the article only one piece of reporting, commentary, or blog post and only one source is named; the “One Helluva Beating” piece from Fox News. An internet search traces that one piece in question back to here:
    It’s not clear to me what is so objectionable about the piece. While it does contain some political spin it’s reporting of the science concludes with a qualified:

    “If the cooling effects of aerosols turn out to be much smaller than the IPCC thinks, then what this means is that the rise in global temperatures attributable to man-made CO2 is also much smaller than the alarmists’ computer models acknowledge.”

    Given the poor quality of reporting and the amount of (often covert) spin the authors of “How to Misinterpret” give to the story they are in a poor position to criticize the political spin in articles. Especially so when the political spin comes from overtly political, rather than supposedly scientific, sources. To borrow a legal concept scientific american comes to this story with “dirty hands”.

    Also recommended is:

  29. hunter
    Posted May 16, 2015 at 7:23 AM | Permalink

    The corruption and devolution of Scientific American magazine is sad to witness.

  30. nevket240
    Posted Jun 2, 2015 at 2:48 AM | Permalink

    interesting take on the standards of science.

  31. Skiphil
    Posted Jun 15, 2015 at 2:53 PM | Permalink

    OT: NY Times article on retractions of scientific articles — are there climate related articles, from Mann to Lewandowsky, which ought to be retracted?

    • Skiphil
      Posted Jun 15, 2015 at 2:57 PM | Permalink

      should have used a hyperlink:

      Science, Now Under Scrutiny Itself

      • Posted Jun 15, 2015 at 7:11 PM | Permalink

        From the NYT piece, “The blog has charted a 20 to 25 percent increase in retractions across some 10,000 medical and science journals in the past five years: 500 to 600 a year today from 400 in 2010.”

        Math is hard.

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