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KR at 17:19 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
gallopingcamel - Scafetta's work is simply curve-fitting to a limited period. When taken outside the 'training period' for his cyclic+quadratic fit, it fails horribly:
This is simply a rather limited Fourier decomposition (over-attributed to larger frequencies within the timeframe that happen to somewhat match selected astronomical periods) of the period under analysis, with no predictive power whatsoever - correlation without causation, unable to make any predictions as it is not based upon any physics related to the system. That's fine as long as the inputs/forcings do not change, but cannot predict future (or past, as shown above) behavior if they do, for example as CO2 levels change.
I'll note that the quadratic term in Scafetta's most recent work (oddly without emphasis in his papers) does roughly correspond to CO2 forcing. With no conclusions drawn, or analysis applied...
Where is your skepticism?
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KR at 17:07 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Jose_X - I will (putting my 2 cents in, if that) note that it is a bit difficult to follow a stream of consciousness post. It would be easier to follow if you were to note your assertion(s), followed by the backing. Otherwise it's a bit difficult to identify any issues you might raise. That said - Huffman appears to think that plate tectonics is nonsense (not the best recommendation), N&Z have apparently used basic curve fitting to re-derive the S-B relationship without acknowledging it, PV=nRT requires a separate temperature driven by convection and radiative physics to set the pressures, etc. Even WUWT has pointed out N&Z issues with significant justification. Which aspect(s) of those postings do you consider significant issues with basic radiative physics? -
gallopingcamel at 17:03 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
scaddenp @71, Scafetta has shown that planetary motions correlate with global temperature. At first blush this sounds like astrology rather than science. You should be skeptical as I am but maybe we should suspend judgment. Suppose that the gyrations of the major planets somehow modulate the reactions taking place in the sun's core. If this was happening, how long would it take for the effects to reach the sun's radiating surface? If you rely on Radiative Transfer the answer is tens of thousands of years. So is there any process that could explain the very short time constant that matches observations? If such a mechanism exists it may take decades to understand it just as in Wegener's case. -
Composer99 at 15:58 PM on 1 March 2012DenialGate - Highlighting Bob Carter's Selective Science
The CASS-CFI report I linked to indicates Patterson was for some time the teacher of the course; the year they audited the course's videos it was taught by a Tom Harris. -
Bob Loblaw at 13:54 PM on 1 March 2012DenialGate - Highlighting Bob Carter's Selective Science
Carleton University is the home of Tim Patterson - a well-known climate change denier. That's probably where the guest lecture was done. The geography department used to have people who actually knew about climatology, but I'm not sure who they have there now. Tim Patterson is in geology, and would probably consider Tim Ball to be a peer (which is not a strong recommendation). -
KR at 13:45 PM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
Michael Hauber - Your post is contradictory, I would assume not intentionally. Your hypothetic source/sink will emit/absorb CO2 above a specific level? This is not comprehensible. The oceans have (as per the ice core record) absorbed or release ~90ppm of CO2 over a 5-6C temperature swing, with a time delay of 500-800 years. Not due to atmospheric CO2 concentration changes, mind you, but due to solubility changes with temperature. The oceans therefore do not fit your hypothetical, as atmospheric concentrations have changed in sync with our emissions for the last 150 years or so, with natural sinks (primarily the oceans) absorbing only half of our emissions. In regards to the oceans, I would suggest reading the OA Is Not OK series, Why ocean heat can’t drive climate change, and What is causing the increase in atmospheric CO2 to review the mass balance issues. We certainly understand enough of what CO2 is doing in the oceans to determine that the oceans are not the source of CO2 increases over the last 150 years. -
Composer99 at 13:44 PM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
Michael: Fortunately, we are already very well aware that the oceans are taking up CO2 at a very high rate, leading to an ocean acidification which is effectively unprecedented in geological history. There is a long series here on Skeptical Science going through the chemistry which demonstrates this is the case. This is despite the rise in temperatures, which would normally result in the oceans outgassing CO2. -
Michael Hauber at 13:26 PM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
The logic of this argument is flawed. Hypothetically imagine a natural carbon sink that emits Co2 if current concentrations are above a specific equilibrium level, and absorbs Co2 if it is above this level. And assume that this equilibrium level increases as temperatures increase, and that the carbon sink acts quickly enough to maintain Co2 concentrations close to the equilibrium level. Then it would be possible for man to emmit Co2, this hypothetical sink to be a net absorber of Co2, and the overall increase in Co2 be determined not by man's emissions but by the hypothetical sink. The ocean does act a little like this, and has a preferred equilibrium for Co2 concentration that depends on temperature, and will tend to absorb or emit Co2 as required to maintain this equilibrium. Some more understanding of what Co2 is doing in the ocean is required to rule out natural sources of the Co2 increase. -
Jose_X at 12:26 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Moderator JH from #69, I thought I asked a reasonable question about radiative balance. If I kept quiet about the resolution, the question stays on the comment thread unanswered. Was that the preferable option? Is it my fault I didn't know the answer when I asked it and later realized it? Is there no use to detailing an answer? Is it not useful to present the sort of honest thought process that goes through people's minds? I thought this thought process (the form of #69) is useful to a website trying to understand its audience so as to better communicate the website's message. I'm not the best writer. Was that the problem?Moderator Response: [JH] Suggest that you do your calculations off-line and keep your comments focused. People are just not inclined to read lengthy rambling posts. -
Sceptical Wombat at 11:56 AM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
The thing I don't understand is what Essenhigh et al think the CO2 content of the atmosphere would be if the industrial revolution had never happened. Do they really think it would be the same as it is today - or do they think it would be higher? If I take the plug out of the handbasin in my bathroom I can turn on the cold water tap to a point where the basin remains half full - ie the water runs in from the tap at the same speed that it escapes through the plug hole. If I then turn on the hot tap a little the water will rise in the basin and eventually overflow. The residence time in the basin is very short, the percentage of hot water in the basin at any time will be very low but I defy anyone to argue that the overflow was not caused by my turning on the hot tap. -
PluviAL at 11:04 AM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
Boba10960, Strong second on the critical value of this explanation. I have been studying ths subject for some time, and most discussion gloss over this as if everybody knows it. But we don't we just assume someone did thier work and so we can just wave our arms as the article sais to communicate. I am mostly an avid arm-waver; who knows it might help to cool the planet. Like so many ither posts here, this is really valuable instruction. A hardy thanks to all who work so hard to provide such good stuff. -
owl905 at 10:37 AM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
@jimb 29 and DMCarey 28 - DM's fear is warranted. It's sanctified by the National Post, upheld by most of the other 'national' newspapers. And a decade of national governance that's power-base is built on the tar pits has taken the old phrase 'blue-eyed Arabs' to a whole new level. Here's the latest (c/o CCTNG): Heartland Does Carlton University Any claim that the Greenhouse Effect is 'generally accepted' is a pitch in the dirt daring everyone to argue from square one - waiting for a chance to butwhatabout. -
scaddenp at 10:20 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
"Remember that Alfred Wegener had been dead for many years when the scientific world stopped laughing at his theory of "Continental Drift"." So who stopped laughing? The idea that continents could move over the seafloor was and still is ridiculous. His observational evidence that eventually helped lead to modern tectonics was not ridiculous and not laughed at. However, where are the unexplained puzzles in climate theory comparable to Wegener? -
Jose_X at 09:56 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
I think I resolved my Venus/Earth conflict http://www.skepticalscience.com/news.php?p=2&t=53&&n=1310#75971 . Believe it or not, that particular planet comparison had been nagging me for at least a few weeks. None of my few replies addressing it (on a different forum) had simply calculated the 10^6-fold increase scenario to make it apparent that there was no inconsistency between that data and GHE. -
Jose_X at 09:40 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
The majority of this comment (middle on down) serves to illustrate a misunderstanding that perhaps a number of people might be having. >> please, stop quoting from bad science sites Riccardo, I brought up a point that presumably is based on data and which is a reasonable question to ask of the GHE since on the surface appears to suggest the amount of ghg does not matter. I linked the webpage for reference to reduce the number of replies asking for more detail. >> If you have a transparent atmosphere you end up with a isothermal atmosphere at the same temperature as the surface My second scenario is not 100% N2 (which is this simple case you answered). Essentially, I have not verified that there is an appreciable difference between having a small amount of CO2 vs having almost the entire atmosphere be CO2. In Venus, we have a number of similarities to the Earth but the opposite extreme as here in terms of relative proportion of ghg. Has no one published a paper applying GHE equations to Venus? [See conclusion below, as it suggests a classroom exercise might be more appropriate.] >> In the real case, use the adiabatic lapse rate, the emission altitude from the effective radiation temperature and extrapolate back to the surface. This approach was exactly what gave me a little concern. I think it's also what Joel Shore describes in part (c) of his reply here http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-849734 Let me take this slowly. If we initially only concern ourselves with a rough approximation, then the webpage I linked takes you through the data to suggest that we would get exactly the same answer regardless of the amount of CO2. The slope of that lapse rate appears to be about the same for Venus as for Earth.. again, to first approximation. Now, I would not have expected this result.. even to first approximation. Now, on to more precise estimate considerations. One of my next thoughts was that the lapse rate is basically linear over a narrow pressure range (or more linear nearer to TOA?) but then bends on the way down in very high pressures. This would perhaps solve the problem. As we go deeper into Venus, the curve would bend towards higher temperatures.. in comparison to the path it would take if Venus has the % makeup as the Earth has. [Update to self: the graph here http://en.wikipedia.org/wiki/Atmosphere_of_Venus#Troposphere appears to show a slight bend towards higher temperatures in the low part of the line] This is why I ask about a precise calculation. Now, let's look at a few potential curves more closely. First, I have the question of what to expect, so let's consider some possibly hypotheses. H1: I know that 100% CO2 perhaps might not make much of a difference vs 10% CO2 + N2. I don't know but some degree of saturation certainly could be in play. H2: In fact, the actual physics could potentially make the 100% CO2 case do worse. These are all possibilities a priori. H3: A different form of reasoning might hypothesize that more CO2 should *always* lead to greater GHE within the limits imposed that a doubling of concentration leads to linear temperature increases. This is the standard model, I think, so I will look at it first. I now look towards the Earth predictions. We have a few degrees.. or let's say 1 K for 2xCO2. Extending this, 1 million xCO2 (approx 20 doublings) would lead to 20 K increase. 20K increase!! OK, maybe the model is being driven out of range by my example of 1 million fold increase. This would lead to about 390 atmospheres of pressure at the surface of the Earth and near 99.99% CO2. Or maybe the model would hold. Very interesting result. I did not expect that. I'll stop here since it appears I might have my answer from standard theory. My conclusion is that the climate models would appear to be consistent with the Venus example since a small change in slope is enough to change the temperature at the surface of Venus by about 20 K (or vicinity) rather easily. My concerns have been dispelled for the most part (pending a recheck of the logic and math). After thought: On earth we can have a very modest change in pressure of 40% via 1000 fold increase in CO2 yet get a full 10K. This 10K would be more than half of the 18K or so ballpark figure representing the super hot and high pressure Venus. This result is certainly a bit counter-intuitive (thanks to the log relationship).Moderator Response: [JH] Please refrain from using this comment thread as your personal scratch pad. -
Dikran Marsupial at 09:36 AM on 1 March 2012Scafetta's Widget Problems
Volker Doorman I don't believe in repetition either, especially if the cycle in question has no statistical significance nor a plausible physical mechanism that can explain the strength of the effect. Sorry, the irony of your response was just too tempting! ;o) -
Volker Doormann at 09:18 AM on 1 March 2012Scafetta's Widget Problems
@Dikran Marsupial I do not belief in repipition. I'm off.Response:[DB] If you did not wish to participate in science-based dialogue, of which experimental repeatability is an integral part, than why are you here?
As an FYI, this forum has witnessed curve-fitting exercises based on the CET before. And is therefore dubious.
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gallopingcamel at 09:12 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Jose_X at 16:41 PM on 29 February, 2012, You have identified the main weakness in the references I cited. They lack a physical mechanism to underpin them and that leaves them open to the charge of "curve fitting". Remember that Alfred Wegener had been dead for many years when the scientific world stopped laughing at his theory of "Continental Drift". Nicola Scafetta is all too well aware that even if his prediction of global temperatures to 2040 proves to be more accurate than that of the IPCC's AR4, it proves nothing unless he can explain the underlying processes. He is making progress and I find his ideas quite plausible. When he "goes public" we will be able to take this discussion to the next level. In my opinion, N&K are in the same boat but I have not had the opportunity to meet them. (-snip-) Early drafts of the AR5 Working Group 1 have been leaked and I have a team working on them. You are clearly a deep thinker so would you be interested in participating? http://www.gallopingcamel.info/IPCC.htmResponse:[DB] Imputations of impropriety and fraud snipped. Please pay more than a passing nod to the Comments Policy of this site.
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jimb at 08:23 AM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
@28- This is not being helped by the latest news re this year's proposed budget in Canada. From our local newspaper;"The federal Conservatives are planning significant spending cuts for the upcoming 2012-13 budget years in areas such as environmental monitoring, fisheries and oceans, Via Rail, national defence, the Canadian Space agency and green energy initiatives." The budget, according to the report, will cut funding to the Canadian Environmental Agency by 43%. (Edmonton Journal February 29th) And, of course, Canada pulled out of Kyoto earlier this year. -
Pete Dunkelberg at 07:56 AM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
Dikran is right that denial of the cause of the increase in atmospheric CO2 is worth treating in print. He might offer to educate Heartland's chosen educator David Wojick. From a comment at Eli'sI made the mistake of visiting the House of Curry, and followed some links from Curry's laudatory description of Lindzen's talk (and having _been_ to one of Lindzen's talks in person, I find it hard to think that there is anything of laudatory content in there). Some interesting quotes from delving into the rabett-hole... First, David Wojick, Climate Educator: "I am not convinced that the CO2 increase has caused any warming, nor that the CO2 increase is due to human emissions. So I certainly do not agree with AGW, in any form." While this was in 2010, this one quote pretty much demolishes his (already non-existent) credentials as someone who should receive money for creating a climate curriculum: if you can't accept that the CO2 increase is due to human emissions, you are pretty much in Moon-landing-denial territory. (comment from http://judithcurry.com/2010/12/14/co2-no-feedback-sensitivity-part-ii/) Quote 2 is of note because Curry tries so hard to never let herself get pinned down on anything, and is so hard on anyone who doesn't acknowledge uncertainty in their conclusions: she states as "almost certain" something that I consider "likely wrong". "This is how I would do the analysis to determine the CO2 no feedback sensitivity. The number would almost certainly be less than 1C." from http://judithcurry.com/2010/12/11/co2-no-feedback-sensitivity/ -MMM
Thanks Dikran for doing this. -
Riccardo at 07:34 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Jose_X you have three possibilities, look at what other scientists published on the topic or read a textbook on radiative transfer and do proper calculations yourself or satisfy your curiosity with a crude semi-quantitative model. The latter is straightforward. If you have a transparent atmosphere you end up with a isothermal atmosphere at the same temperature as the surface; the latter is determined by simply balancing the fluxes. In the real case, use the adiabatic lapse rate, the emission altitude from the effective radiation temperature and extrapolate back to the surface. But please, stop quoting from bad science sites ... -
scaddenp at 07:32 AM on 1 March 2012Newcomers, Start Here
My 2c. 1. Distinctions need to be made. I consider myself a skeptic - most scientists do. However fake skepticism is skepticism of a theory you dont like for reasons not based on data and no skepticism at all for alternatives or criticism that support your position. There is no name-calling of genuine contrary studies, that are published in media. They are interesting - just very rare. People who make misleading statements to the naive and take a different line when talking to their peers deserve all the criticism they get. As do those who knowingly skew and present science for the purpose of misleading the public. 2. Well there is only valid answer - you cant have personalised reality. However, there are different opinions on what that is obviously. Contrary opinions have to be supported by data and to be taken seriously, published in peer-reviewed literature. "Blog science" doesnt count. "Surely there must be some evidence of a contrary viewpoint." Not much. Plenty on blogs - not in the literature. 3. "I can’t imagine any scientist applying for grant money to research a theory that humans are not to blame. " Correct - because real scientists do not do research for a predetermined outcome and grant committees would reject such a proposal out of hand. That's SPPI/Heartland stuff. Instead scientists put in application to research what is not known - whether the results support or conflict with established theory is of no interest to granters. The common criteria for funding are: - is it novel? - does the team have the relevant expertise? - and for many grants, is the research relevant? I would say you objections are due to misconceptions. Fortunately, that is easily fixed. -
Riccardo at 07:13 AM on 1 March 2012Scafetta's Widget Problems
The sea level data are detrended and retain the seasonal cycle which is what the solar tide function apparently matches. Temperature anomalies are detrended as well and not a very compelling proof. The best case scenario is that it contributes to variblity, though I'd wait for a proper analisys by Volker Doormann. -
dana1981 at 06:59 AM on 1 March 2012Michaels Misrepresents Nordhaus and Scientific Evidence in General
Indeed, I was very happy to see Nordhaus come out and dispel the misrepresentations of his research so emphatically. Look for a blog post featuring his article in the near future. -
Albatross at 06:57 AM on 1 March 2012Michaels Misrepresents Nordhaus and Scientific Evidence in General
Dana @11, That is an excellent essay by Nordhaus. I also like this statement: "The skeptics’ summary is based on poor analysis and on an incorrect reading of the results. The first problem is an elementary mistake in economic analysis." Beautiful, this seems to be a common problem with claims, science and research undertaken by fake skeptics :) I wish more scientists were more outspoken about misrepresentations and distortions of their work by fake skeptics. -
Dikran Marsupial at 06:53 AM on 1 March 2012Scafetta's Widget Problems
Volker, correlation is not causation. If the coherence exists over the extend of the satelite record, then plot a graph of the coherence across the satelite record, better still, perform a proper statistical analysis. I suspect the coherence doesn't extend over the whole period of the observations, which would imply that the correllation is no more than a temporary correllation and is essentially meaningless. This advice is well intentioned. Perform statistical tests to determine whether your results can be explained by random chance. It is the safeguard that is widely used in science to prevent jumping to conclusions. If you don't do that, then your efforts are likely to be wasted investigaing meaningless correllations. You wouldn't be the first, you won't be the last, but it would be better if you applied more self-skepticism and didn't make this mistake at all. -
CBDunkerson at 06:44 AM on 1 March 2012Postma disproved the greenhouse effect
While I too consider the Postma paper under discussion a travesty, YOGI's statement that 'most of it is very good' could almost be true in a way... if this is an indication that YOGI is accepting that the 'greenhouse effect violates the 2nd law of thermodynamics' argument (i.e. the central premise) of the paper is incorrect then there actually is quite a bit of other information in the paper which is accurate and detailed enough to be useful to someone who hasn't been exposed to the more nuanced intricacies of the greenhouse effect previously. However, as Dikran notes, it isn't entirely clear whether YOGI is accepting that or not... and in any case there are many other references which can provide a similarly detailed background without the occasional shockingly wrong argument sprinkled in. -
Volker Doormann at 06:42 AM on 1 March 2012Scafetta's Widget Problems
@Dikran Marsupial “Volker Doormann I have had a look at the sea-level/temperature/Mercury/Earth phase coherence, and I have to say that the evidence isn't very compelling. “ OK. But it is scientifically not relevant what your evidence detector reject; relevant would it be, if you would state, that there is only a correlation coefficient of about ~0.0 between the solar tide function and sea level and no significant phase coherence between the solar tide function and see level oscillation on the graph seen. “Why show only data from 2009 to 2012? We have sea level and UAH data extending further back than that and if there is a meaningful phase coherence then it should be coherent as far back as the satelite observations extend.” Old trick. How many black swan want you to see, to accept that there are really black swans living? http://www.volker-doormann.org/images/sealevel_1996.gif http://www.volker-doormann.org/images/sealevel_2000.gif http://www.volker-doormann.org/images/sealevel_2004.gif http://www.volker-doormann.org/images/ghi_had_1960_3.gif http://www.volker-doormann.org/images/ghi_11_had1960.gif http://www.volker- doormann.org/images/ghi4_vs_patzelt_dsh1.jpg http://www.volker-doormann.org/images/ghi_11_1.gif http://www.volker-doormann.org/images/echo_g_vs_ghi.gif “The problems with correllations between noisy signals is that if you look hard enough, you will almost always be able to find one purely due to random chance. This is why statistical tests should be used to determine if the degree of correllation is surprising given the noise levels of the data and the number of correlations investigated.” You miss the core of the object. These two graphs are examples of the result of more than two years research in astronomy and climate proxies, and the results are unique in the field of climate simulation and prediction. There is no better tool as summing up solar tides from real objects. Scafetta’s cycle’s have no astronomical basis; time cycles of ~60 years are not astronomy based. My have. V. -
CBDunkerson at 06:34 AM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
Thanks Dikran. Very good stuff. Even if we can't come to agreement there is alot to be said for polite discussion. It will be interesting to see if there is further analysis and discussion around this. -
Jose_X at 06:33 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Ricardo, (-snip-) I summarized the results. I am curious what you think about what I wrote. If you want more details, ask or glance at that page I linked. My problem essentially is that I don't have a handy solver to test out what the GHE calculates for the surface temperature of Venus. Next (problem 2), replace most of that CO2 by N2 and see what is the result. Can you help me with these two calculations to see if the first one fits the data and then to see (out of curiosity) what the second one produces?Response:[DB] Inflammatory snipped.
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DrTsk at 06:30 AM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
It really saddens me... -
DrTsk at 06:28 AM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
the original paper should neeeeveer have been published. This is so 1st year Chemical Engineering it is not even funny. -
DMCarey at 06:21 AM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
Steve Case @1, the scarey thing is I'm encountering an increasing number of people in Canada who seem to doubt the existence of even the greenhouse effect. The far-reaching disinformation campaign seems to be muddying the waters rather effectively. In light of this, I feel its the duty of the choir to sing loudly to bring sanity back to this (should be) non-debate -
KR at 06:20 AM on 1 March 2012Postma disproved the greenhouse effect
YOGI - "...most of the paper is very good." As stated in the OP, and in multiple comments, this is simply not the case - Postma's paper is riddled with basic errors. An object is in thermal equilibrium when it is radiating/conducting/convecting away as much energy as it is receiving from it's surroundings. A nearby mirror (as part of those surroundings) increases the amount of energy coming in over and above the light source (relative to a cold background), and the only way for that object to radiate away that increased energy is to become warmer. That holds whether the mirror is perfect, or a 50% mirror with wavelength dependencies (more akin to the atmosphere). Increased energy from the surroundings, or rather decreased energy absorbed by the surroundings, will drive the temperature of the object up until it is radiating as much energy as it absorbs. Postma's statement that the object would not heat up, as Dikran noted here, is completely wrong, violating the first law of thermodynamics, conservation of energy. There's nothing wrong with the mirror example, just with Postma's incorrect description of what would happen. Leaving behind inexact language (such as "implies") - do you, or do you not, agree with Postma? -
Dikran Marsupial at 06:13 AM on 1 March 2012Postma disproved the greenhouse effect
YOGI Please can you state unequivocally whether the mirror example in Postmas paper is incorrect or not. Do you agree that with the mirror in place the blackbody will have a higher equilibrium temperature. Also please state unequivocally whether you agree that in the example you provided that the presence of another blackbody increases the equilibrium temperature of both bodies. In a scientific debate it is essential that such things are stated absolutely unequivocally, rather than "which implies there is a problem", which is vague enough for there to be a question of whether it is actually right or wrong. -
Riccardo at 06:07 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
I understand that it might be just my prejudice but I'm not sure I want to read something (as Jose_X suggests) written by someone introduced by these words, they doesn't sound much like well founded science:"Science today recognizes the world was remade (through a presumably long process of continental breakup, worldwide drift, and rejoining), incredible as that seemed a hundred years ago. "The End of the Mystery" establishes the even more astounding, and even surer, fact that the world was deliberately changed, to enable a great design. It is only the overwhelming scale of the design that has up to now stymied man's understanding, eluding even the finest modern scientific minds. The discovery of a great, world-encompassing design, confirmed alike by new, overwhelming physical facts about the Earth and by the universal ancient testimony, invalidates the presumption against design of the current scientific consensus, and enlightens both religion and science. We are in fact at the start of a new age of unprecedented, unified understanding, of the real history of the Earth and man.
For what is worth, I don't understand why Jose_X keeps quoting pages of "strange" science while leaving the door open to the possibility they're at least in part correct and that "it seems to cast some doubt to what all of that CO2 is doing." -
dana1981 at 06:06 AM on 1 March 2012Michaels Misrepresents Nordhaus and Scientific Evidence in General
Note that in an article today, Nordhaus has confirmed that Alex and SkS are right, and Michaels and the WSJ 'skeptics' are wrong:"The authors cite the “benefit-to-cost ratio” to support their argument. Elementary cost-benefit and business economics teach that this is an incorrect criterion for selecting investments or policies. The appropriate criterion for decisions in this context is net benefits (that is, the difference between, and not the ratio of, benefits and costs)... ...My research shows that there are indeed substantial net benefits from acting now rather than waiting fifty years. A look at Table 5-1 in my study A Question of Balance (2008) shows that the cost of waiting fifty years to begin reducing CO2 emissions is $2.3 trillion in 2005 prices. If we bring that number to today’s economy and prices, the loss from waiting is $4.1 trillion."
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YOGI at 06:03 AM on 1 March 2012Postma disproved the greenhouse effect
That`s what I thought, which implies that there is a problem with the mirror example, as equal and mutual exchange amounts to the same as reflection. A mirror is hardly an analogy of the real atmosphere as re-emission after absorption is in all directions, and there are gaps between absorption bands. So I would not throw the baby away with the bathwater, most of the paper is very good. -
Jose_X at 05:56 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Tom Curtis #57: I think I understand where Tgb comes from. The part inside the integral of eqn 2 (which looks like eqn 1 without the 4 denominator) is just Stefan-Boltzmann in a form that shows the value of T explicitly as a function of power flux. This starting point is independent of the shell radiative model, and numerous people accept it and use it to calculate the temp of the planet if it had not atmosphere. The albedo would be to sun's radiation and the emissivity would be for the planet radiating in its own spectrum range as graybody. This is consistent with how it refers to Tgb later on, "the average temperature of a Standard Planetary Gray Body (SPGB) with no atmosphere (Tgb, K)." And then it clarifies that it is using that Tgb with reasonable parameter values: > We employ Eq. (2) to estimate Tgb assuming an albedo αgb = 0.12 and a surface emissivity ϵ = 0.955 for the SPGB based on data for Moon, Mercury, and the Earth surface. Using So = 1362 W m-2 (Kopp & Lean 2011) in Eq. (2) yields Tgb = 154.3K and NTE = 287.6/154.3 = 1.863 for Earth. This prompts the question: What mechanism enables our atmosphere to boost the planet surface temperature some 86% above that of a SPGB? I agree then that step b is correct. -
RonManley at 05:53 AM on 1 March 2012Scafetta's Widget Problems
I've now updated my model using CO2-equivalent rather than CO2. The regression is slightly improved. What is interesting is that new model gives less influence to sunspots and a better estimate of sensitivity for CO2-equivalent doubling - 0.89 C. -
Dikran Marsupial at 05:49 AM on 1 March 2012Postma disproved the greenhouse effect
YOGI Forgetting the mirror avoids discussing the error in Postmas' paper. However, in the case of two black-bodies in close proximity and at the same temperature, there will be a constant exchange of photons between them, but this exchange will be balanced (assuming symmetry). However this exchange flux will mean that both bodies would be at a higher equilibrium temperature than they would be at if the other body were not there. This is because the outbound photons that would have been absorbed by the other body will now simply be radiated out into space and won't be balanced by the reciprocal photons from the other body. -
boba10960 at 05:45 AM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
Thanks to everyone who responded to my inquiry! I'm an oceanographer and can hold my own on most discussions of carbon in the ocean, but the processes that influence the radiation balance in the atmosphere remain a challenge. Consequently, I appreciate the opportunity provided by SkS to learn about climate-related processes outside my own field. Glenn Tamblyn - I look forward to reading your post! -
YOGI at 05:37 AM on 1 March 2012Postma disproved the greenhouse effect
Postma`s mirror... OK forget the mirror atm and imagine the experiment to be in the vacuum of space, and there are two identical black bodies being warmed by the same light bulb at the same distance to the same state of equilibrium. When the two black bodies are in close proximity but not touching each other, is there a reciprocal warming in both bodies ? -
Dikran Marsupial at 05:03 AM on 1 March 2012Scafetta's Widget Problems
Volker Doormann I have had a look at the sea-level/temperature/Mercury/Earth phase coherence, and I have to say that the evidence isn't very compelling. Why show only data from 2009 to 2012? We have sea level and UAH data extending further back than that and if there is a meaningful phase coherence then it should be coherent as far back as the satelite observations extend. The problems with correllations between noisy signals is that if you look hard enough, you will almost always be able to find one purely due to random chance. This is why statistical tests should be used to determine if the degree of correllation is surprising given the noise levels of the data and the number of correlations investigated. -
Dikran Marsupial at 04:52 AM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
Cheers Composer99 and Doc Snow! @CBDunkerson No faults in the logic were identified, IIRC most of the reviewers comments were related to adding caveats and clarifications (the models used were very crude, and only really represents the initial fast response of the carbon cycle, so the true adjustment time is likely to be longer than the estimate of about 74 years given in the paper). Essentially the caveats explained why the models were unduly optimistic about the rate at which CO2 levels will fall following a cessation of anthropogenic emissions (most of this is in the penultimate section "limitations of the one-box model", Philip Goodwin's help was invaluable in writing that section!). @Dana1981 I should add that my email correspondance with Prof. Essenhigh was entirely good-natured; while I didn't convince him that his conclusion was incorrect, he was unfailingly a gentleman in setting out his position and in the subsequent discussion. -
Jose_X at 04:48 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Tom Curtis #57, I see IanC spotted a mistake, and I have not read the whole article; however, this remark they made would make me very suspicious that they would decide to use this Tgb value: > Since in accordance with Hölder’s inequality Tgb ≪ Te (Tgb =154.3K ), GHE becomes much larger than presently estimated. > According to Eq. (2), our atmosphere boosts Earth’s surface temperature not by 18K—33K as currently assumed, but by 133K! This raises the question: Can a handful of trace gases which amount to less than 0.5% of atmospheric mass trap enough radiant heat to cause such a huge thermal enhancement at the surface? Thermodynamics tells us that this not possible. We know that this Tgb is very low compared to observations of T, so I take this as a rejection of the modified 1 shell model rather than as a way for the authors to introduce a model that they believe does justify 133K. I'll try to finish reading soon. @Everyone: I wanted to ask people here what they think about this: http://theendofthemystery.blogspot.com/2010/11/venus-no-greenhouse-effect.html . Skimming should give an idea of the main claim. A summary might be that the top section of Venus' atmosphere (50km altitude and up, where the pressures exist on Earth) matches the Earth's atmosphere in temperature once we factor in the ratio of the Stefan Boltzmann calculation for Venus to that of Earth (ignoring albedo!). Although I have been critical of it without passing an official final judgement (note how Venus has similar mass, radius, and hence gravitational constant as Earth), it seems to cast some doubt to what all of that CO2 is doing. Note, the albedo is entirely ignored by Huffman (and this appears to present conservation of energy issues or information traveling faster than speed of light so that emitter A can generate extra radiation beyond S-B to match what B will reflect, etc.. but maybe not (I won't detail guesses I have)). Note that the values used for Venus might be a little off. I found what looked like an authoritative source (need to hunt down the link). While the numbers are a little off from what I saw, they are in the right ballpark (but the deviation is a bit greater). I can imagine that the lapse rate changes shape deeper into Venus, but I think data suggests it is close to a line of similar slope to that of the earth (?). It's also true that right below the top 1 atm isn't a body of water and earth but instead just more air so it is not the same scenario as Earth. A question that follows would be, if the atmosphere was largely N2, would this same general lapse rate exist down to the ground, possibly with only a little bit different slope? Also, would the slope be significantly different or would the rate be a different very distinct curve? Anyway, my main problem is that I don't yet know clearly the equations/algorithm that predict GHE (eg, Ramanathan and Coakley '78), so I can't carry out a few quick checks. If all there was to average temperature was the pressure, we would not experience large oscillations. I don't know what level of variation (eg, deviations from solar tracking.. as CO2 on earth is predicted to be causing for decades now) would be consistent with such a view. There is too much data I have not seen/analyzed and too much theory I still haven't covered. Obviously, I can consider that maybe there are some mistakes in our current understanding of GHE. Or, I can consider that a strong GHE effect leads to 1%-10% or other maximum variations near the surface (a limit I did not think existed). This would bound the earth temperature above (against GHE predictions I think), if still allowing great threat to humans. Anyway, I assumed the WUWT paper being discussed was related to what the Huffman webpage shows. Assuming it is, I don't worry too much about astral rocks with light atmospheres (our high altitude low pressure atmosphere deviates from the lapse rate), but moon Titan might be another example following the Earth/Venus ratio. Any opinions? -
Composer99 at 04:47 AM on 1 March 2012Climate Sensitivity: Feedbacks Anyone?
Now that we're on a (hopefully topical) thread, Matthew L, I'll take a crack at answering. I'm not one of the professionals participating here, so I may well have some major or minor details incorrect. As you state, correctly, positive feedbacks will amplify both warming and cooling forcings in the climate. This is what allows the otherwise weak Milankovitch cycles, for example, to cause climate to shift between glacial and interglacial periods during the current Ice Age. At the time scales you are thinking of, 1-2 years (to say nothing of shorter time scales), the noise in the system (seasonal & diurnal variability, large-scale energy-shifting oscillations such as ENSO, and the like) will tend to either dampen or amplify the forcings & feedbacks in play. So, for example, in terms of surface temps 1998 was aberrantly warm compared to the rest of the 1990s (despite their being, at the time, the warmest decade on record) because of the very strong El Nino, which made the warming seem much stronger. Likewise the recent La Nina phase has dampened the warming of the 2000s and early 2010s. In addition, multiple forcings are at play, some warming (e.g. greenhouse gases, shrinking ice albedo) and some cooling (e.g. solar activity until very recently, aerosols) so contradictory forcings will have contradictory positive feedbacks. Hopefully that helps! -
KR at 04:42 AM on 1 March 2012Climate Sensitivity: Feedbacks Anyone?
Matthew L - Quite correct, a 'positive' feedback amplifies the climate response to forcing changes whether positive or negative. Note that the 'loop' for feedbacks is a diminishing one (gain <1), meaning that there is no "runaway" affect in either warming or cooling directions - just a rather larger movement than one would expect with a forcing change an no feedback. Also keep in mind that feedbacks have time constants to their forcing response - water vapor responds in a matter of days, vegetation in years, ice in years/decades, and ocean temperature/CO2 solubility (to name a few) in centuries. Short term (weather) changes, including the yearly cycle, simply don't last long enough for the longer term feedbacks to take effect - they get averaged out. -
dana1981 at 04:31 AM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
CBD - Dikran corresponded with Essenhigh, who he says didn't really budge, and eventually said something along the lines of "one of us is wrong." He did not raise any valid objections to Dikran's response. -
Volker Doormann at 04:25 AM on 1 March 2012Scafetta's Widget Problems
“Since Scafetta's hypothesized astronomical cycles have no impact on the long-term warming trend, his prediction that future global warming will be minimal is based entirely on his interpretation of the scientific literature. For example, he twice mentions that galactic cosmic rays may play a significant role in influencing global temperatures, but fails to mention any of the dozens of papers which have found little if any correlation between cosmic rays and cloud cover on Earth. Scafetta also fails to mention that solar magnetic field, which influences the amount of cosmic rays reaching Earth, has no long-term trend over the past ~60 years, nor does cosmic ray flux on Earth. Thus how can cosmic rays possibly explain the rapid warming over that period? This question remains unanswered.” Agree. But there are real astronomical cycles – I prefer the dimension frequency [1/sec] or [1/y] – called heliocentric synodic tide functions, which have correlations with some terrestrial data. Solar tide function of Mercury/Earth is phase coherent with the measured sea level oscillation but also visible in the global temperature data from UAH. http://www.volker-doormann.org/images/sealevel_vs_xyzo.gif Solar tide functions of some two or three objects in the solar system are in coincidence with the reconstructed TSI anomaly after F. Steinhilber, et al. over 5 ky: http://www.volker-doormann.org/images/ghi_vs_tsi_6ky.gif Because the solar tide functions easy can be calculated from NASA ephemerides 1000 years ahead daily, a prediction of the global climate with a resolution of month is now possible. V.
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