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Charlie A at 22:22 PM on 23 May 2011Roy Spencer’s Latest Silver Bullet
I gave a reference to the homepage of Isaac Held's blog and mentioned blogposts 3 through 6 as being the relevant ones. I see there is a need to be more specific. Blogpost #3. The simplicity of the forced climate response shows how the globally averaged results of the CM2.1 model can be emulated with reasonable precision with a very simple 2 term model with 4 year time constant. The parameters for this emulation include a sensitivity of 3.5 W/(m2 K0, which is the equivalent of about 1.5 C increase for a doubling of CO2. Willis Eschenbach has detailed a similar calculation for both GISS E and the CCSM3 models. See Zero Point Three Times Forcings and Life is like a Black Box of Chocolates For more details and a replication of the same toy model of GISS E in R, see Climate audit post Willis on GISS Model E". ------------------- If you prefer to see what Hansen says about this, then look at figures 7 and 8 of his recent self published white paper, "Earth's Energy Imbalance and Implications". Here's a copy of Figure 8A, showing the response function of GISS E for the first 123 years. Fig 7 shows the longer term response, with about 80% response at 600 years and almost to equilibrium after 2000 years. So if the GISS E equilibrium response is 3.0C for a doubling of CO2, the GISS E models predicts only a 1.2C rise 8-10 years after a doubling of CO2; about 1.5C rise at 50 years after a doubling of CO2, rising to 2.4C after 600 years and then 3C after 2000 years. -
JMurphy at 22:12 PM on 23 May 2011Coral atolls and rising sea levels: That sinking feeling
Arkadiusz Semczyszak, when I saw that your first 3 links were from WUWT and CO2SCIENCE (i.e. non-scientific), I didn't read any further. You really do need to ask yourself why you rely so much (especially in that last post of yours) on second-hand information filtered through blogs. -
les at 22:07 PM on 23 May 2011Skeptical Science Educates My Students
81 - Chris. It's a little difficult. the SkS site isn't a bulliten board or such. There's no 'like' button and chat / off topic meanderings is largely not appreciated... so people may not reply or respond to all your posts. Could be the best place for your contributions re: Aristotle, physics etc. would be FaceBook? -
Marcus at 22:06 PM on 23 May 2011Carter Confusion #1: Anthropogenic Warming
I'm also curious-how did these people, supposedly with backgrounds in physics, miss something as basic as the ability of Carbon Dioxide to absorb infrared radiation. I'm no expert in physics, but even *I* know about this basic property of the Greenhouse Gases. They also don't seem to understand that evapo-transpiration is good at explaining heat transfers over very short time frames, but really isn't a very good model for explaining the long term build up of heat in the atmosphere & our oceans. Maybe a remedial education is in order? -
Arkadiusz Semczyszak at 22:05 PM on 23 May 2011Coral atolls and rising sea levels: That sinking feeling
So look past changes in “coral” sea level (eg. Maldives) compared with the current. Ocean acidification and coral bleaching ... In area of the tropical reefs just changed acidification ( here and here) ... when coral bleaching we must remember the conclusions of this work: Suggett & Smith, 2010. - notes contained therein - the recommendations: “While this synonymous association has undoubtedly been key in raising public support, it carries unfair representation: nonlethal bleaching is, and always has been, a phenomenon that effectively occurs regularly in nature as corals acclimatize to regular periodic changes in growth environment (days, seasons etc).” “While bleaching induced coral mortality must remain our key concern it must be better placed within the context of bleaching signs that do not result in a long-term loss of reef viability.” -
Marcus at 22:02 PM on 23 May 2011Carter Confusion #1: Anthropogenic Warming
@ Tom Curtis: Hasn't that always been the Denialist meme? The idea that 97% of the world's climate scientists don't *really* understand how the climate works-only a handful of "truth-seekers"-like Nicol, Kinninmonth, McLean & Plimer really understand what's going on. Or at least that's what they want the media & policy-makers to believe. I've seen Kinninmonth's "hypothesis" before, & they sound just as bogus when Nicol lays it out as it did when Kinninmonth originally proposed the idea. Of course the hypothesis doesn't work, because it then doesn't explain how the planet has managed to warm by around +0.5 degrees C over the last 30 years. After all, what happens to that heat once it reaches the atmosphere? Tropospheric Warming & Stratospheric Cooling would suggest that its not getting beyond the troposphere, which is pretty much as high as evaporative processes actually work anyway. After all, what goes up, must come back down again. -
les at 21:55 PM on 23 May 2011Carter Confusion #1: Anthropogenic Warming
33 jonicol - Thanks for that! It's very encouraging to know that you need no more than 2nd year physics to understand climate science. -
Marcus at 21:55 PM on 23 May 2011Carter Confusion #1: Anthropogenic Warming
Just a few points John Nicol. #1: Being a meteorologist-no matter how distinguished-is not the same thing as being a climate science. This is a distinction which still appears to be utterly lost on the members of the Denial-o-sphere. #2: Weather is chaotic & hard to predict; long-term climate is relatively stable & easy to predict *if* you know what the long-term inputs & feedbacks are-because all the chaos of individual weather events tend to cancel out over periods of years to decades to centuries. Heck, if *weather* were so unpredictable over the longer-term, then we'd have no such thing as *Seasons*-but seasons represent one form of long-term stability that climate represents. #3: Whatever William Kinninmonth's past calling, his current close ties with organizations like the Lavoisier Group & now ACSC-both organizations fully funded by the Fossil Fuel Industry-makes any statements made by him highly suspect & incredibly biased. Same is true of Plimer & McLean, both of whom have shown a willingness to misrepresent the data to advance the denialist agenda. You see, John, your little song & dance might get you loads of attention from your mates at The Australian, but here we hold contributors to a much higher standard of evidence-& evidence is something which Carter, Kinninmonth, Plimer & McLean have never had. -
chris1204 at 21:53 PM on 23 May 2011Skeptical Science Educates My Students
Shucks, les, and here I was taking you seriously all this time. Win some, lose some. -
Tom Curtis at 21:43 PM on 23 May 2011Carter Confusion #1: Anthropogenic Warming
jonicol @33, so I am to understand that the new denier position du jour is that the climate is much to complex to be fully understood ... except by Kinnimonth who understands everything. -
Marcus at 21:42 PM on 23 May 2011Humlum is at it again
Jarch-The Theory of Evolution is full of holes-with breaks in the evolutionary record & an inability to properly quantify the *rate* of evolution in various species. Yet we still accept the theory of evolution because its backed by the fossil record & by our knowledge of how genetics, anatomy & a host of other biological processes work. Compared to Evolution, the Theory of Anthropogenic Global Warming is much more robust & more easily quantifiable. So I see once again, Jarch, that your claims are completely without any substance. Indeed, they're utterly nonsensical & display a complete lack of knowledge of how science actually works. -
Arkadiusz Semczyszak at 21:39 PM on 23 May 2011Corals are resilient to bleaching
And what happened with this paper? Interpreting the sign of coral bleaching as friend vs. foe, Suggett & Smith, 2010.: “While this synonymous association has undoubtedly been key in raising public support, it carries unfair representation: nonlethal bleaching is, and always has been, a phenomenon that effectively occurs regularly in nature as corals acclimatize to regular periodic changes in growth environment (days, seasons etc).” “Observations of non and sublethal bleaching (and subsequent recovery) are arguably not as readily reported as those of lethal bleaching since (1) the convenient tools used to quantify bleaching yield major ambiguity (and hence high potential for misidentification) as to the severity of bleaching; and (2) lethal bleaching events inevitably receive higher profile (media) attention and so are more readily reported.” “While bleaching induced coral mortality must remain our key concern it must be better placed within the context of bleaching signs that do not result in a long-term loss of reef viability. [...]” -
Bob Lacatena at 21:36 PM on 23 May 2011Skeptical Science Educates My Students
apiratelooksat50,The various science departments at that school are heavily slanted towards support of the AGW theory. However, the faculty at the state university of about 30,000 students generally leans toward support of natural causes of GW.
And what does this tell you? The people who are qualified to make the call (i.e. that understand and respect the science) are "heavily slanted" towards accepting AGW. The rest don't want to believe, and don't have the foundation in the sciences which would force them to accept the truth, so they rather casually refute it. I say "casually" because I know that if they understood it, or even talked to the science department, they would not hold the position on the issue that claim. I think it's your job to teach science, not your own interpretation of the science. So far, actual climate scientists (that whole 97 of 100 thing) say "AGW," and the science departments at your nearby university say "AGW. The English and history and art teachers all say "natural," and the uneducated student body says "natural," and you say "natural", and then you present that as a "balanced" position to your own students (and probably with more than a little "hint" in your voice, because you agree with the English teachers and the uneducated college students). Where are you failing in this picture? No one who understands the sciences has doubts about this. If you honestly have doubts, then you don't understand the science. If you are a science teacher, that's unacceptable. Comment less and study more, pirate. -
jonicol at 21:34 PM on 23 May 2011Carter Confusion #1: Anthropogenic Warming
Marcus, I just thought I should let you know that Bill Kininmonth happens to be one of Australia's most distinguished meteorologists. To help you understand what that means, he has studied the atmosphere, its changes and the physical processes which influence its behaviour in great detail. He is first a physics graduate, with an understanding of a great deal of the necessary mathematics and thermodynamics as well as advanced Newtonian mechanics involving Lagrange's equations, Euler's equations in various appropriate co-ordinate systems whether Cartesian, Spherical or Cylindrical. He understands the connditions in the atmosphere where it is appropriate to describe the mechanics in terms of Lagrange's equations and where it is necessary to apply an Eulerian approach. He understands the differential equations of fluid dynamics and the interaction between the ocean and wind together with the effects on the atmosphere of evaporation and condensation. He understands the mechanism in its totlaity involved in warming the atmosphere by evaporation from the oceans and water bodies, as well as the cooling effect this has on the water. He understands the cooling of the land surface by wind associated also with the ewarming oif the air followed by upwards convection. Over the past many years since his retirement he has continued to apply this knowledge in analysing climatic situations which after all are largely, though of course not totally, an extension of meteorology. My question to you is: Do you understand all of these things? -
les at 20:40 PM on 23 May 2011Skeptical Science Educates My Students
78 Chris: I did appreciated the humor of 70 and, even more so, your other weird takes on the history of physics and philosophy... but 'repeating' a witticism (76) seems to indicate that it is you who are taking your ideas seriously! But, yes, the appropriate audience may, indeed, be amongst the more easily impressed. -
dhogaza at 20:34 PM on 23 May 2011Humlum is at it again
Nitpick on "AGW theory". There really is no such thing. We have: 1. a theory of how changing concentrations of GHG and associated feedbacks affect climate. 2. an *observation* (not hypothesis or theory) that humans are dumping large quantities of CO2 into the atmosphere, and various projections of what that means for the future derived from applying #1. "AGW theory" is typically used by the denialsphere to emphasize the "A" part, which many want to believe is politically driven, from the physical underlying theory, for which no conspiracy theory fits. Let's not help them out. It's a small thing, but it annoys me. -
chris1204 at 20:30 PM on 23 May 2011Skeptical Science Educates My Students
Dear les and scaddenp The world comprises two groups of people - those who appreciate my sense of humour and those who don't. Admittedly, there might just happen to be other ways of classifying people but let's not go there :-) Oh well, I'll have to pick my audience more carefully next time. -
Kevin C at 20:10 PM on 23 May 2011Roy Spencer’s Latest Silver Bullet
Great post! I was particularly interested in the following paragraph:In a recent blog post, climatologist Isaac Held examined just this issue. He actually took a model exactly like Spencer’s and fit it to the output from a GCM that he uses. Then he estimated the equilibrium climate sensitivity of both models by running them with a constant forcing equivalent to doubling the CO2 in the atmosphere, and finding the temperature they settled into after a while. It turned out that whereas the GCM had a sensitivity of about 3.4 °C (2x CO2), the simple model only had a sensitivity of about 1.5 °C. This is interesting, because the simple model was parameterized specifically to mimic the output of the GCM. Could it be that the issue of overall climate sensitivity is more complex than a model like Eqn. 1 can address, at least over timescales of a few decades? Could it be that such a model would consistently low-ball its estimated climate sensitivity? One thing is clear–Roy Spencer hasn’t asked questions like these, whereas bona fide climate modelers like Isaac Held have.
I've been reading back over some of Authur Smith's old posts on two-box and other models, and had just come to this one (link) on calculating the response function directly by what is essentially a parameterised deconvolution. He also gets a low sensistivity: about 1.7C/2x over 50 years, although this increases to 2.7C if you integrate the long tail beyond 50 years. Tamino's 2-box model gives 2.4C, but he is also integrating a long tail. Integrating over a long tail seems suspect when you are deconvoluting a 130 year time series which shows probably only 40 years of unambiguous CO2 forcing, so from both of these I draw the same conclusion as you: simple models give low values of sensitivity compared to GCMs. (I'll try my own deconvolution when I get time). The question 'why?' is certainly the interesting one. Could the long tail issue be the key? e.g. suppose GCMs include a significant contribution from a heat resevoir (presumably the deep ocean) with a characteristic time in the high-decades to centuries? And that the simple models can't reproduce this because of the short period over which CO2 forcing has been dominant? I guess that's a question which could be answered by simulation. Or alternatively by using paleoclimate data in deriving the parameterisation of the simple model. Kevin p.s. Possible sources for Spencer's 2003-2010 data: he may have reconstructed the forcings himself from the raw data, but NASA also provide predictions for the future forcings here: http://data.giss.nasa.gov/modelforce/ - go to the 'Future scenarios' section just above the citations. I would have started here and updated the CO2 and solar data. -
les at 19:57 PM on 23 May 2011Skeptical Science Educates My Students
76 - Chris: Totally off topic, but that is a cheep bit of philosopause you're doing there. Quintessence is not re-cycling of an ancient concept, but an ancient name - indeed, in a tongue-in-cheek way. Nor (re 70) is Quintessence identical with Dark Energy - it's a mathematical formulation of a kind of scalar field which may be a candidate for modeling dark energy. I wouldn't bother mentioning it; but this is exactly the kind of woolly reasoning that crops up in "skeptical" arguments - like "well, the sun produces heat so much be responsible for GW", in which folks don't appreciate the details and the degree to which these things are quantifiable can calculable. -
chris1204 at 18:48 PM on 23 May 2011Skeptical Science Educates My Students
Sorry, I can't get the link to work. However, if you trawl through the Wikipedia entries on Quintessence and Dark Matter, you'll find references to the ether of early classical physics (not the same thing but nevertheless we see some evidence of recycling of an ancient concept). After all, leeches are now all the rage in some fields of medicine today (but of course, they're bred in aseptic settings). -
scaddenp at 18:47 PM on 23 May 2011Skeptical Science Educates My Students
"However, the faculty at the state university of about 30,000 students generally leans toward support of natural causes of GW." The science faculty? The basis for such a statement would be very interesting. Frankly, I would expect science departments of all varieties to support the view of published science. If it doesn't, then sounds like your country is utterly stuffed. The typical "skeptic" scientist is someone from outside climate science who has "gone emeritus". This isnt too unusual - look at Pauli and Hoyle - but finding an instance of such folk being actually right is whole lot tougher. Examples anyone? -
scaddenp at 18:34 PM on 23 May 2011Skeptical Science Educates My Students
Missed the tongue in cheek - nothing to do with ether theory. -
chris1204 at 18:19 PM on 23 May 2011Skeptical Science Educates My Students
scaddenp @ 71: Maybe this link will help: http://en.wikipedia.org/wiki/Quintessence_%28physics%29 However, I was being tongue in cheek. -
John Donovan at 18:12 PM on 23 May 2011Skeptical Science Educates My Students
apirate said: "Interestingly, of the two universities I work with the most in getting CEUs or placing students, one has 18,000 students and is just up the road. The various science departments at that school are heavily slanted towards support of the AGW theory. However, the faculty at the state university of about 30,000 students generally leans toward support of natural causes of GW. There exist somewhere a survey conducted at all the state colleges on this subject and I will see if I can find it. Neither school is religious based or labeled liberal or conservative. " These conclusions of yours are based on this state survey you mentioned previously? By "faculty" do you mean the non-expert faculty? Again I would assume that non-expert opinion would generally follow along ideological lines much as public opinion does. A recent Gallup survey published April 22, 2011 has the US opinion at 34% attributing global warming to humans and 47% attributing it to natural causes (these numbers are somewhat reversed in Asian and other developed countries). Since the faculty at most US schools are usually more progressive than the general public that would explain part of your observations. However, the fact that you claim the faculty at these two schools are so different suggests an unusual ideological mix at the other school to cause such a pronounced divergence. But I would be very surprised if the climate science (and even the general earth science) faculty at either school would be generally opposed to the scientific consensus on this (or any other) field of study. Do you have a breakdown by fields of study? Was the survey only on climate issues or also other fields of science inquiry as well? Can you provide a link to the survey data you base your conclusions on? Or at least supply the names of the two state schools so we can research this ourselves? The academic survey data I have seen (Doran and Zimmerman, 2009 for example) showed that 97% of climate scientists agreed with statements that attributed human causes to global warming, which dropped to 82% for all earth scientists with meteorologists at 67% and economic geologists agreement at 47% (which brings to mind Upton Sinclair's observation that which is paraphrased something along the lines of "it is difficult to get a man to understand a proposition if his salary depends on him not understanding it". But the phrase that struck me most of all in your response was the statement "The various science departments at that school are heavily slanted towards support of the AGW theory." I find that wording itself "heavily slanted". How can the faculty be "heavily slanted" if they agree with the current expert scientific consensus? Would we not expect that a science faculty agrees with current scientific expertise? Would you also describe the science faculty there as "heavily slanted" towards evolutionary theory? I find your wording most problematic. Please share the survey data with us as I would be most interested to understand why one college in your area (even considering it is in the southern US!) is noticeably outside the scientific mainstream on any field of science. I can't provide an opinion without more data. -
MattJ at 18:11 PM on 23 May 2011Humlum is at it again
There is one part of the Conclusion that strikes me as particularly well-written, almost worth memorizing! It is: "their letters provide with a perfect example of the strategies deployed by climate "skeptics" to twist the debate and sow doubt in the minds of the public. BHS articulate their argumentation around the defense of an ideal of scientific method they believe in while clearly violating the rules they pretend to respect. Citing irrelevant quotes or taken out of their context, misunderstanding fundamental concepts, concentrating on precise points without looking at the broad picture, cherry-picking or even inventing scientific facts and data in order to provide with justifications to their hypotheses, etc." -
scaddenp at 18:06 PM on 23 May 2011Skeptical Science Educates My Students
Chris, I am lost or puzzled. In what way is dark matter puzzle in physics related to ether theory in physics? This isnt a connection that I can see. -
chris1204 at 17:59 PM on 23 May 2011Skeptical Science Educates My Students
KR @ 56: Oddly enough, ether, or aether is coming back into fashion in modern physics known variously as Dark Matter or Quintessence. Maybe rumours of Aristotle's demise are somewhat premature.Response:[DB] Fixed html.
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jarch at 16:52 PM on 23 May 2011Humlum is at it again
I know how to evaluate the likelihood of a given set of numerical parameters when a theory has been proved (by the probability that the observations would have given a result at least as distant from the prediction as what has been actually observed). But I have no idea of how to give a probability to the hypothesis that some theory is true. Do you have other examples in the history where this has been done ? I think that quantifying a likelihood can be done only for the numerical value of parameters, when you have a certitude that the underlying theory to handle them is true - you cannot quantify anything is you're unsure that the theory is true. -
Albatross at 15:31 PM on 23 May 2011Roy Spencer’s Latest Silver Bullet
Hi Stephen, No worries, no offence taken. I was being critical of myself. -
Stephen Baines at 15:21 PM on 23 May 2011Roy Spencer’s Latest Silver Bullet
Albatross...No criticism was intended! I just wanted to point out (to anyone who cares) that Charlie A was referring to a different graph in the Held paper than the one you posted (fig 4). The one you post is actually much more relevant to the climate sensitivity of the model, but someone looking at it might have no idea why Charlie A said the things he did, and why they were incorrect. I was just trying to avoid future confusion. The red lines in your posted graph (where Held is doing the opposite experiment and suddenly forcing to preindustrial levels at different times) are depicting the inverse behavior depicted in Fig 1. -
Albatross at 15:00 PM on 23 May 2011Roy Spencer’s Latest Silver Bullet
Stephen @11, Thanks. I realized a while after posting that "my caption" (from Held's blog) did not speak to the red lines. Thanks again for clarifying....although you were probably being polite....I should have been more diligent. -
adelady at 14:46 PM on 23 May 2011Humlum is at it again
Thanks DB. I realised as soon as I hit the button that you'd say something like this. I'm happy to have it on the to-do list. Unfortunately, we're in the middle of selling the house. Constant vacuuming, dusting and all the rest for inspections (as well as packing or discarding 30+ years accumulated stuff before moving) doesn't leave much brain space for real work. I promise to start assembling dot points and references and a few key paras. I'm a horribly prolix writer so it'll take me dozens of iterations to get it readable. (Or I'll give up and send it for someone competent to edit and polish.) Serves me right. -
Stephen Baines at 14:37 PM on 23 May 2011Roy Spencer’s Latest Silver Bullet
Just to clarify Albatross's point...Charlie A clearly misinterpreted Fig 1 in Held et al 2010, which was a model experiment involving a sudden doubling of CO2. The point of that figure is that an initial increase in temp due to the "fast" response component of the model is separated from the increase due to the "slow" response component by a transient plateau in temps. Charlie A has misinterpreted this plateau as "equilibrium" despite the authors explicitly stating "the system is clearly still far from equilibrium when it plateaus, and Fig. 1 shows only the initial steps of the transition to the equilibrium response." This text and the text quoted by albatross was directly discussing that figure, so how Charlie A missed it is a mystery. -
Stephen Baines at 14:19 PM on 23 May 2011Humlum is at it again
Camburn, when you go from... "I still stand that OHC of 0-700 meters is flat to negative." to "As I have stated, there are problems with OHC. " it's equivalent to saying, "I can use the data to say what I want, but it's not good enough for you to say anything different." Basically, you're having your cake and blowing it up, too. Is that what you mean by thinking outside the box? -
Tom Curtis at 13:33 PM on 23 May 2011Humlum is at it again
Camburn @13, if you mean the link provided @2, there is no discussion by you on that thread. I am not here to play some silly guessing game about which comments by other posters you may or may not agree with. If you have problems with Von Schuckmann et al (2009 or 2011) you should explicitly state them on the appropriate thread. Otherwise, as I have said, you are rightly considered to be merely hand waving. @14 and @15: you left out some quite revealing quotes."I do not agree with your comments[that absent of measured ocean heat content is best interpreted as lack of OHC]. We are well aware that there are well over a dozen estimates of ocean heat content and they are all different yet based on the same data. There are clearly problems in the analysis phase and I don’t believe any are correct. There is a nice analysis of ocean heat content down to 2000 m by von Schuckmann, K., F. Gaillard, and P.-Y. Le Traon 2009: Global hydrographic variability patterns during 2003–2008, /J. Geophys. Res.,/*114*, C09007, doi:10.1029/2008JC005237. but even those estimates are likely conservative. The deep ocean is not well monitored and nor is the Arctic below sea ice."
(Kevin Trenberth, 16/4/2010, my emphasis) So if you appeal to Trenberth's authority, the proper conclusion is that Von Schuckmann and Le Traon 2009 is superior to previous papers, but probably still underestimates OHC. That is hardly supporting your position."Actually, Kevin, I do not think that they are all very different. It sounds like you are familiar with Lyman’s upcoming Nature paper and in both Figure 1 and Figure 2 of that paper, you can see that the estimates after 2005 all have the same basic variability. In fact, if these estimates did not include the XBT data, they would be even more similar in terms of their variability. I have personally verified that my own estimtes of OHC variability are very similar to those made by von Schuckmann, Eric Leuliette and another Argo-only analysis by Dean Roemmich for the post 2005 period. During this period, the technique and statistics used to interpolate the data is really not that important because the data coverage is very good. In fact, the same is true for the period of the 1990s. One of the main points of the Lyman Nature paper is that the data biases are by far the most important remaining error–much larger than the differences caused by different interpolation techniques or differences in the assumed statistics."
(Josh Willis, 17/4/2010, my emphasis) So, you have one expert who thinks the analysis is inadequate, and that it underestimates OHC increase; and another who thinks the analysis is adequate, and that it shows significant OHC rise (as in Von Schuckmann and Le Traon 2009 and Von Schuckmann et al 2011). From this you conclude, "When looking at a lot of literature, the error bars overlap enough that about all that can be concluded is that the OHC is flat with a negative bias." In other words, from expert agreement that there is a positive trend in OHC, you conclude that there is a slight negative trend in OHC. No more needs to be said.Response:[DB] Closed missing html tag.
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Albatross at 13:27 PM on 23 May 2011Roy Spencer’s Latest Silver Bullet
Charlie @9, "I find Spencers finding of 1.3C sensitivity for doubling of CO2 as entirely unsurprising." Please pay attention, it has been demonstrated by Dr. Bickmore that Spencer was wrong, again. I do agree that this finding is unsurprising, but for very different reasons than you think. You are misrepresenting Held's research, that or you do not understand what his 2010 paper was about.Caption: The black curve in this figure is the evolution of global mean surface air temperature in a simulation of the 1860-2000 period produced by our CM2.1 model, forced primarily by changing the well-mixed greenhouse gases, aerosols, and volcanoes. Everything is an anomaly from a control simulation. (This model does not predict the CO2 or aerosol concentrations from emissions, but simply prescribes these concentrations as a function of time.) The blue curve picks up from this run, using the SRES A1B scenario for the forcing agents until 2100 and then holds these fixed after 2100. In particular, CO2 is assumed to approximately double over the 21st century, and the concentration reached at 2100 (about 720ppm) is held fixed thereafter. From Held et al. (2010): "The model’s equilibrium climate sensitivity for doubling, as estimated from slab-ocean simulations, is roughly 3.4 K. Consistent results for the equilibrium response are obtained by extrapolation from experiments in which a doubling or quadrupling of CO2 is maintained for hundreds of years." Held's work doesn't support a low equilibrium climate sensitivity, regardless of your efforts to distort his findings. The sensitivity of the GISS-E model, at least the last time I looked was +2.7 C. So you misrepresented them too.
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Charlie A at 13:06 PM on 23 May 2011Roy Spencer’s Latest Silver Bullet
I find Spencers finding of 1.3C sensitivity for doubling of CO2 as entirely unsurprising. The GISS E model has a sensitivity of only about 1.2C/doubling in the short term (5 years, for example) and only about 1.8C over a century timeframe. This is about the same as the NOAA GFDL CM2.1 model. See blogposts 3 through 6 at Isaac Held's blog that is hosted on the NOAA website, or look at Held et al 2010 (full text pdf). Held describes the NOAA GFDL CM2.1 response to a 100% step in CO2 as a rise to 1.5C in 3 or 4 years, then a plateau at that level for 70 years until it starts to slowly rise. Looking at the graphs, I would characterize it more like a 1.4C sensitivity CO2 doubling with a tau of 4 years, followed by 0.35C per hundred years slope for the next few hundred years. -
Charlie A at 12:56 PM on 23 May 2011Roy Spencer’s Latest Silver Bullet
It appears that he extrapolated. Between 2007 and 2011 Hansen changed forcings very signficantly. As I noted, in his latest paper, he chooses to set total aerosol forcing equal to to 1/2 that of GHG forcing (opposite sign of course). Obviously, this has the effect of reducing the net forcings by that amount. On the other hand, for the AR4 runs of GISS E, they more or less flatlined the aerosols from 1990 onward. So each incremental additional GHG forcing post-1990 would have full effect. In other words, he effectively cut the post-1990 GHG forcings in half by waving a magic wand. This 50% reduction in net forcings for GH gases post-1990 makes for a better match to the observed OHC. I have not been able to find a listing of detailed breakout of aerosol forcings for Hansen 2011, which would allow me to see if the choice to set aersol to -0.5 GHG forcing was as arbitrary as it appears. -
adelady at 12:37 PM on 23 May 2011Humlum is at it again
cloa513 "...not able to evaluate whatever precise AGW hypothesis is formed. A theory is more vague than a hypothesis." John, any other contributing writer, anyone who cares. I've just done a quick topic search on here for 'theory' and 'hypothesis' and didn't come up with anything directly relevant. (But a fair bit on consensus.) One constant skeptic/ denier/ contrarian theme is this silly dictionary diving, thesaurus stretching argy-bargy on personal interpretations of words like law, theory, hypothesis. They're often alluded to in posts and comments, but I think it would be a worthwhile rebuttal in its own right. "Only a Theory" or some such title would be a handy addition to the short titled references. I realise that you're all just sitting around idly waiting for suggestions on how to occupy your time, but someone might put this on the to-do list.Moderator Response: (DB) Beware of suggestions (that's how I came to be a part of this great adventure). That's a good idea. Would you like to write a guest post on it? -
Camburn at 12:33 PM on 23 May 2011Humlum is at it again
Tom: From Dr. Trenbeth's email: " Roger I don’t believe any of the current dozen or so estimates of ocean heat content are correct. The TOA estimates are probably closer to being correct but they too have problems. The data may be robust since 2005 but the analysis methods are not. Kevin" As I have stated, there are problems with OHC. I will just leave it at that as I will show you evidence, but I am not going to try to force you to think outside of the box per se. -
cloa513 at 12:26 PM on 23 May 2011Humlum is at it again
The IPCC never did rigorous scientific analysis because they were never set to do that- They were set up to summarise the scientfic record which is not the same thing. If there was such a massive paper (it would have to be a meta-study), Skeptical Science would leap to point to it. The IPCC was a massive opportunity wasted to either prove or disprove or more likely indicate that the scientific tools/data is not able to evaluate whatever precise AGW hypothesis is formed. A theory is more vague than a hypothesis. -
Camburn at 12:25 PM on 23 May 2011Humlum is at it again
Tom: I have to let others who are immenently qualified speak clearer than I can I guess: I do think that Pielke Sr, Dr. Trenbeth and Josh Willis have a pretty good idea of what they are talking about: http://pielkeclimatesci.wordpress.com/2010/04/19/further-feedback-from-kevin-trenberth-and-feedback-from-josh-willis-on-the-ucar-press-release/ -
Camburn at 12:12 PM on 23 May 2011Humlum is at it again
Tom@11: The discussion is on a link provided by Dana 1981. No, it is not the dislike of the conclusion. It is the probability the conclusions are correct that is in question. I refer you to the link. -
bbickmore at 12:04 PM on 23 May 2011Roy Spencer’s Latest Silver Bullet
Hi Charlie, I used the GISS data through 2003, because that's all I could find, but for the next few years I just digitized the data from Spencer's graph. I don't know where he got it, or if he just extrapolated. -
camandjac at 11:56 AM on 23 May 2011CO2 limits will harm the economy
I am new to this site and am yet to get my head around a lot of what I am reading. I do want to protect the environment, I would love to see more effort being put into renewable resources. Taxing carbon might be the best way on paper. The part that makes it so scary for me is the ongoing greed of big business. I fear that the cost of living will increase dramatically due to their greed, not based on the logically put predictions made by those proposing the solution. -
Tom Curtis at 11:35 AM on 23 May 2011Humlum is at it again
Camburn @10, the appropriate conclusion when you claim that Schukmann has problems in her paper but do not link to a discussion of those problems is that this is just hand waving, and you are rejecting the paper solely based on your dislike of the conclusions. -
Tom Curtis at 11:33 AM on 23 May 2011Humlum is at it again
Camburn @7: Your memory fails you:"The basic materials for this study are the monthly gridded fields of temperature and salinity properties of the upper 2000m over the period 2003-2008. These fields were obtained by optimal analysis of the large in-situ data set provided by the Argo array of profiling oats (www.argo.net). Complementary measurements from drifting buoys,CTDs and moorings are also used. Two important data sets have been excluded from the analysis because of proven or suspected biases. They are first, the XBTs and XCTDs for which uncertainties in the accuracy of the fall rate remain, and second, a small subset of Argo float profiles of type SOLO (Sounding Oceanographic Lagrangian Observer) that suffer a labelling error in the pressure [Willis et al., 2007]. The data set was downloaded from the Coriolis data center (one of Argo Global Data Acquisition Center, GDAC) at three dates: the period 2003-2006 was extracted in August 2007, the year 2007 in January 2008 and the year 2008 in February 2009. In total, the Argo measurements account for at least 90% in 2003 and increase to more than 95% since 2006."
As you can see, all XBT and XCTD profiles where excluded because of uncertainties related to the pressure at each data point. ARGO profiles for which there was similar uncertainty were also excluded. I am sure that, being consistent, you would want all the XBT profiles included if and only if you were to include ARGO profiles of uncertain pressure readings are also excluded. Or do you just want to cherry pick? -
Camburn at 10:39 AM on 23 May 2011Humlum is at it again
Bern: My comments on OHC were derived from what was written in the post: "The informed reader will notice that so-called climate skeptics very seldom mention the ocean in their quest against the AGW theory, since doing so would severely impact their conclusions." I still stand that OHC of 0-700 meters is flat to negative. I have not read parker yet, so I will not comment on his paper. Schuckman has problems in his paper. I had read it earlier, and will do so again. However, I will not discuss it on this thread as it is considered off topic. -
Bern at 10:25 AM on 23 May 2011Humlum is at it again
Thanks for the article, julienx2k2. As you state, a classic example of why what the 'skeptics' are doing is not science. It would interesting to see if a rebuttal argument, demonstrating why the BHS opinion piece was incorrect, was able to be published in the same newspaper, or whether editorial policy only provides 'balance' when it suits their agenda (as seems to be the case in many media outlets around the world). Re the 8 off-topic comments above: I, too, struggled to make any connection between the article and a discussion of OHC. Camburn's first comment strikes me as a typical denier misdirection away from the demonstrated flaws in the anti-AGW case ("Look over here at this super-strong floodgate, don't pay any attention to the torrent pouring out of that crack in the dam over there"). The SkS comments policy clearly states that off-topic comments are not permitted. Perhaps a slightly firmer moderation policy needs to be enforced, with such posts deleted? It might reduce the thread hijacking that goes on sometimes. -
Marcus at 10:16 AM on 23 May 2011Carter Confusion #1: Anthropogenic Warming
"Nevertheless, discussion of ACSC and John's membership therein isn't relevant to this topic, so let's leave it at that." Well I only mentioned it because both he *and* Bob Carter are part of this Group, so I thought everyone should know...but you're right, Dana, I won't say anything more on the subject.
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