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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 101151 to 101200:

  1. The 2nd law of thermodynamics and the greenhouse effect
    damorbel writes: "But don't GHGs also absorb the downward radiation? Surely they absorb the downward radiation from the upper atmosphere long before it gets to the ground" As SteveS has pointed out, this is pure nonsense. Let's say the atmosphere was 100% greenhouse gases. In such a circumstance every photon of IR in the impacted wavelengths would be absorbed immediately after leaving the ground. It would then be re-emitted... possibly back down to the ground or possibly upwards... where it would immediately be absorbed by another molecule of greenhouse gas and then re-emitted... possibly back down to the previous 'just above the surface' molecule and from there either up again or back down to the surface. Continue ad infinitum. With less than 100% atmospheric greenhouse gases the process works the same way except that most photons travel past several molecules of other types (e.g. Nitrogen) before being absorbed by another greenhouse gas molecule. Yes, the further up a photon gets the less likely it is for that energy to eventually be transmitted back to the ground... but we are talking about ridiculously large quantities of energy. Even 0.00000000001% is a tremendous amount of heat. The question also ignores everything below the "upper atmosphere"... as if photons magically teleported from the surface to the upper atmosphere without having to pass through all the space in between - with its much higher probabilities of the energy being 'bounced' back down to the surface. Also: "...few seem to recognise that, if the outgoing radiation exceeds the incoming, then the temperature cannot rise." If outgoing radiation exceeds incoming then we've violated the law of conservation of energy.
  2. An Even Cloudier Outlook for Low Climate Sensitivity
    Albatross (#83), I was incorrect in #80 (answering your #77). I read the paper body (p. 1525) and forgot about the caption where Dessler only plotted ECMWF, not MERRA. When I looked them up originally I found the MERRA tech report which explained assimilation very nicely so I used that. I need to find a similar reference for ECMWF. Both "reanalyses" (i.e. models with data assimilation) are used in the same way for his conclusion (the models with real world data matches the models without). My argument is that the cloud parameters are internal (at least in MERRA) and therefore depend on the radiation, convection and cloud process equations plus an assortment of parameters which are determined by fitting the model to the real world data. I think my argument will apply to ECMWF, but I will have to look that up to find out their model details, particularly for clouds. Sorry about the confusion (starting with my #16). Obviously I need to look at Spencer next. I am pretty sure that you are correct that his model is too simple and that his model assumptions are what creates his result independently of the real world measurements. I'll also try to evaluate how he states and tests his hypothesis. Dessler was quite clear about his.
  3. Ocean acidification isn't serious
    Muoncounter - How is it possible for oceans to simultaneously absorb and emit CO2? The temperature of the ocean is heterogeneous too. Generally the flux of CO2 to the atmosphere originates from the tropical regions where the ocean is warmer and CO2 less soluble. The uptake is occurring in the larger region of cooler waters where CO2 is more soluble. Much more complicated than that of course, as others have already pointed out, but why over-complicate matters?. The overall effect of human fossil fuel combustion is to increase CO2 dissolved into the oceans at a rate that is unprecedented. Papers are practically screaming that the oceans are sucking up CO2 to what will become dangerous levels (at least to plankton) in not very many years. From McNeil and Matear 2008 The Arctic Ocean is projected to reach aragonite (more soluble form of calcium carbonate) undersaturation within a decade, meaning the waters will be corrosive to calcifying marine organisms that make their shells from aragonite. Imminent ocean acidification in the Arctic projected with the NCAR global coupled carbon cycle-climate model "Aragonite undersaturation in Arctic surface waters is projected to occur locally within a decade and to become more widespread as atmospheric CO2 continues to grow. The results imply that surface waters in the Arctic Ocean will become corrosive to aragonite, with potentially large implications for the marine ecosystem, if anthropogenic carbon emissions are not reduced and atmospheric CO2 not kept below 450 ppm." It amazes me how little attention is being given to such a serious issue. It will have profound effects for life on Earth, and the changes to ocean chemistry are pretty much irreversible for many ten of thousands of years.
  4. The 2nd law of thermodynamics and the greenhouse effect
    "But don't GHGs also absorb the downward radiation? Surely they absorb the downward radiation from the upper atmosphere long before it gets to the ground" I've seen this statement a number of times and it makes no sense to me. If the GHGs absorb the downward radiation, they would still have to re-emit some of it again, some of which would again be downward. Only if there were a layer of GHGs next to the surface that somehow magically didn't re-emit any radiation downward could this mean that none of the downward radiation reached the surface. Imagine if things worked the way you think they do, then wouldn't the same be true for the radiation going upward? All of the reflected radiation would be absorbed within a few mean free paths of the surface and never make it to the TOA, let alone into space. The layer next to the surface would become extremely hot since all the reflected IR never leaves that layer.
  5. The 2nd law of thermodynamics and the greenhouse effect
    Re #238 KR - The temperature of any object,... ..(physical changes), etc. Agreed. - Under the conservation of energy... ...equilibrium is reached when incoming = outgoing again. Agreed - Outgoing energy in a vacuum ... ...a change in temperature can change outgoing energy until it balances incoming energy. Agreed "- The atmosphere is quite transparent to visible light (from the sun), hence the incoming energy is fairly constant." The incoming energy - agreed (the atmosphere is not transparent to solar infra red) "- Outgoing energy to space leaves the Earth as thermal IR, to which the atmosphere is partially transparent." Agreed (you are refering to the IR window) But what follows is unclear:- "- Greenhouse gases absorb IR, re-radiating it in all directions, including back to the ground, which re-absorbs most of what hits it." But don't GHGs also absorb the downward radiation? Surely they absorb the downward radiation from the upper atmosphere long before it gets to the ground And:- " This means that less IR goes to space at any particular temperature, and the Earth has a lower effective emissivity to space due to greenhouse gases." For me this is unclear. How does the downward radiation mean "less IR goes to space"? You said (above) "Greenhouse gases absorb IR, re-radiating it in all directions" - care to explain? You write "The thermal mass of the atmosphere is irrelevant." Not true, the atmosphere, with or without CO2 is a very important contributor to climate because it is a major distributor of heat between equator and poles. As such the mass and mean temperature are very important since they determine the thickness, from the thickness and the lapse rate you can determine the surface temperature This statement of yours is too vague:-> "Therefore the greenhouse effect means that the Earth must have a higher temperature than it would in the absence of the greenhouse gases in order to radiate away the energy it's receiving from sunlight. Don't be misled by convoluted side-tracking arguments." -> to dispute. When making claims about planetary temperature and climate change, all effects that may influence the temperature must be taken into account. Many posters here recognise that incoming radiation adds energy to a given location, few seem to recognise that, if the outgoing radiation exceeds the incoming, then the temperature cannot rise.
  6. Ocean acidification isn't serious
    michael sweet #41 "stop speculating about processes you do not understand" Thanks for answering my question. In reading 41, 42, 43, and 44 it becomes clear that the problem is not simple.
  7. An Even Cloudier Outlook for Low Climate Sensitivity
    HR the coefficient of determination need not be high; if the dependent variable depends on many factors you won't get a high r^2 anyways. As Dessler says "This does not mean that ΔTs exerts no control on ΔRcloud, but rather that the influence is hard to quantify because of the influence of other factors". Having said this, I'm sure no one is "satisfied" with a non statistically significant result, but what a scientist must do is to obtain as much informations as possible from the available data. Dessler conclude that the feedback is probably positive, a large negative feedback is very unlikely and that models do a decent job. This can be said even with a low r^2.
  8. An Even Cloudier Outlook for Low Climate Sensitivity
    HR, "when things start dropping below this we're worrying about reproducibility. r^2 of 2%, and being satisfied with that, are beyond my comprehension." Dessler is clearly not "satisfied with that" as you claim, please read the quote again carefully. The climate system is obviously not the controlled lab setting with which you are familiar. Although, I agree that 2% is extremely low, even for 120 data points, and even in the realm of feedbacks when r^2 tend to be relatively low. Then again, one doesn't need to change cloud cover much to have a marked impact on the energy budget of the climate system. And remember, that low r^2 applies to anyone working on this problem (including Spencer) and trying to extract a signal from noise in the system.
  9. An Even Cloudier Outlook for Low Climate Sensitivity
    I obviously need to get some sleep. Murphy and Forster (2010) was written to address problems with Spencer and Braswell (2008), not Spencer and Braswell (2010). Sorry. With that said, it looks like Spencer and Braswell (2010) used the same, or similar, simple model used in Spencer and Braswell (2008).
  10. An Even Cloudier Outlook for Low Climate Sensitivity
    Oops, sorry, hit return too soon. You also say that "The difference is that the MERRA AGCM assimilates the GEOS satellite data so the model numbers match reality" Both ECMWF-interim and MERRA assimilate satellite data, which includes data from the GOES sounders, and other satellite platforms. Above I said "GOES-5", which should have been "GEOS-5"-- they are even confusing me with their acronyms. For what it is worth, ECMWF-interim is considered to be the Rolls-Royce of all the reanalysis products (e.g., NCEP, NCEP-DOE, JMA etc.), although it would be nice if they could match the 0.5 degree grid spacing used in MERRA. I'm surprised that it does into bother you that Spencer and Braswell used a much, much more simplistic model in their recent paper on feedbacks in JGR. In fact, it did bother Murphy and Forster, so much so that they wrote a paper, Murphy and Forster (2010) back in September 2010, in which they summarize some serious problems and consequences related to Spencer and Braswell using that simple model. Murphy and Forster conclude: "This paper shows that Spencer and Braswell overestimated the difference. Differences between the regression slope and the true feedback parameter are significantly reduced when 1) a more realistic value for the ocean mixed layer depth is used, 2) a corrected standard deviation of outgoing radiation is used, and 3) the model temperature variability is computed over the same time interval as the observations. When all three changes are made, the difference between the slope and feedback parameter is less than one-tenth of that estimated by Spencer and Braswell." The outlook for those trying to argue for a marked negative cloud feedback gets cloudier and cloudier.
  11. An Even Cloudier Outlook for Low Climate Sensitivity
    79 NewYorkJ If that's all it takes to get published in JGR then I guess we should all have a go. "I think clouds cause ENSO" Can you quote from Spencer's paper where he makes or infers this? (it's linked in the article) In fact he states the following as the drive behind the paper. "The central issue we will examine is that satellite measurements of variations in radiative flux contain a mixture of forcing and feedback and the presence of one will affect the identification and estimation of the other. Our specific interest is a better understanding of the impact that unknown levels of time‐varying radiative forcing have on feedback diagnosis and what that might mean for the estimation of climate sensitivity." Maybe we could also discuss what Spencer is trying to do here rather than what you (or Dessler) think he is doing. From the Spencer paper I couldn't actually see any estimate of short term feedback.
  12. An Even Cloudier Outlook for Low Climate Sensitivity
    78 Albatross Thanks, part of the problem is this is a Science article which means much of the detail is omitted, not even any SI. r^2 = 2%. I work primarily with well controlled laboratory experiments. r^2 is generally well over 90%, when things start dropping below this we're worrying about reproducibility. r^2 of 2%, and being satisfied with that, are beyond my comprehension. I know why it's happening, this is a complex, uncontrolled experiment, I just don't understand what that does to the certainty behind the result.
  13. Human CO2 is a tiny % of CO2 emissions
    Questions about Fig 7.3 IPCC AR4. I find it necessary , in order to think about climate relevant properties or quantities, to know the time span and area to which they relate. As regards the 338 GT down arrow and the 333 GT up arrow on Fig.7.3: 1. What is the relevant surface area? If it is a whole earth average, it seems to me, the only meaningful arrow is a net downward 5 GT arrow. Furthermore if the time is for one year, how do I reconcile several hundred GT changes in the atmosphere with the ca. 5 GT annual change of the Keeling curve? In short, what is the meaning of the up and down arrowa and how were the quantities determined? If this is simply a way of saying that the CO2 in the ocean goes into and out of the aqueous phase then it is misleading because that is true for any solution-vapor coexistence and is irrelevant to the net changes in the quantity of significane in climate change, namely the amount of CO2 in the vapor. Fritz
  14. An Even Cloudier Outlook for Low Climate Sensitivity
    Eric @80, Not to be a pain, but you originally referred to the the "top chart in the post". That figure is Fig. 2 in Dessler (2010), and the figure caption makes no mention of MERRA: "Fig. 2. (A) Scatter plot of monthly average values of DRcloud versus DTs using CERES and ECMWF interim data. (B) Scatter plot of monthly averages of the same quantities from 100 years of a control run of the ECHAM/MPIOM model. In all plots, the solid line is a linear least-squares fit and the dotted lines are the 2sigma confidence interval of the fit." The model at the heart of the ECMWF interim, is IIRC, a similar version of their operational global NWP model. So I do not know why you are focusing on MERRA and the AGCM used in the GOES-5 data assimilation system.
  15. Ocean acidification isn't serious
    Ah, I see your problem. The simple (probably non-informative answer) answer is that the ocean is heterogeneous. Depending on where you are it can be a source or a sink for CO2. What increasing atmospheric CO2 concentration has done is to shift that balance uniformly toward the sink side of things. Still, there are large areas where upwelling of deep, CO2 rich water and limited phytplankton growth (often due to relatively low Fe availability) results in surface waters that are supersaturated with CO2. This is particularly true in the Eastern Equatorial Pacific because the cold CO2-rich waters warm significantly after reaching the surface, making them even more supersaturated. It's the largest natural source of CO2 on the planet. In the Southern Ocean things are more complicated because the deep water upwells vigorously there and can be subducted beneathe warmer, light water after moving northward, or can sink to great depths if it gets particularly cold and salty after moving south. I need to read the paper when I have time, but the quote you cite seems to have something to do with the fact that under positive SAM and steady state CO2 conditions, vigorous upwelling brings CO2 rich water continually to the surface where it can lead to net evasion of CO2 on the whole. However, in some places there may net uptake of CO2, or net evasion depending on initial CO2, the evolution of water temperature and mixing with surrounding waters. Under higher atmospheric CO2 levels, though, the net flux would be into the ocean across the Southern Ocean because, while the atmopsheric concentration is changing, the concentration in the upwelled water stays constant because it reflects past atmospheric conditions 200-1000 years ago. If that difference is high enough, then the same vigorous upwelling during SAM could actually enhance net storage of CO2 by continuously bringing new undersaturated water to the surface across the entire region where it can soak up CO2 and then sink to depth again.
  16. A new resource - high rez climate graphics
    mbayer - John mentioned he prepares the graphs in Excel. I don't think Excel does SVG, though I believe there are add-on programs that will do it for you (SVGmaker comes up on a Google search, though I haven't looked any further than that).
  17. Stratospheric Cooling and Tropospheric Warming
    mars @241, whether the 2nd effect is over ridden by other factors is a complex issue, involving, as I see it, four factors. 1) With the addition of extra CO2, the amount of CO2 leaving the troposphere is reduced by two effects. First, because of increased optical thickness, the average altitude of emmission increases and hence becomes cooler. On an emmission spectrum, this means the trough around 15 microns (due to CO2) will be deeper. Second, because of a variety of factors, that emmission/absorption band will also be broader, as shown in figure 2 in the revised article. Both effects reduce the amount of energy escaping the atmosphere around 15 microns, requiring more to escape at other wavelengths to maintain equilibrium, which in turn requires the Earth's surface to heat. However, the emmission/absorption band of CO2 in the stratosphere is much narrower than that in the troposphere due to its low partial pressure. The stratospheric emmission band can be seen as the small spike at the center of the tropospheric emmission/absorption band in the graph below. Because the stratospheric emmission/absorption band is so narrow, broadening of the tropospheric band has no (or almost no) effect on amount of IR energy absorbed by CO2 in the stratosphere. Therefore, Bob's seoond mechanism is entirely a function of the first effect (increased altitude of emmission), and how strong it is depends on the relative strengths of the two effects I have just described. Unfortunately, I cannot tell you what the relative strength is. The first factor describes completely the initial responce to the addition CO2 to the atmosphere. However, after that addition, the atmosphere adjusts bringing in factors that act as negative feedbacks to Bob's second mechanism. Consequently, Bob'second mechanism will undoubtedly cool the stratosphere initialy, but may not do so in the final state. Indeed, it is possible it will slightly warm the stratosphere in the steady state. Dealing with these feedbacks, we come to: 2) As the atmosphere responds to the greenhouse effect, the surface warms, and with it all altitudes above it in the troposphere. This increases the temperature at the effective altitude of emmission, reducing the effect of Bob's second mechanism. 3) Further, warming the atmosphere drives a water vapour feedback. The enhanced greenhous effect due to the water vapour feedback will also increase the temperature at the effective altitude of emmission, again reducing the effect of Bob's second mechanism. 4) Finally, as you mention, the lapse rate feedback (the reduction of the lapse rate due to the presence of additional water vapour) will also reduce the temperature at the effective altitude of emmission. How these factors play out is beyond my means to calculate. If only factors 2 and 4 were involved, then I could confidently state that they do not eliminate the second mechanism in the steady state, for if they did so, net radiation from around the 15 micron band would not have reduced, meaning there was no increase in the greenhouse effect. However, because of the broadening of the band (factor 1) it is possible that factors 2, 3, and 4 could result in a net increase in temperature at the altitude of effective emmission while still reducing outgoing IR radiation because of line broadening. This is one reason I would like to see comments by someone who was genuinely expert on this topic (eg, Gavin Schmidt). Finally, there is at least one positive feedback on both mechanisms. Specifically, as tropospheric temperatures increase, a greater proportion of CO2 will be found at a higher altitude, thereby increasing optical thickness. I suspect it is a miner effect compared to the others mentioned.
  18. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    Finally, Ben Santer did beat the crap out of Pat Michaels. Very great video :-)
  19. Ocean acidification isn't serious
    #42: "outgassing from a warmer ocean affects atmospheric CO2 concentrations significantly" I'm not referring to RSVP's mathiness. Papers are practically screaming that the oceans are sucking up CO2 to what will become dangerous levels (at least to plankton) in not very many years. From McNeil and Matear 2008, Southern Ocean acidification via anthropogenic CO2 uptake is expected to be detrimental to multiple calcifying plankton species by lowering the concentration of carbonate ion (CO3-2) to levels where calcium carbonate (both aragonite and calcite) shells begin to dissolve. ... Southern Ocean wintertime aragonite undersaturation is projected to occur by the year 2030 and no later than 2038. On the other hand, the language of outgassing is very complicated, as in Lovenduski et al 2006: In contrast, there is a simultaneous anomalous uptake of anthropogenic CO2 during a positive phase of the SAM in the southernmost regions of the Southern Ocean, due to increased upwelling of deep, older waters and their subsequent exposure to higher atmospheric CO2 levels. The anthropogenic uptake only slightly mitigates the natural outgassing from the Southern Ocean, so that a positive SAM is associated with anomalous outgassing of contemporary CO2. In a future characterized by higher atmospheric CO2, however, positive phases of the SAM may be associated with a greater oceanic uptake of anthropogenic CO2. And they say clouds are complicated beasts?
  20. The 2nd law of thermodynamics and the greenhouse effect
    Joe Blog writes: [...] it raises the height that radiation can effectively escape, so its necessary for this new altitude, to heat enough that it is emitting the incoming, and next layer down must heat enough [...] Yes. That's the point I was making in this comment. KR also sums the situation up nicely. I agree with archiesteel's point that damorbel has wasted too much of everybody's time on these two threads. The physics of the greenhouse effect have been explained quite well, by many people, over and over again, in different ways. Further attempts to cure damorbel's misunderstandings are not likely to be more successful than the earlier ones.
  21. Ocean acidification isn't serious
    @ muoncounter. "I'm not understanding this ocean acidifying-ocean CO2 feedback question." As I understand it RSVP is claiming (incorrectly) that there can be no CO2 oceanic solubility feedback during northern latitude warming phases of Milenkovitch cycles because outgassing from warming oceans would have resulted in similar relative increases in CO2, N2 and O2. Summing up succinctly, RSVP fails to understand that the pool of exchangeable CO2 in the ocean is very large relative to that in the atmosphere (for a number of reasons), while the opposite is true for N2 and O2. As a consequence, outgassing from a warmer ocean affects atmospheric CO2 concentrations significantly, but it does not affect N2 and O2 concentrations in any measureable way. As far as I can tell, pH only comes into the discussion because of its effect on the relative abundance of carbonic acid, bicarbonate and carbonate ions (and protons) as temp changes the solubilty of CO2.
  22. An Even Cloudier Outlook for Low Climate Sensitivity
    scaddenp, thanks for that paper. It's going to take a while to read.
  23. Stratospheric Cooling and Tropospheric Warming
    I admit that I have not studied all the previous posts in detail. What I am interested to know is whether there is agreement that the 2nd mechanism that Bob refers is valid or not? My view at this stage is that while it true for Bob's model, it is overridden by other factors when considering the Earth's atmosphere, particularly the extra heat gained at altitude from latent heat in a warmer more humid world.
  24. The 2nd law of thermodynamics and the greenhouse effect
    "Radiative transfer models, the Marty et al paper and many other sources indicate that the amount of IR radiation reaching the surface is not that small." Damorel doesnt believe the radiative transfer equations, however how about direct measurement of DLR at the surface? Matching the spectrum and amplitude of the models no less. For life of me, I cant see how damorel explains that in his strange world.
  25. A new resource - high rez climate graphics
    It's good to provide SVG versions of the graphs. This is the standard vector format for the Internet Age. I tried UniConvertor, http://sk1project.org/modules.php?name=Products&product=uniconvertor on the WMF file. It works, but it loses the text of the graphs. Can you export to SVG from your application?
    Response: I've added SVG format for each of the graphics. Looking at them in a browser looks a little dodgy but they come up okay in Coreldraw. Please let me know how they look for you.
  26. Philippe Chantreau at 10:45 AM on 15 December 2010
    The 2nd law of thermodynamics and the greenhouse effect
    "I answered the question." I don't see that. How can the surface temperature not be higher when receiving extra IR photons compared to a situation in which it would not be receiving these photons? Radiative transfer models, the Marty et al paper and many other sources indicate that the amount of IR radiation reaching the surface is not that small. "The GHE says that CO2 high in the atmosphere at 255K can raise a surface to 288K" This belongs in the category of "not even wrong." As for the stratospheric temperature profile, I don't see how it is possible for GHGs to have radiative properties there and not affect it. Are you saying that the temperature profile is identical in the stratosphere to what it would be in the absence of these gases? How can the stratosphere not be colder than it would be if these photons were not radiated to space?
  27. Ocean acidification isn't serious
    RSVP, Coming in from the cool ice data thread. Three factors of ten is ten times ten times ten or one thousand times different. The pH affects the different ion distribution as Stephen Baines points out. The pH in fresh water with CO2 dissolved is around 5 and the pH in the ocean is around 8 or 1000 times less hydrogen ions. This affects the carbonate concentration and therefore the solution of CO2. N2 and O2 are not pH sensitive. That is part of why Henry's law seems to not work according to your calculations. As I said here and Alec said here, carbon dioxide is soluble in water and O2 and N2 are not. Because CO2 is soluble in water its properties are different from O2. The calculations are very difficult (I have not done them) and to get better than a qualatative answer you will have to read the peer reviewed literature. My understanding is that research continues to estimate how much CO2 the ocean can absorb before it is saturated. (Currently the ocean is absorbing CO2 as the concentration increases according to Henry's law. The warming of the ocean is not as important today as it was in the past) CO2 running out: stop speculating about processes you do not understand. We better pray that the CO2 in the ocean never outgasses enough to run out. There is an enormous amount of CO2 in the ocean and the surrounding land would start to dissolve as the CO2 outgasses. That would be Venus for sure.
  28. Ocean acidification isn't serious
    I'm not understanding this ocean acidifying-ocean CO2 feedback question. Oceans are indeed acidifying as they absorb atmospheric CO2, as the figure above shows. From Caldeira and Wickett 2005: The SRES pathways considered here produce global surface pH reductions of about 0.3 to 0.5 pH units by year 2100. ... Atmospheric emissions of 5000 Pg C and 20,000 Pg C produce global surface pH reductions of 0.8 and 1.4 pH units, respectively by year 2300. We depend on these CO2 sinks to take up to 50% of our fossil fuel waste product out of the atmosphere each year. There's evidence that ocean sinks are weakening, as in LeQuere et al 2007: Based on observed atmospheric carbon dioxide (CO2) concentration and an inverse method, we estimate that the Southern Ocean sink of CO2 has weakened between 1981 and 2004 by 0.08 petagrams of carbon per year per decade relative to the trend expected from the large increase in atmospheric CO2. We attribute this weakening to the observed increase in Southern Ocean winds resulting from human activities ... How is it possible for oceans to simultaneously absorb and emit CO2?
  29. The 2nd law of thermodynamics and the greenhouse effect
    @damorbel, your latest attempt at obfuscation won't work. You've been unmasked. "The part (30%) of the radiation coming from is reflected by the Earth, this is called the albedo. The same effect happens to radiation leaving the Earth, 30% of it is reflected back and doesn't escape, it is trapped." False. "Well I don't think it is irrelevant because in an atmosphere of CO2 all the molecules are absobing and emitting radiation all the time; they absorb those wavelength they emit particularly well, just where is the radiation warming the surface coming from, isn't the lapse rate warming enough?" Lol...are you really claiming what I think you're claiming here? That there wouldn't be room for the photons to reach the surface? In case you haven't noticed, at the temperatures we're talking about, CO2 is a gas. Now, a layer of liquid CO2 might act as an insulator, I don't know, but if you want to see what effect a dense CO2 atmosphere will have, I suggest you check out Venus, which is hotter than Mercury even though it is much farther from the sun. Seriously, it's obvious you're trying to make the debate run in circles. I mean, no one would take that much humiliation if he hadn't an ulterior motive in mind. Again, I call on other posters to ignore damorbel's fake science, which he makes as confusing and outlandish as possible in order to waste our times. Instead, just point him to KR's excelelnt post at 238, or to his own response to my questions at 220, where he basically agreed with the greenhouse effect.
  30. Ice data made cooler
    RSVP, If you want to continue the thread muonconter suggested is a more appropriate place. I will post a reply there.
  31. The 2nd law of thermodynamics and the greenhouse effect
    damorbel at 07:45 AM I can see where you are coming from, the lapse rate and convection are important to the movement of energy out of the system, its the altitude at which energy can effectively escape however, that is responsible for the T gradient, which is necessary for the transport of energy to this altitude... So the lower atmosphere is already largely opaque to some wavelengths, but the path length shortens with altitude, so by adding more opaque molecules, it raises the height that radiation can effectively escape, so its necessary for this new altitude, to heat enough that it is emitting the incoming, and next layer down must heat enough that it is able to transport this energy up to this height, etc etc... So the radiation incident on the surface, is just a product o the atmospheric T at that altitude, but the height it can escape the troposphere, effects the T gradient.
  32. Stratospheric Cooling and Tropospheric Warming
    Ebel at 21:10 PM says "This is not true. The cooling does not follow from the increase in potential energy, but from the pressure decrease during rapid ascent." Yes, the decrease in potential energy, as it performs work, as i understood it that is what mars said. The pressure decreases because it expands, and displaces/pushes the air around it. The opposite is true of adiabatic heating. Tom Curtis at 03:01 AM Good post, my comment about "violating the first law" was simply saying, that if radiation wasnt moving the energy that convection was lifting, it would result in a build up of energy, raising the troposphere until it was able to shift it. So radiation, must at some stage become the dominant mover. And at equilibrium must be moving out the same amount of energy that is coming into the system. I dont disagree with anything in this post however.
  33. The 2nd law of thermodynamics and the greenhouse effect
    For anyone visiting this thread - a bit of clarification on what's been discussed. - The temperature of any object, including the Earth as a whole, is determined by the amount of internal energy it has, vibrating it's molecules (reflected as temperature), forming endothermic chemical bonds (physical changes), etc. - Under the conservation of energy/mass, if there is an imbalance between incoming energy and outgoing energy, the energy in the object will change. This is generally observed as a change in temperature. The rate of change is dependent on the thermal mass of the object, dynamic equilibrium is reached when incoming = outgoing again. - Outgoing energy in a vacuum (like the Earth) is via radiation. Thermal radiation scales with emissivity and with temperature T^4, meaning that a change in temperature can change outgoing energy until it balances incoming energy. - The atmosphere is quite transparent to visible light (from the sun), hence the incoming energy is fairly constant. - Outgoing energy to space leaves the Earth as thermal IR, to which the atmosphere is partially transparent. - Greenhouse gases absorb IR, re-radiating it in all directions, including back to the ground, which re-absorbs most of what hits it. This means that less IR goes to space at any particular temperature, and the Earth has a lower effective emissivity to space due to greenhouse gases. The thermal mass of the atmosphere is irrelevant. Therefore the greenhouse effect means that the Earth must have a higher temperature than it would in the absence of the greenhouse gases in order to radiate away the energy it's receiving from sunlight. Don't be misled by convoluted side-tracking arguments. As to the "2nd law violation" skeptical argument; see the topic itself and also the post here.
  34. The 2nd law of thermodynamics and the greenhouse effect
    Re #227 Philippe Chantreau you wrote:- "Incidentally, the reality of the "greenhouse" effect can be verified with a relatively simple experimental set-up. The ESPERE site describes it quite well:" Philippe, what the ESPERE experiment shows is how a lamp simulating the Sun but with a temperature (probably) of 3000K (instead of 5780K) heats a box of CO2 by 30K from a starting temp. of 290K; note 290K is a lot cooler than 3000K. That is just what I would expect a heat source at 3000K to do. The GHE says that CO2 high in the atmosphere at 255K can raise a surface to 288K - not possible! The 288K surface actually send heat energy to the upper troposphere. The energy sent from the surface tends to raise the temperature of the upper troposphere but clearly has little effect.
  35. The 2nd law of thermodynamics and the greenhouse effect
    A not so minor note about albedo: Albedo is not constant across all wavelengths. As an example, a very pale friend of mine (who uses SPF 80 sunscreen) has a quite high albedo/reflectivity (or 1-absorptivity) at visible wavelengths. She has an albedo of perhaps 0.3-0.4 (just guessing) for visible light. However, the human skin at body temperature has a thermal IR emissivity/absorptivity of 0.99 regardless of visible light skin color - almost a perfect blackbody! Hence her albedo for IR is (1 - absorptivity) = 0.01. Average emissivity for the surface of the earth at IR wavelengths is ~0.96-0.97, meaning an albedo/reflectivity of only 0.03-0.04 at maximum, an order of magnitude less albedo than at visible wavelengths.
  36. The 2nd law of thermodynamics and the greenhouse effect
    Re #226 Philippe Chantreau you wrote:- "As if it was possible to measure the temperature of something but not know what it is at all. "I measured the temperature of that object but I have no idea of its size, what it's made of and all that" Sorry you think this way. But don't thermometers work this way all the time? After all, when you put your thermometer outside to measure the air temperature you don't have to know how much air there is 'outside', do you? You wrote :- "It is well known that GHGs cool down the stratosphere. Line by line radiative transfer models show how much, with the altitudinal distribution. That has been verified by observation too (Iacono and Clough 1995 and later papers)." I don't doubt that the stratosphere loses energy to deep space through GHGs, any satellite IR image will show that. But surely know that the temperature increases with height in the troposphere, there must be something happening in the stratosphere other than energy loss through GHGs. That 'something' is the absorption of ultraviolet energy (from the Sun) that is what causes the temperature to rise. Now in my view explanations of the GHE should also show a temperature rise (In the troposphere) if there really is a GH effect. You wrote :- "In post #220 you agree that IR radiation is re-radiated to the surface. How can this happen without the surface temperature to increase if thermodynamic compliance is respected?" I answered the question. How much reaches the surface depends on the concentration of GHGs, with very low concentrations a small amount of radiation will reach the surface, as the concentration increases effectively all of the radiation from GHGs will be reabsorbed long before it reaches the surface. As for the out going radiation, the density of GHGs (and O2, N2 etc) falls steadily to about 100km. T this point the radiation mostly escapes without being reabsorbed.
  37. A new resource - high rez climate graphics
    http://www.esrl.noaa.gov/gmd/ccgg/trends/weekly.html http://www.esrl.noaa.gov/gmd/ccgg/trends/history.html
    Moderator Response: [Daniel Bailey] Changed links to hyperlinks.
  38. The 2nd law of thermodynamics and the greenhouse effect
    Re #225 you wrote:- "I never claimed 100% of the Energy was radiated. Stop putting words in other people's mouth in order to peddle your incorrect interpretation of physics, please." Sory for that. but almost every other person, including the editors writing for the IPCC on the temperature calculation and all the contributions on the NASA websites, make that claim. The you cite me and comment like this:- ""What you should realise is that the % 'trapped' by a radiating planet is exactly the same as the % of the incoming radiation reflected as albedo." Wrong. The higher the albedo, the less energy is transferred to the surface, as the visible light is mostly reflected back into space" My statement is not clear, it should read like this:- The part (30%) of the radiation coming from is reflected by the Earth, this is called the albedo. The same effect happens to radiation leaving the Earth, 30% of it is reflected back and doesn't escape, it is trapped. You wrote:- "Scattering and reflection are not equivalent," I didn't say they were. What I said was that the scattering which causes the albedo is independent of the direction of arrival of a wave, that is why scattering is as effective at reducing outgoing radiation as it is at reducing incoming radiation from the Sun. You responded to a question of mine like this:- ""In an 'Earth' atmosphere, but of pure CO2, can you tell me, on a scale of 1 to 100, what % of photons emitted at a height of 5km will reach the surface without being reabsorbed?" No, I can't, but the exact figure is irrelevant. As I said, some IR energy will escape to space, some will warm the surface," Well I don't think it is irrelevant because in an atmosphere of CO2 all the molecules are absobing and emitting radiation all the time; they absorb those wavelength they emit particularly well, just where is the radiation warming the surface coming from, isn't the lapse rate warming enough?
  39. The Scientific Guide to Global Warming Skepticism
    Johns book is already being used by some educational institution. John's Book
  40. An Even Cloudier Outlook for Low Climate Sensitivity
    Eric, I believe the process of conductive energy transfer is embodied within the solution to the RTE which model does. Had a look at Ramanathan and Coakley 1978 for the gruesome mathematical detail.
  41. The 2nd law of thermodynamics and the greenhouse effect
    Damorbel, I think it's clear at this point your only goal is to waste people's time by constructing deliberately complex fallacious arguments. This seems to be a favored new tactic of political skeptics, and aims at making sure intelligent people waste their time debunking the same old arguments over and over instead of doing something more constructive. That's what Ken Lambert used to do, and that is now what damorbel is doing. To everyone who has patiently been responding to damorbel, just be warned that he doesn't really want to win this debate - he knows his position is ultimately untenable. Rather, his goal is likely to make sure this dead end of a thread go as long as possible. Personally, I've done my part demolishing his bizarre argument. I don't think he'll convince anyone anyway: most skeptics, deniers and contrarians don't actively argue that AGW violates the 2nd Law of Thermodynamics (because it's too easy to demonstrate that it doesn't - one has to choose his battles, after all). I invite all of you to stop feeding this particular one...
  42. The 2nd law of thermodynamics and the greenhouse effect
    @damorbel: "I ceratinly said I didn't agree with archiesteel's first question:- "...they emit IR energy, as described by black body theory... " Actually it was my second question, and you were completely wrong in replying that. It's hard to me to qualify exactly how wrong without having this comment censored. What I said is: "When objects increase in temperature, they emit IR energy, as described by black body theory" This is easily provable. You can even do it yourself if you have IR goggles or something similar: Take a raw roastbeef and look at it with the IR goggles. It will be rather dark. Put some mustard on the roastbeef. You can insert litle pieces of garlic in it if you want. Put the roastbeef in the oven at 375F for about an hour. Take it out and look at it with IR goggles again. It will appear much brighter, because it is emitting a lot more infrared (IR) photons than it was before. Ergo, increasing the temperature of an object causes it to emit more IR photons. "The idea that a body that reflects 30% or more of incident light can emit 'as described by black body theory' is completely absurd." It's not. It's physics. Unless you're *really* arguing that black body theory is incorrect, but I can't believe someone would argue anything that stupid. "The measuring of emissivity (e) is difficult to do directly; it is more easily done by measuring the reflectivity (r) and calculating emissivity as e = 1 - r" So, according to what you just argued, an object that reflects 30% light (i.e. which has an albedo of 0.3) therefore has an emissivity of 0.7, right? Emissivity is the ratio of energy radiated by a particular material to energy radiated by a black body at the same temperature. A true black body would have an ε = 1 while any real object would have ε < 1. In what sense is this incompatible with Black Body theory...unless you actually believe Black Body theory is only about black bodies (it isn't). "No the temperature would not be different." And yet you have agreed to the contrary in responding to my four questions. You have just contradicted yourself, even though you tried to get out of this predicament by making a blatantly false statement (i.e. that heated objects don't produce more IR radiation).
  43. An Even Cloudier Outlook for Low Climate Sensitivity
    #77, Albatross, no I am referring to the GOES-5 assimilation system called MERRA which is an AGCM. Essentially as far as radiation, cloud processes and convection goes, Dessler compared a GCM to another GCM. The difference is that the MERRA AGCM assimilates the GEOS satellite data so the model numbers match reality. But that doesn't mean that internal modeled parameters like the clouds or their feedback in warming scenarios match reality. In the top figure in the head post, there is a scatterplot resulting from an AGCM and in the next figure, a scatterplot that results from the other GCMs and AGCMs. Since they use much the same equations for their dynamics, the scatterplots should be similar.
  44. Renewable Baseload Energy
    I would think that microgeneration would be the ultimate goal of energy production. If you could get all your energy needs cost effectively from a generation unit in your home, why would you NOT want that? It may not be economically feasible now but that does not mean it won't be in the future. Maybe in the not-so-distant future. If the cost of PV continues to fall and battery technology continues to improve and also fall in price... what's to prevent microgeneration from being a reality? It just doesn't seem that far fetched to me.
  45. An Even Cloudier Outlook for Low Climate Sensitivity
    Spencer's argument is basically "I'm right and Dessler is wrong because I think clouds cause ENSO, a hypothesis I'm throwing out there based on no real evidence, and contradicted by all studies on the topic to date".
  46. Renewable Baseload Energy
    As far as cost is concerned, I wonder if they include the fact that mass production of solar and wind microgenerators would continue to lower costs overtime, making it more competitive. Personally, I like the idea of renewables as part of third world development strategy. Africa has enormous solar potential (mostly in the form of concentrated solar), and the technology is easier to master for what sadly remain regions with limited technical/technological education. In this context microgeneration plays a part, especially for tribal population who do not use much (but would like some) electrical power. As I said, there is no single solution. I wish we would at least agree on that, as I've already spent too much time arguing about this. After all, that time used a significant amount of that precious electricity (I don't type with the monitor off, for example). So in the spirit of conservation I'll say no more about this, and will leave you with the last word. I know my case is strong enough to challenge yours and keep the debate open for others, and that's fine with me.
  47. The 2nd law of thermodynamics and the greenhouse effect
    With increase in GHGs: 1. Altitude of emission increases 2. Temperature at new altitude has to increase to maintain incoming/outgoing radiation balance 3. With constant lapse rate, surface must warm. You would learn a lot if you'd spend more time reading Science of Doom.
  48. The 2nd law of thermodynamics and the greenhouse effect
    Re #224 DSL You asked for a y/n answer to this question :- "do you think the temperature of the 1) Earth's surface and/or 2) lowest ten meters of the troposphere would be different in the absence of atmospheric CO2?" No the temperature would not be different. Your response was to my statement:- "3/What is in your or anyone else's writing, that explains just how the presence of GHGs change a planets surface temperature from that in the absence of GHGs?" The temperature profile (dT/dz) of the troposphere is fixed by the lapse rate which is a function of the specific heat of the atmospheric gases. If the GHE was serious i.e. produces a 30K rise in surface temp. there is not a lot of room for it in the lapse rate calculations. NB the lapse rate would be no different without GHGs.
  49. The 2nd law of thermodynamics and the greenhouse effect
    damorbel - Did you see my post here? It was addressed to you - you've replied (in one fashion or another) to several other posts since that one.
  50. Ice data made cooler
    michael sweet #51 "...three factors of ten" As I know nothing, is it OK to ask what three factors of ten is? At any rate, it looks like this subject has been shut down, so you're in luck and dont have to answer that question, even though it has nothing to do with CO2 or polar caps. My last peep (if permitted) would be that as CO2 out gasses I assume there will always be less and less in the ocean, so this effect would curtail at some point, would it not, or should we assume there will always be plenty more CO2?
    Moderator Response: [muoncounter] No, the subject isn't 'shut down'; all you need to do is move to the more appropriate thread. You can refer back to comments here by right-clicking the red date and time, copying the link location and inserting that as a link in your subsequent comment.

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