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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 101351 to 101400:

  1. What would happen if the sun fell to Maunder Minimum levels?
    Henry justice, that paper is here: http://ecrs2010.utu.fi/done/posters/session1/1.62_Stozhkov.pdf IMO it is an oversimplification to equate solar activity with a particular cooling from low clouds. The way I see it (in the cosmic ray thread) is that the extra cosmic rays reduce warming amplification whatever the warming sources might be. They do this by creating more atmospheric blocking, by clouds, and probably other effects. So IMO what will happen is CO2 warming will be less amplified, or not amplified at all. I'm not so sure that there will be cooling.
  2. Medieval Warm Period was warmer
    #24: All well-known deniers. Nice work on the Phoenix CO2 dome, though.
  3. What would happen if the sun fell to Maunder Minimum levels?
    Whether the authors are right are not (wonder if they are friends of the other russian solar scientists losing the bet with Annan on global warming), the article shows effect of such a minimum will be small compared to GHG forcings. And of course when such a minimum ends...
  4. Medieval Warm Period was warmer
    Besides, its probably a bit off topic, but you have a look at this co2science organisation : chairman : craig d. Idso president : sherwood b. Idso vice-president : Keith e Idso a nice family business :)
  5. What would happen if the sun fell to Maunder Minimum levels?
    #94: "Cosmic ray flux will increase and lead to more clouds. further cooling ..." That is still highly unsubstantiated; some would say, debunked, here. Cosmic ray flux was at a high during the most recent solar minimum through end 2009; where were the clouds? Where was the cooling? As for the rest, are you reading Landscheidt?
  6. What would happen if the sun fell to Maunder Minimum levels?
    @Henry Justice: "The trigger for the initiation of sunspots is the falling of celestial bodies (comets, asteroids and others) from the Oort cloud and Koiper belt onto the Sun." There is no indication whatsoever that a comet falling into the sun will trigger sunspots. I don't think you realize what the size difference between a comet and the sun is. Also, it is unlikely a comet would ever get through the ultra-hot corona to reach the sun's(relatively) cooler surface. There is also no solid evidence we are heading to a new Maunder minimum, and that this will somehow offset the current warming trend. Was the article in question peer-reviewed? (I saw there was a reference to a Willie Soon, which makes it highly suspect in my view.) After all, we should expect to be as skeptical of such claims as you seem to be about established science
  7. An Even Cloudier Outlook for Low Climate Sensitivity
    @RickG: I get posts deleted here regularly because I get off-topic sparring with tro..."skeptics". I don't mind, those are the rules and I admit I do tend to be combative when confronted with the same debunked argument over and over again (that, and "skeptics" who hide their pseudo-science behind a wall of jargon, formulas and appeals to sources that do not actually support their views). The moderators here do a great job, even if I'm sometimes on the receiving end of their moderation stick. I'm completely fine with that.
  8. Climate's changed before
    @tobyw: interesting study, but right now we haven't seen any increase in vegetation due to additional CO2 in the atmosphere (so far, it's been the opposite), so I'm a bit skeptical about this expected negative feedback.
  9. The 2nd law of thermodynamics and the greenhouse effect
    damorel - the idea that text book use of heat flow (you can call it heat transfer or whatever) implies that the text book writer is confused about the historical "fluid" theory is ridiculous in the extreme. A few minutes reading the framework would dispel that notion. The standard, textbook theory of thermodynamics gives us a predictive framework. If your eccentric ideas fail to predict the outcome of an experiment and the textbook method does, then do you accept that you need to change your ideas? At the moment you are clinging to a false notion of GHE based as far as I can see on an incoherent thermodynamic framework. The argument can progress if we can discuss an experiment where your notions produce a different an answer to standard textbook ones.
  10. The 2nd law of thermodynamics and the greenhouse effect
    I also would like damorbel to answer the counter-arguments presented to him rather than dismiss them off-hand. So far, he has failed to make a compelling case to support his bizarre interpretation of accepted science.
  11. What would happen if the sun fell to Maunder Minimum levels?
    We are now in a repeat Dalton Minimum. There is a very good chance that afterwards by 2020, a grand Maunder like minimum will begin. Cosmic ray flux will increase and lead to more clouds, further cooling the Earth. Long term solar activity minimums have occurred in the past when the center of mass of the solar system (the Sun and external planets without Jupiter) was outside of the Sun. The trigger for the initiation of sunspots is the falling of celestial bodies (comets, asteroids and others) from the Oort cloud and Koiper belt onto the Sun. The gravitation of fields of the Sun and planets govern the motions of these bodies and direct these celestial bodies to the Sun's surface. When the center of mass of the solar system is outside of the Sun most of these celestial bodies do not fall on the Sun and a long-term solar activity minimum begins. The maximum value of Rz is predicted not to exceed 50. See ref: New Maunder Minimum in Solar Activity and Cosmic Ray Fluxes in the Nearest Future, Stozhkov and Okhlopkov, 3-6 August, 2010, 22d European Cosmic Ray Symposium, Turku, Findland.
    Moderator Response: A duplicate copy of this comment was deleted from the thread "Are we heading into a new Little Ice Age?" Please do not post multiple copies of the same comment. Thanks!
  12. The 2nd law of thermodynamics and the greenhouse effect
    @damorbel: "I am intrigued to know how contributions based on the scientific arguments presented by the IPCC or their lead authors for preventing AGW can be described as political." Simple, it was because of your unsupported claim that any energy alternative leads to financial catastrophe (ignoring the fact that inaction will lead to much bigger financial woes. In particular, these words: "much more expensive 'wild (or supposedly renewable) energy sources, all of which will have a devastating effect on the environment." There is no evidence that alternative energy sources (solar, wind, tidal, geothermal, hydro, etc.) have "devastating effects" on the environment, especially when use of fossil fuels (oil, coal, gas, etc.) *already* has a deleterious impact on the environment. What you said was not a scientific statement, but a political one that has no basis on objective reality. Perhaps it's time for you to re-evaluate your motivations and start understanding the science rather than spout off incorrect arguments in an arrogant assault on established science.
    Moderator Response: [muoncounter] Archiesteel - Well put!
  13. The 2nd law of thermodynamics and the greenhouse effect
    Oops, I should note that contra my comment #203 greenhouse gas distribution is not exclusively limited to the troposphere. Mea culpa.
  14. The 2nd law of thermodynamics and the greenhouse effect
    damorbel: What does O2 absorption of Sun-sourced UV-spectrum EM radiation in the stratosphere have to do with tropospheric greenhouse gasses (CO2, CH4, H2O, &c.) absorbing surface-sourced infrared-spectrum EM radiation, or with your claim that the latter process is nonexistent on account of the 2nd Law of Thermodynamics (or at least your interpretation of it)?
  15. The 2nd law of thermodynamics and the greenhouse effect
    Moderator Response: [muoncounter] I am intrigued to know how contributions based on the scientific arguments presented by the IPCC or their lead authors for preventing AGW can be described as political. When geoengineering is under consideration it is essential to run the scientific arguments to their proper conclusion.
    Moderator Response: [Daniel Bailey] This thread is on the 2nd law of thermodynamics and the greenhouse effect. Subjective remarks on the economic effects of rising CO2 or comments on geo-engineering are off-topic. Keep that in mind if comments disappear.
  16. Medieval Warm Period was warmer
    Hi, Well if i have some time, i will look at the refs they give, cause a popular method is giving good refs but in a completely wrong way...
  17. Medieval Warm Period was warmer
    Re: stefaan (21) Hello again, sir! I felt you were in agreement with the science end of it, but wanted to provide a framework of a response for the other readers to see. A logical evidenciary chain builds credibility. :) As to:
    "I think they just gave the data that fit their story in this case."
     I believe you have the right of it. Not all have the ability to overcome cognitive bias and have the strength of mind to logically go where the data takes one, regardless of presuppositions. The Yooper
  18. Medieval Warm Period was warmer
    Hi Daniel, I think the theory about GW is rather solid. In my opinion there are only 2 possible attitudes towards the effect of (extra) CO2 - it has little or no effect (this demands of course that you reject the idea of the natural greenhouse effect). Although even most "climate skeptics" reject this point of view, its often encountered in popular media. An argument which is often found in this discussion is that 'the moon is 60 K too hot' but its never accompanied by any proof - or you recongnize the existence of the natural greenhouse effect and then its impossible for me to understand how people can think that doubling the amount of CO2 wont have (almost) no effect Nevertheless its often difficult to sepparate the wheat from the chaff especially when i see rather well documented sites like the co2science site i gave earlier. I think they just gave the data that fit their story in this case. best regards stefaan
  19. Climate's changed before
    Re: tobyw (146) There has been some discussion of the Bounoua et al study on another thread, specifically comments 15-24 located here. But thanks for the heads-up! The Yooper
  20. The 2nd law of thermodynamics and the greenhouse effect
    Re #199 CBDunkerson you write :- "damorbel #198:Numerous people, including me, have repeatedly shown you conclusive proof... " In #198 I asked who you thought are the scientists who have moved on from Tyndall. My personal concern in this matter is not the historical side but how modern physics handles the arguments put forward by the IPCC when they are advising governments to change the basis for energy supply to much more expensive 'wild (or supposedly renewable) energy sources, all of which will have a devastating effect on the environment. Half of the IPCC thesis is that the Earths albedo reduces the surface temperature when some simple physics familiar to all shows that this simply isn't true. The other half of the IPCC thesis is that gases that emit/absorb infrared can change the heat distribution in the atmosphere. On this last I have cited the stratosphere where the temperature profile really is modified by absorption. But the planet with a very nearly pure CO2 atmosphere, Venus, does not have a stratosphere like the Earth with its characteristic temperature inversion. Surely if GHGs absorbed IR in the same way O2 absorbs UV there would be some trace of temperature inversion but I don't think you will find any.
    Moderator Response: [muoncounter] You were asked politely in #193 to keep your politics to yourself. Yet you continue in #198, #201. Next political rant is gone -- and all the prior ones go, too.
  21. Ice data made cooler
    @RSVP #40 It's not negating anything you could posibly post, as you could post things that are right. For instance, you took my advice to look at partial pressures and quoted Henry's Law (You see, nobody is telling you that is wrong) but still you don't catch the difference between an ion and a di-gas. But it remains, among other things, the set of problems related with arithmetics that your post #29 shows (it is still there for everyone to see). As I say, I won't give the solution nor point the several mistakes for you, and I think everybody else are of the same opinion. I'm only going to point your mistakes and give you some hints as suggesting you to reconstruct the reasoning in post #29 on paper with simple diagrams and paying attention to what you take and what you add here or there, understand the % you are talking about, and then get the data and apply it to your now carefully weighted formulas. I'm sure you agree that we all -including you- must avoid giving answers to people who don't want to ask directly what they clearly ignore and pretend instead pull out information by promoting dialogues like: "-Water boils at 500° - No, it boils at 100°C - Yes, as water boils at 100°C, the sky is brown - No, the sky is blue ... "
  22. An Even Cloudier Outlook for Low Climate Sensitivity
    it's surprising how quickly somebody here will jump all over you correct you when they think you're wrong. What's even more surprising is how quickly people return to their errors after being corrected. Sometimes it's almost like the discussion never happened, and everyone has to go back to square one.
  23. An Even Cloudier Outlook for Low Climate Sensitivity
    I wouldn't spend much energy trying to figure out what Roy Spencer's position is really supposed to be as it relates to Andy's paper. I'm afraid that Roy is somewhat narcissistic. Trying to engage the likes of Spencer and Lindzen in meaningful dialogue is simply an exercise in futility. In Roy's own words: " First, we skeptics already know your arguments …it would do you well to study up a little on ours. And second, those of us who have been at this a long time actually knew Galileo. Galileo was a good friend of ours. And you are no Galileo.". Neither is Roy, but he looks good on TV. I've read all the exchange and there is certainly the insinuation by Roy that ENSO is driven by clouds. But who am I to question Roy's science, after all, as he states, everybody else is wrong and only he is right. I find it hard to believe that Roy took the time to break from his politicizing at Cancun to even read Andy's paper. And as has been indicated in discussion, it was totally absurd of Roy to criticize the timing of the release of Andy's paper as these paper's are submitted and the author(s) have no control over the timing of the release, and Roy is quite aware of this. Amazing how people turn to dirty pool when their backs are against the wall.
  24. An Even Cloudier Outlook for Low Climate Sensitivity
    I'll make an easy statement, too: put up or shut up. Seriously. Go show Dressler where he's wrong. Seconded. Talk's cheap. Stop casting petty aspersions and show your work. As for the people who are complaining about comment moderation at RC, I don't see that RC's commenting policy is all that different from SkS. It's more inconsistent, probably, but it also tends to be more tolerant of "skeptical" conspiracy-mongering and ad hom. Certainly, outright trolling disrupts more threads there than it does here. Still, even if this complaint were accurate, you could avoid having your comments deleted by submitting strictly rational and respectful criticisms of Dessler's methodology. Implying that your criticisms will be deleted makes it seems as though you're simply avoiding a real test of your pet theories. You're fortunate to be have an opportunity to engage with Dessler. Make use of it. You might learn something.
  25. Medieval Warm Period was warmer
    Re: stefaan (19) Appreciate the response. As a scientist, I'm sure you appreciate the value of peer-review in discerning the wheat from the chaff. As such, the purpose of the IPCC Working Group 1 is to establish the consensus of the available peer-reviewed literature in the field of climate science. From the IPCC, an overview of the past 1,200 years: Examples of regional variability over that time period: The IPCC's summary statement on the MWP:
    "The weight of current multi-proxy evidence, therefore, suggests greater 20th-century warmth, in comparison with temperature levels of the previous 400 years, than was shown in the TAR. On the evidence of the previous and four new reconstructions that reach back more than 1 kyr, it is likely that the 20th century was the warmest in at least the past 1.3 kyr. Considering the recent instrumental and longer proxy evidence together, it is very likely that average NH temperatures during the second half of the 20th century were higher than for any other 50-year period in the last 500 years. Greater uncertainty associated with proxy-based temperature estimates for individual years means that it is more difficult to gauge the significance, or precedence, of the extreme warm years observed in the recent instrumental record, such as 1998 and 2005, in the context of the last millennium."
     Source: IPCC WG1 Chapter 6.6 . Weigh that against the CO2Science position statement on global warming, formulated in 1998. As a scientist, I'm sure you also appreciate the need to first weigh all of the available evidence before formulating an explanation that best explains all of that evidence. And to revise that explanation as newer data becomes available over time. The science says one thing about the human attribution of CO2 and its effects (known since the days of Tyndall and Fourier). CO2Science says another. What does your skeptical scientist mind say? The Yooper
  26. The 2nd law of thermodynamics and the greenhouse effect
    Re #197 Philippe Chantreau you write :- "Damorbel, are you suggesting that CO2, CH4 and H2O are not present or do not absorb/emit in the stratosphere? Why would that be?" I don't think any of the gases you mention are responsible to a great extent for absorbing UV in the stratosphere. It is O2 (diatomic oxygen) that absorbs UV at 200microns and below; this creates two separate (monatomic) oxygen atoms which then react with O2 (diatomic oxygen) to form O3; which is actually triatomic oxygen or perhaps more familiar with the name ozone.
  27. The 2nd law of thermodynamics and the greenhouse effect
    damorbel #198: "The troposphere is colder than the surface below it, nobody contests this. That is all that is neccesary to destroy the hideously expensive CO2 reduction policies required to save us from AGW." Numerous people, including me, have repeatedly shown you conclusive proof to the contrary. Your refusal to see (or address) those proofs is "all that is necessary" to demonstrate that you cannot make your case.
  28. The 2nd law of thermodynamics and the greenhouse effect
    Re #196 CBDunkerson you write :- "you rewrote this as me citing just Tyndall." Feel free to add who you like, I cannot do this for you. Meanwhile, if you think name dropping like this is a substitute for arguments, then what about Boltzmann, Joule, Clausius, Kelvin and many more who made remarkable contributions to thermodynamics. You will be hard pushed to discover anything of substance in their work that supports the strange predictions of AGW. The troposphere is colder than the surface below it, nobody contests this. That is all that is neccesary to destroy the hideously expensive CO2 reduction policies required to save us from AGW.
  29. Climate's changed before
    New NASA computer model shows plants slow warming by 0.3C-0.6C when CO2 is doubled against the predicted 1.94C globally. No mention of atmospheric sulfur (a source of particulates which help form rain) having declined from a peak in 1970 to 100-year lows in 2000. Don't you love it when they use data that stops 10 years ago in a current article? Far too much data is left out of models to assure accuracy, IMHO. Worse still, there is no mention of missing/incomplete data, only mention of major consensus. -T . http://www.nasa.gov/topics/earth/features/cooling-plant-growth.html 'Greener' Climate Prediction Shows Plants Slow Warming A new NASA computer modeling effort has found that additional growth of plants and trees in a world with doubled atmospheric carbon dioxide levels would create a new negative feedback – a cooling effect – in the Earth's climate system that could work to reduce future global warming. The cooling effect would be -0.3 degrees Celsius (C) (-0.5 Fahrenheit (F)) globally and -0.6 degrees C (-1.1 F) over land, compared to simulations where the feedback was not included, said Lahouari Bounoua, of Goddard Space Flight Center, Greenbelt, Md. Bounoua is lead author on a paper detailing the results that will be published Dec. 7 in the journal Geophysical Research Letters. Without the negative feedback included, the model found a warming of 1.94 degrees C globally when carbon dioxide was doubled. Bounoua stressed that while the model's results showed a negative feedback, it is not a strong enough response to alter the global warming trend that is expected. In fact, the present work is an example of how, over time, scientists will create more sophisticated models that will chip away at the uncertainty range of climate change and allow more accurate projections of future climate. "This feedback slows but does not alleviate the projected warming," Bounoua said.
  30. Medieval Warm Period was warmer
    Hi Daniel, I am a bit familiar with the most common explanations about GW and as i scientist i am find the arguments in favor of an antropogenic gw effect more convincing than the against-arguments. However, in a discussion about the MWT someone gave me the linkt i mentioned here. If those data are correct (and they appear to be so as they are collected from lots of different articles) the MWT seems to have been a global warm period. So, what I think that the explication can be : - MWT was indeed a global warm time so there is something wrong with the graph you gave me - The data sets given in that cited ref are almost 80 % situated in the northern hemisphere and so dominating the overal view (although even the points on the southpole display a warm period) - the results are cherry picked to display a wrong image - the results are not cherry picked but just (intentionally or not) wrong... best regards stefaan
  31. Philippe Chantreau at 04:56 AM on 14 December 2010
    The 2nd law of thermodynamics and the greenhouse effect
    "The stratosphere is formed by O2 & O3 absorbing UV coming from the Sun which heats it, giving it its characteristic temperature profile." Damorbel, are you suggesting that CO2, CH4 and H2O are not present or do not absorb/emit in the stratosphere? Why would that be? There is a considerable body of litterature showing that they are present and absorb/emit as expected.
  32. An Even Cloudier Outlook for Low Climate Sensitivity
    #60: "I have read estimates of a meter of sea water evaporating annually. This represents a mammoth amount of energy." Doesn't the bulk of that vapor condense back out and don't we 'recover' the bulk of the energy of evaporation upon condensation? If we had a net loss of a meter of sea water each year and still have measurable sea level rise, we must really be melting some ice! For other evaporation questions, See the thread on Humidity increase
  33. The 2nd law of thermodynamics and the greenhouse effect
    Damorbel, I cited "over a hundred and fifty years of direct scientific practice" ... "since Tyndall" and you rewrote this as me citing just Tyndall; "Do please explain why you think Tyndall's interesting but minor papers should take precedence." I don't think that. I think that the 150+ years of science consistently verifying Tyndall's work should take precedence. Tyndall was the first to show experimentally how 'greenhouse gases' cause the 'greenhouse effect' (though he did not use either term)... but his instruments were not accurate enough to get precise readings of the magnitudes involved. Thus, we should not go to Tyndall for that information... hundreds of better sources are now available. By your 'logic' we should look ever backward to more and more limited understandings of science for the answers. Clearly the ultimate authority on all sciences would be the pre-caveman who developed the first tool by picking up a stick and hitting something with it.
  34. Ice data made cooler
    @RSVP: by "bad science" I mean science that does not follow the empirical method, or that contains glaring errors. It also includes basic math errors, like the one you made earlier. Perhaps you should stop criticizing for a while, and start learning with an open mind free of politically-motivated preconceptions.
  35. Renewable Baseload Energy
    @quokka: "The US deployed 140 MW of PV in the first 11 months of 2010 and over 6000 MW of new coal. Assuming a generous 20% capacity factor for PV and 80% for coal, it would take 28 years of PV deployment at this rate to equal the output of just one 1GW coal fired power station. This is the harsh reality that the purveyors of the micro generation nonsense would rather hide." Another illogical fallacy: the 140 MW of PV were not, AFAIK, microgeneration sites. Even then, you can't use the timid move towards PV as evidence that microgeneration can't help in the fight against emmissions. It's the same thing as faulting antibiotics for curing a disease when the doctor gives you only 1/20th of the required dose. Another mistake which you continue to make (willfully?) is that microgeneration advocates believe it is *the* solution. In fact, we believe that a mix of technologies - including nuclear - will be necessary. Again, your absolutist stance is highly suspect. This isn't even about opinion, it's about simple logic. You should make sure your arguments are logically consistent, otherwise you just sound like you're making a sales pitch.
  36. An Even Cloudier Outlook for Low Climate Sensitivity
    Hi all, IMHO, continuing to discussion about alleged censorship and moderation at certain sites is not at all constructive, especially given that doing so does it speak to the science at hand. Could we please focus on the science? My two cents worth.
  37. The 2nd law of thermodynamics and the greenhouse effect
    @michele: the issue is not that I and other disagree with you, it's that you do not present compelling responses to the counter-arguments being presented to you. I'm not looking for a fight, but I'm tired of people coming here trying to challenge the science when it's clear they haven't done their homework first.
  38. The 2nd law of thermodynamics and the greenhouse effect
    Re 189 VeryTallGuy I can see absolutely nothing in your diagrams that shows the GHGs have the characteristic emission spectrum of a black body. The dotted lines are only there as a reference to what a black body spectrum looks like. The heavy black lines are (or are very similar to) the GHG radiation spectrum and it fluctuates wildly, going almost to zero between 600cm^-1 and 700cm^-1. This is the well known window where radiation from the Earth goes directly to deep space, GHGs do not have any effect in this region.
  39. We're heading into an ice age
    Game, set, match: CBDunkerson.
  40. Renewable Baseload Energy
    An interesting aside on this topic: Israel has endorsed a plan for a network of electric cars, built by Renault-Nissan and using swappable battery packs for 5-minute charge changes. They plan a network of "switching stations", estimating a cost of $150M or so to build a network capable of covering the country. Plans by the network provider Better Place are to expand to Denmark (aiming for 100,000 cars there), and then to a (ahem) small island network - i.e. Australia, with a network covering the entire southern coast. Given some of the concerns on renewable baseline power, if a network of switching stations with packs of car-sized cells on chargers is available, that could provide a potential buffer for short-term demand variations. There would have to be a compensation mechanism (subtracting drawn power from charged power on the bills, at the least?), but that would represent quite an accumulation of energy.
  41. The 2nd law of thermodynamics and the greenhouse effect
    @damorbel: "before supporting an economy shattering 'theory' of AGW!" Please provide concrete evidence that adressing AGW would "shatter our economy." That seems to be political opinion, not a rational assessment of reality. That could explain why you are resorting to inflammatory language after failing to produce any rational explanation as to why AGW would violate the 2nd Law of Thermodynamics. In other words, you have failed to present a convincing case. At this point, all you seem intent on doing is derailing the debate. Please stop.
  42. The 2nd law of thermodynamics and the greenhouse effect
    Re #187 DSL you wrote:- "C02 and CH4 absorb and emit in the stratosphere." The stratosphere is formed by O2 & O3 absorbing UV coming from the Sun which heats it, giving it its characteristic temperature profile. Now the question is, why doesn't back radiation, which originates from GHGs cause similar heating by being absorbed by the (relatively) uniform GHG distribution in the troposphere? For the rest, the Sun's energy comes in in a very non-uniform way, strongly at the equator and much less at the poles. The Earth radiates to a more or less uniform 2.7K thus there is a thermal gradient over the surface from the tropics to the poles. This gradient causes fluid flow in both the atmosphere and the oceans, the fluid flow tansports heat over the surface thus giving us climate and weather. Convection has a smallish role in climate, transporting heat from the surface into the atmosphere where it subsequently is either radiated to deep space or transported polewards. Heat from the Sun is also transported to the poles by ocean currents. The thing about convection is its very variable nature. When a lot of warm tropical surface water is drawn together by surface winds, a dynamic feedback takes place as convection increases, fed by the thermal energy contained in the surface water, producing spectacular hurricanes. A similar effect produces tornados over land.
  43. The 2nd law of thermodynamics and the greenhouse effect
    damorbel it's your understanding of those great physicists and pretending that I didn't read them and that you know better than me for ths reason. Anyways, this discussion has taken a dangerous slope of personal attacks. I'd invite everybody to end it here before it badly derails.
  44. Are we too stupid?
    Apologies are in order. I inadvertently deleted this comment by embb, which I re-post here in it's entirety: -------------------------------------------------------------------------------------------------------------- embb at 01:56 AM on 14 December 2010 Hi Jacob, I thought the discussion pointless earlier, but now that the Cancun agreement is a such a nice illustration of what the game theory predicts (namely that nations will back out of the pointless Kyoto agreement) I am really curious how your negative reciprocities will kick in. After all, you said it all along, that defection will be punished by "negytive reciprocities" but you could not give any practical example. So, now, here is the test case - how will negative reciprocities work after Cancun?
  45. The 2nd law of thermodynamics and the greenhouse effect
    #185: Please refrain from accusations of 'slavish behavior.' That's enough to get your comments deleted; the speed at which you reverted to such is also a testament to the poverty of your overall position. You were asked to identify a textbook solely for the purpose of a identifying a common language for discussion and have thus far declined, because you can't find one that is 'error free'. I suggest that your fear of identifying a source for common language is that your semantic distinctions will evaporate in the glare of daylight. For example, "heat transfer, also known as heat flow, heat exchange" are well-understood equivalencies in common usage. So, under 'damorbel's law', we find yet another 'mistaken' originator. Einstein and Szilard's refrigerator patent contains 3 uses of the term 'heat exchange' and two of the words 'heat exchanger'. If there are neither 'heat flow' nor 'heat exchange', why does Einstein use a 'heat exchanger'? Either the meaning of 'heat flow' transcends the concept of caloric or 'damorbel's law' has an exception. But that's off topic. This thread doesn't need to be mired in your pedantry.
  46. Stratospheric Cooling and Tropospheric Warming
    Joe Blog @222, I went through the discussion at Science of Doom, and found that though the issue we are discussing was raised, it was not often adressed. One interesting titbit was the claim by DeWitt Payne that it takes "...on the order of a few months ..." for the stratosphere to reach an equilibrium temperature. This compares well with the approximately 50 day characteristic time for radiative transfer to reach equilibrium in the troposphere in the absence of convection, showing that it is not an increase in the rate of heat transfer by radiation which changes between troposphere and tropopause. What does change is path lengths. I did notice, however, a comment in the extract of Goody and Walker posted by SOD to the effect that the lapse rate due to radiative transfer is small at high altitudes, and becomes large at low altitudes, so that at low altitudes, radiation will generate sufficient heat differences to generate convection, but at higher altitudes it will not (p 63). This seems to be what you are saying, so I followed up on it and found out something very interesting. Specifically, I found a graph of the radiative-convective equilibrium for atmospheres including H2O, H2O and CO2, and H2O, CO2 and O3 (fig 3.17, page 19/35). This clearly shows that, in the absence of ozone, atmospheric temperatures decline in lapse rate above 15 km to a point at which convection no longer operates. However, they also show that: in the absence of ozone, there is no temperature inversion; and that with ozone, temperature passes from a convecting zone to 0 lapse rate at around 12 km. In other words, based on this graph, I was correct in ascribing to ozone the particular temperature profile and altitude of the tropopause; but you were correct in assigning the cessation to convection as a dominant player at about that altitude to the improved efficiency of radiation as a heat change mechanism. I should also note, though it is not shown on the graph, that the mesosphere would not exhibit convection where it not for the presence of ozone either - a point on which you were correct. Also of interest is the graph on figure 3.16 (p 8/35), which shows temperatures profiles for radiation only, for radiation plus convection on the dry adiabat, and for radiation plus convection with a lapse rate of 6.5 degrees per km. As convection becomes more efficient in transferring heat, the tropopause climbs, in these graphs from 10, to 11, then to 15 km. Presumably sufficiently moist air, and sufficiently high surface temperatures will cause it to rise still higher, to 18-20 km as found in the tropics. Conversely, drier air, and colder will cause it to drop. If the radiative lapse rate where constant with altitude, then the strength of convective forces it generates would also be constant with altitude, so that in the absence O3, the adiabatic lapse rate would be sustained to the edge of space. Clearly that is not the case, and the fact that the radiative lapse rate drops below a level that can sustain convection at around 15 km is clearly relevant to the altitude of the tropopause. However, this evidence, together with the emperical evidence previously indicated, suggest to me that while the drop in radiative lapse rate determines the general region of the tropopause, the actual altitude depends critically on a variety of factors, some of which (such as water vapour, and surface temperature) govern the strength of convection, while others (such as the presence of ozone) govern the particular temperature profile. Finally, you suggest that my proposal violates the first law of thermodynamics. This cannot be the case in that the altitude at which radiation absorbed by water vapour becomes optically thin is about half that as for the average of the atmosphere. At that altitude, convection dominates the temperature profile. Clearly, you can have a larger escape of radiant energy to space coupled with a convection dominated (ie, adiabatic) lapse rate without violating the first law.
  47. Medieval Warm Period was warmer
    Re: stefaan (17) Welcome to Skeptical Science, wherein we debunk crap climate science, on both sides of the aisle. If you have an open mind and are here to learn (why else would you be here?), then Enter! This Door is always open. In order for the MWP to be considered a global event, there would have to be global data showing that it's effects were felt simultaneously around the globe. Unfortunately, while some regions were warmer at some times, other areas were cooler. While those other areas were warmer, yet other areas were cooler. The best understanding at present is that of a multi-century period of regional variation. We have a pretty good understanding (from multiple lines of converging evidence, independent of tree ring data) of forcings and feedbacks and the resulting overall temperatures going backwards in time into deep into the paleo record. So the MWP, the Roman Warming and the LIA are pretty well understood. Here's a good discussion of the MWP. The thing that differs today is the injection of the massive slug of CO2 long-sequestered from the carbon cycle back into it. And these effects are (and will be) truly global: The Yooper
  48. The 2nd law of thermodynamics and the greenhouse effect
    Damorbel "Really CBDunkerson, I suggest it is quite reasonable to ask for something better than 'a black body assumption' before supporting an economy shattering 'theory' of AGW!." Yes, we could measure the outgoing radiation and see if it followed the blackbody assumption... ...which it clearly does. (blackbody lines dotted, solid line measured 20km looking down over arctic ice) Why you continue to state that the blackbody assumption is wrong in such contemptuous language when it's clearly valid is a question only you can answer. However, I suspect there may be a clue in your "an economy shattering 'theory' of AGW!. "(my emphasis) Unfortunately, physics doesn't respond to political polemic. Could I politely ask that you take some time to honestly reflect on how likely it is that you are right on this and look at your own arguments sceptically.
  49. The 2nd law of thermodynamics and the greenhouse effect
    Re #186 Riccardo you wrote:- "You're talking for yourself aginst the understanding of generations of physicists." Sorry, I don't understand how by recommending a minimum of Planck or Einstein or Maxwell I can possibly be against 'generations of physicists'; can you explain please?
  50. The 2nd law of thermodynamics and the greenhouse effect
    Damorbel: "The lower atmosphere (288K) will absorb some of the photons emitted by the GHGs (255K) but we know that the balance of temperatures will not rise because the atmosphere would then become more stable because convection currents would be suppressed." You seem to be saying the following: 1. C02, CH4, and H20 absorb and emit in the troposphere. 2. C02 and CH4 absorb and emit in the stratosphere. 3. If levels of these gases are stable, the planet will have a stable atmospheric temperature. Convection will occur as we know it. 4. If levels of these gases are increased, the troposphere will, uh, energy up, convection will decrease, and more energy will be carried to the stratosphere where it will be radiated more easily out into space. This release of energy will allow convection to once again take place and return the planet to the current, stable state. Is this your model?

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