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Tom Curtis at 15:03 PM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
apsmith @22, great blog post, and your fourth figure illustrates very well your claim about the Planck function. As indicated, I wasn't sure you were disagreeing with anything. I was just uncertain as to why you thought it important to mention the Planck Function in this context. -
actually thoughtful at 14:45 PM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
HR - I would be more inclined to agree with your criticism if Spencer didn't try to poke holes in the Milankovitch cycle theory. Given that he did, I think it is fair to critique his argument against Milankovitch cycles. I think the idea that there is a 60 year, 1,000 year, etc cycle has some problems, one of which is we are 40 years into a 60 year "cycle" - the sun is about to end its quiescence and while it is theoretically possible, it is highly doubtful that the next 20 years will show any cooling. So that blows up the 60 year cycle. The data for longer term, non-Milankovitch cycles is even weaker. I think Spencer is essentially looking for a miracle in the 5% probability that the IPCC leaves on their predictions. So in the sense that anything is possible - sure. In the sense that we have a pretty good understanding of the climate system, and at this point studies are confirming model-predicted behavior, not so much. ____________ Kevin C @ # 3 - excellent comment. Very well said and I agree. I was squirming in my chair, realizing the analysis was pretty good, but the tone is not up to SKS standards. -
michael sweet at 14:33 PM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
Moderator, I agree with from Peru that Roy Spencers anti scientific ideas about Evolution and Creation cast doubt on his scientific judgement. I do not like the suggestion of ad-hominem at #6. Can you suggest what is appropriate on this site in this situation so that I know for future reference? Thank you for your help.Moderator Response: [Dikran Marsipial] The Comments policy explicitly forbids ad-hominem attacks, which are an attack on the source, rather than the content of an argument. Dr Spencers views on evolution have no bearing on whether his theories on climate are correct or not, and they should stand or fall on their own merits. Several contributors to Skeptical Science are committed Christians (and other faiths), including myself, there are plenty who would say that such views are unscientific (I would agree) and/or delusional (I don't agree there ;o). Does that mean skeptics can dismiss any of my arguments on the basis that I have religious beliefs? It is a slippery slope, and it is part of the distinctive nature of Skeptical Science that the discussion is centered on the science and logical fallacies such as the ad-hominem are discouraged, it is one of the features that makes Skeptical Science (in my view) the best of the climate discussion forums. Note that Spencer has frequently refuted other skeptic arguments, such as that CO2 is not a greenhouse gas, that the greenhouse effect contradicts the second law of thermodynamics, or demonstrating that the results of Lindzen and CHoi were substantially flawed. Are those arguments devalued by doubt on his scientific judgement? No, their value is determined by their internal consistency and support from the data and experiments. -
apsmith at 14:31 PM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
Tom (@20) - I don't think we're disagreeing, I recently blogged on the subject of the temperature associated with emission to space. My only point was the Planck function for a given wavelength is not proportional to T^4, only the integral over all wavelengths is. -
scaddenp at 14:26 PM on 2 March 2011Australia's departing Chief Scientist on climate change
I hope you are wrong. I think we need to leave thermal coal in the ground and get energy elsewhere. However, making steel without coking coal is challenging. Surely the climate can cope with steel emissions provided other CO2 source are brought down? -
muoncounter at 14:24 PM on 2 March 2011CO2 lags temperature
287: Bruce, A couple of misconceptions in your comment: CO2 is not the only driver of climate. It happens to be a strong positive forcing now; that does not mean it always was. Oceans are acidifying, meaning they are absorbing CO2 from the atmosphere. At some point (or perhaps at some locations) they will warm sufficiently to release dissolved CO2. As always, the picture is more complicated than one can sum up in a sentence or two. There is a wealth of information here at SkS designed to inform and dispel some of the myths, half-truths and outright distortions that kick around the internet. Use the Search function to browse the most commonly heard 'skeptic arguments.' -
michael sweet at 14:18 PM on 2 March 2011Australia's departing Chief Scientist on climate change
In order to deal with the AGW problem the world needs to leave all the rest of the coal in the ground. When politicians realize that it is cheaper to leave the coal in the ground than to pay to rebuild after floods, like this years in Queensland, than something may be done. The developed world will have to lead before the developing world will follow. It is too bad that Australia has such a dependence on coal. They will have to find new sources of revenue. Hopefully they will not wait until AGW has destroyed their agriculture base before the change is made. If they wait that long it will be even more difficult to adjust. Right now the deniers are succeeding in delaying any action. -
muoncounter at 14:15 PM on 2 March 2011Measuring CO2 levels from the volcano at Mauna Loa
Nice non-technical summary article on the history of atmospheric CO2 measurements at climatecentral. The Mauna Loa volcano rises high above the Pacific on the Island of Hawaii. “Here, the background concentration of carbon dioxide should not be influenced by forests or soils, or an inversion or the weather,” Tans says. “All that is stripped away.” -
scaddenp at 14:15 PM on 2 March 2011CO2 lags temperature
A positive feedback does not necessarily mean runaway feedback. See run away warming -
adelady at 13:58 PM on 2 March 2011Crux of a Core, Part 1 - addressing J Storrs Hall
Thanks for that Tom. I had an unkind thought about how often certain people deign to put "Dr" before many well-known names. And "...greenhouse warming is not an unusual explanation... any change of climate needs some explanation." You're right. Far too many people of this ilk talk about global warming "theory" as if it were some discrete academic discipline. "Global warming" is just a sub-set of general climate science. Climate science shows that certain events and circumstances have predictable outcomes. The current circumstance, of releasing an unusual amount of GHGs at an unusually fast rate, is displaying fairly predictable responses. Usually called global warming. Those responses being in accordance with the general theory mean that we have a fairly high level of confidence that events in the future will unfold in accordance with the theory. More data, better technology, more experience working with the information we've already accumulated just makes it less and less likely that current evaluations of the historical record and any consequential projections for the near or distant future will turn out to be "poppycock". -
Bruce Frykman at 13:55 PM on 2 March 2011CO2 lags temperature
Since we have accepted the fact that atmospheric CO2 concentration is a primary driver of the earth's climate and also the fact the the earth has been much warmer in the past this presents a dilemma. The oceans contain about 50 times more carbon dioxide than does the atmosphere. It has been well noted that warming oceans release more of their absorbed carbon dioxide than they at the same time sink from the atmosphere. So remembering that atmospheric carbon dioxide concentrations are the primary driver of our climate any previous warming in excess of what we see in modern times should have driven a runaway warming cycle, driven by massive releases of oceanic carbon dioxide in a positive feedback loop. But somehow this didn't happen. I wonder why? -
HumanityRules at 13:30 PM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
bbickmore, I think you're being a little disengenuous or atleast knit-picking here. I think you know that he thinks that multi-decadal to centennial natural variation are ignored by the IPCC. Technically your right in what you're saying, and sure you've highlighted some sloppiness in some out-of-context sentances but why use the example of millions of years cycles to criticism like this "...on time scales of thirty years or more...". I think to provide a substantive critique of Spencer you should be showing the solidity of the understanding of multi-decadal change. So far you have managed to skillfully avoid it. In some respects this is part of the problem with the plethora of recent 'skeptic bashing' articles on this website. It's more concerned with point scoring and discrediting the individuals than it is about understanding their concerns. -
Tom Curtis at 13:27 PM on 2 March 2011Crux of a Core, Part 1 - addressing J Storrs Hall
Charlie A @31, first let me second scaddenp's comment which is exactly to the point. Let me add, first, that Hall feeling slighted about not being called "Dr" is extraordinarily precious from somebody who dismisses climate scientists as "The Hockey Team" and dismisses (his straw man version of) their theories as "poppycock". More substantively, it is very noticeable that when he compares Antarctic and Greenland ice cores, he does so over the period of the Last Glacial Maximum. Unsurprisingly, there is a correlation between temperature differences between the LGM and the Holocene (the last 10 thousand years). But even during the last glacial there are clear anti-correlations between the three ice cores, even between the two Greenland ice cores on a scale of thousands of years. Therefore his failure to show a comparison of GISP2 and Vostok over the period of the Holocene with sufficient resolution is very damming. Such a comparison can be made in Figure 3 above. Vostock is shown in Dark Blue, GISP2 in light blue. If you look closely you will see that they are anti-correlated for most of the holocene. That means their average will have far fewer and smaller fluctuations then either seperately. The rapid rises and declines in the Greenland ice core during the Holocene are not global events, but the equivalently precipitous rise in late twentieth century temperatures is. Finally, he claims "The 20th-century warming was hardly unprecedented, and doesn’t call for unusual explanations." Let's leave aside that greenhouse warming is not an unusual explanation. The fact of the matter is that any change of climate needs some explanation. For global temperatures to change by up to a degree or more without explanation would violate conservation of energy. As it happens, the only substantive explanation is anthropogenic emissions of Green House Gases. (On a side note, Hall's PhD is in "computer science", which may well make him a skilled programmer, but it does not make him a scientist despite his claims.) -
Tom Curtis at 12:50 PM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
apsmith @19, I'm curious as to why you bring up the Planck function. I don't doubt what you say, but it does not mean you cannot judge temperatures of gases from the relative intensity of their emission spectra at a give wavelength relative to the intensity predicted by a black body curve. Thus, in your illustration, and ignoring complexities related to emissivity, we can see the surface temperature was less than 275 K, and hence close to freezing. We can also see that the average temperature of CO2 molecules emitting to space was around 223 K at that location. That is what Peter was doing, and quite correctly. In fact, physicists often do the same thing more formally by plotting the spectrum as brightness temperature against wavelength instead of radiance against wavelength. One example (from here) is this plot, clearly from a tropical sounding:
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Ken Lambert at 12:37 PM on 2 March 2011Australia's departing Chief Scientist on climate change
michael sweet #13 My points are simple ones. The Australian economy relies on coal and iron ore exports for a large chunk of its export income. The Federal Govt counts on this income and the taxes raised therefrom to run its budget - and so do State Govts in Qld and NSW. Our own carbon emissions are a tiny fraction of what carbon we export to China, Japan, Korea, India, Taiwan and other emitters. There is a massive contradiction in a Federal Govt imposing a carbon tax on Australians for negligible real effect on global CO2 emissions, while depending on and factoring in the income from increasing coal exports. Some would call it breathtaking hypocrisy. -
apsmith at 12:28 PM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
Peter, regarding the very center of CO2 absorption, you should take a close look at a graph of the measured outgoing spectrum from Earth, for example this one posted at ScienceOfDoom here - http://scienceofdoom.com/2010/05/12/co2-an-insignificant-trace-gas-part-eight-saturation/
You'll notice that right at the center of the 15 micron dip there's a narrow spike. That higher level of emission right in the center of the absorption band is from the warmer temperatures in the stratosphere, just as you guessed. But the dependence is not the T^4 rule, that applies only to the overall integral of emission over all wavelengths. The specific law for a single wavelength is the Planck function, which is roughly linear in temperature for high temperatures, but drops very quickly to zero at low temperatures.
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scaddenp at 12:28 PM on 2 March 2011Crux of a Core, Part 1 - addressing J Storrs Hall
Charlie A, put your serious skeptical hat on and closely read that post yourself. Spot the switch from absolute to anomaly? Perhaps read the papers instead of the quotes. As for "the only substantive point was..". Ho, ho. The zero point of 1855 isnt a substantive point? The actual temperature measurements? Does the original article still make sense when you look at the correct construction. (eg in #14 ) -
Philippe Chantreau at 12:26 PM on 2 March 2011Crux of a Core, Part 1 - addressing J Storrs Hall
"The author of the post being rebutted, J Storrs Hall, has taken exception to not being addressed as doctor and feels this is a deliberate slight upon him." Funny. I have read so many skeptic rants about appeal to authority, use of titles to suggest authority, how one does not need degrees to be qualified, what an expert is, etc. I had construed that skeptics did not care much about academic titles. Silly me. -
Tom Curtis at 12:16 PM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
Peter Offenhartz @17, you may well be interested in the post on Theory and Experimant at Science of Doom. It contains (amongst other gems) this illustration of the effect of doubling CO2 on radiative forcing:
As you can see, most of the effect is in the wings of the 15 micron trough, although there is a slight deepening of the trough in the center, which is the second largest effect. Some other absorption bands currently barely detectable in atmospheric spectrums also start to strengthen.
This is the non-equilibrium response. As the Earth warms to restore equilibrium, there will be an increase in radiation at all frequencies, so that in the equilbrium case, there would be more radiation from the center of the 15 micron band, not less.
Although KR has found mention of 215 K as the brightness temperature at the center of the 15 micron band, I have noticed it as being centered around 220 K, with tropical spectra above that, and polar spectra below.
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Tom Curtis at 12:01 PM on 2 March 2011Various estimates of Greenland ice loss
Climatewatcher @15, that graph is currently being discussed on the Crux of a core thread. Essentially its problems for your use are that the most recent temperature from the ice core itself is actually 1855. The red spike at the end is supposed to show global temperature increases to the present, but they do not show global temperatures since 1855, and nor should global temperatures be compared with regional temperatures. Based on a recent analysis of Greenland temperature records, the decadal average of temperatures in Greenland has increased by approx 1.5 degrees C since the 1850's, so current tempertures on that graph should be around -30.5 degrees C, or about the peak of the MWP. 2010 temperatures are another degree warmer than that, or about equivalent to the peak of the Roman Warming. That means the current warming in Greenland is unparalleled in magnitude and abruptness in the last 6,000 years. What is more, the overall decline in Greenland temperatures evident in your graph has a well known cause, the decline in arctic summer insolation related to the Milankovitch cycles. Summer insolation is still declining. To what, then, do you attribute the sudden reversal of thousands of years of cooling? -
Peter Offenhartz at 11:57 AM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
@KR (16) MANY THANKS for pointing me toward the Daniel J. Jacob reference at Harvard. His article is at once brief, comprehensive, and clear. As you note, the main CO2 effective emission temperature is about 215K, which is, I'll bet, right at the knee in the lapse rate curve, which means that rising CO2 concentrations will have little climate effect IN THE MAIN ABSORPTION PEAK. Lest anyone think I've become a global warming skeptic, the real action from changing CO2 concentrations must be taking place on the absorption wings, where the effective temperature is much higher and where rising CO2 concentrations should indeed cause a falling emission temperature. This picture clarifies my understanding considerably, but I'll have to spend more time studying Jacob's chapter. Thanks again KR. -
Charlie A at 11:35 AM on 2 March 2011Crux of a Core, Part 1 - addressing J Storrs Hall
The author of the post being rebutted has a "rebuttal to the rebuttal" posted at http://wattsupwiththat.com/2011/03/01/rebuttal-to-the-skeptical-science-crux-of-a-core/#more-35045 If you have an open mind and would like to be informed, I suggest clicking on over and taking a look. -
dorlomin at 11:08 AM on 2 March 2011Crux of a Core, Part 1 - addressing J Storrs Hall
The author of the post being rebutted, J Storrs Hall, has taken exception to not being addressed as doctor and feels this is a deliberate slight upon him. Perhaps the author would be so good as to address this as a courtisy to Dr Halls wishes? -
KR at 11:04 AM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
Peter Offenhartz - From Daniel J. Jacob, Harvard, working from CO2 emission lines rather than H2O: The 15 mm blackbody temperature in Figure 7-8 is about 215 K, which we recognize as a typical tropopause temperature. It looks like the CO2 effective emission altitude is around 10km or so. -
Trueofvoice at 10:45 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
Damorbel is doing here exactly what he has been doing on the Wikipedia Temperature talk page. He makes repeated objections based on his flawed understanding of the subject, then accuses others who have taken the time to correct his nonsense of attempting to distort the issue. He has absolutely no interest in understanding anything you guys may say to him. He simply wants to argue. -
From Peru at 10:37 AM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
Re:#6.michael sweet Thanks you for the link to the wiki article showing how deep the anti-scientific beliefs of Roy Spencer reach. Roy Spencer accuse climate scientists of a "Great Blunder" in which he blames recent warming on ocean cycles like PDO and ENSO instead of greenhouses gases. He is dead wrong because in the past, the ENSO-PDO climate connection brokes down: during the so-called Medieval Warm Period, the Tropical Pacific was in a protracted COOL state, dominated by a NEGATIVE PDO: Variations in the Pacific Decadal Oscillation over the past millennium And a LA NIÑA protracted dominance: Fossil coral snapshots of ENSO and tropical Pacific climate over the late Holocene Proving that radiative forcing (in the case of the MWP, solar + volcanic) is by far the main driver of climate, not internal oceanic oscillations like ENSO and PDO like people like Roy Spencer want us to believe. Saying all this, I can also show that Roy Spencer, not having enough with spreading nonsense about the climate science, it is an advocate of a pseudoscience far worse than climate "skepticism": intelligent design, that is just a Trojan Horse for Creationism (or as can be described better, evolution denialism). The wiki page given by michael sweet links to this "gem" written by Roy Spencer in the right-wing magazine TCS daily: Faith-Based Evolution The nonsense seen here can be quoted: "Twenty years ago, as a PhD scientist, I intensely studied the evolution versus intelligent design controversy for about two years. And finally, despite my previous acceptance of evolutionary theory as "fact," I came to the realization that intelligent design, as a theory of origins, is no more religious, and no less scientific, than evolutionism." "While similarities between different but "related" species have been attributed by evolutionism to common ancestry, intelligent design explains the similarities based upon common design. An Audi and a Ford each have four wheels, a transmission, an engine, a gas tank, fuel injection systems ... but no one would claim that they both naturally evolved from a common ancestor." Can we trust a "scientist" that wrote such a piece of disinformation? This is not a matter of religious beliefs. The problem here is that he believes that "intelligent design" is a valid scientific theory and should be teached alongside mainstream evolution. This is just crazy. Strange that many climate "skeptics" are also evolution "skeptics". I suspect an ideological, right-wing common root on both positions.Moderator Response: [DB] Fixed link. -
actually thoughtful at 10:14 AM on 2 March 2011Various estimates of Greenland ice loss
Climatewatcher- what does it mean that the temperatures go up as you go down the right axis. Is the negative sign to be believed? Or does your data show that the medieval warming period was over 1C higher than now? To what do you attribute that sharp spike in red on the right side of your graph? -
Peter Offenhartz at 09:43 AM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
@hank(12) Thanks. I'll have a look at your reference when I have some time. @KR (13) I know the mean height for outgoing LW radiation is 4-5 km (that's where the H2O concentration gets very low, due to cooling), but I'm interested in the height for the CO2 band, since CO2 concentration relative to O2 and N2 doesn't change with altitude. I'll keep trying. Thanks. -
dana1981 at 09:14 AM on 2 March 2011How We Know Recent Global Warming Is Not Natural
Jesus - if climate sensitivity is 2°C (0.54 Wm-2K-1), it means the equilibrium warming from the CO2 forcing thus far is: 0.54*5.35*ln(390/280) = 0.96°C. Now certainly it's possible to come up with some convoluted argument that less than 0.4°C surface warming thus far has come from the CO2 radiative forcing that will result in 0.96°C surface warming at equilibrium. You could argue that ocean thermal inertia is huge (but "skeptics" argue that it's small). You could argue that there is a large aerosol forcing offsetting the CO2 warming, and a large unaccounted for 'natural' forcing causing more warming than CO2 (but again, "skeptics" usually argue that the aerosol forcing is small). But realistically, if sensitivity is no less than 2°C, you can't come up with a plausible argument that CO2 isn't responsible for most of the warming we've seen this century. I've got another article on a very similar subject that will be published later this week, called "Climate Sensitivity: The Skeptic Endgame". -
RickG at 08:43 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
@449, Agreed, especially with your last comment. -
ClimateWatcher at 08:39 AM on 2 March 2011Various estimates of Greenland ice loss
Not particularly remarkable when one considers Greenland temperatures through out the Holocene:
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KR at 08:28 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
Folks - we've now had 'natural cycles', 'cosmic rays', 'heat of compression', 'it's the sun' and 'thermodynamics and temperature are poorly defined'. And that's just in the last three days. Before that there was 'albedo', multi-layer insulation, 'sunlight can't make it out of the water', 'constant disequilibrium', 'elastic collision of photons', and the lovely bit of obfuscation, "All materials, even gases, have a refractive index >1, consequently no material substance can behave according to the definition of a black body". And without really defending any one position - just moving to the next whenever getting nailed down in contradictions - not the behavior of someone who actually deeply believed anything they were stating. damorbel is, I believe, a troll. His sole purpose here appears to avoid any answers or conclusions, rather than to reach one. I suggest we not feed the troll... -
scaddenp at 08:18 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
I'm still waiting to see whether damobel would change his mind if an experiment showed a result that was incompatible with his application of 2nd Law (and compatiable with standard radiative physics textbooks). -
muoncounter at 07:34 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
damorbel: "Svensmark's cloud generating cosmic rays" Wow, you think that thermodynamics is 'wildly misunderstood,' but you accept Svensmark as a 'powerful effect'? The GCR->clouds->cooling idea fails rigorous scrutiny; even the CERN CLOUD experiment, tailor made by Kirksby to test the idea, is producing "underwhelming" results. See Its cosmic rays. Are we on ABC territory here? Anything but CO2? -
KR at 07:28 AM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
Peter - Excellent question. Science of Doom has a page on that very topic here: Height of emission of OLR and DLR. Outgoing LW radiation occurs at an average of 5km near the tropics and 4km near the poles, as judged by spectra and the Stefan-Boltzmann law. This is well below the altitude of temperature reversal in the lapse rate. -
hank at 07:27 AM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
> At what height (and temperature) is this "top" There's no "top" in that sense -- most of the total heat radiates away from lower down. You can find infrared photographs from satellites and see that. The air is so thin near the "top" that relatively very few molecules exist to radiate -- and those radiate in all directions of course. Here's someone working on building an explanation starting from a simple model and working up to a multiple-layer model and explaining why that's useful: http://how-it-looks.blogspot.com/2010/05/multi-layer-model-of-carbon-dioxide.html -
michael sweet at 07:22 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
I think I should have stayed out of this conversation, but I will answer your direct question. More CO2 does not mean more radiation into space. The increase in CO2 raises the level in the atmosphere where radiation escapes into space (see post 442 above). Since it is colder higher in the atmosphere less radiation is emitted into space and the planet warms. You are defining what is "warming" and what is "heat transfer" incorrectly. CO2 warms the lower atmosphere by reducing heat loss. This is consistant with the second law. The IPCC says the greenhouse effect "warms" the lower atmosphere 33C by reducing heat loss to space. The CO2 does not contribute energy to the system. My blanket warms me 10-15C every night by reducing heat loss from my body to my room. Where is the problem? I will leave this to the others who are trying to explain it to you, I don't think I have anything to add that they have not said before. -
DeanL at 07:17 AM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
What Kevin C says @3 is extremely important. I point to SkepticalScience often and the credibility of the site and its scientific response to the issues is crucial to being useful as a weapon against deception and misconception. I'd go so far as to suggest some of the recent articles on Spencer and Monckton should be reviewed in the light of maintaining a non-political, purely science based approach at SS. I am profoundly grateful for the job John has done in adhering to this approach and I'd hate to see it derailed by a few I'll advised comments in an otherwise very well reasoned post. I think that it will still be very obvious to objective readers as to the motivations and intentions of those being critiqued and, at the end of the day, all scientists make mistakes and deserve the benefit of the doubt. Despite some evidence to the contrary, most people can discern a trend when subtly pointed out! -
bbickmore at 07:05 AM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
Peter #8, I'm not the guy to answer that question, unfortunately. You'd have to find someone who is way into radiative transfer calculations. -
bbickmore at 07:04 AM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
Hi Kevin C #3, I honestly tried very hard to keep the tone moderate. In any case, I certainly didn't say everything that popped into my head! In the example you bring up, note that I didn't ascribe any particular motivation for why Roy Spencer said things about his colleagues that he knows are false. For all I know, he's just never thought about it hard enough to attain some sort of logical consistency. -
Dikran Marsupial at 06:52 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
damorbel The "higher altitude radiation" and "backradiation" are both parts of the same theory (neither violate the second law of thermodynamics). Again you are demonstrating that you do not understand the mechanism of the greenhouse effect. I'm also not going to get drawn into a discussion of the definition of temperature, that is just another attempt at to derail the discussion. You are still avoiding answering the questions I posed in earlier posts. -
damorbel at 06:42 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
Re #442 Dikran Marsupial you wrote:- "If you were familiar with the basic mechanism of the GHE you would know that" I am familiar with a variety of GHE explanations including the "higher altitude radiation" one you cite which is quite different from the "backradiation" one; the one that busts the 2nd law of thermodynamics. None of these AGW - CO2 models stand up to serious examination. But I agree that there are rather too many understandings of how thermodynamics works; even simple matters like the definition of temperature are wildly misunderstood and wrongly taught, particularly at universities. -
damorbel at 06:33 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
Re #440 RickG you wrote:- "Then to what do you attribute AGW?" I am much happier with 'Climate Change' or even better 'Climate Variability' Most of the Sun's heat comes in at the tropics, the atmosphere and the oceans spread this over the globe by various currents that do not follow stable routes; the re is a great tendency to turbulence in fluid flow, even on a global scale. The most obvious example of this is the El Nino current which is highly unstable but there are many, many other currents all of which have powerful heat carrying capacities. Monitoring current flows would go a little way to explaining climate changes. Also Svensmark's cloud generating cosmic rays would have a powerful effect on heat transport in the atmosphere, quite enough to explain ice ages. -
Dikran Marsupial at 06:33 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
damorbel I see you have gone back to refusing to answer direct questions again and instead are opting for evasion instead. "Like I said to Mike Sweet, more CO2 in the atmosphere means the atmosphere become a more powerful radiator of heat, don't you agree?" Even though your question is evasion, to avoid answering my question, I'll answer it anyway. No, I don't agree. The more CO2 in the atmosphere, the higher in the atmosphere IR has to be emitted before it isn't absorbed by CO2 in the layers above. The lapse rate means this layer will be colder, and hence the less radiation that is emitted and so the atmosphere below and hence the surface will become warmer. If you were familiar with the basic mechanism of the GHE you would know that. -
damorbel at 06:23 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
Re #438 Dikran Marsupial you wrote:- "Do you agree with the fundamental point that the atmosphere being warmer than outer space means that the surface looses heat energy to space more slowly than it would if the atmosphere were not there?" Like I said to Mike Sweet, more CO2 in the atmosphere means the atmosphere become a more powerful radiator of heat, don't you agree? -
RickG at 06:18 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
damorbel: Seems to me 'AGW due to CO2' has no validity. Then to what do you attribute AGW? -
damorbel at 05:58 AM on 2 March 20112nd law of thermodynamics contradicts greenhouse theory
Re #438 michael sweet you wrote:- "The energy from the cold atmosphere is not enough to "raise the temperature" of the warmer Earth." But the IPCC says GHE is warming the Planet by 33C - up from 254K to 288K. That is not just a little bit, it's a whacking great amount. Also you wrote:- "It keeps the Earth from cooling as fast as it used to." But radiation from water and CO2 is the way the atmosphere loses heat to deep space. GHE theory says 'more CO2 absorbs more heat' (I thoroughly agree) But doesn't 'more CO2' also radiate more heat into deep space? Seems to me 'AGW due to CO2' has no validity. -
Peter Offenhartz at 05:36 AM on 2 March 2011Roy Spencer’s Great Blunder, Part 2
I think your post was excellent. I know it is hard not to say that a man IS a fool when he BEHAVES like a fool, but I think you did a pretty good job staying on the right side of the line. I have a question that is off-topic, and I hope you will feel free to relocate it elsewhere as you please. My question is about the mechanism of radiative heat transfer in the region of the strong CO2 absorption band. In this band absorption is so strong that the sky is essentially black. All outgoing radiation in the band is initially absorbed close to the surface of the earth. According to the Schwarzschild equation, the absorbed radiation is re-radiated upward and downward, so there is a balance of energy fluxes; it is not until, near the "top" of the atmosphere, that the radiation escapes entirely. Thus, the net flux in this band depends almost entirely on the temperature at the earth's surface and the temperature at this "top", both to the fourth power, of course. My question is simple: At what height (and temperature) is this "top" where the radiation flux is overwhelmingly upward? Is it above or below 10,000 meters? The reason I ask is that the lapse rate changes sign in the 10,000-15,000 meter region; rather than cool with increasing altitude, the atmosphere begins to warm (because of heat/radiation originating in the absorption of the sun's ultraviolet). The usual explanation for the CO2-caused greenhouse effect is that increased CO2 concentrations push this "top" region to higher altitudes where it is colder, and the reduction in radiative flux caused by colder temperatures causes warming at the surface. I understand this, I think. But what if this "top" is at or above 10,000 meters? That's the part I really do not understand, and I would appreciate any help in clarifying this picture. Thanks in advance! -
hank at 05:01 AM on 2 March 2011Climate sensitivity is low
Tom, I agree; same for Spencer's comparable effort at http://www.drroyspencer.com/2010/07/yes-virginia-cooler-objects-can-make-warmer-objects-even-warmer-still/ -
Jesús Rosino at 04:11 AM on 2 March 2011How We Know Recent Global Warming Is Not Natural
Thanks for your answer, dana1981. However, I don't think a low climate sensitivity opens up any window to a natural effect. If such natural factor existed, it might affect climate sensitivity (it might not), but it doesn't work the other way around, i.e., the fact that climate sensitivity was low, IMHO, wouldn't say anything about the likelihood that such natural factor existed. Consider, for example, the uncertainty in radiative forcing from aerosols. Imagine that, within the said uncertainty, aerosols happened not to have cooled the planet much, and their negative radiative forcing is in reality at the lower end of our estimate (close to zero). This would imply that total net radiative forcing would be in the upper end of our estimate (around 2.4 W/m2), and therefore climate sensitivity would be in the lower end of our estimate, with the 'percentage' of warming attributed to human activities unaffected (likely more than 100%). I'll give some numbers, in case it makes my point clearer: Let's assume that equilibrium temeprature change due to current forcing is 1.2ºC. Then, Eg.1: standard (most likely value) estimate of forcing and sensitivity is: Net forcing = 1.6 W/m2 And therefore, Climate sensitivity = 1.2 / 1.6 = 0.75 (W/m2)−1 (that means ΔT = 3.7*0.75 = 2.8 ºC for CO2 doubling) Eg.2 Weaker aerosols (less negative forcing) -> higher net forcing: Net forcing = 2.4 W/m2 --> Climate sensitivity = 1.2 / 2.4 = 0.5 (W/m2)−1 (this means ΔT = 3.7*0.5 = 1.9 ºC for CO2 doubling, with human contributiong being exactly the same) Therefore, I still think that the sentence:even a 2°C climate sensitivity would mean that humans have been responsible for more than half of the global warming over the past century
is misleading, because "a 2°C climate sensitivity" doesn't mean anything by itself about the portion of global warming attributed to human activities.
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