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  1. Glad to see you post on this study. We fired off a story on this last night, after the Forbes column was highlighted on Drudge. According to Mike Lemonick, who wrote the Climate Central piece, it seemed to be a case where a study was saying 1 thing, and the author was saying/writing another to the press, inspiring all sorts of online shenanigans. http://www.climatecentral.org/blogs/global-warming-debunked-or-not/

    Best,

    -Andrew

    Comment by Andrew Freedman — 29 Jul 2011 @ 4:50 PM

  2. “The paper’s title “On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earth’s Radiant Energy Balance” is provocative and should have raised red flags with the editors.”

    Hmm. On the cynical side, one wonders if the editors published this article because of the provocative title and content. Remote Sensing is not listed on Web of Science; one wonders if they’re trying to increase their visibility with the old adage, “there’s no such thing as bad publicity…”

    Comment by robert — 29 Jul 2011 @ 4:56 PM

  3. > visibility

    The fee is 500 Swiss Francs to publish:
    http://www.mdpi.com/about/apc#amount-apc

    and, a bit outdated, that page says
    “currently planning for the implementation of a discount system for peer-reviewers that kindly offered their services to our journals. This new discount system will be in place in middle of 2010″

    > the editors
    There may be an opportunity for someone:

    Open positions at MDPI
    Assistant Editor
    Posted: 1 February 2011
    Location: Office in Haidian, Beijing, China
    Contact: kelly.chen@mdpi.com

    Comment by Hank Roberts — 29 Jul 2011 @ 5:21 PM

  4. Andrew Dessler seems to have summed the goal of this publication up well in a comment published on Climate Progress:

    “[This] paper is not really intended for other scientists, since they do not take [Roy Spencer] seriously anymore (he’s been wrong too many times). Rather, he’s writing his papers for Fox News, the editorial board of the Wall St. Journal, Congressional staffers, and the blogs. These are his audience and the people for whom this research is actually useful — in stopping policies to reduce GHG emissions — which is what Roy wants.”

    http://thinkprogress.org/romm/2011/07/29/282584/climate-scienists-debunk-latest-bunk-by-denier-roy-spencer/#more-282584

    Comment by Chris McGrath — 29 Jul 2011 @ 5:23 PM

  5. “Spencer has made this error of confounding forcing and feedback before and it leads to a misinterpretation of his results”.

    If CauseA initially produces EffectB = CauseB which then produces EffectC, is EffectC the result of a Forcing (CauseB) or a Feedback (EffectB)?

    Methinks we need some rigorous definitions of Forcing and Feedback.

    Comment by simon abingdon — 29 Jul 2011 @ 5:53 PM

  6. Just to be a contrarian here: Despite your superb dissection, the paper was wildly successful. And it has nothing to do with it’s scientific worth. This was another PR assault masquerading as a serious science paper.

    It garnered terrific publicity in Fox, Forbes and other Murdoch outlets. It further stoked the emotional embers of confusion and doubt in the public. Politicians and climate policy wonks can wield and wave this one.

    People are getting assaulted by heat waves, droughts and floods. It succeeded wonderfully in distracting attention and feeding the hunger for pseudo validation of magical thinking. Some will fiercely refuse to accept anthropogenic climate change – no matter what the evidence or science.

    It managed to suck up your time in evaluating the data and methodology and authoring this response but I must thank you so much for doing some excellent analysis, and for correcting this paper. You have turned this into a teaching opportunity. Something that is endless.

    There will be more efforts like this – this was too easy. The slight downside of writing a bad science paper is a trivial cost for such a PR success.

    The current tally for Google citations for the title is 3,3800
    http://bit.ly/p8pKyN

    Comment by richard pauli — 29 Jul 2011 @ 6:37 PM

  7. I think the comment from Andrew Dessler (quoted above by Chris McGrath).

    This publication is “Ditto-Head Science”. It is not intended as a serious contribution to climate science. It is merely fodder for the deniers, who will for the most part not even look at Spencer’s paper itself, but will simply run around the Internet bellowing that anthropogenic global warming has been “refuted”, and trying to prove that they can shout “alarmist” more times than the Heartland Institute’s propagandist Taylor did in his ludicrous “news article”.

    Comment by SecularAnimist — 29 Jul 2011 @ 6:40 PM

  8. Has anybody given my critique of the paper any thought?

    http://www.realclimate.org/?comments_popup=8345#comment-211747

    His feedback loop only gives lower results if and only if he selects any period other than -λT, his conclusion is clearly off and maybe his model as well if not done correctly..

    [Response: I'm not sure I follow you. The regressions he is doing are on the deseasonalized monthly anomalies - there is no selection there. - gavin]

    Comment by anthropoggedon — 29 Jul 2011 @ 7:10 PM

  9. Well, here’s one blogger not taken in by Taylor.

    Spencer and Braswell’s paper is actually a pretty good example of academic fraud. The authors clearly understand enough climate science to know that what they are suggesting is impossible, absurd, and simply wrong. The editors of Remote Sensing must have been very clever with their choice of peer reviewers to let this one past, and one wonders what their intentions are.

    [Response: This is going too far. I doubt the editors of Remote Sensing are guilty of anything more than poor choice of peer reviewers. The problem with the paper is that it is just poor, not fraudulent - though the overheated commentary in the blogosphere clearly crosses the line into misrepresentation. People are too eager to toss around extremely strong language that does the discourse no good at all. - gavin]

    Comment by J Bowers — 29 Jul 2011 @ 7:13 PM

  10. More about Spencer:

    http://bartonpaullevenson.com/Spencer.html

    Comment by Barton Paul Levenson — 29 Jul 2011 @ 7:19 PM

  11. A little more on Spencer:

    http://bartonpaullevenson.com/Spencer.html

    Comment by Barton Paul Levenson — 29 Jul 2011 @ 7:20 PM

  12. About RS:

    http://bartonpaullevenson.com/Spencer.html

    Comment by Barton Paul Levenson — 29 Jul 2011 @ 7:20 PM

  13. @ Richard Pauli

    Have you read the blogs in your Google list, though? Even the moms at Cafe Mom rip into Spencer’s paper, beginning with…

    Some of you may have heard of a pack of paid shills called The Heartland Institute.

    Guess the rest.

    Comment by J Bowers — 29 Jul 2011 @ 7:39 PM

  14. simon abingdon @ 5 Methinks we need some rigorous definitions of Forcing and Feedback.

    Hey! I’ll bet climatologists never thought of that! Write a paper. You’ll get hundreds of citations.

    Comment by Pete Dunkelberg — 29 Jul 2011 @ 8:14 PM

  15. #13 J Bowers…right you are. However a PR success is not measured by the sides of an argument… it is measured by putting the issue in front of the audience. Success is by how many people see the controversy continue. The promotion is for the very idea of dispute. Logic is irrelevant to a PR campaign. A wrong paper creates a bigger controversy – and more buzz – than a correct one.

    Pity.

    Comment by richard pauli — 29 Jul 2011 @ 8:24 PM

  16. Someone at NASA needs to check a few links; searching on the authors of that paper comes up prominently with links leading to this page:

    http://spacescience.spaceref.com/newhome/headlines/essd12mar97_1.htm

    “Despite the fact that Hurrell and Trenberth _estimate_ of the temperature of the atmosphere through a simple linear regression model based only on the sea surface temperatures, and a global climate model simulation with the same sea surface temperatures but no stratospheric volcanic aerosols, while the MSU data actually _measure_ the temperature of the free atmosphere, Hurrell and Trenberth conclude that the satellite data must be wrong….”
    —–

    and that page links to this page:

    http://spacescience.spaceref.com/newhome/essd/atmosphere_today.htm#anchor547043

    “Maps of Global atmospheric temperatures are available …. All data are available in global or continental U.S. projections. Interactive access for selection of daily temperature data is available.”

    Comment by Hank Roberts — 29 Jul 2011 @ 8:28 PM

  17. And still no one can explain why incremental GHG ‘forcing’ will be amplified by over 400% when solar forcing is only amplified by about 60%. I think the peer review process is broken, but the nonsense continues on.

    [Response: Where do you get that from? Climate sensitivity is pretty close to equivalent for most forcings. - gavin]

    Comment by RW — 29 Jul 2011 @ 8:53 PM

  18. Gavin,

    The ‘direct’ warming from 3.7 W/m^2 is about 0.7 C from the S-B law. The additional 0.4-0.5 C to get the often referenced 1.1-1.2 C of ‘intrinsic’ warming from 2xCO2 comes from adding on net transmittance to space of about 62% (0.7 C x 0.62 = 0.43). Net transmittance to space (aka the planet’s ‘effective’ emissivity) is directly derived from the system’s response to solar forcing (240/390 = 0.615), whose inverse of 1.63 W/m^2 is the amount of radiative surface flux required to allow 1 W/m^2 to leave the system (1/0.615 = 1.63; 1.63 x 240 = 390).

    0.43C/0.7C = 0.62 (62%); 3.0C/0.7C = 4.29 (429%).

    If you really think +3.7 W/m^2 from 2xCO2 is going to become +16.6 W/m^2 required for a 3 C rise, you should explain why it doesn’t take 1077 W/m^2 of surface power to offset the 240 W/m^2 of incident solar power (16.6/3.7)*240 = 1077.

    [Response: You are confusing surface energy balance with the response to a TOA/tropopause forcing. Similarly, you are thinking that the Earth's greenhouse effect can be modelled purely as an effective emissivity (i.e. 'grey' body). This does not actually fit the reality of why the surface temperature responds to the greenhouse effect since the emissivity itself is not independent of temperatures and greenhouse absorbers. Read Ray's Climate Book for a more thorough treatment. - gavin]

    Comment by RW — 29 Jul 2011 @ 10:19 PM

  19. re: #9
    Yes, people *really* need to be careful to not say academic fraud, just for bad paper.
    Plagiarism is academic fraud, and once found, is easy to show. Falsification/fabrication is harder, especially as it takes more expertise to explain convincingly to a larger audience. See the first page of the PDF here for commentary on the differences, and then some examples that go beyond plagiarism.

    Comment by John Mashey — 29 Jul 2011 @ 10:31 PM

  20. Lest we forget, this paper made its public debut four years ago as Roy’s after dinner speech at the 1st Heartland conference. He said at the time it had been submitted for peer review (JGR, IIRC) the year before!

    Comment by Russell — 29 Jul 2011 @ 10:38 PM

  21. “but instead what appears to have been done is to use only the one hundred year set by itself.
    Did you mean:
    “but instead what appears to have been done is to use only the one ten year set by itself.”?

    From:
    http://www.climatecentral.org/blogs/global-warming-debunked-or-not/
    “Spencer……says that changes in cloud cover are a major cause of climate change.”
    Is obviously nonsense because that would lead to a very unstable climate.

    Could you go over how you make an “Inter-Decadal Span of Regression” please? I get that you are making a graph of the lead and lag in the timing of the ENSO and then doing statistics on it. I don’t think I took that statistics course yet.

    Comment by Edward Greisch — 29 Jul 2011 @ 10:43 PM

  22. Well, Gavin, what RW says is perfectly correct: no one can explain why GHGs are forced 7 times as much as solar. Of course, no one tries to explain it because no one believes it, but maybe RW isn’t in on that part of the joke ;)

    Comment by JBL — 29 Jul 2011 @ 10:50 PM

  23. Drs. Trenberth and Fasullo,

    Many thanks for the prompt and devastating refutation of Spencer’s latest example of bad sicence. Sorry that you have to waste your valuable time dealing with such BS.

    Comment by MapleLeaf — 29 Jul 2011 @ 11:27 PM

  24. I agree with Richard Pauli’s post at #6.

    Spencer has already won his PR victory, and the job of this paper is done. The biases in the vast morass of the collective denialist mind have been confirmed, and inaction has been cemented for yet another critical period – and these days critical periods are able to be measured in months rather than years.

    Corrections such as this one of Kevin’s and John’s, and of others such as Barry Bickmore’s, are of course very necessary – but I think that the best answer to Spencer’s shitting in the pool of scientific understanding is to either publish a peer-reviewed rebuttal, or to move for a withdrawal of Spencer’s paper itself. Or both. Less than that, and the appropriate scientific response will not reach the general public, where the damage has been done in the first place.

    (ReCaptcha says “dentis subalgebra”…!?)

    Comment by Bernard J. — 29 Jul 2011 @ 11:51 PM

  25. > where do you get that from

    William Connolley asked for cites for his numbers, repeatedly: http://scienceblogs.com/stoat/2011/06/lindzen_goes_emeritus.php#comment-4227967 — he also posted the claim at Spencer’s and was ignored, and also a couple of times at site:skepticalscience.com “amplified by over 400%”

    Comment by Hank Roberts — 30 Jul 2011 @ 12:10 AM

  26. As an aside, I noted a significant error in the first sentence of the Fox News article, documented here:

    I’m not saying Fox News is stupid, but…

    It sure did make me chuckle. Editing is more than just spelchecking! Consider this my “peer review” of Fox News.

    Comment by Oakden Wolf — 30 Jul 2011 @ 12:25 AM

  27. Thanks for posting a substantive criticism which does not engage in ad hominem or poisoning the well. I have been looking for a post which criticizes the study which does not also engage in fallacious rhetoric, and yours is the first I have found.

    Comment by Joseph Thiebes — 30 Jul 2011 @ 12:47 AM

  28. Re: Prof Schmidt’s response to #9: wise words indeed – perhaps there is nothing more sinister than confirmation bias going on. What is your opinion of recent developments in the UK? It concerns me that “regulation” of peer review has a very real potential to have a chilling effect on research, and certainly of outlying views, in exchange for limited benefits if any at all. Fraud will be extremely difficult to prove, but easy to allege, and you don’t have to be a climate scientist to figure out where most of these allegations will be coming from. It seems to me that this will provide another weapon for the Cuccinellis of this world to harass researchers, and yet it will not prevent papers such as Spencer and Braswell being published (assuming such prevention is desirable).

    Comment by One Anonymous Bloke — 30 Jul 2011 @ 12:52 AM

  29. #14 Pete Dunkelberg

    So what are the definitions of Forcing and Feedback? How are they to be unambiguously distinguished? I think I might reasonably claim that the Sun is the only real Forcing and that all climatic effects are consequent Feedbacks.

    Comment by simon abingdon — 30 Jul 2011 @ 2:40 AM

  30. Further to my earlier post: If you want to study the behaviour of a “system” you might start by defining its boundaries. Then any external influence is a Forcing on that system while its internal behaviours are the Feedbacks resulting from that external Forcing. The choice of the “system” is arbitrary, in the sense that it’s whatever you choose to study. So one man’s Feedback is another man’s Forcing. To say that Spencer confounds the two looks to me unreasonably dismissive.

    [Response: I agree that the boundaries of a modelled system define what is forcing (external) and what is feedback (internal), but Spencer's idea of 'internal radiative forcing' is nonsense even by your definition. Furthermore, the system we are talking about almost exclusively is already well-defined, and so there isn't that much ambiguity. Only if you have a forcing that specifically affects clouds by means of some aspect of their physics that is already within the system will you have a specific forcing from clouds (in this sense). For instance, indirect aerosol effects (via increased SO2 pollution, or cosmic ray modulation of ionisation) count as forcings, but the response of clouds to dynamical changes, circulation, temperature or humidity do not. - gavin]

    Comment by simon abingdon — 30 Jul 2011 @ 3:20 AM

  31. The arguments are incomprehensible for a naive Sustainable Development scientist, like me and therefore useless for a debate with me at least. Either one believes one side or the other.

    But one of the comments No. 6, Pauli, deserves special attention, me thinks. It says the scientifc quality is unimportant. It’s the PR and confusion generated that counts.

    That’s why the speech of Mr Achim Steiner, head of UNEP at the UN Security Council, some ten days ago is so utterly stupid and a waste of time. (Link to Steiner’s speech:
    http://www.unmultimedia.org/tv/webcast/2011/07/achim-steiner-unep-security-council-meeting-part-1.html )

    The whole flipping climate debate is one huge distraction from the underlying I=PAT.

    Human Impact on the planet
    equals
    Population size times Affluence (standard of living) times Technology.

    The very same IPCC is beset by people who believe the market and technology will provide solutions, whereas growth is no issue.

    Earlier this year a main author of the IPCC’s 4th report said in a public presentation at the Geneva Graduate Institute that we’ve lost the battle against GreenHouseGas emissions. (cf.
    http://www.wachstumsforum.ch/climate/e/index.htm )

    Yet he does not call for a growth stop, he said, obviously suffering from the same omnipresent growth virus.

    This Climate Craze does not influence the bureaucrates at the WTO, ICTSD et al. They’re functioning because a job is a job is a job.

    My next trip is to Korea, the country that’s on it’s Green Growth trajectory, for a series of talks to explain why Aid for Trade is good
    for hungry Africans and will help stopping Climate Change and resource
    depletion.

    Yours climatolocrazically … Helmut

    PS: Did anybody enroll for the next WTO public Forum, in September?
    Try to tell Mr Lamy that the temperature predictions have been debated and how important that is for the success of the DOHA round.

    Comment by Helmut Lubbers — 30 Jul 2011 @ 3:27 AM

  32. My view of climate is basically similar to Trenberth and Fasullo’s. But I do not think their words “Clouds … they do not cause the weather systems” are adequate in the tropics. Tropical weather systems are driven by cumulus cloud convection, and what we see as weather systems are their collective behavior. They are modulated, of course, by the planetary-scale circulations, land-sea contrast and sea surface temperature anomalies. But they do not seem fully determined by large-scale forcing, but they seem considerably stochastic or chaotic.

    Clouds respond to radiative forcing and feed back to large-scale climatic states. But that is not straightforward. Radiative forcing has, first, day-night contrast, and second, land-sea contrast. Forcing due to climate change comes as modulation to these complex spatio-temporal structure. So what we can do is to try partial understanding our based on either statistical analyses or simplified models.

    Comment by Kooiti Masuda — 30 Jul 2011 @ 4:14 AM

  33. richard pauli — “However a PR success is not measured by the sides of an argument… it is measured by putting the issue in front of the audience.”

    I think that’s oversimplistic, and the method can also backfire. People do click on the links. The difference with this paper is that it isn’t being splashed all over the web in general comments as usual, that I can see. Sure, FOX will run with it, and Forbes, but up would be down if they didn’t. It just ain’t cropping up as proof of “a scam” everywhere else. It’s actually a bit weird.

    And sorry, perhaps I shouldn’t have quoted in #9. Harsh words, though. Harsher than you’ll usually find.

    Comment by J Bowers — 30 Jul 2011 @ 4:57 AM

  34. “vast morass of the collective denialist mind. . .”

    Surely it’s only half vast?

    Comment by Kevin McKinney — 30 Jul 2011 @ 6:21 AM

  35. A feedback is just a response to a forcing. If that response causes a further effect, it becomes a new forcing. Feedbacks by themselves are merely passive; only when they become forcings do they cause changes. So there’s your definition: forcings cause changes, feedbacks as such do not, until or unless they become forcings, when their erstwhile feedback status is no more than interesting history.

    [Response: This definition makes no sense at all. The whole point of a forcing/feedback analysis is to be able to predict the response of the system to external perturbations. We are interested in the internal responses to those perturbations that then cause further perturbations (i.e. water vapour response to temperature which then further affects temperature via the greenhouse effect). If we define them away as forcings we end up with no actual feedback at all, and an unknown amount of forcing. I don't see how that is useful in the slightest. - gavin]

    Comment by simon abingdon — 30 Jul 2011 @ 6:46 AM

  36. gavin, apologies. Please disregard my #35 (or so, awaiting moderation) written before reading your response to my #30.

    Comment by simon abingdon — 30 Jul 2011 @ 6:54 AM

  37. Gavin,

    “You are confusing surface energy balance with the response to a TOA/tropopause forcing. Similarly, you are thinking that the Earth’s greenhouse effect can be modelled purely as an effective emissivity (i.e. ‘grey’ body). This does not actually fit the reality of why the surface temperature responds to the greenhouse effect since the emissivity itself is not independent of temperatures and greenhouse absorbers.

    Are you trying to say that the 240 W/m^2 from the Sun is not forcing the climate system? The +3.7 W/m^2 from 2xCO2 is supposed to be equivalent to +3.7 W/m^2 of post albedo solar power, is it not?

    The bottom line is the the 240 W/m^2 from the Sun is only amplified by a little over 60% (to about 390 W/m^2). If watts are watts, you can’t apply some nebulous new ‘feedback’ to an additional 3.7 W/m^2 from 2xCO2 and ignore the way the system is responding to the original 240 W/m^2 from the Sun.

    If, as you believe, +3.7 W/m^2 is to become +16.6 W/m^2 through ‘feedback’, quantify specifically how the feedback will cause this much change on the next 3.7 W/m^2 and why it does not on the original 98+% (240 W/m^2) from the Sun. You should also explain why the planet doesn’t have an emissivity of 0.22 (3.7/16.6 = 0.22).

    [Response: The basis of your error is the attempt to define sensitivity from the overall surface energy balance. This assumes a) no feedbacks and b) linearity from no atmosphere/same albedo to present day. Neither assumption is justified. See the workings of a 'simple' model and demonstrate to yourself that even in the simplest case your calculation does not correctly define sensitivity. When it comes to equivalent forcings from either solar (say +2% irradiance) or GHGs, sensitivity and feedbacks are very similar. - gavin]

    Comment by RW — 30 Jul 2011 @ 8:00 AM

  38. Would you guys consider a separate small post (maybe more easily quoted for blogs) on some of the different problems with the study?

    I think it would be comprehensible and hugely influential for the average reader (not anti-global warming ideologue) who sees even the “news” / blog summaries about the variation in cloud cover which is central to the article, to get the basic point that clouds are caused by related mechanisms, and not the *cause* of the described phenomena.

    It may seem to require a bit of attention to the relation of clouds to forcings (a word foreign to most), but the general point of confusing (or intentionally reversing) *cause and effect* is a very, very powerful punch.

    And I say “you” because people will want to quote this blog.

    Comment by El Cid — 30 Jul 2011 @ 8:23 AM

  39. Speaking about papers that should not have been published, I’ve been blogging with a person who keeps insisting the greenhouse effect theory has been disproved. She keep citing news releases about “studies.” I don’t have time to follow these, but are there any peer-reviewed studies that have disproved the greenhouse effect (or thrown it into doubt), aside from one in a Hungarian science journal we discuss here sometime back (and the scientists here said it was bunk)?

    Or are these just bogus “studies” that don’t really make it into a journal?

    [Response: These are just bogus studies, though some have made it into (not very good) journals. See the information here: which includes various links to paper and commentaries explaining why these claims are false.--eric]

    eric]

    Comment by Lynn Vincentnathan — 30 Jul 2011 @ 9:04 AM

  40. Sorry for being OT, but here’s something I just got — http://hol.sagepub.com/content/21/5/793.abstract?ct=ct — and I’m wonder what they are saying. Is it: we would be much cooler now and heading for an ice age, if not for our GHG emissions during the pre-idustrial & industrial times during the Holocene?

    Are they saying that the human GHG emissions of PI times led to greater positive GHG feedbacks from nature that thought before. And in a non-human-GHG world, the cooling feedbacks during the Holocene would have been greater than thought.

    Which then would mean, what, the climate is more sensitive (thru these positive warming & cooling feedbacks) in both the warming & cooling directions than thought?

    Meaning ?? we’re pretty much in deeper do-do now.

    Comment by Lynn Vincentnathan — 30 Jul 2011 @ 9:12 AM

  41. Re: Hank Roberts #3 and Gavin’s response at #9.
    Perhaps the following is not too far off topic.

    http://www.mdpi.com has a portfolio of 60 open-access journals
    listed. Of those 60, 26 are new in 2011, 10 new in 2010, and 12
    new in 2009. Remote Sensing dates from 2009.
    The oldest of mdpi.com’s journal is “molecules”, 1996.

    A Google search will turn up some interesting comments, etc. Not sure
    what, if anything, to make of it all.

    Comment by BillS — 30 Jul 2011 @ 9:56 AM

  42. #35 [gavin response] “The whole point of a forcing/feedback analysis is to be able to predict the response of the system to external perturbations”; “the system” and “external” referring to what, exactly?

    [Response: Gavin's point is a general one. If you want specifics in this case, the answer is system = 'the earth's atmosphere and surface', 'external forcing' means the radiative forcing from extra (meaning 'above pre-industrial levels') CO2 and other greenhouse gases. This is what Spencer has purported to do but he has not done, because clouds are part of the 'system'.--eric]

    Comment by simon abingdon — 30 Jul 2011 @ 10:18 AM

  43. #35 [gavin response] “The whole point of a forcing/feedback analysis is to be able to predict the response of the system to external perturbations”. Had you said the whole point of a forcing/feedback analysis is to be able to predict the [ultimate] response of the system to external perturbations [and their consequent internal perturbations] I might have agreed with you, but you’d still have to accurately draw that line in the sand between external and internal. I don’t think you can do it convincingly. You said earlier #30 [gavin response] “indirect aerosol effects (via increased SO2 pollution, or cosmic ray modulation of ionisation) count as forcings, but the response of clouds to dynamical changes, circulation, temperature or humidity do not”. I don’t understand the reasoning behind this categorisation. It looks arbitrary to me, tendentious even.

    [Response: Why? The dynamics, temperatures etc are all part of the system for which you are calculating prognostically. In a standard model without interactive aerosols or micorphysics, the impact of GCR or SO4 on nucleation and aerosol growth is simply not included. Therefore they have to be put in as a forcing. For interactive models, it is the ionisation change or SO2 etc. emission change that is the forcing. - gavin]

    Comment by simon abingdon — 30 Jul 2011 @ 11:03 AM

  44. Gavin,

    “The basis of your error is the attempt to define sensitivity from the overall surface energy balance. This assumes a) no feedbacks and b) linearity from no atmosphere/same albedo to present day. Neither assumption is justified.”

    What then is controlling the surface energy balance of 390 W/m^2, which is just the net surface energy flux in an of itself? If not all the feedback mechanisms and physical processes in the climate system, then what? I presume you’re aware that the climate is a dynamic equilibrium system – not a static steady-state system. And one that is remarkably stable to boot, despite a large degree of local, regional, seasonal hemispheric, and even sometimes globally averaged variability. Hardly consistent with net positive feedback – let alone positive feedback of 300%.

    I’m aware the there is some non-linearity, but relative to GHG ‘forcing’ all that matters is the global average.

    Also, let’s not forget that only the Sun truly forces the system – all additional GHGs can do is slightly modify the response of the system to the forcing of the Sun. Claiming the system will respond 3 times more powerfully to a slight modification like this in such a highly dynamic – yet very stable and tightly constrained system, is an extraordinary claim that requires extraordinary proof.

    You cannot arbitrarily separate the feedback mechanisms controlling the surface’s energy balance of 390 W/m^2 from those that will act on the +3.7 W/m^2 from 2xCO2 without explaining and answering the questions I posed. If you can’t answer those questions, I suggest you rethink the feasibility of a 3 C sensitivity, as some pretty simple fundamentals strongly suggest it’s way outside the system’s measured bounds.

    [Response: I gave you the link above so that you could perhaps learn something. I still urge you to do so. - gavin]

    Comment by RW — 30 Jul 2011 @ 11:12 AM

  45. i thinks y’all needs a comma in dere “what we can produce but use” (or even a dreaded semicolon) like this “what we can produce; but use” (?)

    Comment by David Wilson — 30 Jul 2011 @ 11:13 AM

  46. #42 [eric response] “the answer is system = ‘the earth’s atmosphere and surface’, ‘external forcing’ means the radiative forcing from extra (meaning ‘above pre-industrial levels’) CO2 and other greenhouse gases”. I’m not at all sure I even begin to understand this. I was under the impression that “external” meant “outside the system”. The only CO2 external to the system you’ve defined is overwhelmingly in the oceans. Is that what you meant?

    [Response: I didn't mean to imply that the system boundaries have to be spatial boundaries (e.g., the sides of a box containing the atmosphere). CO2 from fossil fuel burning is being added to the atmosphere quite independently of everything else. From a modeling perspective --- in the context of what Spencer and Braswell are trying to do -- the interaction of CO2 with the ocean and atmosphere is being entirely ignored, and that's just fine because the timescales are totally different. Increased radiative forcing from CO2 will affect the carbon cycle on the long term, but not on the short term, and so it can be ignored. Indeed, in this context, CO2 is not being modeled at all, merely the radiative forcing at a given CO2 concentration (and that radiative forcing is obviously independent of how the CO2 got there). This is *not* the case with clouds, which are much more quickly (like in a matter of hours to days) linked with dependent on the state of the atmosphere, and so cannot be treated as 'forcing' in anything like a comparable way to CO2. Does that help? --eric]

    Comment by simon abingdon — 30 Jul 2011 @ 11:18 AM

  47. I made this comment on the Unforced Variations thread, but it’s on-topic here as well: scienceblogger Greg Laden posted on the Spencer and Braswell paper yesterday. Deniers are spewing familiar nonsense in the comments, and the realists can use some expert help. TIA.

    Comment by Mal Adapted — 30 Jul 2011 @ 11:29 AM

  48. @Lynn Vincentnathan says:
    30 Jul 2011 at 9:12 AM

    Sorry for being OT, but here’s something I just got — http://hol.sagepub.com/content/21/5/793.abstract?ct=ct

    Are they saying that the human GHG emissions of PI times led to greater positive GHG feedbacks from nature that thought before. And in a non-human-GHG world, the cooling feedbacks during the Holocene would have been greater than thought.

    Yes, seems like it. Hansen recently stated one coal-fired plant is enough to overwhelm natural variation. I’m assuming he was serious and that I didn’t misunderstand what I read.

    Which then would mean, what, the climate is more sensitive (thru these positive warming & cooling feedbacks) in both the warming & cooling directions than thought?

    No, just that we’ve been nudging the climate with a twig, now we’re beating the heck out of it with a club.

    Meaning ?? we’re pretty much in deeper do-do now.

    Actually, it’s good news. We could live like Hobbits and still maybe never have to worry about glacial periods again – assuming there is no absolute need for a healthy biosphere to go through glacials.

    Comment by ccpo — 30 Jul 2011 @ 12:13 PM

  49. Thanks for doing the work/math to address this paper. As the droughts in the US continue, and the record heat waves continue, and the record breaking of record breaking continue, a lot of deniers are finding thier idolatry tested. The Spencer paper is just another idol, I think, soon to topple.

    Comment by Tobbar — 30 Jul 2011 @ 12:26 PM

  50. re: #40
    Yes.

    That’s part of an interesting special issue, which relates somewhat to the topic at hand, i.e., better paleo modles may help further constrain uncertainties. Very nice interdisciplinary issue.

    Read the Introduction, 2nd page and then you can at least peruse the abstracts for free. I especially recommend the last 2 articles.

    Comment by John Mashey — 30 Jul 2011 @ 12:28 PM

  51. 38, Lynn Vincentnathan

    Just garbage, as far as I know (and some pretty outlandish garbage at that), but if you provide a link to where those citations are listed, I’ll be happy to do a little leg work for you, if I have time myself, to try to track down the nature of those “proofs.”

    Comment by Sphaerica (Bob) — 30 Jul 2011 @ 12:34 PM

  52. simon,

    The “reference system” can be defined in different ways, and if you change the reference system then you change the feedback.

    But it is customary in climate feedback analysis to make the reference system the Planck radiative response, in part because it is well understood. This just says that a warmer planet will increase its emission to space (based on the Planck law). The dependence of the IR emission on temperature is about 3.2 W/m2 per Kelvin. It is this baseline from
    which “positive” or “negative” feedbacks are traditionally referenced. Positive feedbacks lower this value, so that for the same perturbation (e.g., increased CO2), the response is a bit more “sluggish” and the temperature must rise more in order for equilibrium to be established.

    The extreme end of this would be when the planets IR emission does not increase with temperature, so the temperature continues to rise whenever a radiative imbalance can be sustained. This also defines the runaway greenhouse scenario.

    Comment by Chris Colose — 30 Jul 2011 @ 1:06 PM

  53. Bob / Sphaerica, Eric has responded inline giving links in answer to Lynn’s question above at http://www.realclimate.org/index.php/archives/2011/07/misdiagnosis-of-surface-temperature-feedback/comment-page-1/#comment-211825

    Comment by Hank Roberts — 30 Jul 2011 @ 1:20 PM

  54. @David Wilson
    I think you are setting too high a standard for blog posts. Since you made it through moderation, though, I think a comma would be fine but a “the” would help. That is: “what we can produce, but the use…”

    Comment by Greg Simpson — 30 Jul 2011 @ 2:19 PM

  55. “What this mismatch is due to — data processing, errors in the data or ***real problems in the models*** — is completely unclear.” — Gavin Schmidt

    So are you admitting that this paper *MAY* have identified “real problems” in the models?

    [Response: This is an odd game of gotcha you appear to be playing. Whenever someone does an analysis and shows a difference between a model and the observations there is always the possibility you have revealed something interesting about model imperfections (since no-one is of the opinion they are perfect). In some cases that imperfection is well known (like the double ITCZ problem in tropical rainfall), sometimes it isn't, and other times the data is wrong. Very often though it is the comparison that is faulty (comparing apples to oranges for instance), or the implication that is at fault and that seems to be the case here - the big differences in this diagnostic between different models is not related to overall climate sensitivity (which you can easily see in Spencer's figures), but between models that have a reasonable ENSO or not (see above). Some models did not have sufficient ENSO variability (GISS-ER was one) and this appears to affect this particular diagnostics. It is however, unrelated to climate sensitivity. - gavin]

    Comment by JamesD — 30 Jul 2011 @ 3:42 PM

  56. The third graph “All models” shows that the actual satellite data regression coefficient is more than double than what is predicted by “all models”. Granted, it is inside the uncertainty region, but this is what I would call “something interesting about model imperfections”. Thanks to Dr. Spencer for contributing to science. Face it, even if this turns out to be an ENSO artifact, it still has contributed to our knowledge of the climate. And I would also caution people to differentiate what Dr. Spencer actually wrote, and what was written in the Forbes article. They are very different.

    [Response: ENSO isn't an artifact. And this is one of the cases where averaging models together doesn't make much sense. Panel a and b show clearly that models with and without good ENSO signals make all the difference to this diagnostic, which makes a lot of sense because over the 10 years of the data, the most important source of variability is related to ENSO. So had Spencer+Braswell said 'look, the data allows us to see how temperature and radiation co-evolve over ENSO cycles, and some models don't do a good job - probably because of their inability to reproduce ENSO variability' - no one would have criticised them. Instead, they erroneously link it to climate sensitivity and encouraged (via their press release) all manner of nonsense. - gavin]

    Comment by JamesD — 30 Jul 2011 @ 4:49 PM

  57. I am quite sure SB11 did not average together the models. I only read through it once, but I believe they study 6 models. Unfortunately both servers with SB11 are currently overwhelmed, and I can’t verify this. Whether any of these 6 models (assuming my memory is correct) have “good ENSO signals”, I do not know.

    An interesting question.

    Comment by JamesD — 30 Jul 2011 @ 5:25 PM

  58. I certainly appreciate the efforts taken by those of you who are PhD’s to respond to this paper, and think they are certainly worthwhile for those of us non-PhD’s who seriously want to understand the merits (or lack thereof) of such research. So thank you…

    On a the larger question of forcing vs. feedback I do have some questions, and it seems the more I read, the more confusing it becomes. On the broadest scope, aren’t positive feedbacks actually just a new forcing? Take Milankovitch cycles and CO2 for example. At least the notion is that small changes in forcings in this astronomical cycle alter insolation on the planet, releasing more CO2 from the oceans, which in turn, through a positive feedback process, causes more warming (i.e. become a forcing itself). So in this way, what was initially an effect of a forcing(i.e. outgassing of CO2) becomes a new forcing that amplifies that initial forcing through positive feedback.

    In the case of clouds, it seems the entire issue is that sometimes they are forcings (i.e. downwelling longwave from stratus at night for example) and sometimes are serve to reduce forcing by reflecting more sunlight. Certainly this issue of the uncertainty of the net effect of clouds is complex as they can sometimes provide positive feedback and sometimes they can provide negative feedback.

    So at least the current way I understand it, a forcing in the climate system is something that causes a change to the system beyond the natural variability of weather. Positive feedbacks can become forcings of their own, and negative feedbacks serve to dampen the effects of the initial forcing. Clouds can be both?

    Comment by R. Gates — 30 Jul 2011 @ 7:22 PM

  59. Scribd has the full text:
    http://www.scribd.com/doc/61161272/On-the-Misdiagnosis-of-Surface-Temperature-Feedbacks-from-Variations-in-Earth%E2%80%99s-Radiant-Energy-Balanc

    A link on that page for downloading either .PDF or .TXT

    Comment by Hank Roberts — 30 Jul 2011 @ 8:15 PM

  60. > R. Gates
    http://www.enviroliteracy.org/article.php/678.html
    http://www.azimuthproject.org/azimuth/show/Climate+forcing+and+feedback
    http://www.springerlink.com/content/w52g473471w88rl1/

    Comment by Hank Roberts — 30 Jul 2011 @ 8:26 PM

  61. ‘The canonical way to think about clouds is that they are a feedback—as the climate warms, clouds will change in response and either amplify, (positive cloud feedback) or ameliorate (negative cloud feedback) the initial change.

    What this new paper is arguing is that clouds are forcing the climate, rather than the more traditional way of thinking of them as a feedback.’ Dessler today

    ‘Much work has been done on ENSO over the past few decades and pretty much everyone agrees that it’s a stochastically triggered, coupled dynamic mode of the atmosphere, ocean system. I’ve never seen any suggestion that it’s triggered by clouds. To the extent that clouds amplify ENSO, that’s the cloud feedback, and that is what I measure in my paper.’ Dessler yesterday

    ‘Finally, since much of the temperature variability during 2000–2010 was due to ENSO (Dessler 2010) we conclude that ENSO-related temperature variations are partly radiatively forced. We hypothesize that changes in the coupled ocean-atmosphere circulation during the El Niño and La Niña phases of ENSO cause differing changes in cloud cover, which then modulate the radiative balance of the climate system.’ Spencer and Braswell 2011

    ‘It is not controversial to state that climate models are deficient in terms of tropical variability in the atmosphere on many timescales [Lin et al., 2006; Lin, 2007] and a more realistic simulation of ENSO events in coupled simulations remains a high priority for model developers. During El Niño, the warming of the tropical eastern Pacific and associated changes in the Walker circulation, atmospheric stability, and winds lead to decreases in stratocumulus clouds, increased solar radiation at the surface, and an enhanced warming.’ Trenberth et al 2009

    S&B11 say that the CERES radiative flux differs from the models. Uncontroversial. That climate sensitivity can’t be calculated this way because of ENSO radiative and non-radiative feedbacks. Not surprising.

    It seems veracity of science communication is a casualty of the climate wars.

    Comment by Chief Hydrologist — 30 Jul 2011 @ 9:04 PM

  62. R. Gates …aren’t positive feedbacks actually just a new forcing?

    Or are you confusing yourself semantically? Yes a positive feedback makes it even warmer, but it is a feedback because it happened as a consequence of a prior forcing. And yes, different types of clouds may be either positive or negative feedbacks. On balance, slightly positive it appears.

    But the idea that clouds are an original forcing, not a feedback, thus much more CO2 may be burned before the planet is ruined, is incoherent. What energy source causes the supposed increase in clouds (which cause warming that gets blamed on innocent CO2)? Meanwhile how can CO2 (without feedbacks, notably water vapor) cause the warming that Spencer admits it does, and somehow not cause the water vapor feedback (which would explain clouds)?

    Comment by Pete Dunkelberg — 30 Jul 2011 @ 9:34 PM

  63. Gavin,

    “I gave you the link above so that you could perhaps learn something. I still urge you to do so.”

    I did follow the link and read what is there. I didn’t really see anything I’ve brought up addressed.

    [Response: Then you aren't understanding what you saying. Your claim is that climate sensitivity is defined by the solar fluxes, upward long wave flux etc. Use the terminology and algebra in that post to calculate what you think the sensitivity is, compare it to the actual sensitivity and then think about why they are different, - gavin]

    Let me ask you this question: How is the often referenced 1.1 C of ‘intrinsic’ warming from 2xCO2 derived? Also, the +6 W/m^2 incoming surface flux needed for the 1.1 C rise in temperature – can you explain where this is coming from?

    Comment by RW — 30 Jul 2011 @ 9:45 PM

  64. I do believe the fossil fuel industry is scrambling desperately as they see the global events unfolding. This is clearly about ideology and politics. Spencer reportedly also does not believe in evolution. I think that says much about this and the interests he represents.

    Comment by Jan — 30 Jul 2011 @ 9:50 PM

  65. FYI post #6 – richard pauli – is flatly wrong. click through to the last result to check the count. it doesn’t take long. http://goo.gl/WSFCO

    more info: http://blog.xkcd.com/2011/02/04/trochee-chart/

    Comment by andrewo — 30 Jul 2011 @ 10:01 PM

  66. 34 Kevin McKinney: ““vast morass of the collective denialist mind. . .” Surely it’s only half vast?”

    The minds are few and far between but the morass is vast. I continue to read social science stuff to try to figure it out. I just finished “The Authoritarians” by Bob Altemeyer, which is downloadable free from http://home.cc.umanitoba.ca/~altemey/

    The human mind is indeed amazing[ly flawed]. The more I know the less hope I have.

    Please tell me a textbook that covers “Inter-Decadal Span of Regression.”

    Comment by Edward Greisch — 30 Jul 2011 @ 11:47 PM

  67. Gavin,

    “Then you aren’t understanding what you saying. Your claim is that climate sensitivity is defined by the solar fluxes, upward long wave flux etc. Use the terminology and algebra in that post to calculate what you think the sensitivity is, compare it to the actual sensitivity and then think about why they are different.”

    Can you be more specific and/or ask me some specific questions?

    You use the term ‘actual sensivity’. What do you mean by this? Also, can you answer the question I posed in my last post?

    [Response: In the simple model of the greenhouse effect one can write down exactly what the climate sensitivity is as a function of a change in the solar irradiance or greenhouse gas (via the absorption). One can also calculate the ratio that you claim defines sensitivity. Compare them. Note that they are different. And then think about why that is. - gavin]

    Comment by RW — 31 Jul 2011 @ 12:37 AM

  68. [Response: I'm not sure I follow you. The regressions he is doing are on the deseasonalized monthly anomalies - there is no selection there. - gavin]

    My critique is not related to the model as that is beyond me, I am merely viewing his conclusion backwards that:

    “Yet, as seen in Figure 2, we are still faced with a rather large discrepancy in the time-lagged
    regression coefficients between the radiative signatures displayed by the real climate system in satellite
    data versus the climate models. While this discrepancy is nominally in the direction of lower climate
    sensitivity of the real climate system, there are a variety of parameters other than feedback affecting
    the lag regression statistics which make accurate feedback diagnosis difficult.”

    He claims a discrepancy in the lower climate sensitivity which I think is flawed by his premise if you look at the graph

    http://thumbsnap.com/i/5S5vCMlG.png

    You can clearly see that he does not take the whole period needed. This might be a crude example but apologies, he claims that there is lower sensitivity because he only takes la nina periods into account and discards el nino, I do not know how this would affect his model..

    Comment by anthropoggedon — 31 Jul 2011 @ 12:55 AM

  69. @ R. Gates, #58

    You are getting confused by Spencer’s incorrect use of terminology.

    Anthropogenic greenhouse gases are a forcing agent because we can DECIDE to increase or decrease our output of them, INDEPENDENT of what the climate is doing.

    Solar radiation is a forcing agent because it increases or decreases INDEPENDENT of what the climate is doing.

    Clouds and water vapor are feedbacks because they are DEPENDENT on other factors within the climate.

    Think of “forcings” as independent variables and “feedbacks” as dependent variables, and you should quickly understand why Spender’s “internal forcing” paradigm is nonsense.

    Comment by Settled Science — 31 Jul 2011 @ 1:54 AM

  70. RW – the fact that the climate sensitivity, without feedbacks, is around 1.2ºC is completely non-controversial. It is based on physical properties of CO2 gas that have been known for almost 2 centuries, and cogent explanations of how that number is derived are easy to find. Here is one:

    http://www.skepticalscience.com/empirical-evidence-for-co2-enhanced-greenhouse-effect-advanced.htm

    This is all based on observable phenomena. How the three primary known feedbacks increase the climate sensitivity to 3ºC, with a range of uncertainty from 2ºC to 4.5ºC, is outlined in the IPCC AR4.

    If you disagree with these figures, then what are your figures, and what scientific evidence do you have to support those figures? Or do you have any figures at all? “That’s impossible, it can’t be, it’s too extraordinary!” are not really scientific arguments.

    Comment by Craig Nazor — 31 Jul 2011 @ 2:01 AM

  71. It appears that the party line of the forcing/feedback issue is that the climate is the result of external forcings and everything that happens within the climate system is a feedback from these external forcings, with the important exception of human-produced CO2 CH4 SO2 (etc) which are to be regarded as independent forcings.

    Why should some CO2 be regarded as a forcing while the rest is regarded as a feedback? The provenance of a molecule makes no difference to its subsequent behaviour. And can we be sure there are not forcings within the climate system (perhaps to do with oscillations in the biosphere at large for example) which science has yet to investigate?

    It seems to me that the discipline of climatology is not so much concerned with developing a wider understanding of climate as providing a focus for establishing the possible extent of human influence on it. Maybe such exclusive preoccupation is a hindrance.

    [Response: You have this very wrong. The forcing/feedback definition is simply a distinction that allows something that is fairly universal (the feedbacks) to be examined independently of the particular causes (forcings). That the response of the system to increasing solar and increasing GHGs is similar in terms of feedbacks is a very important result. This is important for paleo-climates (the PETM, LGM etc.) as well as the situation today, but I get very tired of people claiming that general results are only because of some supposed political agenda. Please stick to the science or go somewhere else where people like discussing speculations untethered to reality. - gavin]

    Comment by simon abingdon — 31 Jul 2011 @ 2:16 AM

  72. “Maybe such exclusive preoccupation is a hindrance”. Or not, depending on your agenda.

    Comment by simon abingdon — 31 Jul 2011 @ 3:54 AM

  73. #15: richard pauli
    13 J Bowers…right you are. However a PR success is not measured by the sides of an argument… it is measured by putting the issue in front of the audience. Success is by how many people see the controversy continue. The promotion is for the very idea of dispute. Logic is irrelevant to a PR campaign. A wrong paper creates a bigger controversy – and more buzz – than a correct one.
    —-

    But what is happening on the counter-PR side? If logic and solid science is marketed well, and there were enough passionate proponents of good science, and the scientific method, to “echo chamber” as noisily as the deniers do, then there’d actually be a fight. Even highly-conditioned Fox viewers respect the view of the majority of scientists (though a lower proportion of them believe global warming is happening than do viewers of other news channels). IPCC does a great job on collation, but, frankly, a sh*t job of the PR– it is quiet when it should be defending its methods, its scientists, its team. As the producers of THE definitive accepted collective body of climate change related science– on which, btw, the entire Convention on climate change is based, and around which all international climate discussions revolve– they are awfully quiet in all this. I’m sorry, but that’s irresponsible. IPCC does NOT have to get into political discussions to defend its aggregation of the science. AR4 reads like Old Testament revelations; and it errs on the side of the conservative. Communications is about repeated messages combined with new and supportive data– and there is more new and supportive (and SOUND) data emerging all the time than there is against.

    Comment by Marie — 31 Jul 2011 @ 4:42 AM

  74. Numerous people have tried valiantly to educate RW about this piece of nonsense over at Skepsci. As far as I can see, he either cant learn or wont.

    Comment by Phil Scadden — 31 Jul 2011 @ 4:44 AM

  75. #67–um, Ed, it was a pun. . .

    Comment by Kevin McKinney — 31 Jul 2011 @ 6:52 AM

  76. Spencer’s pugnacious attitude about the whole thing is revealed in his own blog:

    http://thegwpf.org/science-news/3453-new-paper-the-misdiagnosis-of-surface-temperature-feedbacks.html

    If anyone can verify an IPCC supporter in the GWPF as they claim please post. Any money checking on GWPF and Lord Lawson (another Lord? isn’t Monckton more than enough?)

    Comment by Dave123 — 31 Jul 2011 @ 7:24 AM

  77. Re. 76 Dave123

    * Powerbase – Global Warming Policy Foundation: Funding and links with skeptic think tanks
    * Guardian – Wanted: GWPF assistant director to reveal thinktank’s funding
    * Guardian – Global Warming Policy Foundation donor funding levels revealed

    Shady.

    Comment by J Bowers — 31 Jul 2011 @ 8:49 AM

  78. Gavin,

    “In the simple model of the greenhouse effect one can write down exactly what the climate sensitivity is as a function of a change in the solar irradiance or greenhouse gas (via the absorption). One can also calculate the ratio that you claim defines sensitivity. Compare them. Note that they are different. And then think about why that is.”

    I need you to be more specific. I’m not quite sure what you are referring to. Which formula specifically?

    And BTW, I’m not claiming that emitted surface radiation/incoming solar radiation precisely ‘defines’ sensitivity – I’m saying it establishes a measured boundary of sensitivity, especially in such a highly dynamic yet tightly constrained system. That the sensitivity to a non-direct ‘forcing’ or slight imbalance such as from 2xCO2 will be greater than this is an extraordinary claim requiring extraordinary proof.

    [Response: You need me to more specific? I really don't want to have to spell it out for you since working it out for yourself is likely to be the only way you will make any progress (if indeed you make any). Work out what the connection is between your 'bound on sensitivity' and the actual sensitivity in a simple model. - gavin]

    Comment by RW — 31 Jul 2011 @ 9:02 AM

  79. 62. R. Gates …aren’t positive feedbacks actually just a new forcing?

    Consider a large rise in atmospheric [CO2]. The troposphere warms as a result (say by 1 oC) and induces a rise in atmospheric [H2O vapour]. The troposphere warms further due to the water vapour feedback (let’s say the water vapour rise adds an additional x oC). Your idea might be that this additional warming results in an additional temp rise due to recruitment of more water vapour (i.e. sounds like the water vapour feedback becomes a new forcing). In fact the total temp rise will be 1 + x + x^2 + x^3…

    …which is 1/(1-x).

    So if the primary water vapour feedback is 0.5 oC (say), then the total temperature rise is 2 oC (due to enhanced [CO2] plus water vapour feedback).

    What’s the origin of this 2 oC temperature rise. It’s all due to the rise in [CO2]. Of course the proximate cause of the extra (feedback) 1 oC from the water vapour is due to the water vapour. But the ultimate source is the rise in [CO2]. The [CO2] is the forcing; the change in [water vapour] and its associated contribuion to warming is a feedback. The same would apply if the primary [CO2] and feedback [water vapour] warming produced a reduced albedo (ice melt) with a further feedback contribution to warming.

    Comment by chris — 31 Jul 2011 @ 9:50 AM

  80. The Spencer – Braswell paper was also featured prominently on Climate Depot, “A project of CFACT” — Committee for a Constructive Tomorrow. CFACT is a 501(c)3 supported by ultra-conservative causes. Climate Depot is a cesspool of anti-global warming propaganda.

    Comment by Richard — 31 Jul 2011 @ 10:32 AM

  81. “Or not, depending on your agenda.”

    Got Projection?

    Comment by Jeffrey Davis — 31 Jul 2011 @ 10:34 AM

  82. Simon Abingdon @71, although it is true that the provenance of a [greenhouse gas] molecule makes no difference to its subsequent behaviour in the atmosphere, your problem of understanding stems from your failure to grasp that those molecules can act as either a feedback or as a forcing, depending on how they got into the atmosphere.

    When added as a result of some initial direct forcing, say an increase in solar insolation that causes CO2 or CH4 molecules to be emitted by a warming ocean or thawing permafrost, for example, they would be acting as a feedback to that initial forcing.

    But when CO2 is added directly in the absence of some initial forcing, such as by the deliberate burning of sequestered fossil carbon, then its addition is not a feedback to some initial forcing, but rather it is itself a direct forcing. No change in earth’s energy budget or in the coupled ocean-atmosphere climate system caused the CO2 to be emitted to the atmosphere in that case, only the deliberate burning did.

    Comment by Jim Eager — 31 Jul 2011 @ 11:16 AM

  83. In comment #56, JamesD wrote: “I would also caution people to differentiate what Dr. Spencer actually wrote, and what was written in the Forbes article. They are very different.”

    Gavin replied: “… Instead, they erroneously link it to climate sensitivity and encouraged (via their press release) all manner of nonsense …”

    Gavin, by “press release”, are you referring to the Forbes op-ed by the Heartland Institute’s Taylor, or the University of Alabama’s press release?

    As I understand Spencer’s study from the abstract and from the helpful discussions provided by the climate scientists here, it appears that the UA press release does accurately describe the content and claims of the paper (whatever their merit or lack thereof), in lay terms.

    Whereas the Forbes article appears to exaggerate and inflate Spencer’s actual claims into something resembling a sweeping assertion that all of climate science has had a “hole blown through it”, combined of course with belligerent ideological ranting (e.g. repeating the phrase “alarmist models” at least a dozen times).

    It would be interesting to know if Spencer has endorsed the Forbes piece. Presumably such an article would get his review and approval before publication?

    Has Spencer made public statements that go beyond what’s in the actual paper itself? Perhaps on the Rush Limbaugh radio program, where he is the self-proclaimed “Official Climatologist”?

    [Response: I doubt very much Forbes got Spencer's permission to say what they said about his article, and I very much doubt he would 'endorse' it. That said, it would be awfully nice to see him rebut it, since in the paper itself he says nothing (even if you take his study as accurate) that supports what the Forbes article says.--eric]

    Comment by SecularAnimist — 31 Jul 2011 @ 12:28 PM

  84. Simon Abingdon: “It seems to me that the discipline of climatology is not so much concerned with developing a wider understanding of climate as providing a focus for establishing the possible extent of human influence on it.”

    THIS is absolute horse doo-doo. Have you even cracked a climatology text or journal in the past decade. Only a minor portion of what you will find there relates directly to anthropogenic climate change.

    Really, Simon, don’t you have a Library somewhere near you so you can do some research before spouting off an utterly ignorant and stupid opinion.

    Comment by Ray Ladbury — 31 Jul 2011 @ 12:46 PM

  85. Marie@73,
    The problem is not with people accepting what science tells them. When science delivers good news, it receives accolades. The problem comes when we try to tell people what they don’t want to hear. Americans love to hear that chocolate, wine and coffee are good for them. Research revealing that we are a bunch of lardasses is less well received.

    Comment by Ray Ladbury — 31 Jul 2011 @ 12:50 PM

  86. Simon Abingdon #71, #72: “Party line…”? Your “agenda” is showing (again). The difference between a forcing and a feedback is so basic even I understand it. The naturally occurring CO2 is a forcing, not a feedback as you state. The additional anthropogenic CO2 increases this forcing. “It seems to me” that your inability to grasp this is being driven by something other than genuine stupidity.

    Comment by One Anonymous Bloke — 31 Jul 2011 @ 1:19 PM

  87. Further to my comment @81:
    The burning of sequestered carbon need not be a deliberate human act, it could be from an entirely natural event, say lightning-ignited large scale forest fires during a normal drought event, or the ignition and slow burn of an exposed coal bed. The injected CO2 doesn’t even need to be from combustion, it could be due to a temporary (on a geologic time scale) excess of volcanic CO2 emissions above the natural rate of uptake of CO2 by silicate rock weathering.

    In all of the above cases the injection of CO2 would *not* be due to changes in earth’s energy budget or in the coupled ocean-atmosphere climate system, so they would not be feedbacks to some initial forcing but instead would themselves be an initial forcing.

    Comment by Jim Eager — 31 Jul 2011 @ 1:20 PM

  88. #81 Jim Eager “those molecules can act as either a feedback or as a forcing”.
    How can you tell which are which?

    Comment by simon abingdon — 31 Jul 2011 @ 1:22 PM

  89. > the satellite data shows the climate system starting to shed energy more
    > than three months before the typical warming event reaches its peak.
    > “At the peak, satellites show energy being lost while climate models
    > show energy still being gained,” Spencer said.
    > This is the first time scientists have looked at radiative balances
    > during the months before and after these transient temperature peaks.

    — that’s from the UA press release.

    Are those all supported by the paper?
    How much of ‘the climate system’ do the satellites cover, how much is extrapolated?
    What happens during transient temperature valleys?
    Does the result average out including peaks and valleys, over longer spans?

    Comment by Hank Roberts — 31 Jul 2011 @ 1:41 PM

  90. I have a couple of questions about the graphs in your top article:

    1. You regress TOA radiation against surface temperature, and the y-axis gives values in W.m-2.K-1. A value of 2 indicates that the TOA radiates an excess 2 W.m-2 per 1 oC rise in surface temperature (at that particular lag time and averaged over the 10 year period).

    First Q: Is this globally-averaged?

    2. For the models that deal well with ENSO there is an unlagged component of TOA radiation, but the maximum response occurs with a lag of 2-3 months.

    Second Q: What’s the origin of this lag? Is it simply the time for the troposphere to fully respond to changes in surface temperature? Or is it due to a water vapour feedback that (for El Nino) amplifies the tropospheric temperature change (and thus TOA radiation) during the lag period?

    3. Regressions for negative lags are shown.

    Third Q: Do negative lags have any sensible meaning? Or are these simply influences on TOA radiation resulting from surface temperature events that occurred earlier than the zero lag-timed event?

    4. The amplitude of the regressions.

    Fourth Q: How does this relate to the expected change in TOA arising for example from application of the Stefan-Boltzmann eq.? Is 2 W.m-2.K-1 smaller, equal, or larger than the expected S-B value? Presumably the amplitude is what Spencer uses to assess the rapid component of feedback on which he bases his interpretations re climate sensitivity..

    Comment by chris — 31 Jul 2011 @ 2:36 PM

  91. One other brief comment: I think Kevin is just slightly mixed up in his terminology as well, or maybe it’s just that his climate-speak is different than my physics-speak. In any case…

    If you a shift in cloud patterns in relationship to a shift in the ENSO pattern, that could reflect a change in net albedo, which in turn of course would alter radiative forcing. In my parlance, this would be an example of a parametrically forcing associated with internal variability (as opposed to an example of external aka exogenous forcing.

    So in principle, you should be able to use the modulation of radiative forcing by ENSO to estimate climate sensitivity, though it would appear to me you’d need something closer to a full-scale model than the parametric model used by Spencer.

    Comment by Carrick — 31 Jul 2011 @ 2:38 PM

  92. Re: response to #82 (SecularAnimist)

    [Response: I doubt very much Forbes got Spencer's permission to say what they said about his article, and I very much doubt he would 'endorse' it. That said, it would be awfully nice to see him rebut it, since in the paper itself he says nothing (even if you take his study as accurate) that supports what the Forbes article says.--eric]

    Here’s what Spencer himself said about the Forbes article on WUWT:

    The short answer is that, while the title of the Forbes article (New NASA Data Blow Gaping Hole In Global Warming Alarmism) is a little over the top (as are most mainstream media articles about global warming science), the body of his article is — upon my re-reading of it — actually pretty good.

    Comment by tamino — 31 Jul 2011 @ 3:58 PM

  93. SecularAnimest, Eric Steig,

    The only thing I have seen Spencer say directly about the Forbes article was:

    ¨The short answer is that, while the title of the Forbes article (New NASA Data Blow Gaping Hole In Global Warming Alarmism) is a little over the top (as are most mainstream media articles about global warming science), the body of his article is — upon my re-reading of it — actually pretty good.¨

    Comment by Chris Colose — 31 Jul 2011 @ 4:29 PM

  94. Looks like Spencer is standing by the Forbes article:

    “The short answer is that, while the title of the Forbes article (New NASA Data Blow Gaping Hole In Global Warming Alarmism) is a little over the top (as are most mainstream media articles about global warming science), the body of his article is — upon my re-reading of it — actually pretty good.

    About the only disconnect I can see is we state in our paper that, while the discrepancy between the satellite observations were in the direction of the models producing too much global warming, it is really not possible to say by how much. Taylor’s article makes it sound much more certain that we have shown that the models produce too much warming in the long term. (Which I think is true…we just did not actually ‘prove’ it.)”

    http://wattsupwiththat.com/2011/07/30/fallout-from-our-paper-the-empire-strikes-back/

    Comment by Karmakaze — 31 Jul 2011 @ 4:47 PM

  95. Further to Jim Eager #81, #87: perhaps I am a little confused – I can see why additional CO2 released from the oceans as a result of an increase in solar energy can be considered a feedback, but (if I may be allowed a musical metaphor) isn’t one of the characteristics of a feedback that it stops when you switch the amplifier off? Additional CO2 acts as a forcing no matter what else happens. Am I trying to oversimplify?

    Comment by One Anonymous Bloke — 31 Jul 2011 @ 5:15 PM

  96. I explained how, Simon. Try reading for comprehension.

    The source of the present increase in atmospheric CO2 has until recently been entirely due to human action, primarily direct injection by combustion of fossil carbon and from our land use changes, although we are starting to see natural feedback emissions in response, such as increased thawing of permafrost and methane hydrates and rising atmospheric water vapour due to the warming caused by our additions.

    Comment by Jim Eager — 31 Jul 2011 @ 6:07 PM

  97. 57 James D
    Here you go: http://www.thescienceisstillsettled.com/references/bogus
    The rest of the site is a work in progress, but I can upload one pdf easily enough.

    89 Hank Roberts

    I think I can answer some of your questions, not as an expert, but with direct references to the portions of the paper which are the basis of my reasoning, so you can decide how much salt to take with each of my attempts. I hope most of the following is correct.

    > the satellite data shows the climate system starting to shed energy more
    > than three months before the typical warming event reaches its peak.
    > “At the peak, satellites show energy being lost while climate models
    > show energy still being gained,” Spencer said.
    > This is the first time scientists have looked at radiative balances
    > during the months before and after these transient temperature peaks.

    — that’s from the UA press release.

    HR: “Are those all supported by the paper?”

    Just looking at inflection points of the LW and SW radiation in 2b, three months looks about right. After a peak in LW, there is a lag until the next peak in SW, and it’s definitely not always the same, but it is definitely always less than a year. Maybe a little bit “more than 3 months” as their press release states, sure.

    Press Release: “At the peak, satellites show energy being lost while climate models show energy still being gained,” Spencer said.

    I cannot say whether that’s true in the general case, but for the six climate models analysed in SB2011, the lags in Figure 3 look like about 9 months.

    Press Release: “This is the first time scientists have looked at radiative balances during the months before and after these transient temperature peaks.”

    Gosh, that doesn’t seem likely. :-)

    Hank: “How much of ‘the climate system’ do the satellites cover, how much is extrapolated?”

    I don’t pretend to know the exact coverage of the CERES data set, but off-hand, one of the problems I’ve read about repeatedly with satellite measurements for climate science is that satellites tend to orbit about the equator, whereas the impacts of climate change are greatest at the poles. On page 5, Spencer & Braswell refer to temperature data from 60°N to 60°S (ie around the equator, and stopping 30° from each pole) in a way which to me implies that they do extrapolate their findings from non-global data.

    Global monthly anomalies in surface temperature were similarly computed from the HadCRUT3 surface temperature dataset [12] between March 2000 and June 2010. In addition to globally averaged anomalies, we also computed area average anomalies over the ice-free oceans, between 60°N and 60°S, for all variables. (Spencer & Braswell 2011, page 5)

    That only makes sense to me if that matches a limitation in their satellite data, in which case, yes, any inferences they make beyond that 60° N to 60° S range, or which they claim are true globally, would be extrapolations.

    Hank: “What happens during transient temperature valleys?
    Does the result average out including peaks and valleys, over longer spans?”

    The word “variation” appears many, many times throughout the paper, and the following excerpt from page two suggests to me that the entire paper is based on a statistical model only of variations, ie, what the rest of the scientific community calls “natural variability.”

    For the interannual temperature climate variability we will address here, the heat capacity Cp in Equation (1) is assumed to represent the oceanic mixed layer. (Note that if Cp is put inside the time differential term, the equation then becomes one for changes in the heat content of the system with time. While it is possible that feedback can be more accurately diagnosed by analyzing changes in the heat content of the ocean over time [6], our intent here is to examine the problems inherent in diagnosing feedback based upon surface temperature changes.) (Spencer & Braswell 2011, page 2)

    In my experience, phrases like “we will address here” always refer to the topic of the paper. In this case, that clause is “the interannual temperature climate variability.” So it looks to me like they know very well that all they have is a correlation between Random Fluctuation A and Random Fluctuation B and nothing that could possibly help understand or explain any multi-decade surface temperature trend, such as that from 1975, much less any useful predictive model.

    Comment by Settled Science — 31 Jul 2011 @ 7:25 PM

  98. #95, One Anonymous Bloke – ‘isn’t one of the characteristics of a feedback that it stops when you switch the amplifier off?’

    If you switched off the power to the Earth there wouldn’t be any feedbacks either. To continue the metaphor, increasing or decreasing the power of an amplifier is a forcing, which will change the amount of feedback.

    ‘Additional CO2 acts as a forcing no matter what else happens.’

    All feedbacks cause a change in radiative forcing so using that definition would mean there are no feedbacks.

    One way to look at it is that there isn’t any absolute distinction between forcing and feedback – the distinction lies in conceptualising what question we’re trying to answer. In this case the question could be ‘What happens if we double the amount of CO2 in this system?’ This has a direct forcing effect but it also has a number of side-effects, one of which could be the release of extra CO2 from various sinks.

    Hopefully you can see from this that something is a forcing if it is explicitly defined in our scenario. In this case our scenario was ‘Doubled CO2′ so that is our forcing. Anything that happens which isn’t a direct radiative effect of doubled CO2 is a feedback.

    Comment by Paul S — 31 Jul 2011 @ 7:30 PM

  99. Further to my reply to Simon @88, where he asks: “How can you tell which are which?”

    Other than for determining the source or cause of the flux (by comparing isotope ratios, for example), we really don’t care about the origin of any individual CO2 molecule. What we are interested in is the source and cause of the aggregate change. If the net change is mainly in response to a known forcing then it is a feedback. If it is mainly a direct increase independent of any measurable forcing then it is itself a forcing. The net effect will be to warm the atmosphere and surface, regardless of if it is as a feedback or as a forcing, which may be your point.

    If you are heading down the road of questioning the source of the present increase in CO2, and thus if it is a forcing or a feedback, I’m not interested.
    There are multiple independent lines of evidence that support that it is mainly from burning fossil carbon. See here.

    Comment by Jim Eager — 31 Jul 2011 @ 7:37 PM

  100. Bloke @95, the feedback does stop after the initial forcing ends and the system reaches a new equilibrium state, but that takes a long enough time to happen that it takes place well after the initial forcing has declined or ended.

    For example, the peak increase in northern hemisphere solar insolation occurred well before the end of the last glaciation, yet the peak warming produced by that insolation plus all feedbacks occurred several thousand years later during the Holocene Climate Optimum.

    Comment by Jim Eager — 31 Jul 2011 @ 7:47 PM

  101. Carrick (re: the post that is mistakenly in the other thread) – ‘What climate sensitivity you end up with seems to have more to do with the assumed aerosol forcings’

    Could you elaborate on what you mean here because it doesn’t make sense to me. Climate sensitivity is defined as the magnitude of temperature response to an amount of radiative forcing. Aerosols change the amount of net forcing, not the climate sensitivity.

    Comment by Paul S — 31 Jul 2011 @ 8:03 PM

  102. simon abingdon says: 31 Jul 2011 at 1:22 PM “#81 Jim Eager ‘those molecules can act as either a feedback or as a forcing’.
    How can you tell which are which?”

    Well, if those dastardly profiteers at Exxon/Mobil and Peabody coal hadn’t cleverly disguised Fossil Fuel Emissions as ordinary CO2, and had instead labeled them properly, we would be able to tell them apart!
    Oh, wait, my bad – they did! Thanks, fossil fuel industry.

    ReCAPTCHA say – lyintike out

    Comment by Brian Dodge — 31 Jul 2011 @ 8:16 PM

  103. Gavin,

    “You need me to more specific? I really don’t want to have to spell it out for you since working it out for yourself is likely to be the only way you will make any progress (if indeed you make any). Work out what the connection is between your ‘bound on sensitivity’ and the actual sensitivity in a simple model.”

    Is it too much to ask for some specific questions from you? I’m more than willing to answer them (or at least try).

    From your link, I see the equations for the GHE, where ‘G’ (ground flux) equals half of what’s absorbed by the atmosphere plus ‘S’ (the incident post albedo solar power of 240 W/m^2. I don’t have an issue with this, as it properly depicts that half of what is absorbed by the atmosphere goes to space and half is returned to the surface. You’re using an atmospheric absorption of 0.769, or perhaps more importantly a ‘window’ transmittance of 23.1% or about 90 W/m^2 (390 x 0.231 = 90). Are you backing your way into these numbers from an assumption of a 288K surface temperature, which emits about 390 W/m^2 from the surface, or are you getting them from some other means? I don’t really have an issue with these numbers, as I think they are at least roughly accurate. I’m just curious.

    [Response: The 0.769 comes from trying to match the surface temperature. - gavin]

    In the ‘Radiative Forcing’ section, the equations to get Ftop/(1-0.5*lambda) where you’re using ‘S’, which is the post albedo solar flux of 240 W/m^2 to get ‘G’, the ground flux of 390 W/m^2, is the surface response to solar forcing ‘S’ that I’ve been talking about. The result of the equations is the same as multiplying the 3.7 W/m^2 by the inverse of net transmittance to space of 0.615 (240/390 = .615) as I mentioned before. 1/0.615 = 1.63; 1.63 x 3.7 = 6 W/m^2. 3.7/(1-0.5*0.778) = 6 W/m^2.

    An additional 6 W/m^2 is about equal to a 1.1 C rise in temperature. 396 = 289.1K from S-B.

    You then go on to define ‘feedback’ as that which is acts only the +3.7 W/m^2 while ignoring the feedbacks acting to maintain 390 W/m^2 flux at the surface from the 240 W/m^2 flux from the Sun.

    [Response: No. Your claim is that sensitivity can be defined from the ratio of S to G. Specifically, that the ratio 1 \over { (1-0.5\lambda_0)} provides some sort of bound. However, using the simplest form of the feedback shows that the sensitivity is 1 \over { (1-0.5(\lambda_0+\lambda^\prime))} which can be larger or smaller than your number depending on what the feedbacks are doing. The more basic issue is that you are linearising the GH effect from 0 to the present value - and that is simply not sensible. More generally, I can show you any number of simple models to complex models all of which have the same S and G but which do not have the same sensitivity. Doesn't that make clear that the former does not constrain the latter? - gavin]

    Let me pose the question to you in a different way. If the radiative ‘forcing’ from 2xCO2 is 3.7 W/m^2 and the current atmosphere only provides 2.3 W/m^2, where is the additional 10.6 W/m^2 incoming surface flux required for a 3 C rise (16.6 – 6 = 10.6) coming from? If you think it’s the ‘feedback’, from where specifically? If from a reduced albedo, how? If from increased atmospheric absorption, again how? And why doesn’t the ‘feedback’ cause anywhere near proportionally this much change on the 240 W/m^2 flux from the Sun?

    Comment by RW — 31 Jul 2011 @ 8:46 PM

  104. From basic physics, water evaporates and clouds form (or not) in response to water temperature and vapor pressure, which are results of amount and distribution of energy in the system. So clouds are a dependent variable, not an independent variable, ie not a forcing, and no lagging statistics can do anything about that. As far as I’m concerned, that alone totally disproves the entire hypothesis Spencer has contrived of “internal radiative forcing,” including but not limited to this most recent paper of his with Braswell, and I find it difficult to focus on this paper long enough to fully appreciate the statistical manipulations.

    But it does raise a general question about the computer modeling of climate, or possibly about advanced statistics, I’m not really sure what exactly I’m getting wrong here. From page 1610 of Remote Sensing, page 8 of the pdf of Spencer / Braswell 2011, third paragraph:

    For the radiative forcing N(t) we used a time series of normally-distributed monthly random numbers with box filter smoothing of 9 months to approximate the time scales of variations seen in the climate models and observations in Figure 3. A separate time series of random numbers without low pass filtering was used for the non-radiative forcing S(t). This mimics what we believe to be intraseasonal oscillations in the heat flux between the ocean and atmosphere seen in the data [5,13]. The model time step was one month, and the model simulations were carried out for 500 years of simulated time.

    I don’t understand the validity of using random numbers to model all forcing, and from their equation (1) and discussion of it on page 2, it’s clear that S(t) & N(t) are all the forcing terms they consider in their simple model. And both S(t) & N(t) are random. So they seem to be modelling only randomly fluctuating forcing.

    CO2 concentration obviously fluctuates, but seasonally, not randomly, and it increases over time, as anybody can see from the full Mauna Loa record, or any several consecutive years even. So, what’s with the “random” forcing? That seems to me just too obviously invalid. It seems to be blatantly setting up the consensus theory as a straw man “hypothesis” that can’t help but fail! But their methodology can’t possibly be quite that bad, can it? What am I missing? Is that really natural variability which they’re modelling with random numbers, and I’m just thrown by their misuse of the word “forcing” or what?

    Comment by Settled Science — 31 Jul 2011 @ 9:04 PM

  105. #89, Hank Roberts asked:

    How much of ‘the climate system’ do the satellites cover, how much is extrapolated?

    The CERES instrument data Spencer used was from the TERRA satellite, which is in a sun synchronous orbit. The time of equator crossing is 10:30 AM local time in the descending direction, moving NNE to SSW mol, and the orbital period is 98 minutes. The fact that the vehicle is sun synchronous means that the cross track scanning measurements take a quick snapshot of the radiances at a fixed time of day for each point in latitude. There are 14.7 orbits a day, thus for each latitude in the 60N to 60S range, only 2/14.7 of a day, once on the sun side and once on the dark side, or 3.3 hours of coverage is available. The raw measurements must be run thru a mathematical process, which involves scene identification as well as a model of the specular albedo which uses the angle of the scan to convert to emissions. I’ve not deeply studied the process, but my WAG is that there are several potential sources of error in this processing. Kevin should be able to provide a better answer regarding the accuracy of the CERES data…

    Comment by Eric Swanson — 31 Jul 2011 @ 9:06 PM

  106. Paul S #98, Jim Eager #100: thank you.

    Comment by One Anonymous Bloke — 31 Jul 2011 @ 9:16 PM

  107. #86 #95 One Anonymous Bloke

    I’m glad my questions caused sufficient feedback to help clear up your confusion.

    Comment by simon abingdon — 31 Jul 2011 @ 11:53 PM

  108. gavin, Ray Ladbury, Jim Eager et al

    Thank you for helping to disabuse me of prejudice.

    simon abingdon

    Comment by simon abingdon — 31 Jul 2011 @ 11:58 PM

  109. 73 Marie: “If logic and solid science is marketed well”

    If only we had a marketing budget……

    We don’t. RealClimate is it for NASA-GISS. And neither does the IPCC. The IPCC cannot do any job of PR at all because the IPCC is under the control of member governments.

    There is nothing irresponsible going on on our side. It is just that RC is run by poor but poverty stricken scientists, not a rich corporation. NASA is a government agency. That means NASA is under the control of congress which is under the control of…..

    Now, if you happen to have a billion dollars to spare, I’m sure it could be put to good use.

    Climate Science is not a money making corporation. The fossil fuel industry is a lot of money making corporations.

    [Response: RC is nothing to do with NASA, or NASA-GISS. If you want to see their public outreach efforts go to http://www.giss.nasa.gov or http://climate.nasa.gov etc. - gavin]

    Comment by Edward Greisch — 1 Aug 2011 @ 12:50 AM

  110. Simon Abingdon, it’s easy to get confused by these issues. “Forcing” and “feedback” are best described in Mathematical terms, English can only provide metaphors. I am pleased to hear your confusion (or prejudice if you prefer) has also diminished. If you and I can be better informed, perhaps there is even hope for Roy Spencer.

    Comment by One Anonymous Bloke — 1 Aug 2011 @ 2:54 AM

  111. “…From basic physics, water evaporates and clouds form (or not) in response to water temperature and vapor pressure,…”

    (#103)

    Obviously not everyone thinks it’s that simple, starting with Svensmark and the cosmic ray/cloud forcing theorists. Svensmark’s paper on Pacific cloud response to forbush events indicates there are situations where clouds could be a forcing element. Whether this triggers ENSO events in turn, I don’t know, but then neither does anyone else, as the science of ENSO cause has not yet progressed to the point where we can actually predict it in advance (apologies to the late Theodor Landscheidt).

    [Response: Even in this situation the clouds are acting in response to a forcing (as they would be doing with any indirect aerosol effect). The point above is that clouds do not spontaneously decide to have decadal variability - the time scales for their creation/dissipation are just too short (hours to days, vs. years). - gavin]

    Comment by Tea Partier — 1 Aug 2011 @ 2:57 AM

  112. #101, my response to Carrick – After some thought I believe I understand what you’re getting at: If two models have been tuned specifically to match 20th Century observations then any difference in climate sensitivity between them could partly be explained by differing forcing inputs.

    Comment by Paul S — 1 Aug 2011 @ 5:14 AM

  113. Gavin @ 111, do you mean the climate system didn’t just decide in 1880 to drive itself uphill?

    Comment by Pete Dunkelberg — 1 Aug 2011 @ 9:11 AM

  114. A question–Gavin (inline response to #111) wrote that “. . .clouds do not spontaneously decide to have decadal variability – the time scales for their creation/dissipation are just too short (hours to days, vs. years).”

    True as far as it goes, I’m sure–but couldn’t some precondition for cloud formation persist over much longer timescales than the clouds themselves?

    Reasoning by analogy is dangerous, I know, but tornado outbreaks last longer than the individual tornadoes do, and (on a vastly longer timescale) the Quaternary has outlasted its individual glaciations and interstadials. Might there not, in principle at least, be some analog to these examples that affects cloud formation rates?

    (Of course, it’s essentially empty speculation unless there’s some physical mechanism that one might at least guess at. Presumably the cosmic ray thing doesn’t really cut it, since IIRC there’s no evidence of a trend there, or at least not one that matches temps.)

    [Response: Of course. No-one doubts that there may be significant changes in clouds over decadal and longer timescales, but you put your finger right on the issue - there has to be a precondition that has a longer memory. This might be the oceans (changes in SST patterns altering convection, jet streams etc., changes in atmospheric composition (via ozone depletion, or aerosols, or GHGs) etc. In such circumstances the clouds are acting as a feedback to the original change, not a forcing in and of themselves. Cosmic rays would be a forcing that caused forced changes in clouds, but that wouldn't constrain the climate sensitivity (and as you say, has little or nothing to do with recent trends - although that is a different issue). - gavin]

    Comment by Kevin McKinney — 1 Aug 2011 @ 11:50 AM

  115. @113: Well, you see, around 1880 there was an invasion of Maxwell’s Demons, and….

    Comment by Meow — 1 Aug 2011 @ 11:58 AM

  116. #114 “the clouds are acting as a feedback to the original change, not a forcing in and of themselves”. The original change, eh? Surely you glimpse the flinty path of the infinite regress here gavin?

    [Response: Not in the slightest. We are not discussing the "First Mover" problem, but rather the impact of a boundary condition change on a system. If the solar irradiance increases, it doesn't matter in the slightest for this conversation whether it happened because of chaotic dynamics in the photosphere or the massing of a legion of solar fire dragons pointing their breath in our direction. - gavin]

    Comment by simon abingdon — 1 Aug 2011 @ 1:28 PM

  117. “….Response: Even in this situation the clouds are acting in response to a forcing (as they would be doing with any indirect aerosol effect)…”

    (Gavin)

    True enough, but I thought this Spencer paper (SB11) was about divulging climate sensitivity to temperature change. At the risk of over-simplification, Dessler 2010 (D10) seems to say: changes in ocean currents cause SST changes, which in turn cause radiative flux changes (including those from cloud cover change); thus the sensitivity of the climate system can be divulged by regressing radiative flux against SST.

    SB11 is saying you cannot divulge climate sensitivity to temperature change by this method since cloud cover change drives radiative flux changes which in turn drives SST change, which in turn drives radiative flux changes etc. It doesn’t matter whether cloud cover change is driven by smoke from forest fires, or cosmic rays, or natural oscillations as Spencer claims, the pertinent fact is that cloud cover change precedes SST change.

    [Response: No-one is disputing that cloud changes affect radiation or that ocean temperature changes can affect clouds (or at least I hope not). The net radiation changes Spencer is correlating is not just clouds though, it is the whole system. For the period in question (10 years), I doubt very much whether total climate sensitivity can be constrained - and as far as I can tell Dessler does not claim this. Indeed, nor does SB11, which is odd given the press they got (which claims that they indeed have). What can be constrained is the behaviour of aspects of this problem - i.e. some of the fast feedbacks. ENSO variability is a coupled mode that does it's own thing without regard to cloudiness (since it is driven by Kelvin waves in the ocean etc.), so looking at the cloud response to the ENSO-related SST variables gives a clue as to the cloud feedback to surface warming. It is only a clue though because the pattern of ENSO SST changes is not a perfect analog to the SST changes related to 2xCO2. In that situation, we have that global surface temperatures are lagged by a few months to the ENSO index, and Spencer's calculation shows a maximum regression to energy loss a few months after a temperature max. This makes sense and is seen in the models above as well. Similarly, we see (in both models and obs) that things that cause an energy gain cause a temperature rise after a few months. Again, unsurprising. If you are claiming that this pattern doesn't constrain sensitivity, then I am in violent agreement. What Kevin's pictures above show is that this pattern is clearest when you have strong ENSO variability (since that dominates coordinated/coherent interannual variability). - gavin]

    Comment by Tea Partier — 1 Aug 2011 @ 1:41 PM

  118. > original change … flinty path

    Simon’s assumption is that human fossil fuel use can’t be the original cause for the rapid change in climate. Anything but ….

    Comment by Hank Roberts — 1 Aug 2011 @ 2:46 PM

  119. From a social science perspective it’s interesting how predictable the highly critical posts are here at realclimate. Peer reviewed papers by authorities who challenge the prevailing view are disparaged as worthless and unscientific, where even the most pathetically uninformed alarmist comments are welcome and only rarely challenged. It remains incredible to me how few here are willing to characterize the transparent and obvious bias as anything but objective and analytical truth. More importantly, it would sure be nice to see a lot more testable assertions about both the accuracy of climate models and climate modelling.

    [Response: Oh please. I spend almost all my time trying to find testable assertions about climate change responses in models to compare to observable data. It is surprisingly non-trivial to find useful comparisons that actually constrain something important - something we have discussed here frequently. Yet the contrarian media can go nuts with a misinterpretation of some new study that doesn't constrain what they think it does, and when we point that out, you accuse us of being un-objective. That's pretty funny. You might want to consider the thesis that the papers challenging the orthodox view are indeed mostly worthless and unscientific. That is not to say that are not worthless and unscientific papers that support the orthodox view, but they don't generally make it to Drudge and we don't get a ton a phone calls asking us what we think. - gavin]

    Comment by Joe Hunkins — 1 Aug 2011 @ 3:33 PM

  120. Chris @ #79:,

    Thanks for that, and it does make sense to a point, but it seems that the distinction between positive feedbacks and a “forcing” gets to be a bit blurry, and perhaps this is partially related to the nature of a system like the climate existing on the edge of chaos. Here’s what I mean: Milankovitch cycles are the initial forcing agent that seems to control the onset of glacial periods and interglacials. In these situations, CO2 becomes a positive feedback response that amplifies this slight nudge from the additional NH insolation. Milankovitch could be viewed at the “trigger” forcing agent, but then, CO2 outgassing from the oceans becomes a secondary forcing agent via it’s positive feedback. And here’s to me, the unique aspects of these secondary forcings agents. They must be internal to the system and along with their amplifying positive feedback mechanism, they must also create some ultimate negative feedback that can shut down the positive feedback so that we don’t get a “run-away” situation. In essence, a secondary internal forcing must act as a governor or thermostat.

    [Response: The factor that prevents run-away conditions is always the same - the basic Planck response, none of the amplifying feedbacks come close to challenging this despite their importance for assessing net climate sensitivity. (Note that constraints on sensitivity on paleo-timescales are not related directly to sensitivity to Milankovitch since the seasonality/latitude dependence of this forcing combined with the hemispherical asymmetries means that the global radiative forcing/response concept does not work). The factors that translate Milankovitch forcing to climate change (the ice sheet and carbon cycle response mainly) are external to the principle model system (as described above) and so can be thought of as external boundary condition changes for which the radiative forcing concept works well. - gavin]

    Comment by R. Gates — 1 Aug 2011 @ 4:06 PM

  121. #109: “The IPCC cannot do any job of PR at all because the IPCC is under the control of member governments.”

    I beg to differ. IPCC is mandated to aggregate the science. All member states sign off on the collation and therefore all member states agree with whatever eventually comes out of this process (there are fights over the more politically-sensitive numbers, I’ll bet). Which means they can very well better-market the science. It IS irresponsible. Science is of no use if you scrabble away at your craft and don’t bother learning to communicate it to the world. You have receptive media, you have receptive journalists, you have the potential to collaborate on PR. By the way, good PR is not necessarily costly. I have seen great PR campaigns run on very little. On the proactive side, it’s about good targeting, good collaborations, good use of all possible media, good and consistent messaging; and on the reactive side, it’s about not just milling around discussions like these, and actually getting these messages out to the public via the media! Not having enough money is just an excuse for not trying. You can have a billion dollars and a crap PR agency and still not get your message across. I was not talking about RC specifically. IPCC draws on the work of thousands of scientists from thousands of institutions which all have marketing and PR personnel; IPCC itself has or has had communications people. There are thousands of PR firms who do pro-bono work, and thousands of bright communications graduates looking for an internship, for a shot, and to contribute to something bigger.

    It IS irresponsible not to communicate your work to the world well, when so much hinges on it. Look at the simplicity of how this piece of work was communicated in the first place. The right article to the right media at the right time.

    Pull your head out of the sand. Work with your communications departments, or educate them better. I am still reeling from the pathetic defeatist attitude and the lack-of-money argument. This should be your time, and yet you roll over without a fight and bleat about a lack of funds, when you have so much truth and responsibility and the persistence of the scientific method on your side. (The bloodthirsty hunger to rip apart each other’s work alone should convince the world that whatever survived the process is pretty damn kosher.)

    Comment by Marie — 1 Aug 2011 @ 4:39 PM

  122. Spencer claims they measure much more infrared heat escaping the atmosphere than climate models predicted. Could the incoming sunlight that reflects off the aerosol clouds, a condition that is artificially cooling the climate system, be interpreted by the satellite’s instruments as infrared? I doubt it, but thought I’d ask.
    Secondly, why did he wait 10 years to announce that finding? I would think it would have been detected in a matter of days. Too bad we don’t have a new satellite up there to make these measurements. It seems every time we launch one to measure some aspect of global warming, it either blows up on the pad, or fails to achieve orbit. Isn’t that interesting?

    Comment by Jack Roesler — 1 Aug 2011 @ 4:40 PM

  123. …. papers challenging the orthodox view are indeed mostly worthless and unscientific.

    Gavin I certainly respect the fact that you must spend/waste a lot of time addressing nonsense, such as the mischaracterization of this Spencer paper in Forbes and the tendency of skeptics to ignore obvious truths. But I’m not talking about that – I am noting the challenges of accepting what seems to be a premise here at RC along the lines that “… papers challenging the orthodox view are mostly worthless and unscientific.” Such a predisposition is a pretty slippery slope even for a fine scientist like you and the others posting here.

    [Response: It is a predisposition that has a pretty strong Bayesian prior at this point. Is everything written by Spencer automatically flawed? Not at all. However, are the blatant 'dog whistle' press releases and lame counter arguments ('people that disagree with me don't believe in the conservation of energy') completely transparent? Yes. It would be great if people were to bring their best arguments forward instead of continually bringing their worst, and for me, it would certainly be more interesting. But these periodic blogospheric explosions almost inevitably are based on misreadings and misrepresentations of the most obvious kind. If we ignore them, we are accused of either a lack of communication nous or of elitist arrogance, and if we deal with them, we get accused of only focusing on the easy-to-rebut nonsense. I don't see any way to win those p***ing contests so I don't try. If people aren't interested in what I or others here have to say, they don't need to read. If you have constructive suggestions for might be more interesting to discuss, I'm all ears. - gavin]

    Comment by Joe Hunkins — 1 Aug 2011 @ 4:41 PM

  124. Joe Hunkins, #119: You are mistaken. There is nothing “disparaging” about pointing out the error in someone’s calculations. You are also mistaken about climate models having no testable predictions, see BPL’s list, for example. That is not to say that individuals don’t have their own particular confirmation biases, along with 100% of the rest of the human race. As one of the ‘pathetically uninformed’, I find people here are more than willing to address my errors, despite having no obligation to do so – especially in light of the numerous articles herein.
    Appeals to the social sciences will not avail you: try Physics and Chemistry.

    Comment by One Anonymous Bloke — 1 Aug 2011 @ 5:41 PM

  125. Gavin,

    “No. Your claim is that sensitivity can be defined from the ratio of S to G. Specifically, that the ratio 1 \over { (1-0.5\lambda_0)} provides some sort of bound. However, using the simplest form of the feedback shows that the sensitivity is 1 \over { (1-0.5(\lambda_0+\lambda^\prime))} which can be larger or smaller than your number depending on what the feedbacks are doing. The more basic issue is that you are linearising the GH effect from 0 to the present value – and that is simply not sensible. More generally, I can show you any number of simple models to complex models all of which have the same S and G but which do not have the same sensitivity. Doesn’t that make clear that the former does not constrain the latter?

    I’m not claiming that sensitivity can be precisely ‘defined’ by the ratio of G to S. I’m saying in such a highly dynamic, yet very stable system as the climate clearly is, it establishes a boundary – or an upper limit on sensitivity because the net feedback on the whole must be negative in order to keep the system as tightly constrained as it obviously is.

    I do think some more longer term positive ‘feedbacks’ of a few percent are possible, but not 300% or more of the initial response of atmosphere. The system would be massively unstable if this were the case.

    [Response: I'll let Gavin respond to the rest, but let me jump in right here and point out that this statement is wrong. The net feedback need not be negative. The net feedback can be (and is) positive. Note that a net positive feedback can be result in a tightly contained system too: how much so depend on how the feedback strength goes with the mean state. To understand this better, I highly recommend Roe, G.H., 2009: Feedbacks, timescales, and seeing red. Annual Reviews of Earth Plan. Sci., 37, 93-115, or if you don't want to get into it that much, read Chris Colose's post on feedbacks at RealClimate (here). --eric]

    Besides, most of the enhanced warming supposedly comes from combined water vapor and cloud feedbacks, which operate on the order of hours to days or weeks – not over years or decades.

    Also, I’m not linearising the GHE from 0 to the present. There is a difference between the absolute response and the incremental response, but it is very small – something on the order of 1% and is infinitesimal. The atmosphere is already absorbing about 300 W/m^2 of the 390 W/m^2 emitted from the surface. An increase in absorption of 3.7 W/m^2 from 2xCO2 is 1.2%. 1.1 C x 0.012 = 1.11 C, or about 1/100th of a degree C. Ant crumbs.

    You do know that the post albedo S is not a constant, right? It varies all the time with varying cloud coverage and via aphelion/perihelion procession. The cloud portion of the albedo is big part of the control mechanism maintaining the net surface flux of 390 W/m^2. If the climate as a sensitive as you believe, we would be see a much greater increase in temperature when the post albedo S is at it’s maximum amount. Maximum S actually occurs in September closer to aphelion rather than at perihelion in January due to maximum surface reflectivity coinciding with the Northern Hemisphere winter in January.

    At the very least, can you tell me where specifically the watts are coming from to cause the 3 C rise? I presume you know that if the surface is to warm by 3 C, it must also emit 406.6 W/m^2 (+16.6 W/m^2) and Conservation of Energy dictates that the +16.6 W/m^2 flux into the surface has to be coming from somewhere, right?

    Comment by RW — 1 Aug 2011 @ 6:37 PM

  126. @71 simon abingdon says:
    31 Jul 2011 at 2:16 AM

    Why should some CO2 be regarded as a forcing while the rest is regarded as a feedback?

    Simpler than Gavin, because you can’t seem to understand simple science:

    Because we put it there, not the climate system.

    I do not believe you misunderstand this, so I ask, why ask such a ridiculous question?

    Comment by ccpo — 1 Aug 2011 @ 6:45 PM

  127. I am noting the challenges of accepting what seems to be a premise here at RC along the lines that “… papers challenging the orthodox view are mostly worthless and unscientific.” Such a predisposition is a pretty slippery slope even for a fine scientist like you and the others posting here.

    Again, let me simplify where Gavin has expounded: You are confusing “predisposition” with “fact.” Gavin gave you a far more learned response, but I think for the non-scientists, it is best to KISS it.

    To be specific: We need to note your premise is faulty. A large number of papers are treated as garbage, so RC scientists are biased.

    You ignore the premise: A large number of papers are treated as garbage because they are garbage, so RC scientists are not biased.

    The only biases we have divined are your biases: When climate scientists discuss flaws in papers that cause those papers to fail to overturn the current understanding of climate, you don’t like it.

    Comment by ccpo — 1 Aug 2011 @ 7:18 PM

  128. RW (125)

    Actually, I don’t agree with Dr. Steig that the net feedback is positive, at least when you include the increased IR emission with temperature. If you include this feedback, the net feedback must be negative to retain a stable system. The problem is in definitions. As Roe explains in his paper (that Dr. Steig referenced), this increased IR emission with T is just the “reference system” (as I mentioned in my post, you get about 0.3 C warming per unit radiative forcing under this system); climatologists like to define positive or negative feedbacks relative to that reference system. Operating under this framework, this allows you to say that feedbacks are more positive than negative without losing physical consistency.

    Mathematically, the response dT is dT = dT_o/(1-f), where the traditional “feedbacks” are encompassed in the definiton of f, but dT_o IS the Planck response (i.e., the reference system).

    Here is another mathematical exercise to constrain the climate sensitivity without additional (non-Planck) feedbacks.

    We know the traditional energy balance equation is S(1-a)=4εσ Ts^4

    where S is the solar constant, a albedo , σ the S-B constant, ε the bulk planetary emissivity, and Ts the surface temperature.

    We can differentiate this equation assuming only a perturbation of CO2 (i.e., the ε term, which decreases). The derivative of the left hand side is zero.

    We have,

    0 = (4σTs^4)dε + 4ε(4σTs^3)dTs

    This yields for the change in surface temperature,

    dTs = (-Ts/4)(dε/ε)

    Note that dε is negative, so dTs will be positive. We know that εσTs^4 is 240 W/m2, and from radiative forcing calculations dε(σTs^4)= – 4 W/m2 (for a doubling of CO2); thus the ratio dε/ε is -4/240.

    Thus,

    dT = (288/4)(4/240)= 1.2 C

    which is the no-feedback sensitivity widely cited. Amplifying this by three is not problematic at all, which you can easily do by putting more water vapor in the air, in addition to some other feedbacks.

    I would also note that the perturbed *surface* energy budget is not just governed by increased upwelling/downwelling IR radiation, but also by adjustment to evaporation and sensible heating fluxes.

    [Response: Chris: yes, of course, the Planck feedback is a negative feedback, but the argument is about the magnitude of the other feedbacks (clouds, water vapor, etc.). My point is simply that in your equations, 'f', which encompasses those, is a positive number, but that doesn't make things "unstable" (as RW seems to think) unless f > 1.--eric]

    Comment by Chris Colose — 1 Aug 2011 @ 7:37 PM

  129. Joe Hunkins,
    ‘Kay, buddy. Time for you to cite your top ten contrarian papers in climate science. Let’s find out just what revolutionary breakthroughs mainstream climate science is missing. But as you cite them, don’t you find it odd that almost to a paper, they aren’t published in top-tier climate journals, and how few citations they tend to receive, and how the authors often publish another paper the following year that contradicts the previous year’s? Do you really think that’s how science works?

    Anyway, I look forward to being wowed by your list.

    Comment by Ray Ladbury — 1 Aug 2011 @ 7:49 PM

  130. Eric,

    “I’ll let Gavin respond to the rest, but let me jump in right here and point out that this statement is wrong. The net feedback need not be negative. The net feedback can be (and is) positive. Note that a net positive feedback can be result in a tightly contained system too: how much so depend on how the feedback strength goes with the mean state. To understand this better, I highly recommend Roe, G.H., 2009: Feedbacks, timescales, and seeing red. Annual Reviews of Earth Plan. Sci., 37, 93-115, or if you don’t want to get into it that much, read Chris Colose’s post on feedbacks at RealClimate (a href = “http://www.realclimate.org/index.php/archives/2010/09/introduction-to-feedbacks/”>here)

    You need to do better than this. The net feedback operating on the Earth’s energy balance or net surface flux of 390 W/m^2 in the current climate has to be negative (and probably really strongly negative). The globally averaged temperature anomaly barely fluctuates by more than a few tenths of a degree per year despite a large amount of local, regional and seasonal hemispheric variability. Even when the globally average mean fluctuates by a large amount like during an El Nino, it always seems to revert to its pre-equilibrium state quickly. Hardly consistent with net positive feedback – let alone net positive feedback of 300% or more. Besides, if very small changes or perturbations resulted in dramatic changes (i.e. net positive feedback), the climate would be fluctuating from year to year over a much larger range and would be a very inhospitable place for life and the biosphere as a whole. Life could not have evolved under such conditions. If the net feedback was that strongly positive, what would prevent the system from going out of control from just a few day or weeks of abnormally warm weather? Yet curiously this never happens.

    With regard to the glacial to interglacial sensitivity, you can’t equate the positive feedback effect of melting ice from that of leaving maximum ice to that of minimum ice where the climate is now. There just isn’t much ice left, and what is left would be very hard to melt, as most of is located at high latitudes around the poles which are mostly dark 6 months out the year with way below freezing temperatures. A lot of the ice is thousands of feet above sea level too where the air is significantly colder. Unless you wait a few 10s of millions of years for plate tectonics to move Antarctica and Greenland to lower latitudes (if they are even moving in that direction), no significant amount of ice is going to melt from a measly 1 C rise in temperature. Furthermore, the high sensitivity from glacial to interglacial is largely driven by the change in the orbit relative to the Sun, which changes the angle of the incident solar energy dramatically. This combined with positive feedback effect of melting surface ice is enough to overcome the net negative feedback and cause the 5-6 C rise. But we are very nearing the end of this interglacial period, so if anything the orbit has already flipped back in the direction of glaciation and cooling.

    [Response: You're confusing 'positive feedback' with 'runaway feedback'. They are not the same thing. I agree with you that the positive feedback cannot be too positive, or the climate sensitivity would be much larger than it is. We may be talking past each other a bit here though -- see Chris's comment above and my response. --eric]

    Comment by RW — 1 Aug 2011 @ 7:57 PM

  131. Eric,

    “You’re confusing ‘positive feedback’ with ‘runaway feedback’. They are not the same thing.

    I’m aware of the difference. Positive feedback of 300% needed for a 3 C is not ‘runaway feedback’. Perhaps “going out of control” was not the best word usage, as it does imply some type of runaway effect. That wasn’t what I meant though.

    Comment by RW — 1 Aug 2011 @ 8:17 PM

  132. Chris Colose (RE: 128),

    Before I respond, have you read all of my posts in this thread from the beginning?

    Comment by RW — 1 Aug 2011 @ 9:17 PM

  133. RW, I don’t really understand what you are thinking, but you may be overlooking the matter of convergent series, the easiest one to show being one half + one fourth + one eight + … = 1.

    Comment by Pete Dunkelberg — 1 Aug 2011 @ 10:32 PM

  134. > Positive feedback of 300% needed for a 3 C

    No, you’re assuming the number you’re being asked to think about.

    Comment by Hank Roberts — 1 Aug 2011 @ 10:50 PM

  135. Here’s a link to the paper Eric recommended (inline response) above:

    Roe, G.H., 2009: Feedbacks, timescales, and seeing red. Annual Reviews of Earth Plan. Sci., 37: 93-115.

    http://earthweb.ess.washington.edu/roe/Publications/Roe_FeedbacksRev_08.pdf

    Comment by Hank Roberts — 1 Aug 2011 @ 11:12 PM

  136. RW-

    I’ve looked through your posts here and on skeptical science.(at least I think it’s you)… you confuse rhetoric with science and math.

    “With regard to the glacial to interglacial sensitivity, you can’t equate the positive feedback effect of melting ice from that of leaving maximum ice to that of minimum ice where the climate is now. There just isn’t much ice left, and what is left would be very hard to melt, as most of is located at high latitudes around the poles which are mostly dark 6 months out the year with way below freezing temperatures. A lot of the ice is thousands of feet above sea level too where the air is significantly colder. Unless you wait a few 10s of millions of years for plate tectonics to move Antarctica and Greenland to lower latitudes (if they are even moving in that direction), no significant amount of ice is going to melt from a measly 1 C rise in temperature. Furthermore, the high sensitivity from glacial to interglacial is largely driven by the change in the orbit relative to the Sun, which changes the angle of the incident solar energy dramatically. This combined with positive feedback effect of melting surface ice is enough to overcome the net negative feedback and cause the 5-6 C rise. But we are very nearing the end of this interglacial period, so if anything the orbit has already flipped back in the direction of glaciation and cooling. ”

    This is all rhetoric and assertion of opinion. Words like {“measly” aren’t admissible without calculations to back them up. I’m not even sure you understand the difference between heat and temperature after all this time, otherwise you wouldn’t write stuff like “1 C isn’t enough to do X”. Temperature is NOT a surrogate for heat as you are using it. If I hold an arbitrarily large mass of ice in presence of air that is always 1 C warmer (or .00001 C warmer) than 0 C (in an otherwise closed system), the ice, all of it, will eventually melt, because I’m supplying an effectively infinite heat source to the ice. So please at least stop saying really wrong things like that. (And your earlier remarks about the increased thermal emission sound like you’re still having 2nd law mis-understandings).

    I’ve built chemical reactor models…simple by comparison to a global climate model, but the underlying principles, physics and chemistry based are the same. When people like Gavin or Chris talk, I know they’re speaking the language and understanding the science and I can trust them to be close to right. You don’t have the ring of either truth or comprehension in anything you write.

    And the thing is this: My models and simulations worked. They were implemented on a large scale and produced thermal profiles, yieids and capacities within measurement error of what the simulation scenarios came up with. (Like climate models, it’s a matter of what conditions I chose…what we chose to operate the plant at, if I said “run it like this and the simulation predicts X under that scenario, then X we would get. Unlike climate models, the plant operators listen to me.)

    In my view, you’re wasting people’s time. You’ve used up more than your fair share. Look, I don’t understand international tax law. I’m seeing accountants about it tomorrow. I’m going to put my trust in them. You clearly don’t, after much ado understand the scientific and mathematical basis of this stuff… at some point you just need to hang it up and trust Gavin and Chris and the rest. And you don’t put your trust in Spencer, again because having read “11″, the critiques published are dead on- it’s a scientific travesty, a breach of norms. It creates false comparisons (which models get compared to).

    Comment by Dave123 — 1 Aug 2011 @ 11:25 PM

  137. PS for RW — did you spend some time reading Roe, before you dismissed the paper? It seems your definitions don’t match the definitions in the publications cited. Do you mean to refer to “feedback factor” above?

    For example Roe cautions about terms:
    “In the electrical-engineering literature and the control-systems literature, both c1 and c1λ0 are referred to as the feedback factor …”
    — and Roe notes the importance of being clear what definition is used.

    For another example Roe says
    “… in Equation 8, the two feedback factors are f1 = 1/3 and f2 = 1/2. Thus from Equation 11, the combined feedbacks produce a total system gain of G = 1/(1 – 1/3 – 1/2), or 600% of the original response—more than twice what one might expect….”

    Could that be where you’re having trouble matching the numbers published?

    Comment by Hank Roberts — 1 Aug 2011 @ 11:38 PM

  138. 109 gavin: Thanks for the outreach URLs. Who hosts RC?

    121 Marie: “Work with your communications departments, or educate them better.”

    WHAT communications departments? Where I worked, communication was forbidden. I worked for the military and everything was secret.

    “IPCC is mandated to aggregate the science.” And that is all. They are not mandated to advertise.

    “which all have marketing and PR personnel” Wrong. None of them have marketing personnel. Climate scientists work for the federal government or for universities. Outreach is a new thing that happens in some agencies. That means the web sites http://www.giss.nasa.gov and http://climate.nasa.gov

    “The right article to the right media at the right time.” WRONG. You forgot a few things about the media: They don’t speak our language [math]. They are beholden to advertisers or owned by the enemy. The public doesn’t know any science. They charge money for advertising. There is no right media.

    Read “Merchants of Doubt” by Oreskes and Conway and “Climate Cover-Up” by James Hoggan. See: http://climateprogress.org/2010/10/14/video-proof-david-koch-the-polluting-billionaire-pulls-the-strings-of-the-tea-party-extremists

    Sorry, but scientists are not marketers. There is a personality difference.

    If you would like to take over the communications job, it is yours. Show us how to do it. Otherwise, I suggest you try being a physicist for a while.

    Comment by Edward Greisch — 1 Aug 2011 @ 11:45 PM

  139. RW,

    I’ve glossed over the exchange, with the exception of the RC post Gavin linked you too. I think Gavin has so far responded quite clearly to you.

    There is enough evidence now to show that the mean climatological fluxes do not constrain climate sensitivity, and must be assessed from examining changes in climate (see Schmidt et al., 2010, JGR). Your attempts at linearization over the mean climate make no sense.

    Comment by Chris Colose — 2 Aug 2011 @ 12:26 AM

  140. RW said:
    “Before I respond, have you read all of my posts in this thread from the beginning?”

    Chris and Eric, you should by now be aware that RW is not really interested in your answer and will continue to obfuscate for as long as you play with him. He tried the same at Stoat and other blogs. My guess is that he fully understands what you are saying but keeps raising the same errors to hijack the discussion.

    He was asked (on another blog) to set up his own blog, present the maths and the model that he believes is operating (along with some hints on the physical basis of his model) and see what comments he gets. Has he done this?

    Comment by IA — 2 Aug 2011 @ 1:08 AM

  141. Joe Hunkins,

    I’m with Ray: what “contrarian” papers do you think are really noteworthy insofar as providing solid alternate theoretical models to explain observations and/or providing solid data to back up these theoretical models? In one sense, I’d love the whole “AGW model” to be wrong, but I just don’t see any consistent and comprehensive alternate theoretical models with good data to support them. And each time a paper like Dr. Spencer’s comes out, folks in certain media outlets and elsewhere are quick to trumpet that this one study has “blown the lid off” the mainstream consensus.

    Of course, there is plenty we still don’t know, but thus far it seems to me that the mainstream consensus model is by far the best, the most consistent, and the most comprehensive explanation of what is going on and what is likely coming in the future.

    Comment by Charles — 2 Aug 2011 @ 2:10 AM

  142. #114 (inline response)–

    Gavin, thanks for the clarification/expansion.

    Comment by Kevin McKinney — 2 Aug 2011 @ 7:33 AM

  143. #130–

    “You need to do better than this.”

    RW, do you have any clue what a condescending jerk this makes you sound like? Particularly when you then go on to make a whole paragraph of unsupported hand-waving?

    Dr. Steig has credibility; you don’t, much, and you’re rapidly losing any that might be granted by way of courtesy. So when you dictate to him, in his forum, how or what he ‘needs’ to do, you’re making a loud (and not very flattering to you) statement about how you view yourself and how you view others. Dr. Steig and the other contributors here don’t, after all, ‘need’ to spend time writing for our edification.

    I doubt that you want to make this kind of impression, but perhaps you don’t realize how you are coming across. My advice, FWIW: if you’ve got points to make, make them calmly and succinctly, and lose the attitude.

    Comment by Kevin McKinney — 2 Aug 2011 @ 7:50 AM

  144. Spencer’s paper. That would be good to return to, eh?
    Focus or lose the thread to hobbyhorse stuff which has been seen before.

    Comment by Hank Roberts — 2 Aug 2011 @ 8:43 AM

  145. RW,
    You claim the feedback in climate is “strongly negative”. ‘Kay, so why does it warm rapidly when the sun comes up? Why does it start to warm right after the equinox? How has it been warming steadily for 35 years? And finally, why isn’t Earth a big snowball since its blackbody temperature ought to be ~255K on average?

    It seems to me that if you would simply stop waving your hands and actually do the math, you’d realize exactly how much trouble you’d be in with a model with “strong negative” feedback. It wouldn’t look much like Earth.

    [Response: Let's keep it civil folks. The point Chris Colose emphasized -- that of course the most important feedback, the fact that as the temperature goes up, the radiation to space goes up too, is negative -- is indeed a stabilizing force and could be considered 'strong'. All this qualitative discussion isn't very helpful evidently, but I'm not convinced RW was trying to be difficult here. In any case, as Hank Roberts says, how about let's get back on topic.

    By the way, for those interested in PDFs of climate sensitivity and the like, Roe has a new paper out this week providing some interesting new points (though their main conclusion is that arguing about the details of the PDFs is largely pointless! Paper is here]

    Comment by Ray Ladbury — 2 Aug 2011 @ 9:23 AM

  146. #126 ccpo “I ask, why ask such a ridiculous question?” Given your assumption, the same query could be applied equally well to your own question, ccpo.

    Comment by simon abingdon — 2 Aug 2011 @ 10:01 AM

  147. #118 Hank Roberts “[my] assumption is that human fossil fuel use can’t be the original cause for the rapid change in climate”. Hank, we’re at cross-purposes here as to the meaning of “original”. I suggest that “the evolutionary trick of fire-control” or “the mammalian niche” are rather more “original” explanations. However, gavin’s (#116) amusing hypothesis of “the massing of a legion of solar fire dragons pointing their breath in our direction” is originality of an altogether different dimension.

    Comment by simon abingdon — 2 Aug 2011 @ 10:40 AM

  148. Joe, from a social science perspective, I have to say that I find this very odd:

    “It remains incredible to me how few here are willing to characterize the transparent and obvious bias as anything but objective and analytical truth.”

    Is that a testable assertion?

    “More importantly, it would sure be nice to see a lot more testable assertions about both the accuracy of climate models and climate modelling.”

    How hard have you looked? What are you assuming here?

    “I am noting the challenges of accepting what seems to be a premise here at RC along the lines that “… papers challenging the orthodox view are mostly worthless and unscientific.” “

    “Seems.” This would all be less impressionistic if you were backing it up. Did you have some specific problem with the critique? I’m only asking, because otherwise your take on this pretty much echos empty, over generalized, party-line rhetoric.

    Comment by Radge Havers — 2 Aug 2011 @ 11:40 AM

  149. The new paper by Roe and Armour that Gavin refers to inline at #145 is available here: http://earthweb.ess.washington.edu/roe/GerardWeb/Publications_files/grl_submit.pdf

    Comment by Rick Brown — 2 Aug 2011 @ 11:51 AM

  150. RC: “the pdf is here. Not exactly but happily it is here.

    And it says

    “So, as noted in RB07, while the probabilities become more focussed,
    in other words the range { however measured } gets less, the cumulative likelihood beyond 4.5 oC remains stubbornly persistent.”

    In other words we cannot bound the risk by any acceptable value. Weitzman must be taken seriously.

    But then the paper continues

    “Secondly, and more fundamentally| T2 is only a
    metric of a hypothetical global mean temperature rise that might occur thousands of years into the future.”

    I thought the discussion was about short term sensitivity (and long term sensitivity may be larger). What am I missing?

    Comment by Pete Dunkelberg — 2 Aug 2011 @ 11:58 AM

  151. By the way, from last night’s Roe paper:

    “It is also worth mentioning that what even counts as a feedback depends on the definition of the reference system. For example, the Stefan-Boltzman relation is often described as a negative climate feedback acting to regulate temperature anomalies. In fact, for a blackbody planet, which is the simplest imaginable reference system for the climate that is still meaningful, the Stefan-Boltzman relation is part of the reference system and therefore not a feedback at all. These are not semantic or esoteric issues—the quantitative intercomparison of different feedbacks can be done only when the reference system is defined and held constant.”

    Later Roe adds “There are other ways of defining feedbacks….”

    Comment by Pete Dunkelberg — 2 Aug 2011 @ 12:14 PM

  152. It looks like one of Roy Spencer’s brain-dead sycophants is attacking me on my blog. See the comments here from a user named Klem:

    http://circleh.wordpress.com/2011/07/28/roy-spencer-pulls-another-misleading-stunt/

    Comment by Dale Husband — 2 Aug 2011 @ 12:49 PM

  153. OK, Spencer claims “This research was sponsored by DOE contract DE-SC0005330 and NOAA contract NA09NES4400017.” Are DOE and NOAA providing funds to Spencer for this?

    Comment by Karen Street — 2 Aug 2011 @ 1:02 PM

  154. Is this relevant?

    Aerosols Affect Climate More Than Satellite Estimates Predict
    http://www.ScienceDaily.com
    08/01/2011

    Aerosol particles, including soot and sulfur dioxide from burning fossil fuels, essentially mask the effects of greenhouse gases and are at the heart of the biggest uncertainty in climate change prediction. New research from the University of Michigan shows that satellite-based projections of aerosols’ effect on Earth’s climate significantly underestimate their impacts … The satellite data that these findings poke holes in has been used to argue that all these models overestimate how hot the planet will get.

    [Response: No. This paper is testing the assumptions that have been made in trying to estimate the aerosol forcing from the pre-industrial from observed correlations between aerosol number and optical depth in the present, combined with estimates of aerosol number in the past. However, if you look at models, the correlations across spatial dimensions now, do not predict the correlations through time. Thus some estimates of the aerosol forcings are way off. Despite what is being said at WUWT, this is not an issue of the models being better than the satellites, but rather using the models to see what can be inferred from the satellites. Indeed, this is very similar in conception to the work we've done with paleo-proxies in models. - gavin]

    Comment by SecularAnimist — 2 Aug 2011 @ 2:05 PM

  155. re Gavins comments in #9, about Remote Response’s poor choice of referees, if one goes to http://www.mdpi.com/journal/remotesensing/instructions/ you will see this stated down the page :-

    Review / Referees
    [quote] Authors should suggest at least 5 potential referees with the appropriate technical expertise, although the Editor will not necessarily approach them. Please provide as detailed contact information as possible about the proposed referees (address, homepage address, phone and fax numbers and e-mail address). At least two of the suggested referees must be from a different country than the authors. Additionally, at least two suggested referees must be from a western country (USA, Canada, Japan, Australia or western European country). To identify potential referees, you may check the Editorial Board of our journal and suggest board members with appropriate research interests. In addition, we suggest searching for related papers in Google Scholar and proposing their authors as possible reviewers. Another possibility is to propose authors that you frequently cited in your paper.[/quote]

    So, one can choose one’s own referees it seems – and so that’s probably why Spencer chose this journal. I also noted, but lost the link again that, with others, Roger Pielke also published a paper therein last year?.

    [Response: Most journals ask that submit possible referee names, and the editors who are on top of the subject will be able to tell immediately if they are suitable or cover enough range of views. Editors who are less familiar with the material have a harder time, and might go with the authors suggestions more often (this might be worth investigating). But we do know that the people most familiar with the data or issue were not consulted. - gavin]

    Comment by Clippo (UK) — 2 Aug 2011 @ 2:48 PM

  156. @146 Simon:

    I have made no assumption. The logic is simple and straightforward. CO2 added due to human activity simply is not a feedback. I have taught science and, particularly scientific method to all, ages of elementary school with great success. I could teach ask 2nd and 3rd grade children the following:

    GHGs get into the air from old, frozen ground. If the air gets warm first and melts the ground, those GHGs are a feedback. If the GHGs get out of the ground because of a landslide or earthquake, the GHGs are a forcing.

    Swamps are always wet. GHGs come out of them. Are they a feedback or a forcing? (We will discuss “sinks” later.)

    We make power plants. They put GHGs in the air. Are those GHGs a feedback or a forcing?

    I guarantee you, Simon, 2nd grade children would have no problem figuring this out. Please don’t expect me to believe you could not. I did read another post by you that might indicate you now understand the feedback/forcing issue. Let us hope so.

    Comment by ccpo — 2 Aug 2011 @ 6:16 PM

  157. @130 RW:

    I’ve got the math skills of a stupid rock, but even I know this is false:

    Even when the globally average mean fluctuates by a large amount like during an El Nino, it always seems to revert to its pre-equilibrium state quickly.

    If you were to say usually or some such, you might be correct, but when the natural cyclical phenomenon get amped by other feedbacks we tend to see a step change as we did in 1998. We’ve been at a significantly higher average since then. I.e, we did not return to the previous temperature regime.

    Besides, if very small changes or perturbations resulted in dramatic changes (i.e. net positive feedback), the climate would be fluctuating from year to year over a much larger range and would be a very inhospitable place for life and the biosphere as a whole.

    You are confusing climate and weather, and the latter does exhibit very wide variance. Also, it is becoming less hospitable. Record events are becoming the norm because of the long-term changes to the climate. It took since 1850 for the GHGs to really start kicking in.

    Also, that small changes in initial conditions occur and can result in large changes also has a time component. Some feedbacks and forcings occur over long time scales so those changes may take lifetimes to be realized.

    no significant amount of ice is going to melt from a measly 1 C rise in temperature.

    Apparently you don’t pay attention to the real world observations of ice. Glacier National Park used to have 150 glaciers; it has a fraction of that now. Arctic Sea Ice are and volume minima are greatly decreased.

    You are making strange, unsupported assertions.

    Comment by ccpo — 2 Aug 2011 @ 6:37 PM

  158. Chris Colose,

    “The problem is in definitions. As Roe explains in his paper (that Dr. Steig referenced), this increased IR emission with T is just the “reference system” (as I mentioned in my post, you get about 0.3 C warming per unit radiative forcing under this system).”

    Why do we get about 3.3 W/m^2 of increased emission per 1 degree C of warming? In other words why is the so-called “Planck response” what it is? Do you know how the “Planck response” is derived?

    “Amplifying this by three is not problematic at all, which you can easily do by putting more water vapor in the air, in addition to some other feedbacks.”

    Can you explain to me specifically where the watts are coming from? Are you claiming that about a 1 C rise in temperature will increase the atmosphere water vapor absorption enough to cause an additional 10.6 W/m^2 flux into the surface? I presume you’re aware that the water vapor in the atmosphere is not homogeneous and condenses to form clouds? In other words, the clouds are controlling the water vapor concentration in a dynamic manner by modulating incoming solar energy and precipitating out the water vapor from the atmosphere.

    Just claiming it “is not problematic at all” or it’s from “the feedback’ suggests to me you haven’t though this through very thoroughly. Remember, the current atmosphere is only going to provide +2.3 W/m^2 and 3.7 W/m^2 are from 2xCO2 – leaving a deficit of 10.6 W/m^2 needed for a 3 C rise, which COE dictates has to be coming from somewhere.

    And BTW, how do you get away with assuming all of the 3.7 W/m^2 will be incident on the surface to affect its temperature? Gavin’s own model of the atmosphere has half of what’s absorbed emitted to space and half returning to the surface, which means the net ‘forcing’ from 2xCO2 is 1.85 W/m^2 – not 3.7 W/m^2. This means the so-called ‘pre feedback’ amount is only about 0.55-0.6 C and not the often referenced 1.1-1.2 C. Or are you claiming that ‘window’ transmittance reduces by 7.4 W/m^2 when CO2 is doubled and the 3.7 W/m^2 is the downward emitted half? I’ve done all kinds of digging on this question and no one in the climate science community can give me a straight answer. The claim is it’s the net change at the tropopause, but is this before or after half up/half down? If it really is 7.4 W/m^2, can you point me to the data and/or evidence showing this? If it’s not 7.4 W/m^2, how can you claim the full 3.7 W/m^2 is incident on the surface for a 1.1 C rise?

    Comment by RW — 2 Aug 2011 @ 8:33 PM

  159. Whoever wrote this:

    “All this qualitative discussion isn’t very helpful evidently, but I’m not convinced RW was trying to be difficult here. In any case, as Hank Roberts says, how about let’s get back on topic.”

    Thank You. My purpose here to challenge and poke what I believe are significant holes in the so-called ‘consensus’ 3 C positive feedback rise theory. Of course everyone here is free to make up their own mind, as they should.

    I don’t dispute that the physics supports a likelihood of some effect, but it’s the magnitude of 3 C that I object to. I also don’t dispute the GHE or the basic accepted understanding of it, as some have eluded to here. I’m not going to respond to those posts or accusations.

    Comment by RW — 2 Aug 2011 @ 8:47 PM

  160. Dave123,

    “I’m not even sure you understand the difference between heat and temperature after all this time, otherwise you wouldn’t write stuff like “1 C isn’t enough to do X”. Temperature is NOT a surrogate for heat as you are using it. If I hold an arbitrarily large mass of ice in presence of air that is always 1 C warmer (or .00001 C warmer) than 0 C (in an otherwise closed system), the ice, all of it, will eventually melt, because I’m supplying an effectively infinite heat source to the ice. So please at least stop saying really wrong things like that.”

    What I’m saying is for existing ice to melt, the yearly average surface temperature needs rise above 0 C. Anywhere there is ice below a 0 C yearly average just isn’t going to melt, regardless of global average temperature increase. A 1 C globally averaged rise in temperature is not going to move the 0 C isotherm to significantly higher enough latitudes to melt very much ice, as we are very close to minimum ice as we are during every interglacial period. And you can forget about Antarctica – not even a 3 C globally averaged rise would come anywhere near melting any significant part of that. The yearly average temperature there is like -40 C. The yearly average temperature in the Artic is like -15 C even though it does get well above freezing in the summer.

    [Response: It depends on what you mean by 'significant'. Yes, not a large fraction of the Antarctic ice sheet is melting, but the collapse of the Antarctic Peninsula ice shelves is largely attributed to above freezing temperatures in summer. As for the Arctic, summer is plenty warm for lots of melt. Mean annual temperatures are not very relevant.--eric]

    Comment by RW — 2 Aug 2011 @ 10:13 PM

  161. http://www.google.com/search?q=amount+of+ice+is+going+to+melt+from+a+measly+1+C+rise+in+temperature

    Canada’s Arctic glaciers, ice caps losing water at an alarming rate
    http://www.physorg.com/…/2011-05-canada-arctic-glaciers-ice-caps.html
    May 4, 2011 “Temperatures were just 1 C to 1.6 C warmer in high-melt summers”

    Enough, already?

    Comment by Hank Roberts — 2 Aug 2011 @ 10:21 PM

  162. PS, the search for the phrase by RW above does — this has to be a coincidence — also find a blog owned by a different “RW”: Roy W. Spencer.

    Same idea as the recently published paper was earlier blogged in January, at:

    http://www.drroyspencer.com/2011/01/update-further-evidence-of-low-climate-sensitivity-from-nasas-aqua-satellite/

    Comment by Hank Roberts — 2 Aug 2011 @ 11:01 PM

  163. RW,

    The last interglacial was worth a few meters of sea level rise, and a good fraction of that came from both Greenland and Antarctica (see the new paper this week in Science by Colville et al 2011)

    I would not be so confident in your claims of cryosphere insensitivity.

    Comment by Chris Colose — 2 Aug 2011 @ 11:33 PM

  164. RW

    You load many assumptions in there, assertions without supporting evidence except your own sense of the rightness of things.

    I agree with other commentators that you owe an explanation of the existing losses of ice in the context of the current number of joules that are added to the near surface earth environment due to the green house gas effects.

    It’s funny what you can do with averages. I can get a global average temperature rise of 1 degree all kinds of ways….because there is no requirement for uniformity. Global surface area ius 5.1 x 10^8 square kilometers, while the poles are together are about 2.6 x 10^7 square kilometers or about 5% of the earth. I could have the average temperature at the poles rise by 10 C, while the rest of the world need only decline by 1/2 a degree to have an average increase of 1 C. I suggest that you reconsider the meaning of average and make a more precise claim about what a 1 C average increase means, and how you are certain that the increase won’t work in a non-uniform manner like the one I’ve calculated.

    Comment by Dave123 — 3 Aug 2011 @ 12:36 AM

  165. RW, google ice shelf buttressing. It’s not all about temperatures, and not like the cube in your whiskey glass…

    Comment by Martin Vermeer — 3 Aug 2011 @ 3:12 AM

  166. #156 ccpo You say “If the air gets warm first and melts the ground, those GHGs are a feedback”. Human activity has been releasing CO2, raising temperatures (warming the air, melting the ground). But you’d started your post by saying “CO2 added due to human activity simply is not a feedback”.

    Comment by simon abingdon — 3 Aug 2011 @ 3:55 AM

  167. RW says: “Of course everyone here is free to make up their own mind, as they should.”

    What is missing from this sentiment is that everyone is free to make up their mind BASED ON THE EVIDENCE. RW has none–just misunderstandings of what is meant by feedback and how it works. There are about a dozen independent lines of evidence for climate sensitivity. All of them favor a value around 3 degrees per doubling. Think about that. Independent lines of evidence all favoring the same value.

    RW, your argument is not with anyone here or with any theory. It is with reality. Good luck with that.

    Comment by Ray Ladbury — 3 Aug 2011 @ 4:50 AM

  168. #166–

    Probably shouldn’t answer on ccpo’s behalf, but he’s being consistent. “CO2 added due to human activity” is pretty clearly meant to denote CO2 emissions resulting directly from such activities as fossil fuel combustion and deforestation, not indirect consequences occurring due to the warming. The former are a forcing for most purposes, the latter a feedback.

    Comment by Kevin McKinney — 3 Aug 2011 @ 6:25 AM

  169. #158 RW:


    Why do we get about 3.3 W/m^2 of increased emission per 1 degree C of warming? In other words why is the so-called “Planck response” what it is? Do you know how the “Planck response” is derived?

    The derivation of the Planck response from Chris Colose (#128) is complete, snow- and waterproof, but one “has to believe” 2 things (there is always at least one intermediate result or axiom a derivatione rests upon):

    1. the validity of the Stefan – Boltzmann law and its applicability for the problem
    (which can be argued very well)

    2. This expertise

    We know that εσTs^4 is 240 W/m2, and from radiative forcing calculations dε(σTs^4)= – 4 W/m2 (for a doubling of CO2);

    I also would appriciate some back of the envelope calculation for this wattages or at least its orders of magnitude, if there is any. In David Archers online model for tutorial purpose (Modtran)

    http://geoflop.uchicago.edu/forecast/docs/Projects/modtran.orig.html

    I zeroed all gas concentrations, including humidity, except CO2, and get 4,4W/m² for doubling CO2 and tropical lattitude. One would surely know how the program works if one had read his book, I suppose it divides the atmosphere in many layers which are iteratively converged to radiation equilibrium.

    Comment by Marcus — 3 Aug 2011 @ 6:36 AM

  170. Anywhere there is ice below a 0 C yearly average just isn’t going to melt, regardless of global average temperature increase.

    So you’re arguing that if the temperature is at -20 C for 99% of the year, and 1500 C degrees for 1%, there won’t be any melt? You might want to explain why you think so – or elaborate on what you actually mean.

    Comment by Lotharsson — 3 Aug 2011 @ 7:25 AM

  171. #156 ccpo You say “If the air gets warm first and melts the ground, those GHGs are a feedback”. Human activity has been releasing CO2, raising temperatures (warming the air, melting the ground). But you’d started your post by saying “CO2 added due to human activity simply is not a feedback”

    Yes and yes.

    The impact of the CO2 added directly by human activities is a forcing (which causes some warming).

    The impact of the CO2 added indirectly via mechanisms that are responses to that warming is a feedback (which also causes more warming…hence the geometric series in terms of the feedback factor).

    By analogy (and being careful not to push analogies too far):

    If I heat a match via an external heat source, that heat source is a forcing which warms the match.

    When the match ignites and as a result warms even further, that combustion process is a feedback.

    Comment by Lotharsson — 3 Aug 2011 @ 7:31 AM

  172. What I’m saying is for existing ice to melt, the yearly average surface temperature needs rise above 0 C.

    RW reminds one of the fellow who drowned trying to ford a river whose average depth was one meter.

    Comment by Adam R. — 3 Aug 2011 @ 8:09 AM

  173. RW,

    Although I already know the answer, because I’ve been down this road with you before at Skeptical Science, I’ll let others deal with the edifying experience themselves.

    One statement you made stands out as the core of your position:

    I don’t dispute that the physics supports a likelihood of some effect, but it’s the magnitude of 3 C that I object to.

    Would you care to clearly support this position? (and I know you would… as Darth Vadar once said, “the Dunning-Kruger is strong in this one.”)

    Although the correct place to do this is the Unforced Variations August thread, not here. This thread is for discussing Spencer’s paper, not tangentially related climate sensitivity issues.

    [Response: I think it was O. W. Kenobi who said that, wasn't it? For the record though, discussing climate sensitivity with respect to Spencer's paper seems entirely on topic to me.--eric]

    Comment by Sphaerica (Bob) — 3 Aug 2011 @ 11:25 AM

  174. > drowned trying to ford a river whose average depth was one meter.

    “Now I’m not going to point any moral —
    I’ll leave that for yourself.
    Maybe you’re still walking, you’re still talking,
    You’d like to keep your health.
    But every time I read the papers, that old feeling comes on,
    We’re waist deep in the Big Muddy
    And the big fool says to push on.”
    – Pete Seeger

    Comment by Hank Roberts — 3 Aug 2011 @ 12:08 PM

  175. #168 Kevin McKinney “The former are a forcing for most purposes, the latter a feedback”. “for most purposes”?

    Comment by simon abingdon — 3 Aug 2011 @ 1:29 PM

  176. 173, inline-response-by-eric,

    Actually, it was Darth, as he lined poor, young Luke up in his sights, while Luke successfully jinked, dipped and zagged down the trench on his way to destroying the Death Climate Change Hoax Star.

    Your choice on the thread… be warned that you will wander into “Trenberth’s energy budget diagram is wrong” and “clouds must represent a negative feedback, because they have a net negative effect on GMT now” territory, among other long and winding roads (which is, by the way, a very famous Darth Vader top-40 single).

    Comment by Sphaerica (Bob) — 3 Aug 2011 @ 1:49 PM

  177. Simon, playing games with definitions, is rearranging the deck chairs.
    He’s good at this, he’s done it repeatedly. He knows what he’s doing.

    Comment by Hank Roberts — 3 Aug 2011 @ 2:00 PM

  178. Eric – I am pretty sure Yoda was the speaker of said phrase :-)

    Comment by BobN — 3 Aug 2011 @ 2:04 PM

  179. #177 Hank Roberts

    gavin has said that forcings originate outside “the system“ (#30). “I agree that the boundaries of a modelled system define what is forcing (external) and what is feedback (internal)”. So we can agree that external forcings cause feedbacks from within the system. But gavin then says (#30) “Spencer’s idea of ‘internal radiative forcing’ is nonsense even by your definition”. But gavin admits (#30) that it is possible to have forcings from within a system. “Only if you have a forcing that specifically affects clouds by means of some aspect of their physics that is already within the system will you have a specific forcing from clouds (in this sense)”. Similar arguments clearly apply to landslides, earthquakes, volcanoes, etc.

    [Response: You (and Spencer) are confusing issues again. Spencer's 'internal radiative forcing' is purely related to changes in radiation as a function of the internal modelled system. These are, by definition, feedbacks. If they were forcings in the sense that everyone else understands, they would clearly be called 'external radiative forcings'. - gavin]

    The purpose of science is to understand the “regularities” of Nature, which is often expressed as the Law of Cause and Effect. Forcings and Feedbacks are no more than the age-old Causes and Effects which mankind has relentlessly pondered. Nature exhibits endless chains of Causes producing Effects which are Causes producing Effects. So to what useful end Forcing/Feedback analysis?

    [Response: The End of Forcing Everyone to Write as Though we were Native German Speakers. I think we have Succeeded. - gavin]

    Comment by simon abingdon — 3 Aug 2011 @ 2:30 PM

  180. Nothing wrong with my (English) syntax, gavin. I could equally well have written “Whither Forcing/Feedback analysis?” Or better, “Wither Forcing/Feedback analysis”.

    Comment by simon abingdon — 3 Aug 2011 @ 3:23 PM

  181. Re #39, Lynn Vincentnathan,
    Hi Lyn, a way of responding to the Greenhouse effect denier, for the benefit of other viewers of the blog you are on, that will show how ridiculous her position is; is to remind her of how much night time temperatures vary from night to night (even using cloudless nights only) with respect to a greenhouse gas that varies a great deal at any given locality, water vapor.

    Comment by Lawrence McLean — 3 Aug 2011 @ 3:25 PM

  182. This is an excellent standard to apply to all scientific papers:

    “The basic material in the paper has very basic shortcomings because no statistical significance of results, error bars or uncertainties are given either in the figures or discussed in the text. Moreover the description of methods of what was done is not sufficient to be able to replicate results.”

    Excellent analysis. I think we can all agree that a paper that does not have all of the following “should not have been published”:

    1. statistical significance of results
    2. error bars / uncertainties
    3. sufficient description of methods to enable the results to be replicated.

    Is that right?

    Comment by SeanNY — 3 Aug 2011 @ 4:01 PM

  183. #160 comment by “RW”:

    What I’m saying is for existing ice to melt, the yearly average surface temperature needs rise above 0 C. Anywhere there is ice below a 0 C yearly average just isn’t going to melt, regardless of global average temperature increase.

    To add to the other comments above, consider that there are many high latitude areas which exhibit permafrost. At these locations, the average surface temperature is below 0 C, which is the reason the permafrost continues to exist. At depths of a few meters or more below the surface, the mass of soil and rock above acts to filter the seasonal changes in temperature, the result being a nearly constant value which tracks the yearly average. The permafrost exists because the average is below 0 C. However, the surface temperature can warm well above freezing during summer, thus any surface ice left from the winter precipitation melts away. The same is true for glaciers, which often experience a surface snow melt, which then freezes as winter returns. This process results in annual layers clearly visible in ice cores. If runoff and evaporation from the yearly melt becomes greater than the amount of new snow in following winters, the result can be a net loss in glacier mass. “RW”‘s comment is clearly incorrect.

    Comment by Eric Swanson — 3 Aug 2011 @ 4:15 PM

  184. Mr SeanNY, on the 3rd of August, 2011 at 4:01 PM, espoused the position that papers with no discussion of “the statistical significance of results” or “error bars/uncertainties” ought not be published.

    I demur. I have in mind, for example, one of the papers from the Annus Mirabilis, 1905:

    http://www.fourmilab.ch/etexts/einstein/specrel/www/

    Sometimes, a paper needs nothing but “sufficient description of methods to enable the results to be replicated.”

    sidd

    Comment by sidd — 3 Aug 2011 @ 4:29 PM

  185. Simon, I think you didn’t get it.

    Comment by Pete Dunkelberg — 3 Aug 2011 @ 4:35 PM

  186. #175–“for most purposes”?

    Yep. If I understand correctly (not a given, sadly), forcings/feedbacks may sometimes be defined differently in order to meet the needs of a different context (say, studies of regional versus global climate, or on different timescales.)

    But in general, the ‘default’ is as described.

    Comment by Kevin McKinney — 3 Aug 2011 @ 4:37 PM

  187. “I think we have Succeeded. – gavin”

    Evidently not, or it would have been “I think we Succeeded have.”

    Comment by Kevin McKinney — 3 Aug 2011 @ 4:39 PM

  188. Which, come to think of it, sounds a lot like Yoda.

    Comment by Kevin McKinney — 3 Aug 2011 @ 4:40 PM

  189. Simon Abingdon #180 Prof. Schmidt’s humour was directed at your OverUse of Capital Letters. I had a good laugh.

    Comment by One Anonymous Bloke — 3 Aug 2011 @ 4:57 PM

  190. Simon – he is referring to your use of capitalization.

    Comment by skg — 3 Aug 2011 @ 5:00 PM

  191. @179 etc.: The partition between climate forcings and feedbacks exists for the very practical reason that it helps us distinguish between the direct effects of externally perturbing a climate factor and the traceable indirect effects that initially arise from the direct effects.

    On the other hand, the practical scientific use of a journey down the epistemological rathole of Causes and Effects is just about zero.

    Comment by Meow — 3 Aug 2011 @ 6:32 PM

  192. I’m going to agree that the need for statistics and error bars as a requirement for publication depends on the discipline. For example it is not common practice to run a new synthetic chemical reaction X times to determine the yield and purity and report statistics. The method alone is sufficient for someone else to attempt replication or use.

    Modeling and simluation of any kind is another matter, as are outcomes of clinical trials and so forth.

    Comment by Dave123 — 3 Aug 2011 @ 7:17 PM

  193. Who´s the more foolish? Those who did this climate sensitivity analysis? Or the fools who follow them?

    Comment by Chris Colose — 3 Aug 2011 @ 8:16 PM

  194. Re 160 RW – consider that if it gets hot enough to melt some ice some time of the year, and the winter precipitation is not sufficient to replace that ice, then you can have net ice loss.

    Ice can be lost by evaporation, melting, and calving. Glacial flow can thin the ice sheet, lower it’s elevation and thus make the surface of the ice warmer.

    For sea ice, meltwater is initially relatively fresh; mixing (impeded by stratification, but presumably not completely prevented) will make the surface water more saline, lowering the freezing point. So you have to raise the temperature higher than the sea-water freezing point to melt the ice (except at the ice-water interface, I’d guess), but you have to bring the temperature down to the sea-water freezing point to get ice to form.

    Some interesting complexity around Antarctica could explain an increase in sea ice resulting from warming – and warming can also increase frozen precipitation (it had been thought East Antarctic could see ice gains from AGW – now I’m not sure if that’s still possible? – but I recall hearing of a Californian mountain gaining ice mass from increased frozen precipitation) – but of course, if you get warm enough you start to lose ice anyway.

    As to some earlier issues -

    Comment by Patrick 027 — 3 Aug 2011 @ 8:48 PM

  195. Warming of the surface by y K increases surface emission by x W/m2. But generally the atmosphere above warms, too, so the increase (if there is any) in net upward radiation is smaller.

    To a first approximation, for globally-representative purposes, the most important radiative forcings are at the tropopause level and above, such as at TOA (top of atmosphere). If you add some CO2, there is positive radiative forcing (increase in net downward, or decrease in net upward, radiative flux per unit area, which is a radiative disequilibrium until the climate system responds) at both levels, but the TOA forcing is (For Earth at least) smaller. The TOA – tropopause level forcing is a forcing on the stratosphere, and the stratosphere will warm** by an amount sufficient to reduce the outward radiative flux by the same amount (**it will cool if that forcing is negative, which is the case at least on Earth). Some of this reduction is (or more generally, could be) realized at the tropopause as a reduction in downward radiation from the stratosphere. The stratosphere is now in equilibrium (within itself), so the remaining unbalanced radiative forcing (representing the remaining disequilibrium) is constant above the tropopause – the forcing with stratospheric adjustment is the same at TOA and at the tropopause, and is a net heating rate for the surface (or material below that) + troposphere.

    Convection tends to respond to variations in how the radiant heating rate is distributed in such a way that the actual temperature increase is more evenly distributed – in particular, the vertical temperature variation tends to be near a moist adiabatic lapse rate (or dry adiabatic lapse rate, below the relevant cloud bases) – with exceptions (radiative heating variations will have more control over the temperature distribution where the air is more stable, as it tends to be in some regions and seasons and times of day).

    So the temperatures below the tropopause generally warm until the increased flux from below the tropopause balances the tropopause level forcing with stratospheric adjustment. There will be some additional feedback (of the Planck-sort) as the stratosphere may absorb some fraction of this increased flux from below, warm up, and increase the downward flux back into the troposphere and surface – I think this may be a small effect for Earth but it could be large on a planet with an optically thick stratosphere (in a wholly grey gas greenhouse effect with no direct solar heating above the tropopause, the eventual warming of the upper atmosphere would be as much or more than any initial cooling (there would be some initial cooling at TOA and extending downward by some amount) – the complete equilibrium would have effective TOA temperature unchanged and all levels below warmed by some amount).

    —-

    Comment by Patrick 027 — 3 Aug 2011 @ 8:49 PM

  196. Feedbacks can be expressed in terms of W/m2 per K (forcing per unit temperature – so it is internal forcing but must then be treated as such (feedback) and not as external forcing), and in that case can be added linearly; including the Planck response in the same terms, the climate sensitivity would just be the negative reci-procal of the sum (I suppose the ‘climate insensitivity’ would be the negative of the sum itself).

    In some contexts, feedbacks are also described as forcings, or not described as feedbacks at all, but an example of such a context is one in which the total greenhouse effect or albedo effect, or both, are being described, without discussion of what sustains the amount of any substance in any form, etc, or else in context where one is considering what would happen if we could remove all the water vapor, etc. For example, the whole greenhouse effect may be something like 155 W/m2 (am I remembering this correctly? see Kiehl and Trenberth (1997?)), which has contributions from H2O, clouds, CO2, and some other gases (two important things there:

    1. There are overlaps in the effects; removing all CO2 and leaving everything else has a smaller effect than removing CO2 after everything else has been removed.

    2. this is the increase in OLR that would occur if they were removed, which is not the same as the decrease in OLR that would occur if they were added to a planet in equilibrium without a GH effect, because GH effects depend on the temperature itself (This is not because of hysteresis. A change in a forcing agent will generally have a forcing that depends on the climate (such as via temperature-depedence of the Planck function and spectral/spatial overlaps), and thus, where equilibrium is allowed to be achieved after each change, A forcing agent change and it’s reverse will have different magnitudes of forcing. But the Planck feedback, and other feedbacks, will also be dependent on climate and so the climate sensitivity will vary in a complementary way, so that the same equilibrium climate can be achieved when forcing agents are placed at the same values, regardless of history – except when hysteresis does occur (Snowball Earth being a profound example of that; also, any biological evolution in response to climate).

    ——-

    It takes time to accumulate heat to result in a temperature change that is able to restore balance. Regionally/locally, and seasonally and especially diurnally (noon vs nightime), conditions are generally not in equilibrium; conditions don’t persist long enough (and advection is not sufficiently slow) to allow equililibrium to be achieved.

    For glacial-interglacial variations, a Charney sensitivity can be infered by including both the changes in CO2, CH4, etc, and ice sheets, and the albedo effects of vegetation and dust. These are all actually feedbacks in the glacial-interglacial variations, but their forcing suggests that the sensitivity including faster-acting feedbacks (water vapor, clouds, some others…) is similar to what is expected for anthropogenic global warming from models.

    Comment by Patrick 027 — 3 Aug 2011 @ 8:55 PM

  197. Re 169 Marcus – How to attempt to find radiative forcing or feedback using David Archer’s Modtran site:

    1. Take TOA (in practice, the highest altitude at which you can place the sensor) fluxes (looking down)
    2. Take tropopause level fluxes (looking up and down, find the net upward value)
    make a change and find the difference. There’s the instantaneous forcing. To find tropopause-level forcing with stratospheric adjustment, you’d have to take the tropopause forcing – TOA forcing and take some fraction of that and subtract it from the instantaneous tropopausel forcing. For a first approximation, maybe apply half of the stratospheric cooling to the tropopause level ? (this would be a good approximation if either enough of the radiant flux out of the stratosphere emitted within the stratosphere is at wavelengths where the stratosphere is not too optically thick, or if the distribution of the change in emission is evenly distributed).

    I think you may be able to use the data output to graph (on your own, not on the website) the spectrum of the forcing.

    Etc. for water vapor feedback.

    I think you may be able to adjust the temperature and then see how the flux at the tropopause changes in response to the temperature change. Maybe not exactly in the way that temperature would actually change, but mabye (I haven’t tried this) you could find the temperature increase for the surface and troposphere (absent a lapse rate feedback?) to produce an increase in the upward flux at the tropopause that matches the tropopause level forcing with stratospheric adjustment. This excludes feedback from the stratosphere, but I think that’s not supposed to be a big effect.

    Of course, there isn’t a global average setting on the website, and anyway it’s more accurate to find radiative forcing at each location and time and then find the global average radiative forcing from that. So you could try the different latitudinally-defined regions and seasons, with different cloud cover and humidity, and then take an appropriately-weighted average.

    PS the surface doesn’t actually emit in the LW part of the spectrum as a perfect blackbody; there is some nonzero LW albedo. David Archer’s Modtran website appears to account for this; the surface emission is less than the blackbody value for a given temperature. However, there should (depending on the surface albedo spectrum) also be some reflection of the downward radiation from the atmosphere from the surface, so the upward flux from the surface will be closer to what it would have been if the surface emitted as a blackbody. If the temperature decreases upward, the upward and downward fluxes will tend to decrease going upward, and the net flux will tend to be upward – especially where optical thickness is large so that only the local temperature variation matters. However, as I recall, under at least some conditions, the upward flux actually increases going upward, up to a point, and with great optical thickness in the lower atmosphere, the net flux is to the surface even with temperature decreasing upward – which is wrong. Thus, it seems as if the model assumes all downward flux is absorbed at the surface. I think this means that estimates of radiative forcing could be underestimated by the model.

    PS CO2 and H2O also absorb solar radiation, but I think (going by memory here) their LW forcings dominate their total forcings – especially I think for CO2, this is a relatively small effect (though not sure offhand just how small), and for H2O, it is relatively small in the stratosphere and absorption of solar radiation in the troposphere doesn’t change the tropopause or TOA-level forcings except for any decrease in albedo that results (such as if the H2O absorbs radiation that would have otherwise have escaped the troposphere).

    Comment by Patrick 027 — 3 Aug 2011 @ 8:55 PM

  198. Marcus (RE: 169),

    “The derivation of the Planck response from Chris Colose (#128) is complete, snow- and waterproof, but one “has to believe” 2 things (there is always at least one intermediate result or axiom a derivatione rests upon):

    1. the validity of the Stefan – Boltzmann law and its applicability for the problem
    (which can be argued very well)

    2. This expertise

    We know that εσTs^4 is 240 W/m2, and from radiative forcing calculations dε(σTs^4)= – 4 W/m2 (for a doubling of CO2)”

    My question is WHY is it 3.3 W/m^2 per 1 degree of warming? Why not 3.3 W/m^2 per 3 degrees of warming or 3.3 W/m^2 per 33 degrees of warming, for example? It appears Chris doesn’t want to answer this, so I’ll answer it:

    The “Planck response” is specifically derived from the surface response to solar forcing. 390/240 = 1.63, where 1 degree C of warming equals +5.4 W/m^2 at the surface from S-B and 3.3 W/m^2 x 1.63 = 5.4 W/m^2. Physically it just means it takes 1.63 W/m^2 of radiative surface emission to allow 1 W/m^2 to leave at the system at TOA, or with these specific numbers, it takes 5.4 W/m^2 emitted from the surface to allow 3.3 W/m^2 to leave at the TOA.

    This already includes the lion’s share of all the feedbacks in the system from decades, centuries, millenia, etc. of solar forcing. How could it not? Afterall, it’s all the feedbacks operating in the system that are maintaining the tightly constrained net surface flux of about 390 W/m^2 and the 1.6 W/m^2 (surface) to 1 W/m^2 (TOA) energy balance, is it not? Why would the same feedback mechanisms that tightly constrain and control the current system not also do the same with such a small additional ‘forcing’ from 2xCO2? How would the feedback mechanisms even know the difference between additional watts from – say, a slightly varying cloud albedo or from GHGs? Let’s not also forget that some of the post albedo solar is absorbed by the atmpophere and emitted to the surface as LW infrared. So what’s another few of watts re-directed back to the surface from GHGs in such a dynamic system that is constantly changing spatially and in time – all the time?

    In short, why would the feedback mechanisms all of the sudden respond to an additional 3.7 W/m^2 of GHG ‘forcing’ so much greater than it does to the original 240 W/m^2 from the Sun?

    [Response: You have spent all this time not paying any attention to people who have tried valiantly to educate you, and now you arrive straight back to where you started. Constructive engagement was clearly not effective, but it was nonetheless worth a shot. In future when you ponder why no-one will take you seriously, read over this thread and think about it. We are done here. - gavin]

    Comment by RW — 3 Aug 2011 @ 10:47 PM

  199. Eric Swanson,

    “To add to the other comments above, consider that there are many high latitude areas which exhibit permafrost. At these locations, the average surface temperature is below 0 C, which is the reason the permafrost continues to exist. At depths of a few meters or more below the surface, the mass of soil and rock above acts to filter the seasonal changes in temperature, the result being a nearly constant value which tracks the yearly average. The permafrost exists because the average is below 0 C. However, the surface temperature can warm well above freezing during summer, thus any surface ice left from the winter precipitation melts away. The same is true for glaciers, which often experience a surface snow melt, which then freezes as winter returns. This process results in annual layers clearly visible in ice cores. If runoff and evaporation from the yearly melt becomes greater than the amount of new snow in following winters, the result can be a net loss in glacier mass.”

    What is so hard to understand about significantly below a 0 C yearly average = permanent ice. Of course there are other things besides just temperature that can affect ice amounts, but temperature is the most significant long term determining factor for. Afterall, why do we have persistent ice in the first place? Ice sheets can break off due to increase ice accumulation and/or glacier physics. Winds can blow Artic Ice away to lower latitudes where it can more easily melt. There are other influences, but they can go both ways. Just as winter precipitation can decrease, it can also increase, etc.

    Comment by RW — 3 Aug 2011 @ 11:10 PM

  200. #189 One Anonymous Bloke “#180 Prof. Schmidt’s humour was directed at your OverUse of Capital Letters”. I get it now. (Might have been sooner if gavin had capitalized only the nouns). Happy times.

    Comment by simon abingdon — 4 Aug 2011 @ 12:55 AM

  201. sidd:

    Good one! I always liked that paper. And, yes, I was being far too general; I didn’t even say “scientific” paper, so you could have as easily linked to the New York Times!

    So I’ll try again:

    I think we can all agree that a statistical analysis that does not have all of the following “should not have been published”:

    1. statistical significance of results
    2. error bars / uncertainties
    3. sufficient description of methods to enable the results to be replicated.

    Does that work?

    [Response: Too prescriptive. All of those things - if relevant - certainly add to a paper's strengths, but not all of these things are relevant to every paper, and many back-of-the-envelope calculations do not warrant extensive back up (or if they do, that would be a new paper in and of itself). Conversely, many papers come with error bars, but for some reason (tractability, knowledge etc.) do not assess some big element of the uncertainty. In short, trying to find a one size fits all description for what is a 'scientific paper' is a pretty thankless task, and one that has pretty much been given up on by philosophers of science, let alone blog comment threads. Accumulating scientific knowledge is much more piecemeal and collective than this approach allows for. - gavin]

    Comment by SeanNY — 4 Aug 2011 @ 9:10 AM

  202. This didn’t get get past the censors the first time, so I will repost the comment. It clearly doesn’t violate any posting guidelines, unless a hidden one is that you are not allowed to use science to question the ‘consensus’.

    You have one thing right. Clouds can’t be considered ‘forcing’. In a strict control theory sense, only power from the Sun can force the system. I don’t agree that this specific objection falsifies S & B, in fact, this specific objection is why the S & B hypothesis is correct, that is, there’s a misdiagnosis.
    What it boils down to is the definition of radiative forcing. From control theory, only the power entering the system is considered forcing, which differs from the IPCC definition. Changing CO2 levels. aerosols, cloud coverage, etc, change the system, affecting its response, but don’t change the stimulus forcing the system to respond.
    This gets more complicated because the characteristics of the system dictating it’s response are surface temperature dependent, while the physical system itself is not a hypothetical system controlling surface temperatures, but a real, physical system controlling the planets energy balance. Of course, to deny the attribute of forcing to the effects S & B says should have them, means that you can’t have it both ways and claim that the effects of incremental CO2 and aerosols are forcing.

    [Response: This is nonsense. Definitions of forcing in climate having nothing to do with whether 'power' is entering the system. If you want to make up your own definitions and then squeeze some weird conclusion out of that about papers that don't share your defintions, you are welcome. but do it elsewhere. PS. Try to be less tedious. - gavin]

    Comment by co2isnotevil — 4 Aug 2011 @ 4:12 PM

  203. @198:

    My question is WHY is it 3.3 W/m^2 per 1 degree of warming? Why not 3.3 W/m^2 per 3 degrees of warming or 3.3 W/m^2 per 33 degrees of warming, for example? It appears Chris doesn’t want to answer this, so I’ll answer it:

    Please read 128 again. The energy-balance equations are quite simple. The only thing that needs additional explanation is the origin of “dε(σTs^4)= – 4 W/m2 (for a doubling of CO2)”. That comes from line-by-line models of CO2′s absorption lines. Those models are derived from a combination of actual measurements of absorption lines (there are a great many of them) and calculations of absorption from its quantum-mechanical origins. See http://www.cfa.harvard.edu/HITRAN/ for more.

    BTW, “the original 240 W/m^2 from the Sun” is what raises earth’s effective blackbody temperature from ~3K (cosmic background) to ~255K; the total greenhouse effect is what adds ~33K to that to give the actual average temperature of ~288K.

    Comment by Meow — 4 Aug 2011 @ 6:09 PM

  204. I’m pretty sure that “co2isnotevil” is George White – http://www.palisad.com/co2/eb/eb.html

    It seems RW gets his nonsense largely from George.

    Comment by Phil Scadden — 4 Aug 2011 @ 6:23 PM

  205. Your important critique of Spencer’s claim is greatly appreciated. Please do not hobble it by making it inaccessible to even a reasonably informed lay audience by using unnecessary professional jargon.

    Is it really too much effort to spell out “El Nino — Southern Oscillation (ENSO)” somewhere?

    Comment by Mark H. Moulton — 4 Aug 2011 @ 7:00 PM

  206. Meow,

    “BTW, “the original 240 W/m^2 from the Sun” is what raises earth’s effective blackbody temperature from ~3K (cosmic background) to ~255K; the total greenhouse effect is what adds ~33K to that to give the actual average temperature of ~288K.”

    I know. What’s your point?

    “The energy-balance equations are quite simple. The only thing that needs additional explanation is the origin of “dε(σTs^4)= – 4 W/m2 (for a doubling of CO2)”. That comes from line-by-line models of CO2′s absorption lines.”

    I also know. When CO2 is doubled, supposedly the power leaving at the TOA reduces from 240 W/m^2 to 236.3 W/m^2. The surface receives +3.7 W/m^2, which the opacity of atmosphere then requires the surface to emit an additional 2.3 W/m^2 (+6 W/m^2) in order to emit the +3.7 W/m^2 at the TOA to restore equilibrium (240 W/m^2 in and out).

    For a 1 degree C rise, it takes about a 3.3 W/m^2 ‘forcing’, so 3.7/3.3 = 1.1 C. This is the origin of the so-called “Planck response”.

    Comment by RW — 4 Aug 2011 @ 7:04 PM

  207. RW, among many of your confusions, 3.7 W/m2 is the reduction in OLR at tropopause, not the forcing at the surface. In fact the TOA forcing controls the surface temperature more than the surface forcing.

    Comment by Chris Colose — 4 Aug 2011 @ 7:32 PM

  208. co2isnotevilisnotverysmart.

    Comment by Ray Ladbury — 4 Aug 2011 @ 7:52 PM

  209. Yes, co2isnotevil is indeed George White, of whom RW/RW1 is an acolyte.

    Both suffer from the same blocking preconceptions that force the physics of the world that the rest of us inhabit to conform to those selfsame preconceptions that those two are unable to rid themselves of.

    Truly a sad situation.

    Captcha: imparts ureaser

    Comment by Daniel Bailey — 4 Aug 2011 @ 9:49 PM

  210. @206, 198, etc.:

    In short, why would the feedback mechanisms all of the sudden respond to an additional 3.7 W/m^2 [4 M/m^2] of GHG ‘forcing’ [from doubling CO2] so much greater than it does to the original 240 W/m^2 from the Sun?

    Climate sensitivity is the ratio of the *change* of a planet’s surface temperature to the *change* in the forcing that causes it. It is not the ratio of the planet’s equilibrium temperature to the planet’s equilibrium forcings.

    Also, there’s nothing extraordinary about sensitivity to CO2. The Milankovich (solar!) forcing is < 1W/m^2 averaged globally and annually, but causes ~6K temperature excursions via feedbacks.

    Comment by Meow — 4 Aug 2011 @ 11:31 PM

  211. Gavin,

    Bode’s feedback system analysis is what the sensitivity model used by the IPCC is said to be based on. And it should be, since this is the definitive control theory text, especially as related to feedback systems. The definition of forcing used by Bode is the stimulus, or input to the system. It wasn’t me that redefined forcing, it was the IPCC, by defining it as a power deficit at the tropopause, yet maintaining the inference to Bode’s definition. This permits calling any effect on this deficit ‘forcing’, independent of the reason driving it. My point is that what’s called ‘forcing’ is really the combination of Bode’s forcing and other effects including natural variability in the planets response.

    The second deviation from Bode is the units of sensitivity, which rather than being gain expressed as a dimensionless ratio of power densities, it’s expressed in degrees per unit power density. Hansen et all, 1984 had the units correct, it just mixed up feedback and gain in addition to assuming unit open loop gain. You should ask him about this, because the assumption of unit open loop gain isn’t acknowledged in the paper and is crucial relative to determining the sign of the feedback. Schlesinger, in DOE/ER-0237 from which his later work was based, fixed some of this, but in doing so, lumped the translation between temperature and power density (Stefan-Boltzmann) with the gain block, which didn’t fix the unit gain assumption, but masked it in a way that required a sensitivity expressed in units that inadvertently obscured the impossibly high values of sensitivity, per Hansen’s corrected dimensionless formulation, that were associated with the expected sensitivity. This plot shows where the dimensionless surface gain corresponding to the IPCC sensitivity and the average among skeptics is relative to the ISCCP data. Each small gray dot represents the measured relationship between the post albedo incident solar power and the dimensionless surface gain for each month and each 2.5 degree slice of latitude in the record, where the dimensionless surface gain is the ratio between the power emitted by the surface and the post albedo power arriving at the planet. The vertical cyan line represents the operating point of the climate system.

    Using the ISCCP data to illustrate this is immune to the calibration issue surrounding discontinuous polar satellite coverage which precludes using the ISCCP data for trend analysis. My last point is that the deltas of the post albedo solar power density at the tropopause (to be consistent with the IPCC definition of forcing) are nearly identical to those measured in space by weather satellites and is what I’ve plotted here.

    George

    Comment by cosisnotevil — 5 Aug 2011 @ 2:25 AM

  212. “co2isnotevil” is a silly name. Nobody thinks CO2 is evil – it’s an essential part of life, and, ultimately, just a simple organic molecule.

    Nobody thinks CO2 is “evil”, any more than a rock used to bash somebody’s brains in is “evil”.

    Comment by Didactylos — 5 Aug 2011 @ 7:43 AM

  213. George,
    The climate is not the same as your stereo system. Why not study the science?

    Comment by Ray Ladbury — 5 Aug 2011 @ 9:01 AM

  214. Ray,

    The planets thermodynamic balance can be expressed as Pi = Po + dE/dt, where Pi is the power from the Sun, Po is the power reflected and radiated by the planet, E is the energy stored in the planets thermal mass and dE/dt is the sensible heat. This can be cast into the form of an LTI with very similar properties (indeed similar solutions) to the equations that describe certain electrical circuits. While clearly the climate differs from a stereo, the same math used to solve circuit problems can be used to solve the equations describing the thermodynamics of the climate system. The science is slightly different, but the math is largely the same.

    BTW, if you want to call certain effects on the climate ‘feedback’, you need to do so within the constraints of feedback system analysis and these constraints are not honored by the IPCC’s definitions of forcing and sensitivity.

    George

    Comment by cosisnotevil — 5 Aug 2011 @ 10:45 AM

  215. George,

    Read this paper

    Comment by Chris Colose — 5 Aug 2011 @ 11:28 AM

  216. Patrick027 thank you for your insightful explanation.
    All in all there seems to be no silver bullet for the conversion from CO2 concentration to radiative forcing.

    Thanks also to Meow for the HITRAN link

    Comment by Marcus — 5 Aug 2011 @ 12:55 PM

  217. George, Ray – I believe what you are looking for is this: http://xkcd.com/793/

    Comment by Didactylos — 5 Aug 2011 @ 3:43 PM

  218. George,
    I’m ‘a make you a deal. I won’t make you refer to the square root of negative 1 as ‘i’ if you don’t insist that climate science follow all the protocols of EE. After all, last I looked climate science wasn’t even a subfield of EE.

    All climate science has to do is be consistent with itself and with the laws of physics. It is. I’ve looked at it. Lots of people have looked at it–even people much, much smarter than you. What is more, the theory of Earth’s climate actually has a pretty damn good record of prediction, and the principles even help us understand what is going on on Venus and Mars.

    So, you can either learn the science (and, no, you clearly haven’t yet) or you can continue to provide entertainment for those who have bothered to do so. Your choice.

    Comment by Ray Ladbury — 5 Aug 2011 @ 5:39 PM

  219. George – “Feedback” in climate systems, does not form a runaway loop. This is not something the IPCC (or anyone else) chose to obfuscate. Ray, Chris and Didactylos all nailed it. It is handled differently in climatology than in many other disciplines (for good reason).

    Comment by arch — 5 Aug 2011 @ 6:19 PM

  220. http://www.tonycliff.com/blog/wp-content/uploads/2011/02/F_MO-3-09.jpg

    Comment by Hank Roberts — 5 Aug 2011 @ 7:42 PM

  221. Ray, Charles, Radge: Ray & Charles you are missing my point and/or I’ve failed to make it well. Personally I’m in general agreement with much of the “consensus model”, though I think the changes in temps and SL will not prove catastrophic or even hard to manage for that matter. I’m simply suggesting the RealClimate environment is not a pristine, unbiased community that treats incoming data and papers without any prejudice, and that’s too bad given the brilliance and qualifications of many posting here regularly. OTOH Radge challenges me very reasonably to provide a test of bias. One approach would be to review how research papers are treated here at RC by both post authors and by the commenters, perhaps with an eye to comments that do not address anything scientific and thus arguably reflect bias such as calling people “ignorant food tubes” and such. Another interesting approach would be to look at peer reviewed predictions to see how they line up compared to observations.
    Radge I have looked (though not extensively) for papers seeking to test for possible climate model prediction bias and also testing climate model accuracy over the past several decades. I’ve failed to find much research addressing this reasonable question:

    Under what circumstances should a climate model be considered a good model / inadequate model / failed model?

    Few here would dispute that we find plenty of bias in the skeptic community where peer review quality is even more lacking than in the mainstream climate community. Yet most here clearly think it’s completely disingenuous to suggest bias is also present here at RealClimate.

    Comment by Joe Hunkins — 6 Aug 2011 @ 11:17 PM

  222. Joe, if you think peer-review is lacking in the mainstream climate community then that demonstrates a lack of understanding in the subject matter.

    Given that, what possible test of “bias” could satisfy someone lacking that understanding?

    A Catch-22 situation.

    [Response: or one might add, what possible test of 'bias' could convince someone who is themselves biased to believe int he presence of bias? But I would add that of *course* there is bias. The bias is towards wanting to see extraordinary evidence for extraordinary claims. Which is exactly as it should be.--eric]

    Comment by Daniel Bailey — 7 Aug 2011 @ 11:30 AM

  223. What I love about papers, such as the subject article, and the “but they are still wrong!” crowd is when we have a summer like this.

    My outdoor thermometer shuts down at 114F, fairly reliably. Because it’s broken, but I digress. Let’s just say that it isn’t working a lot this summer.

    And while I wouldn’t have pegged this year for a record, yeah, I’m thinking 2011 will beat the records, regardless of which set of values are being used. Which is good. I mean, I didn’t think we’d see a new record until 2014, or maybe 2013, but the sooner the better because I’m tired of running into “global warming is a hoax” people.

    [Response: Though you might be a bit naive in thinking that facts -- let alone another single year of facts -- will have much impact. And it can always be declared once all records are broken that scientists have 'fudged' the data.--eric]

    Comment by FurryCatHerder — 7 Aug 2011 @ 11:31 AM

  224. Joe @ 221, is it possible that there is some reason for people not to 100% agree with you, besides prejudice? Like maybe scientists know something, or at least are not just surmising as you may be?

    Comment by Pete Dunkelberg — 7 Aug 2011 @ 11:48 AM

  225. Joe, just to keep things straight, of course all reasonable people agree with me. ;)

    Comment by Pete Dunkelberg — 7 Aug 2011 @ 12:16 PM

  226. Eric wrote: “… But I would add that of *course* there is bias. The bias is towards wanting to see extraordinary evidence for extraordinary claims.”

    The view that a particular claim is “extraordinary” is, itself, necessarily the result of bias.

    For example, some AGW deniers regard the claim that the activities of mere human beings could possibly cause large-scale alterations in the Earth’s climate as so extraordinary — which is to say, so contrary to their basic bias as to “how the world works” — that pretty much no evidence could be sufficiently “extraordinary” to overcome that bias.

    I have always felt that that aphorism, “extraordinary claims require extraordinary evidence” is really a justification for rejecting out-of-hand those claims which one believes, a priori, based on bias and not on evidence, to be impossible, and for protecting oneself against evidence that might show those claims to be true by setting an arbitrarily high hurdle of “extraordinariness” for that evidence.

    It would seem that on the contrary, genuine impartiality — and genuine skepticism — would argue that all claims, regardless of one’s a priori feelings about their “extraordinariness”, require the same level of evidence.

    [Response: That's a thoughtful point, and I agree that the phrase can be missed in the exactly thew way you suggest. In this context of course, what I mean is that "extraordinary claims require at least a modicum of plausible evidence before they are worth putting much energy into looking at...." That would apply well to the contention that the 20th century CO2 rise in the atmosphere is not anthropogenic, don't you think?--eric]

    Comment by SecularAnimist — 7 Aug 2011 @ 1:32 PM

  227. Joe Hunkins: “…though I think the changes in temps and SL will not prove catastrophic or even hard to manage for that matter.”

    And this is based on…what exactly? More and more of the planet is in drought–as predicted by models. We’re seeing more extreme weather events–as predicted by models. We’re seeing crop yields go down–as predicted by models and analyses. The oceans are acidifying–as…well, you guessed it. And so on.

    Joe, the first rule of science is that you go with the evidence. The second rule is that the experts in a field–those most actively publishing–are the most likely to 1)understand the field, and 2)be able to interpret the evidence. Do you really consider coming down on the side of the overwhelming preponderance of the evidence and of the experts to be “bias”?

    Comment by Ray Ladbury — 7 Aug 2011 @ 2:04 PM

  228. Joe Hunkins #221, confirmation bias affects everybody. Finding it everywhere is hardly a surprise. According to you, the bias is far greater among deniers. How much time have you spent looking at climate models that demonstrate skill in making predictions? Have you noticed that RC articles (like the one at the top of this page) regularly discuss testing one model’s reliability against another? Obviously not. Bias much?

    Comment by One Anonymous Bloke — 7 Aug 2011 @ 4:52 PM

  229. Ray, encourage him to stay focused on the topic, eh? You know the pattern.

    Comment by Hank Roberts — 7 Aug 2011 @ 5:14 PM

  230. Secular,

    Science has a long history of extraordinary claims. The very assumptions built into scientific analysis- that the world can be made intelligible and described by physical laws- seems extraordinary. Claims that time can dilate and length can contract as you move with a speed approaching a significant fraction of c are extraordinary. That we stand on moving plates that alter the position of the continents over geologic timescales is extraordinary. And I agree that claims that a gas which makes up roughly 400 molecules in every million can have a significant climate impact is extraordinary.

    It is also evident that we all have our individual biases, even if we cannot notice them personally.

    What makes science so interesting is its self-correcting nature and need to bring in people of different disciplines, and working in many independent groups, to bring together multiple lines of evidence and unify them into the best possible theory. This allows new ideas with high predictive and explanatory power to overturn older ideas with less ability. Indeed, that CO2 could have a significant impact on climate was met with high opposition after Arrhenius, and so were claims that we could even alter the CO2 concentration appreciably. All of the above ideas- plate tectonics and continental drift, the role of CO2 in planetary climate, relativity, etc were all met with initial skepticism (as they should have been) but after multitudes of evidence came together, it was clear that the extraordinary claim was correct.

    This has not been done with the new counter-argument that the CO2 rise is not anthropogenic, and we have every right to be as skeptical as the scientists before us were skeptical of radical ideas.

    Comment by chris colose — 7 Aug 2011 @ 7:38 PM

  231. Exactly Chris, sceptical, but with an open mind. At first blush, it appears that this new paper will be wrong, but let’s wait until it’s published to see if it is worth bringing into the process or not. I doubt that it will take much time to discern this.

    Comment by Leo G — 7 Aug 2011 @ 11:43 PM

  232. Chris C. and S. A., I certainly do not buy that all claims are a priori equally probable, because we do not start with a 100% uninformative Prior probability distribution. I would meet with great skepticism and ask for overwhelming proof for a claim of a perpetual motion machine or cold fusion. On the other hand, that 400 ppmv CO2 could influence climate is not at all incredible when one considers the number of CO2 molecules in the path of an outgoing IR photon.

    Comment by Ray Ladbury — 8 Aug 2011 @ 4:54 AM

  233. I was at the local strip mall, and the guy who owns the comic book store told me that NASA says there isn’t warming. I told him to check the NASA site instead of believing his source.

    He seemed not to understand that his source might be mischaracterizing what NASA said.

    No matter what evidence I gave him, he kept repeating “Nasa says…”

    Comment by Snapple — 8 Aug 2011 @ 6:53 AM

  234. #230–

    Seems to me that the “extraordinary claims” trope is basically an appeal to scientific common sense. No surprise that it doesn’t work WRT those who are bereft of same.

    Comment by Kevin McKinney — 8 Aug 2011 @ 7:31 AM

  235. SecularAnimist
    “all claims, regardless of one’s a priori feelings about their “extraordinariness”, require the same level of evidence.”

    So, the claim “there’s an albino deer living in NYC” would require the same evidence as “there’s a carnivorous deer living in NYC”? Personally, I’m “biased” in such a way as to accepting the albino’s existence with less evidence (say, just a witness) as opposed to a meat eating deer, because of my knowledge of biology and (yes, as you point out) my perception of how the world works. I don’t see how this is unreasonable.

    So, pulling this back to climate change somewhat. When communicating “claims” should one account for the inherent biases of the audience because geologists, for example, probably have a different perception of how the world works than say biologists? What may seem ordinary to some is extraordinary to others, and that’s just the way it is.

    Comment by John W — 8 Aug 2011 @ 10:20 AM

  236. Eric’s reply @ 223:

    Yes, there’s always that. However, there are two main camps that I see –

    “They are fudging the data!”

    Pretty hard to argue they are “fudging” the present nastiness in regards to this summer’s weather.

    “The warming stopped.”

    Well, it seems to have started back up again!

    And while I happen to think the nastiness of Solar Cycle 22 and 23 contributed to an increase over the “baseline” warming, if we make a new record in a “low” cycle — and 24 is somewhat weak — the “It’s the sun!” crowd will have to face facts as well.

    Comment by FurryCatHerder — 8 Aug 2011 @ 10:51 AM

  237. 221 Joe asks,”Under what circumstances should a climate model be considered a good model / inadequate model / failed model?”

    Models evolve, so you can compare models of the same era and rate them. It would be nice to see a post on how models have improved over the years. I wonder how often models are updated?

    Comment by RichardC — 8 Aug 2011 @ 6:52 PM

  238. 226 Secular says, “The view that a particular claim is “extraordinary” is, itself, necessarily the result of bias.”

    In the scientific community the “bias” is the record of published literature. The larger the deviation from the published literature, the more extraordinary the claim, and so the more extraordinary the evidence is needed.

    Comment by RichardC — 8 Aug 2011 @ 6:58 PM

  239. Joe,

    So far the only biases I see being attributed to RC are those against bad science and against suffering fools gladly.

    If you want to suggest that there are more insidious biases at play then perhaps it would be best to first evaluate the science and its critiques, on the merits, specifically and in detail. And if that’s found wanting then investigate how or why that is. That’s opposed to making an assumption and then trying to finagle a demonstration to make the outcome fit…

    As for computer modeling, it’s been a recurrent topic here. If you were to ask specific questions on the matter (respectfully, of course) I’m sure you’d end up with more info and resources on methodology than you can shake a stick at. (Note also the “RC wiki” and “start here” buttons).

    FWIW, I’ve noticed that showing up here while making unsupported accusations will inevitably get you a big red bull’s eye slapped on your backside, courtesy of Fair Game Enterprises.

    Comment by Radge Havers — 8 Aug 2011 @ 7:39 PM

  240. arch, re 219

    Yes, climatology defines feedback (and sensitivity/gain) differently than the way it’s formally defined. I contend that this is a significant error. You can’t claim the kinds of scary things associated with positive feedback in an amplifier (i.e. instability, massive gain boosting, etc.) when the definition you’re using for feedback has nothing to do with the criteria for determining the stability of a system. In response to Ray, I’ll stop using electrical circuit analogies when consensus climate science stops calling the effects of CO2 feedback and claiming that the feedback analysis supporting this is supported by Bode.

    The basic misunderstanding is a failure to grasp the difference between open loop and closed loop. The basic gain equation for a feedback network (electrical, mechanical, climate or otherwise) is, 1/g = 1/G + f, where g is the closed loop gain (sensitivity), G is the open loop gain (intrinsic gain) and f is the fraction of the output sent back to the input closing the loop and whose sign determines whether the feedback is positive or negative. If you assume G==1, the gain equation becomes 1 = 1/g + f, or, g = 1/(1-f), which you should recognize as equation 7 from Hansen et all 1984 which was introduced with the statement ‘it follows that …’. This is where gain and feedback were switched and where unit open loop gain was assumed. This is such a significant error that I consider equation 7) in this paper as where climate science broke.

    Hansen et all’s confusion between feedback and gain still permeates climate science today. What’s considered positive feedback is really gain, yet the scary elements of positive feedback remain associated with it. Ironically, Hansen had it right by considering the static effects of GHG’s gain, he just called it feedback because that was what the paper was trying to show. The Schlesinger correction ‘fixed’ the wrong thing. Rather than correct the terminology, feedback networks were redefined in an obfuscating manner so that the effects of GHG’s could be called feedback without introducing obvious inconsistencies.

    A more correct formulation would ascribe the static effects of atmospheric absorption as a component of the intrinsic, open loop gain, not as the feedback closing the loop. Clouds and dynamic atmospheric absorption from variable water vapor comprise the control plane that introduces feedback and closes the loop.

    [Response: Oh please. Arguing semantics on blogs is almost as bad as going on about spelling mistakes. If it makes you happy, write an awk script that changes every use of the word feedback to zyzyrt and then follow the identical mathematics. To paraphrase, perhaps: "A feedback by any other name would quell a heat"... - gavin]

    Comment by co2isnotevil — 8 Aug 2011 @ 8:31 PM

  241. RichardC @ 237 I wonder how often models are updated?

    I don’t think “update” is the best word. That is, there is no such thing as “OK everybody, it’s time to stop researching and give the model an overall update.” As I understand it from reading RC and Serendipity the big in-use models are meant to be permanent works in progress even as they are used. The aim of course is to use physics plus forcings (data) to explore and understand climate. A particular physical process module may be added (new process) (after separate testing) or modified, and don’t be surprised if this happens during a six month run so by the time the run is done it is not using the latest version. The models are used for, among other things, physics (theory) experiments. The people who know the models best know what their model can be used for. Be glad experiments on climate are done this way rather than directly. Oh wait ….

    How quickly can something like this be added to a model? Beats me.

    No doubt an actual expert can straighten out my attempted explanation.

    Comment by Pete Dunkelberg — 8 Aug 2011 @ 10:23 PM

  242. Gavin,

    If the problem I’m pointing out was that trivial to see and fix, it would have been fixed by now.

    [Response: It's not a problem and it doesn't need fixing. - gavin]

    The issue is that strong positive feedback is claimed to amplify the intrinsic effect of 3.7 W/m^2 of forcing (about 6 W/m^2 or 1.1C) into the 16 W/m^2 required for a 3C surface temperature rise. The 6 W/m^2 intrinsic effect also corresponds to the surface temperature rise that results from each 3.7 W/m^2 of solar power input. The 6 W/m^2 is a factor of 1.6 larger than the 3.7 W/m^2 of forcing and is already a closed loop, or post feedback, result.

    This ratio of 1.6 is equal to 1/e, where e is the planets emissivity (240 W/m^2@255K / 390 W/m^2@288K), which is equal to 0.61 and it follows that 390/240 = 1.6. It’s this factor of 1.6 that represents the climate systems gain relative to Bode semantics and which embodies all feedbacks operating on the system.

    A gain of 1.6 corresponds to an IPCC sensitivity of only 0.3 C per W/m^2. A sensitivity of 0.8 C per W/m^2 corresponds to a Bode gain of 4.3. Since the IPCC defines forcing as a power delta at the tropopause, a 3.7 W/m^2 change in solar power at the tropopause should have the same effect as 3.7 W/m^2 of forcing arising from doubling CO2.

    How can the forcing from incremental atmospheric absorption be nearly 2.7 times more powerful at warming the surface than the same amount of incremental power from the Sun?

    George

    [Response: You are repeating the same errors as RW - to whit: you are defining sensitivity incorrectly even for trivially simple examples, you are linearising a highly non-linear problem over a huge range, and you are blaming a semantic confusion on your part for your inability to actually work through the (relatively simple) algebra. Just as I suggested to him that he work out why his calculation and the real sensitivity in a simple model are not the same, I suggest the same to you. Just telling you so clearly isn't sufficient, and you & RW repeating yourselves ad nauseum is tedious. If you want to know why you're wrong, work out the maths, and if you'd rather persist in ignorance, take it elsewhere. - gavin]

    Comment by co2isnotevil — 8 Aug 2011 @ 11:40 PM

  243. Variation in the satellite infrared noted here:

    ” These changes characterize the state of the atmosphere and ionosphere several days before the onset of this earthquake. Our first results show that on March 8th a rapid increase of emitted infrared radiation was observed from the satellite data and an anomaly developed near the epicenter…. We found a positive correlation between the atmospheric and ionospheric anomalies and the Tohoku earthquake. This study may lead to a better understanding of the response of the atmosphere /ionosphere to the Great Tohoku earthquake

    Comments: Preliminary results reported at EGU 2011 in Vienna, Austria
    Subjects: Geophysics (physics.geo-ph); Space Physics (physics.space-ph)
    Cite as: arXiv:1105.2841v1 [physics.geo-ph]

    Comment by Hank Roberts — 9 Aug 2011 @ 1:01 AM

  244. Aren’t there undergraduate courses that would help George and RW?

    [Response: Working through Ray Pierrehumbert's book would do the trick. - gavin]

    Comment by Didactylos — 9 Aug 2011 @ 8:03 AM

  245. Now this gets weird. Compare this one
    http://arxiv.org/abs/1107.0930
    to the paper I mentioned yesterday yesterday (link above). (Not clear why, in this paper, they aren’t including a baseline before the earthquake, in this paper):

    “Immediately after the March 11, 2011 earthquake and tsunami in Japan we started to continuously survey the Outgoing Long-wavelength Radiation (OLR, 10-13 microns) from NOAA/AVHRR…. On March 14 and 21 we detected a significant increase in radiation (14 W/m2) at the top of the atmosphere which also coincides with a reported radioactivity gas leaks from the FDNPP. After March 21 the intensity of OLR started to decline, which has been confirmed by ground radiometer network. We hypothesize that this increase in OLR was a result of the radioactive leaks released in atmosphere from the FDNPP. This energy triggers ionization of the air near the ground and lead to release of latent heat energy due to change of air humidity and temperature…..”

    My comment — well, something’s going on with some instruments on some satellites, if this is right.

    Is whatever they’re talking about outside the usual variability, and how well are they correlating what they describe with the causes they variously hypothesize?

    Is it ordinary cloud tops, infrared iris, earthquake precursors, atomic radiation leaks, or some or all of the above? Or little green men messing with the satellites?

    Comment by Hank Roberts — 9 Aug 2011 @ 12:13 PM

  246. > co2snot…
    > … RW

    RW has moved over to Roy Spencer’s blog now, to reassert the same notion.
    http://www.drroyspencer.com/2011/08/is-gores-missing-heat-really-hiding-in-the-deep-ocean/#comment-19979
    It’s an inverse Gish Gallop–reiterating one idea, but jumping from one blog to the next.

    Comment by Hank Roberts — 9 Aug 2011 @ 1:30 PM

  247. As far as I can see, George White and his pupil RW have not the slightest interest in working out where they are wrong and since they are sure that they are right, can see no value in working through a textbook. There isnt any point wasting time with them.

    Comment by Phil Scadden — 9 Aug 2011 @ 4:53 PM

  248. And both exhausted both civil dialogue and welcome at Skeptical Science, where the regulars are well-versed in the science and in dealing with skeptics toting bags of hammers.

    ReCaptcha: erilly following

    Comment by Daniel Bailey — 9 Aug 2011 @ 7:11 PM

  249. Gavin,

    “Working through Ray Pierrehumbert’s book would do the trick.”

    I have the book. Which parts in particular?

    [Response: All of it.--eric]

    Comment by RW — 9 Aug 2011 @ 11:20 PM

  250. Ray Ladbury says:
    There are about a dozen independent lines of evidence for climate sensitivity. All of them favor a value around 3 degrees per doubling.

    Please update wikipedia:
    http://en.wikipedia.org/wiki/Climate_sensitivity

    Since “sensitivity” isn’t an intrinsic property, why can’t it be dynamic? It seems to me the sensitivity could be different for different forcings in different situations. For example, an increase in solar irradiance might have very little effect on a snowball earth but a GHE increase might have a huge impact on temperature. (Arctic snow having a high albedo for UV/Visible but low for IR)

    Comment by John W — 10 Aug 2011 @ 10:08 PM

  251. John W – What are you trying to say about the Wikipedia article?

    “More recent work continues to support a best-guess value [of the climate sensitivity to be] around 3°C.”

    Why would this need updating?

    Why can’t the climate sensitivity be what you are defining as “dynamic?” Because, under the general parameters of the present day earth, it’s not. Remember that climate sensitivity is defined as the change in average temperature resulting from a doubling of atmospheric CO2. Any likely change in solar irradiance is an external forcing which will affect the temperature, but by itself won’t change the climate sensitivity. The effect of the climate sensitivity would be an internal forcing on temperature. Direct observations, proxy estimates, and climate modeling all support the fact that the climate sensitivity, including feedbacks, is around 3ºC.

    Comment by Craig Nazor — 11 Aug 2011 @ 2:50 AM

  252. @John W 250
    Craig Nazor has already sufficiently addressed the scientific error you’re making, but the fact that you asked it, in this forum, in this context and not via research of your own, reveals a more fundamental misunderstanding on your part of The Way Science Works. I will now address that.

    Since “sensitivity” isn’t an intrinsic property, why can’t it be dynamic? It seems to me the sensitivity could be different for different forcings in different situations. For example, an increase in solar irradiance might have very little effect on a snowball earth but a GHE increase might have a huge impact on temperature. (Arctic snow having a high albedo for UV/Visible but low for IR)

    Anything is possible, but if you believe that it is so, it is your burden to cite some evidence, or if it doesn’t already exist, to produce it via original research of your own. That is non-negotiable.

    When you dispute the top experts, in this or any field of science (which is what you are doing when you gainsay the consensus that climate sensitivity is ~3C) it is not sufficient to just pull something out of your hat, wave your hands to suggest it “could be” the way you suppose, and then shift the burden of proof to the real scientists. If you really believe that the scientific consensus on climate sensitivity (or any other subject) is wrong, then you need to apply for a research grant to start substantiating your belief And if you are not already working in an climate or an allied field of physical science, then this may require you to obtain some advanced degree(s) as prerequisite.

    Those are the standards of evidence in science.

    That is life.

    And to preempt the anticipated argument from “chaos,” Chaos Theory has a specific meaning. The important thing about that definition for our purposes is high sensitivity to small changes in initial conditions. We know from Lorenz that specific weather events cannot be predicted “reliably” beyond ~5 days, sometimes less and sometimes a little more in some regions, but anyway, there is an accepted limit on the ability to predict the specific events of weather. From that, it does not follow that climate’s aggregate measurements, such as global mean temperature, atmospheric CO2 concentration, water vapor concentration and sensitivity are necessarily “chaotic” too. Such would be a hypothesis, and also your burden to substantiate.

    My apologies if you did not plan to bring up chaos, but I have seen it so many times in online discussions about climate, and usually with claims such as yours, that something “could be” different from the consensus position because is cannot be known that I like to stop such nonsense before it starts. And I have seen “chaos” in several discussions of SB11 specifically, also invoked incorrectly, so I have good reason to suppose it’s about to rear its ugly head again.

    Weather is reasonably predictable up to about five days, and climate is reasonably predictable on multi-decadal time scales using averages including sensitivity. If you sincerely believe any of those quantities is in error, then your duty is not just to make something up and say it “could be,” it’s to do the hard work to show that it is, or at least cite a scientist who has. Failing that, ya got nuthin. Absolutely nuthin.

    Comment by Settled Science — 11 Aug 2011 @ 12:01 PM

  253. Craig Nazor
    The wikipedia article cites studies, whose findings for sensitivity are all over the place, not a dozen “independent” lines of evidence all pointing to 3C for 2XCO2, more like all “average” to 3C for 2XCO2, as you quoted from the article. The difference is subtle indeed and perhaps not worth mentioning.

    Sorry, I didn’t realize the caveat “for 2XCO2″ wasn’t necessary. I was under the impression that “climate sensitivity” was more broadly defined. So, for future reference if I am discussing the climate response to increased solar activity and wanted to use a term that described the temperature increase for a given increase in heat flux what would be the preferred term?

    Comment by John W — 11 Aug 2011 @ 12:11 PM

  254. co2isnotevil says:

    Yes, climatology defines feedback (and sensitivity/gain) differently than the way it’s formally defined. I contend that this is a significant error. You can’t claim the kinds of scary things associated with positive feedback in an amplifier (i.e. instability, massive gain boosting, etc.) when the definition you’re using for feedback has nothing to do with the criteria for determining the stability of a system.

    You know, I kind of agree with you. The fact that climate science defines “feedback” differently from EE creates confusion and unnecessary obstacles to people who come to climate science with a background in EE. EE has been using the term “feedback” for a very long time, and it would be a lot clearer if climate scientists had chosen to use the term in a parallel way. It was an unfortunate choice of jargon.

    But frankly, it is hardly the only unfortunate jargon choice in science. Very often, scientists in one field use a term in a very different way than it is used in common parlance or in another scientific field. EE is hardly immune; after all, in most circuits, the “direction” of current flow is the opposite from the direction of movement of charge carriers. This is unnecessarily confusing and an obstacle to learning for many students who are accustomed to thinking of current in terms of fluid flow. So should we redefine or rename current to correct this “error”? Or maybe swap “positive” and “negative” so at least the direction of current in a wire corresponds to the movement of electrons? Think of the confusion that would result! When you read the literature, you would have to check the date to see if the terms are being used in the old sense or the new sense.

    So face it. When you approach a new technical field, you have to accept that they will have their own jargon. Very often this means using a familiar word in an unfamiliar way, and you just have to learn that the words mean what they are defined to mean in that context, even if you are used to using them differently in another context. Perhaps somebody once upon a time made a poor choice of terminology. It may have been an “error” in the sense of a bad decision, but it is not a scientific error so long as the reasoning follows the definition of the word as it is used in that field. Stomping your feet and insisting that they have it wrong doesn’t enhance understanding or advance knowledge; it just makes you tedious.

    Comment by trrll — 11 Aug 2011 @ 12:26 PM

  255. Settled Science says:
    “If you really believe that the scientific consensus on climate sensitivity (or any other subject) is wrong”

    I did not intend that at all. All I’m saying is that if there is scientist A, B, and C all determining climate sensitivity from different periods over different time frames with different forcings that they could all get different answers and none invalidates the other (they’re all right), because (and I don’t believe I’m contridicting any scientific finding here) climate sensitivity is not rigidly static. Most (if not all) who have published on the subject report climate sensitivity as an average over some time period suggesting it isn’t “a value”. Granted I’m not a climate scientist so I may be misinterpreting what I’ve read; hence, the question mark.

    Comment by John W — 11 Aug 2011 @ 2:44 PM

  256. > suggesting it isn’t “a value”

    Sure it is. It’s calculated: take a world; take its average temperature; double the CO2 in the atmosphere instantaneously, holding everything else unchanged; wait til the temperature stabilizes; take the temperature again; do the arithmetic. There’s your value. That’s the definition (as paraphrased by a non-climatologist).

    Problems arise when figuring this out for real world situations.

    It’s not a “constant” — like gravity or the speed of light.

    Comment by Hank Roberts — 11 Aug 2011 @ 6:30 PM

  257. 255

    You’re just making more claims without any evidence, and these are different claims than you made in 250.

    I did not intend that at all.

    Well it sure looks to me like you did, until you were shown to be wrong.

    Ray Ladbury says:
    There are about a dozen independent lines of evidence for climate sensitivity. All of them favor a value around 3 degrees per doubling.

    That was the statement that you contradicted, like so:

    Ray Ladbury says:
    There are about a dozen independent lines of evidence for climate sensitivity. All of them favor a value around 3 degrees per doubling.

    Please update wikipedia: [snarky! which helps remove all doubt: you were disputing Ray Ladbury there, so stop denying it, will you?]
    http://en.wikipedia.org/wiki/Climate_sensitivity
    Since “sensitivity” isn’t an intrinsic property [unsupported assumption], why can’t it be dynamic? It seems to me the sensitivity could be different for different forcings in different situations. For example, an increase in solar irradiance might have very little effect on a snowball earth but a GHE increase might have a huge impact on temperature. (Arctic snow having a high albedo for UV/Visible but low for IR)

    Now, you’re saying something different. That’s fine, but that does not change the fact that you did start out in 250 claiming that what Ray Ladbury said about the scientific consensus on sensitivity is wrong.

    All I’m saying [now] is that if there is scientist A, B, and C all determining climate sensitivity from different periods over different time frames with different forcings that they could

    And again, anything “could” be but not every imaginable scenario that “could be” is relevant just because the evidence doesn’t rule it out beyond a shadow of a doubt. All that is relevant is which of the myriad possibilities the evidence shows to be so, or at least can be shown by evidence to be likely.

    … all get different answers and none invalidates the other (they’re all right), because (and I don’t believe I’m contridicting any scientific finding here) climate sensitivity is not rigidly static.

    That’s one possibility, but it is not logically implied by the mere fact that slightly different values are obtained by different methods. The fact that they are mostly around 3°C suggests that the real, correct value is around 3°C.

    Most (if not all) who have published on the subject report climate sensitivity as an average over some time period [the time period each one is studying] suggesting it isn’t “a value”.

    That is not a logical inference, because the time period being examined is not the only thing varying from one study to another. They also depend on different measurement methods and different ways of accounting for other influences, some ways undoubtedly better than others. In short, more plausible reasons are evident for the small variations observed.

    In general, a distribution of measured or computed values does not imply that the quantity itself is varying, particularly when the measured or computed values cluster around one quantity, as the values of climate sensitivity do. It takes much more than variation in measurements to establish that the quantity itself is actually varying. In simplest terms, to support your assertion would require measured or computed variation that is greater than the plausible margin of error of measurements and computations, and I don’t believe you have that.

    “Please update wikipedia”

    In the future, I suggest you present your speculations in the form of questions. HTH.

    Comment by Settled Science — 11 Aug 2011 @ 7:01 PM

  258. John W. How are you proposing that the climate system should know precisely whether a watt of forcing comes from IR or UV–particularly since one of the processes in Greenhouse warming is rapid thermalization (e.g. the vibrational excitation relaxing collisionally and imparting the excess energy to another molecule, say N2). Folks have looked into this sort of thing–they really have. And given the diversity of methods and data, doesn’t that make it all the more remarkable that the favored value is so consistently around 3 degrees per doubling? Shouldn’t that tell you something?

    Comment by Ray Ladbury — 11 Aug 2011 @ 7:36 PM

  259. John W., BTW, the following site is a lot more informative (and correct) that the Wikipedia article.

    http://agwobserver.wordpress.com/2009/11/05/papers-on-climate-sensitivity-estimates/

    Comment by Ray Ladbury — 11 Aug 2011 @ 7:46 PM

  260. Settled Science

    In short, more plausible reasons are evident for the small variations observed.

    OK the values are from 0.7 to 6.8; I don’t know but that doesn’t seem like a small variation clustered around 3, so your explanation doesn’t fit the data; it seems more like averaged to 3 (depending on the distribution). But again, it’s a only subtle difference.

    Now, you’re saying something different.

    I’m not saying anything different, if you can’t understand how a dynamic sensitivity means different research findings could all be right, well I guess I’m not explaining it well. BTW: I put at least three variables into the sensitivity dynamics and didn’t claim they are all there are.

    In the future, I suggest you present your speculations in the form of questions. HTH.

    Again, hence the question mark in the original.

    I don’t understand why that idea [dynamic sensitivity] would be controversial. It doesn’t contradict the IPCC or any other scientific research that I’m aware of, personally I kinda thought it explains why RS’s paper (the Topic) doesn’t invalidate anything (as claimed).

    Comment by John W — 11 Aug 2011 @ 8:11 PM

  261. > dynamic sensitivity

    Well, look at what Scholar finds; nothing controversial, but nothing extremely simple either. Here’s the search I tried, for starters:
    http://scholar.google.com/scholar?hl=en&q=climate+%2B“dynamic+sensitivity”

    Three quotes from three result hits on the first page:

    “Typically, the dynamic sensitivity in 2100 is about 2/3 of the static sensitivity.”

    “… the difference between the static and the dynamic approach was negligible for small climate perturbations …”

    “For the 2000-50 period, dynamic sensitivity is distinctly higher than static sensitivity.”

    Shorter: “It depends on what exactly you’re talking about.”

    Comment by Hank Roberts — 12 Aug 2011 @ 12:32 AM

  262. John W, you are quite right to highlight the importance of distribution in measures of climate sensitivity. Your unqualified description of the range omits crucial details of where the estimates cluster, as well as the “long tail” in the distribution.

    This chart summarises climate sensitivity derived from various lines of evidence, showing the distribution. Note that all lines of evidence show a climate sensitivity best estimate within the IPCC “likely” range, and very close to 3 degrees. The fact that these lines of evidence are based on several different climates (or periods of climate) implies strongly that climate sensitivity does not change much over time.

    Please note the long tail shown by each estimate. This rules out lower values for climate sensitivity, but fails to rule out higher values.

    I find it telling that Spencer is futzing around with climate sensitivities of 1 degree – this is the lowest possible sensitivity that the data currently supports, and is a long way from the best estimate and light years away from the worse case!

    Comment by Didactylos — 12 Aug 2011 @ 7:00 AM

  263. Ray Ladbury
    “How are you proposing that the climate system should know precisely whether a watt of forcing comes from IR or UV”
    Well in the example I gave, it would be from the albedo being different for UV than IR.

    “–particularly since one of the processes in Greenhouse warming is rapid thermalization (e.g. the vibrational excitation relaxing collisionally and imparting the excess energy to another molecule, say N2).”

    Well, here’s some of the confusion, y’all seem to take “climate sensitivity” as what I would call “climate sensitivity to 2XCO2″. I was using the term much more broadly than is apparently acceptable. But back to your statement: “vibrational excitation relaxing collisionally and imparting the excess energy to another molecule”; but also, collisionally imparted vibrational excitation relaxing emissively thereby transferring translational energy from another molecule into IR energy, thereby cooling the surroundings (atmosphere) and warming IR absorbing surfaces(earth); this is the “fingerprint” of GHG increase under current conditions. Yes, taking “climate sensitivity” as “climate sensitivity to 2XCO2″ especially under reasonbly similar conditions (ie: not snowball earth, or hothouse earth) I don’t see any reason why there would be much variability, but again, I’m not a climatologist and my question is still not answered: (rephrasing) Does the overall average temperature response differ between forcings under differing conditions? (Yes, No, Maybe) If yes, then are we talking orders of magnitude or tiny shifts?

    Comment by John W — 12 Aug 2011 @ 1:14 PM

  264. @263: Hansen et al 2005 explores the temperature change produced by a range of like W/m^2 of different forcings as compared to a 1.5x CO2 reference (“efficacy”) by applying them individually to the same climate state under GISS Model E attached to three different ocean models. Fig. 25 summarizes the results. Searching for cites to this paper should yield lots of refinements.

    Comment by Meow — 12 Aug 2011 @ 3:50 PM

  265. Re 250 John W -

    see ‘efficacy’ – it is possible that the climate response to the same global average tropopause-level forcing with stratospheric adjustment would be different due to different distributions of that forcing. I’m not sure on the current status of this, but dark aerosols specifically distributed on snow cover/ice could tend to have a larger global average response because there is a local/regional concentration coincident with a concentration in positive feedback.

    But for some specific examples you list, the expectation of different climate response actually comes from different amounts of forcing. The solar forcing, in terms of tropopause-level (or TOA, for that matter) net flux changes, would not be equal to changes in TSI/4. It would depend on changes in the amount of solar heating, which is modulated by the albedo.

    Climate sensitivity often refers to an equilibrium sensitivity but there is also a transient sensitivity, which is affected by the rate of equilibration.

    Comment by Patrick 027 — 12 Aug 2011 @ 4:41 PM

  266. Re 250 John W – also, the effect of solar TSI changes on tropopause-level solar forcing is affected by stratospheric ozone, and solar radiation also affects ozone.

    Orbital forcing is especially idiosyncratic, as it’s big effects on climate depend on the seasonal and latitudinal rearrangement of insolation; the changes in global annual average solar forcing are small.

    And the relationship between temperature and radiation is nonlinear, so of course climate sensitivity could be different when in snowball conditions, but a linear approximation (constant sensivity) could apply with smaller error for a smaller range of conditions.

    There is also the distinction between Charney sensitivity and a ‘fuller’ sensitivity. Charney senstivity includes water vapor, clouds, snow, and I think sea ice (and maybe a few other things?), as feedbacks, and treats ice sheets and CO2 and CH4, among other things, as external forcings. Charney sensitivity will generally tend to be similar to actual sensitivity over shorter time periods, as CO2 and ice sheets can respond to climate changes but generally take a longer time to do so (and thus over short time periods, they act approximately like boundary conditions – thus like external forcings).

    My understanding is that Charney equilibrium sensitivity will vary less over geologic time and over differing conditions. The fuller climate sensitivity can easily vary – for example, at temperatures too warm for significant ice sheets, ice sheets are not available as feedback; for different continental arrangements and other conditions, CO2 feedback could be different. Also, sensitivity has to be defined differently – if CO2 is included as feedback, then the external forcing can’t be the radiative forcing from changes in CO2; it could be a non-climate-induced CO2 perturbation, such as the amount of CO2 emitted directly from anthropogenic fossil fuel burning, deforestation/etc, and cement production – although one could argue that human activity is a feedback to the recent climate history and then to the whole of climate history via evolution and ecological succession, etc. :)

    Comment by Patrick 027 — 12 Aug 2011 @ 5:41 PM

  267. John W.,
    You missed my point. Thermalization occurs regardless of the source of the energy. It is true that different types of energy may enter the atmosphere via different mechanism, but because they will disturb the thermal balance between energy modes, eventually energy will flow into the other modes until local thermal equilibrium is restored. The rapid thermalization is why the climate (to first order at least) will not “remember” where the energy came from, and all sources of energy will likely have the same sensitivity (again to first order).

    Again, I can assure you that folks have thought about this.

    Comment by Ray Ladbury — 12 Aug 2011 @ 6:29 PM

  268. Ray, perhaps you could point John W to one of the places he can learn about this stuff? There must be a teaching site or thread out there.

    RC tends to revisit basic questions a lot, each time a new topic opens, no matter what it’s meant to discuss.

    Comment by Hank Roberts — 12 Aug 2011 @ 7:39 PM

  269. Hank, I wish I knew of a good site for tutorials on thermo. It is unfortunately a subject that doesn’t get enough pedagogical attention.

    If John W. will tell me his level of mathematical comprehension, I could maybe recommend a book.

    Hmm. Maybe I can find something on MIT’s Open courseware site.

    Comment by Ray Ladbury — 12 Aug 2011 @ 9:11 PM

  270. Re 216 Marcus
    Thanks.

    All in all there seems to be no silver bullet for the conversion from CO2 concentration to radiative forcing.

    Actually there is a quick back-of-the-envelope way to roughly approximate it. If you have a spectrum for global time average OLR, you can see where the CO2 valley is, and interpolate across it where (roughly) the spectrum would be if CO2 were removed. Such a spectrum was calculated (using globally-representative conditions) by Kiehl and Trenberh 199x (x is either 7 or 8, I’ll have to get back to you about which) (alternatively, if we took a weighted average of satellite data…). You can compare the area on the graph added to OLR by removing CO2 to the value in Kiehl and Trenberth for total CO2 forcing excluding overlaps.

    Anyway, an approximate answer for instantaneous TOA forcing per doubling of CO2 can be gained by multiplying the depth of that valley (relative to OLR without CO2) by the sum of the spectral intervals over which CO2 optical thickness decreases by half on each side of the CO2 peak

    (a logarithmic plot of CO2 optical thickness graphed over the spectrum using the same units as the OLR spectrum uses would be helpful)
    (this is ignoring the smaller-scale texture of the CO2 spectrum – if this is sufficiently self similar over small intervals, the texture won’t matter, but there is a bit of a larger-scale bumpy wobble in the spectrum that will have an effect – see next paranthetical statement)
    (if this spectral interval value changes a bit, you’d want to look at what it is at those wavelengths or frequencies where the OLR CO2 valley slopes from it’s outer edge to it’s bottom)
    (When I tried this myself, I took the interval (visually estimated) for a tenfold change in optical thickness and multiplied by log(2)/log(10). Perhaps it would have been better to start with the interval for a 100-fold change – perhaps less accurate at any given CO2 value but it would apply over a wider range of CO2 amounts).

    To find the tropopause level forcing, note that the net longwave flux in the center of the CO2 band is nearly zero, while the net upward flux just outside of the CO2 valley is about the same at the tropopause as it is at TOA (because the stratosphere is nearly transparent in that part of the spectrum except for CO2). Thus the depth of the valley to use to calculate forcing at that level is what the OLR would be absent the CO2. The difference between the two values is a forcing on the stratosphere that causes cooling, a portion of which is then transfered to the forcing at the tropopause.

    This takes advantage the shape of the CO2 band centered at 15 microns, and CO2′s saturation or near saturation at/near the band center at the tropopause and at TOA (in the sense that adding CO2, beyond some point, doesn’t decrease OLR farther). This is setting aside the effect of the growth of the little peak in the bottom of the CO2 valley (from the warmer thin upper stratosphere). The interpolation to find the OLR absent CO2 assumes the water vapor spectrum is sufficiently smooth and linear in that (setting aside the finer scale texture) in that part of the spectrum. This sets aside the SW forcing by CO2. This also sets aside the curvature of the Planck function; to approximately(?)**** correct for that, you could put the OLR spectrum in terms of brightness temperature and find the corresponding range in flux for the same brightness temperature rhange at the parts of the spectrum where the CO2 valley’s slopes are, and use that instead of the depth of the valley at the band center (and also, use that value on each side to multiply withthe band-widenning interval on the same side, in case there’s an assymetry in the later; then take the sum).

    **** at some point in the past I think I said that the same optical thickness distribution at a different part of the spectrum would lead to the same brightness temperature in the flux or intensity at that part of the spectrum, but the nonlinearity of the Planck function’s dependence on temperature makes this generally untrue, although it can be an approximation – especially at sufficiently long wavelengths for a given range of temperatures.

    Wrote that up in a hurry, pardon any errors.

    ———

    Re 218 Ray Ladbury I won’t make you refer to the square root of negative 1 as ‘i’ if you don’t insist that climate science follow all the protocols of EE.

    That was awesome! (AC circuits can’t exist because i isn’t j :) )

    PS in order for feedback to be expressed as unitless, you have to exclude Planck feedback so that you’ve got a ratio of temperature changes, or a ratio of flux changes (taking the feedbacks in terms of W/m2 per K and then dividing by … etc.) We can do this, of course, but it’s interesting that then you’re not counting all the feedbacks. I’ve only see a little EE but I’m guessing the forcing and output are in the same units, like the power or amplitude of a sinusoidal signal?

    Comment by Patrick 027 — 13 Aug 2011 @ 12:00 AM

  271. re my comment about graphically estimating CO2 forcing –
    actually it wouldn’t matter so much if H2O had (up to a point) wild variations in optical thickness sufficiently deep inside the CO2 valley; the linear interpolation across the valley to find the depth of the valley at it’s center gives a sense of the height of the area added to the valley as it widens with CO2 doubling (setting aside band asymmetry and Planck function curvature).

    Comment by Patrick 027 — 13 Aug 2011 @ 12:20 AM

  272. … actually , the one key thing that stays relatively constant (up to a point?) over the spectrum is the minimum in brightness temperature that can be achieved by a well-mixed greenhouse gas with sufficient optical thickness. The corresponding Planck function curve gives the flux at any given part of the spectrum; the height of the area added to the CO2 valley on either side is approximately the difference between this flux and that of the OLR absent CO2 (which may have different brightness temperatures at different spectral locations) at the part of the spectrum where the slope of the valley occurs.

    Comment by Patrick 027 — 13 Aug 2011 @ 12:40 AM

  273. Ray Ladbury says:
    “If John W. will tell me his level of mathematical comprehension, I could maybe recommend a book.”

    It’s been a while since I’ve really had to “do the math” myself(management), but I think I can handle anything through third-order nonlinear partial differential equations without sweating it too much.

    I really wasn’t looking for anything that serious though, just kinda curious what the opinion of those “in the know”.

    Comment by John W — 13 Aug 2011 @ 12:26 PM

  274. Patrick027, I appreciate Your efforts and keep a bookmark on this procedure.. actually, for myself its better for the moment *first* to refurbish my spectroscopy knowledge and work through pierrehumberts “principles”

    Cheers,
    Marcus

    Comment by Marcus — 20 Aug 2011 @ 3:22 AM

  275. Thanks for a good analysis of Spencer’s article. It’s too bad that millions will read the sensationalized version of it but he will read the climate scientists opinion. I traced the path of the article to see how it got from from Remote Sensing to Yahoo!News in just five days and posted it at http://jcmooreonline.com/2011/08/18/global-warming-media-bias-and-the-misinformation-pipeline/.

    http://jcmooreonline.com/2011/08/18/global-warming-media-bias-and-the-misinformation-pipeline/

    Comment by J.C. Moore — 20 Aug 2011 @ 9:01 PM

  276. Thanks for a good analysis of Spencer’s article. I traced his path from Remote Sensing to see how I got to Forbes and onto the front page of Yahoo!News in just five days, and posted it at http://jcmooreonline.com/2011/08/18/global-warming-media-bias-and-the-misinformation-pipeline/.

    It’s the same that millions of people may read the sensationalized version but very few will read the climate scientists analysis of all the errors in the paper.

    Comment by J.C. Moore — 20 Aug 2011 @ 9:06 PM

  277. Gavin,

    “You are repeating the same errors as RW – to whit: you are defining sensitivity incorrectly even for trivially simple examples, you are linearising a highly non-linear problem over a huge range, and you are blaming a semantic confusion on your part for your inability to actually work through the (relatively simple) algebra. Just as I suggested to him that he work out why his calculation and the real sensitivity in a simple model are not the same, I suggest the same to you.”

    Which specific formula are you referring to?

    [Response: There is no 'formula' - rather there is a simple model, as outlined in the post I pointed you too weeks ago that has a clear greenhouse effect, a well defined sensitivity and the straightforward possibility to compute any function you like that you think defines the sensitivity. You should then take the equation showing the real sensitivity of this model and compare it to the one based on your definition. They will not be the same. Until you have done this and assimilated what this means, there is very little point in continuing the conversation. - gavin]

    Comment by RW — 21 Aug 2011 @ 1:52 PM

  278. Gavin,

    “There is no ‘formula’ – rather there is a simple model, as outlined in the post I pointed you too weeks ago that has a clear greenhouse effect, a well defined sensitivity and the straightforward possibility to compute any function you like that you think defines the sensitivity. You should then take the equation showing the real sensitivity of this model and compare it to the one based on your definition.”

    I’ve looked at the post and I’m not sure what you are referring to. Is it too much to ask for you to state it specifically?

    Which equation shows the “real sensitivity” you’re referring to?

    [Response: The post is here, and the last two sections are specifically and explicitly about the sensitivity of the simple model system (i.e. the equations just before point 3 and point 4). - gavin]

    Comment by RW — 21 Aug 2011 @ 4:06 PM

  279. RW,

    The simplified model in the post Gavin referred you is oversimplified. With a few simple modifications, it can represent an equivalent representation of the real Earth’s climate system. Interestingly enough, this produces approximately the same sensitivity of about 0.3C per W/m^2 and not the 0.8C per W/m^2 claimed by the IPCC.

    What needs to be corrected are the assumptions that the planets emissivity is due exclusively to the greenhouse effect and that S is independent of Ftop. S is more appropriately expressed as S*(1-a), where S is the average power density from the Sun and a is the albedo. The global albedo is expressed as the cloud percentage weighted sum of the surface and cloud albedos. Similarly, the global emissivity is the cloud percentage weighted emissivity of the clear and cloudy skies. The last thing that must be corrected is the assumption that &Delta T is linear to &Delta G, even though G is proportional to T^4.

    From the ISCCP data, the temperature coefficients of the albedo, clear and cloudy sky emissivities, surface and cloud reflectivities and the global emissivity can all be extracted. The approximate sensitivities, all expressed in equivalent relative units, are as follows:

    global albedo -2.0% per C increase in surface temp
    cloud amount -1.5% per C
    cloudy emiss -1.0% per C
    clear emiss &lt +0.25% per C
    cloud reflect -0.25% per C
    global emissivity -0.06% per C
    surface refl &lt -0.05% per C (above 273K)
    surface refl &gt +10.0% per C (below 273K)
    It’s the change in average cloud coverage as a function of temperatures which is responsible for the corresponding change in most of the other factors, where the consequence is that the net global emissivity remains relatively constant. When CO2 concentrations change, mostly the clear sky emissivity is affected, however; the clear sky sensitivity to temperature has a relatively small contribution to begin with. Also note that the surface reflectivity has a sharp knee at 0C, which is why polar estimates of sensitivity greatly overestimate the global sensitivity since the energy balance related to the global sensitivity is dominated by regions whose temperatures are above 0C.

    The way that feedbacks are added is not really representative of the real system. It’s kind of like dividing both sides by zero and saying zero equals zero. This is because the sensitivity of the global emissivity to the surface temperature is rather small when compared to the other things that are changing. Besides, nowhere is a metric for feedback actually quantified, which I claim is quantified by control theory, where control theory defined gain is equal to 1 / (1 – 0.5 &lambda).

    George

    [Response: No simple model can tell you what the sensitivity is - in all such cases that is just an input. Their role is rather to give an example of a system that has some connection to reality and where ideas such as you and RW have proposed can be tested in verifiable conditions. - gavin]

    Comment by co2isnotevil — 23 Aug 2011 @ 12:46 AM

  280. Gavin,

    A model far simpler than a GCM can be used to provide reliable estimates of the climates sensitivity to many factors, including changes in static GHG concentrations. Consider simulating an internal combustion engine. You can determine the approximate performance by applying thermodynamic laws to inlet/outlet temperatures, etc. and determine how the performance will change as parameters vary or you can take the GCM approach and simulate the chaos in the combustion chamber and hope that the proper high level thermodynamic behavior emerges. Both approaches will get about the same answer. Which is more correct depends on the accuracy of all the various tuneable parameters in the model. GCM’s have far more parameters that must be tuned than the thermodynamic model, providing more degrees of freedom to compensate for flawed assumptions and/or to tweak the model in a desired direction.

    Of the parameters in my thermodynamic model, cloud coverage fraction, clear/cloudy sky emissivity, surface/cloud reflectivity, the power in and out of the planet, the individual power contributions of the cloudy and clear skies and the time constant of the planets thermal mass, most are directly measured in the ISCCP data set and the simple model that you say doesn’t work does an exceptionally good job at predicting the relationships between the 10 variables using a system of 4 equations describing the system (including a differential equation) and where 8 of the variables are directly measured. In effect, there are 4 equations and 2 unknowns, which if the model was incorrect, would never be able to match because it would be far too over constrained.

    George

    P.S. why does &lt, etc. work in preview, but not in the posted comment?

    [Response: Your coefficients are not robust to artificial trends in the ISCCP data, nor to the errors you have made with the water vapour and lapse rate feedbacks. I wish it was as easy as you claim, but it isn't. - gavin]

    Comment by co2isnotevil — 23 Aug 2011 @ 12:42 PM

  281. Gavin,

    The artificial trends in the ISCCP data are predominately caused by incorrect calibration between satellites, model differences across the processing of different samples and the uncorrected movement of satellites.

    My analysis of the sensitivities is based on monthly averages of 3-hour sampled data for each 2.5 degree slice of latitude, where what’s common across a slice is the incident power from the Sun, i.e. 72 unique measurements spanning 72 unique incident power profiles, per 3-hour sample, aggregated into 72 monthly data points. This analysis is largely insensitive to the types of errors found in the ISCCP data, all of which I’ve analyzed in detail. I’ve also started from raw satellite data in the DX data set (well not really the raw data since it has the faulty cross calibration already applied) and ran it through much more sophisticated image processing algorithms to re-linearize, re-normalize and re-align the data from the various satellites which includes robust predictors for missing data. This produces largely the same results for the sensitivity analysis but does produce in a more reliable indication of real trends over the 30 years of the satellite record, which as you probably already know, contradicts GISS temp.

    The analysis includes the effects of water vapor feedback, ice/snow albedo feedback, lapse rate feedback and all other feedback mechanisms, known and unknown.

    BTW, it’s not that easy, but it’s relatively straight forward and matches the data quite well. In fact, I can use my model to identify the flaws in the ISCCP data as these errors are in places where the deviation between the model and measurements is the largest. Every large deviation I’ve identified can be traced to a specific flaw in the ISCCP data.

    George

    Comment by co2isnotevil — 23 Aug 2011 @ 6:12 PM

  282. Gavin,

    “So if \lambda^\prime is positive, there will be an amplification of any particular change, if it’s negative, a dampening i.e. if water vapour increases with temperature that that will increase the greenhouse effect and cause additional warming. For instance, \lambda^\prime=0.1, then the sensitivity increases to 0.33 C/(W/m2).”

    I do not see how you’re getting 0.33 C/(W/m^2). Can you elaborate on this in more detail?

    [Response: 0.25/(.0567*2.88*2.88*2.88*(1-0.5*(0.1+0.769)) = 0.326 C/(W/m2). - gavin]

    Comment by RW — 24 Aug 2011 @ 7:15 PM

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