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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 123801 to 123850:

  1. What would happen if the sun fell to Maunder Minimum levels?
    Like so much in climate science, this just confirms things well known. A U.S. National Academy of Sciences panel estimated in 1994 that if solar radiation were to weaken as much as it had during the Maunder Minimum, the entire effect would be offset by another two decades of accumulation of greenhouse gases. That was at 1994 emission rates, of course; we now find, surprise, that at late 21st century emission rates the delay would be less than one decade. ref.: combining pp. 3 and 4 of National Research Council, Board on Global Change (1994). Solar Influences on Global Change. Washington, DC: National Academy Press (online at http://books.nap.edu/openbook.php?isbn=0309051487)
  2. Visual depictions of CO2 levels and CO2 emissions
    Theendisfar, I suggest you research and calculate how much our "very transparent to IR" atmosphere can attenuate an IR beam in just a few meters - particularly at the 15um range. I can help providing the coefficients and formulas if you want, but I think it would be much more convincing if you figured it out by yourself.
  3. What would happen if the sun fell to Maunder Minimum levels?
    #7 Alexandre, Wang 2005: "The increase in cycle-averaged TSI since the Maunder minimum is estimated to be ~1 W m-2." *Then we do what Tony Noerpel says: divide by 4 for the shape of a sphere and multiply by 0.7 to substract the 30 % albedo: 0.17 W/m2. Krivova 2007: "The model predicts an increase in the solar total irradiance since the Maunder minimum of 1.3^+0.2_-0.4 Wm-2" 1.3 / 4 * 0.7 = 0.23 Balmaceda (Max Plank Institute): "This first physics-based reconstruction of TSI back to the Maunder Minimum suggests an increase of about 0.80 W/m2 since 1700" 0.8/4*0.7 = 0.14 W/m2 (documents hyperlinked in the author's name)
  4. What would happen if the sun fell to Maunder Minimum levels?
    @5 Yes but periods like the Dryas appear to have other influences, such as large influxes of melt water, the MWP is linked to North Atlantic oceanic circulation..... point is that these causes do not appear to be drivers of the current warming trend, nor do TSI levels, but anthropogenic co2 does appear to be correlated with it. Variation has occurred in the past from a number of different causes but unless one can be directly attributed to current observations raising seems somewhat immaterial.
  5. Is CO2 a pollutant?
    I still cannot grasp what point suibhne is trying to make with the double-solar panel. But he'd have to recalculate all the energy flows around the system, if he added something to the system.
  6. What would happen if the sun fell to Maunder Minimum levels?
    Hi Alexandre The 2 W/m2 is the solar constant measured at the top of the atmosphere. This flux is through a circle of radius 6,371 km and an area of pi x r2 but the forcing is measured at the Earth's surface which has a surface area of 4 x pi x r2 so 2/4 = 0.5 W/m2. Then we further must take into account the solar energy which is reflected back into space without warming the planet or about 30%. That leaves 0.35 W/m2. How we get down to 0.17 to 0.23, I don't know but at least you see we are in the ballpark. Tony
  7. Philippe Chantreau at 22:59 PM on 19 February 2010
    Is CO2 a pollutant?
    The bottom panel can not get anything if the top panel intercepts the energy flux going downward. The surface is heated by energy coming from above, once heated it radiates up in the IR spectrum (btw, that gives you the task of devising a solar panel using IR). If it's not heated from above it's not going to radiate anything. Why would you expect otherwise? I did not look at the diagram but I doubt that it could be interpreted such as making a shaded surface radiate heat up as a sunny one would. As for G&T, the quote above contains the essence of the problem. The atmosphere and its entire environement are a system. Not just the atmosphere and the surface, or the atmosphere and stratosphere. G&T consider only a subsystem then say it can't exist.
  8. Is CO2 a pollutant?
    It's odd that their figure and caption are mismatched stratosphere/atmosphere (?) and atmosphere/surface. But either way, yes, it is an argument of principle, not degree. suibhne: Why don't you like the magnitudes of the flows, anyway? You can scale them down if you really like (while keeping balances everywhere), and you'll still get an Earth surface which is warmer than it would be otherwise without an atmosphere, and so G&T would still imagine a Second Law violation.
  9. What would happen if the sun fell to Maunder Minimum levels?
    Jesus, you cite a difference in solar forcing ranging from 0.17 to 0.23 W/m2. The TSI itself is estimated to have been some full 2 W/m2 lower in the Maunder Minimum(according to the Max Planck Institute). I'm sure I'm comparing apples to oranges here. Can you help me understand it?
  10. Arkadiusz Semczyszak at 22:33 PM on 19 February 2010
    What would happen if the sun fell to Maunder Minimum levels?
    Moreover, in small changes in TSI can not be explained by such rapid temperature changes in the past - such as Dryas, LIA, MWA, etc. ...
  11. Arkadiusz Semczyszak at 22:28 PM on 19 February 2010
    What would happen if the sun fell to Maunder Minimum levels?
    sory: not Mounder - of course Maunder
  12. Arkadiusz Semczyszak at 22:26 PM on 19 February 2010
    What would happen if the sun fell to Maunder Minimum levels?
    Beginning - the end of the max. LIA - not equal: the beginning - the end of Mounder minimum. It was NEVER ("NONLINEAR DYNAMICS") a simple connection: TSI - global temperature. 1.66 W / m 2 - right, but the valuation of "CO2 feedbacks" in the IPCC AR4 - no (eg, Lindzen - I recall).
  13. Is CO2 a pollutant?
    Suibhne, see section 3.9.3. Specifically, the comment on figure 32; "A machine which transfers heat from a low temperature reservoir (e.g. stratosphere) to a high temperature reservoir (e.g. atmosphere) without external work applied, cannot exist - even if it is radiatively coupled to an environment, to which it is radiatively balanced. A modern climate model is supposed to be such a variant of a perpetuum mobile of the second kind." Also, later in the same section; "Since this system is assumed to be in radiative balance with its environment, and any other forms of energy and mass exchange with its environment are strictly prohibited, it de fines a system in the sense of thermodynamics for which the second law holds strictly." Ergo, the argument is NOT, as you say, that the amount of energy is trivial (which is also untrue), but that it is absolutely impossible for ANY energy to flow from cold to hot. Which, amongst other things, would make SUNLIGHT impossible.
  14. What would happen if the sun fell to Maunder Minimum levels?
    I was missing a paper like this, thanks for the summary! Fortunately it was already highlighted in this site that "The difference in solar radiative forcing between Maunder Minimum levels and current solar activity is estimated between 0.17 W/m2 (Wang 2005) to 0.23 W/m2 (Krivova 2007)", whereas "the radiative forcing of CO2 since pre-industrial times is 1.66 W/m2 (IPCC AR4), far outstripping solar influence."
  15. Skeptical Science now an iPhone app
    Where can I find this new App? Didn't find it using this link: http://itunes.com/apps/skepticalscience
    Response: If going to http://itunes.com/apps/skepticalscience did nothing, the most likely explanation is you don't have iTunes installed. If you do have iTunes installed, go to the app store and search for skeptical science.
  16. Is CO2 a pollutant?
    Philippe Chantreau The top panel gets 168 +324 The bottom panel gets 390 All units w/m2 That is if you really believe the diagram in the first place. ....... it is exactly G&T's position that not only no radiation flows from the atmosphere to the surface but that this is altogether impossible. Could you give a page number for your quote?
  17. What would happen if the sun fell to Maunder Minimum levels?
    "The IPCC claims the radiative forcing due to changes in the solar output since 1750 is +0.12 Wm-2, an order of magnitude smaller than its estimated net anthropogenic forcing of +1.66 Wm-2. A large body of research suggests that the IPCC has got it backwards, that it is the sun's influence that is responsible for the lion's share of climate change during the past century and beyond." Given that the sun has been steady or in decline over the period of 1950 - 2010 - this surely indicates that temperature increases since then cannot be attributed to it. Given the substantial change in temperature currently do not correspond to changes in solar output I fail to see how such a conclusion can be drawn.
  18. Arkadiusz Semczyszak at 20:33 PM on 19 February 2010
    What would happen if the sun fell to Maunder Minimum levels?
    1. Analysis of solar activity in the Holocene (e.g. Solanki 2004, Usosskin 2007) shows that there is possible another scenario. Just as 5000 BCE to 4900 BCE (Older Peron) may wait for us being 2-3 thousand. years - warm period of with several small minima. 2. Changes in solar activity is not only the TSI, but gravity changes (LNO-LNC - effects on THC - it is really only a "ridiculous theories"?), and a system of climate feedbacks. Rahmstorf, Ganopolski, 2005: "We attribute the robust 1,470-year response time to the superposition of the two shorter cycles [87; 210 years], together with strongly NONLINEAR DYNAMICS and the long characteristic timescale of the thermohaline circulation." http://www.nipccreport.org/chapter5.html - "Solar Variability and Climate Cycles." - "The IPCC claims the radiative forcing due to changes in the solar output since 1750 is +0.12 Wm-2, an order of magnitude smaller than its estimated net anthropogenic forcing of +1.66 Wm-2. A large body of research suggests that the IPCC has got it backwards, that it is the sun's influence that is responsible for the lion's share of climate change during the past century and beyond." - "The role of solar activity in causing climate change is so complex that most theories of solar forcing must be considered to be as yet unproven." [...] We say: that without a proper assessment of the significance Millennium cycles, each evaluation of the impact of natural factors is incorrect. Claiming: that the Millennium cycles: How warms up to N - cooled on the S, is vague - "de facto" - false. 3. If current warming is (mostly) natural and we will have a transgression of the sea as the Older Peron (Australia - 2.5 to 4 meters - 8 to 13 feet) - whether it is worth spending money on CCS?
  19. Philippe Chantreau at 20:11 PM on 19 February 2010
    Is CO2 a pollutant?
    As I recall, it is exactly G&T's position that not only no radiation flows from the atmosphere to the surface but that this is altogether impossible. I believe they state it quite clearly.
  20. Philippe Chantreau at 20:05 PM on 19 February 2010
    Is CO2 a pollutant?
    Suibhne, if you put a solar panel between the surface and the sun, that part of the surface below the panel does not receive the solar 342 joules/s any more. I'm not sure I see how that idea of a 2 sided panel applies to anything.
  21. Is CO2 a pollutant?
    carrot eater ...........I've seen all that. The basic point remains. In the end, G&T have a problem with radiative exchange between bodies of different temperature...... I cant believe that you think that the G&T position is that no re radiation whatsoever from the atmosphere arrives back on Earth. In Physics it is quite common to disregard trivial quantities. An electric kettle contains 1kg of water say. Before (and after) the kettle is switched on the water and the kettles element radiate to one another. When the kettle is switched on heat energy from the element is transferred to the water. The electrical energy input is precisely known as is the internal energy gained by the water by independently derived equations. If the kettle is well insulated the input energy and the internal energy gained by the water are almost exactly equal. I have never heard of anyone including the back radiation from the water to the element in such a calculation
  22. Did Phil Jones really say global warming ended in 1995?
    RSVP ... "What about all the water vapor that comes from combustion? When burning methane for instance, you get twice as much water vapor as CO2. Even if you assume a shorter lifetime of water vapor as compared to CO2, the immediate presence of the extra water vapor must be factoring into the current temperature readings, in which case, CO2 is having less impact than is assumed." Do you have any idea how miniscule an amount this additional water vapor is? Tropical air can contain up to 30,000 ppm water molecules in the form of water vapor. CO2 is around 380 ppm. A quick look in google would seem to indicate that air over dense urban areas can contain an extra 20-40 or so ppm CO2 (there's one reference that talks about a 100 ppm bump but that's right next to a heavily-used freeway in Dallas). The number of H2O molecules from combustion of gasoline is almost exactly the same as the number of CO2 molecules. Miniscule. As far as heat from combustion, mechanical friction in machines driven by combustion, etc ... it's computable. It's been looked at. Science is by its very nature anal. It's an extremely tiny fraction of the forcing that results from the CO2 emissions associated with that combustion, though I'm not in the mood to google it *again* (this question gets asked a lot) .
  23. Skeptical Science now an iPhone app
    Man, what a great idea, I would totally download and use this if it came in Android flavor. Please port it! Thanks.
  24. Visual depictions of CO2 levels and CO2 emissions
    @ RSVP at 00:18 AM on 19 February, 2010 In the long run, energy in equals energy out. After a CO2 molecule, or any gas molecule for that matter, absorbs a quantum of energy, it emits it at the same wavelength as it was absorbed, and it a random direction; this basically means 50% up and 50% down. So, the CO2 in the atmosphere acts like a very fuzzy reflector. The net effect of increasing the amount of CO2 is that the black body radiation emitted at the surface has to shift to a slightly higher mean wavelength to get the same amount of energy out as is coming in. Higher medium wavelength is the same as higher temperature, as far as energy emitted by a solid is concerned.
  25. Did Phil Jones really say global warming ended in 1995?
    Wow, RSVP, way to sidestep the entire point of my previous comment. My *point*, if you were paying any attention, is that the amount of direct energy from the sun utterly dwarfs the very minuscule energy produced directly by human activity. Similarly, the amount of water vapor generated by human activity is utterly dwarfed by the amount of water vapor traveling through the atmosphere due to evapo-transpiration. Lastly, the quantity of water vapor required to enhance the greenhouse effect is more than 10 times greater than the quantity of CO2 needed to enhance the greenhouse effect by the same degree (& methane is 8 times more potent than CO2, so turning methane into CO2 & water has a net *negative* impact on radiative forcing). As much as you try & squirm, RSVP, the reality is that the only thing we're adding significantly to is atmospheric concentrations of CO2, NO2 & methane-all potent trappers of long-wave radiation & all capable of increasing the energy imbalance within our atmosphere. To try & shift the blame to our absolutely minuscule direct heat signature really displays an amazing lack of knowledge of the underlying science of energy budgets, radiative forcing & the like. I'm certainly no expert, but I suspect I'm more up-to-date than yourself!
  26. Skeptical Science now an iPhone app
    Give it to me on Android!
  27. Visual depictions of CO2 levels and CO2 emissions
    Sorry John, I've just learned Andy Jacobson from the same NOAA lab did this version of the Surface Station visualisation. Their team also has CarbonTracker on their ftp, I think this is Andys also but will check. Re 3: (nice) and SCIAMACHY on ENVISAT, worth mentioning that Bremen University have independently matched the CO2 data from Mauna Loa etc and also provided an independent reality check of CarbonTracker (which is observations plus model) as well as producing many impressive real data based images of CO2 and CH4 sources on brand new version of: iup.uni-bremen.de/.../wfmd_image_gallery_co2.html (Michael Buchwitz is the creator). This has grown into a wonderful collection of images since last I looked.
    Response: Thanks, have updated the text. Also updated the post with links to the original source of the two NASA animations for those who'd like to download the animations as movie files.
  28. Is CO2 a pollutant?
    Oh, and as for not being polemical: Thank you for the compliment, but I must admit that the strict moderation at this site forces one to be on their best behavior. So long as you are making an honest attempt to learn and assess, that is good.
  29. Is CO2 a pollutant?
    suibhne I've seen all that. The basic point remains. In the end, G&T have a problem with radiative exchange between bodies of different temperature. They think this violates the Second Law. This is just wrong, on the face of it. Nowhere in the diagram is heat flowing in the wrong direction. This is an example of Dunning-Kruger actually making it into a journal. G&T thought they could tear down an entire field with a single statement of undergraduate level physics. Unfortunately, they can't, but more unfortunately, some obscure journal published their rant. One wonders if the reviewers actually read it.
  30. Is CO2 a pollutant?
    Here's an interesting report w/regard to C02 as a human artifact, where it goes and what it does: "Today, Ridgwell and Daniela Schmidt, also of the University of Bristol, are publishing a study in the journal Natural Geoscience, comparing what happened in the oceans 55 million years ago to what the oceans are experiencing today. Their research supports what other researchers have long suspected: The acidification of the ocean today is bigger and faster than anything geologists can find in the fossil record over the past 65 million years. Indeed, its speed and strength — Ridgwell estimate that current ocean acidification is taking place at ten times the rate that preceded the mass extinction 55 million years ago — may spell doom for many marine species, particularly ones that live in the deep ocean. “This is an almost unprecedented geological event,” says Ridgwell." Beyond the finding of concern, this article includes an excellent primer on the role of C02 in the oceans and is very helpful for putting this matter into context. An Ominous Warning on the Effects of Ocean Acidification
  31. Is CO2 a pollutant?
    carrot eater Of the other contributors an this topic I feel that you have shown most flexibility and discus the topic without being too polemical. I started looking at this area with an open mind. I read the G&T article and the attempts to counter their arguments. I looked up both Arthur P Smiths site and Eli Rabbet among others. I got my old text books out to best follow the points they were making. On the Smiths and Rabbit sites I found that Fred Staples took the discussion back to Smith and Eli and seemed to cut the ground from under them. Look up these sites and follow the discussion on the 2nd law. Don't dismiss the G&T paper out of hand. You may come to a different conclusion to me but your Physics will probably be all the stronger for it.
  32. Visual depictions of CO2 levels and CO2 emissions
    As the saying goes, a picture is worth a thousand words. These videos (I particularly like the first one with the timeline starting in 1979) should be required viewing for anyone who doubts humans are adding CO2 to the atmosphere.
  33. Is CO2 a pollutant?
    suibhne "The em radiation falling on top and on the bottom according to your diagram comes to 882 joules per second." I'm not sure what all you're adding up to get that, but it doesn't really matter, since I can't figure out what point you're trying to make. "On the 2nd law and Greenhouse effect I thought that I had covered that with my flow of IR radiation at the speed of light." Hardly. Your microsecond thought experiment didn't make any sense. At once point, you said the First Law was violated. Nowhere is that true. There is a balance at the earth surface, around the atmosphere, and at the top of the atmosphere. You say the Second Law is violated. Where in this diagram is net heat flowing from a cold body to a warmer body? This is exactly where G&T got hung up. I think you are incorrect: for them it was not a matter of degree; it's a matter of concept. Look at their Figure 32/Figure 3 in the manuscript. They think heat is being transferred uphill from atmosphere to surface, and this is a violation of the second law. They think that somewhere in my (Trenberth's) diagram, heat is flowing uphill. Please show where heat is flowing in the wrong direction in my diagram. If you cannot, then you have yourself refuted a central point to G&T.
  34. Is CO2 a pollutant?
    carrot eater The em radiation falling on top and on the bottom according to your diagram comes to 882 joules per second. But the Sun only supplies 342Joules per second. What I am and have stated is the diagram is utterly stupid. On the 2nd law and Greenhouse effect I thought that I had covered that with my flow of IR radiation at the speed of light. Net heat is always from hot to cold. G&T are aware that radiated IR from CO2 can fall on the Earth; its the massive quantities that are postulated that is in disputed. The 2nd law is a statistical law and can be formulated with entropy as the point of interest. An ice cube placed in warm water will dissolve most likely but for the ice cube to reform is most unlikely. Further the main emphasis of G&T on heat transfer concerns conduction and convection wind and frictional effects such as tides and so on. There was a small residual radiative effect in the Woods experiment but it was so small that it could not possibly account for the insulating effect of the atmosphere.
  35. There's no empirical evidence
    Argus at 00:36 AM on 19 February, 2010 Argus, you'd be comforted if you have a fuller understanding of how these models are constructed. Check here: Simple climate models General circulation models
  36. Is CO2 a pollutant?
    suibhne: Now it seems like you're questioning the fact that the Earth is emitting radiation, period. Is that what you're doing? Are you saying you want to absorb the IR radiation being emitted by the earth, and do useful work with it? Good luck with that. Your device would have to be much colder than the Earth's surface in order for the net heat transfer between the device and the Earth to be inwards to the device in the first place. In any case, please return to the Second Law. G&T say that this diagram is wrong by the Second Law. They say it is impossible for the atmosphere to emit radiation down towards the Earth. Do you agree with them? That is all we need here.
  37. Is CO2 a pollutant?
    carrot eater Given that you think the diagram is accurate. You still have not answered why a solar(or IR) panel Infra Red Down ---------- Double sided solar panel ---------- Infra Red Up I don't see why given the diagram that this wouldn't work But then if the diagram is wrong........
  38. Is CO2 a pollutant?
    suibhne: You are making stranger and stranger statements, to the point it really isn't worth continuing. The First Law requires that the total energy and heat flows into the surface, and out from the surface, are equal and opposite for the surface to remain at the same temperature. The diagram does exactly that, even though you tried to say it didn't.
  39. Is CO2 a pollutant?
    "Venus, too, like Mars, has an atmosphere of nearly pure carbon monoxide. Yet it, unlike Mars, is hellishly hot. RSVP, do you suppose, that, just maybe, distance from the sun has some slight influence here?" "And yes, I am aware that Mars only gets about half the sunshine as the Earth, however, shouldnt all that CO2 be keeping the plantet a little warmer?" I just wanted to add that not only does Mars get less sunshine, it is about half the size of Earth, and has sparser cloud cover. Venus is almost the exact analogy of Earth, being only a few hundred km smaller in diameter. The cloud cover on Venus is much greater than Earth, but that is a consequence of the vast amounts of sulpher dioxide and water vapour. The current state of Venus is much closer to the outcome of our own planet, should we fail to regulate CO2, among other things. Between the CO2 levels, thick cloud cover and strong winds in the higher atmosphere, Venus has a nearly consistent global temperature of 450C. The Earth already has relatively thick cloud cover, if the CO2 starts trapping the heat and evaporating water, that cloud cover will become thicker, leading to a runaway negative feedback loop. The conditions on Mars are not similar enough to our own to draw any conclusions. Venus is the planet we want to study if we wish to avoid the same fate.
  40. Is CO2 a pollutant?
    carrot eater But this is all incoherent em radiation . It does not cancel out. Two equal spotlights facing one another from each side of a room do not produce darkness. Look at my example of a double sided solar panel say one metre above the surface and explain why it cant use all the radiation falling on it!
  41. Visual depictions of CO2 levels and CO2 emissions
    My initial suspicion was that the central African plume derived from gas flaring from Nigeria's oil industry - there are places in Nigeria that haven't seen darkness in decades due to the unceasing flares - and indeed this graph shows they are #2 in the Sub Sahara - but primarily due to land use change and forestry, not fossil fuel production. Of course the two can reinforce one another. Graph from Anthropogenic CO2 emissions in Africa, published March 2009. Thanks for the visuals!
  42. Is CO2 a pollutant?
    suibhne: So you are one-upping G&T, and claiming a violation of the First Law, and not just the Second? Wow. Please look at the diagram again. Terms coming into the surface: 168+ 324 = 492 Terms leaving the surface: 24 + 78 + 390 = 492 You appear to have missed the outgoing arrow on the 390 term, suibhne. "I think this diagram is an even bigger clanger..." If you are going to make such strong statements, do check the arithmetic first.
  43. Is CO2 a pollutant?
    carrot eater I looked at your diagram I take it that the diagram splits out horizontally for the purposes of illustration and it shows the energy balance transfers for a representative one square metre. All units in w/m2 Well what I see is a solar input of 342 and an available energy moving near the surface of the Earth of 168+324+390 = 882 If this square meter had a double sided solar panel it could turn this into useful work. However I don't think it is possible because it clearly violates the conservation of energy. So yes G&T are absolutely correct. I think this diagram is an even bigger clanger than the disappearing 2035 Himalayan glacier
  44. Is CO2 a pollutant?
    suibhne: Let's stay with http://www.windows.ucar.edu/earth/Atmosphere/images/earth_rad_budget_kiehl_trenberth_1997_big.gif A central claim of G&T is that such a diagram violates the Second Law. Do you agree with G&T on this matter? This is the critical question, so please address it directly. And as for the use of Stefan-Boltzmann, again from Eli's manuscript, "A more realistic model would split the atmosphere into a much larger number of layers for integration and take into account the detailed spectral dependence of absorption and emission, as is done with line-by-line radiation codes (HITRAN)." So please discontinue saying that Eli or anybody else is not aware of the details of spectral dependence.
  45. Is CO2 a pollutant?
    CBDunkerson ..... you seem to be forgetting the existence of all matter OTHER than GHGs. As in... some of that IR radiation which is absorbed and re-emitted by GHGs then goes back down to the lands and oceans of the planet. Making them warmer. Ditto non greenhouse gases...... If you read my post I have allowed for that the surface of the Earth(oceans etc) is a much better IR transmitter/absorber than CO2 and it is warmer. So the up flow from Earth of IR radiation is much greater than any that's returning. Whats more the non greenhouse gases seem to be better at retaining their heat than CO2 The speed of light is important and gives a boundary in which the duration of any effect can be quantified. carrot eater "It can only radiate in one of two possible IR bands and it has just lost one !" The 15 micron band is what's relevant here. CO2 is quite happy to radiate there. I don't see what the issue is....... Perhaps I am mistaken but I thought that the IR bands of CO2 corresponded to an intermolecular thermal excitation between its atoms, rather than one of the electrons moving to a higher orbit. If I am correct then in an interaction with a neighbouring molecule this energy may be transferred to that molecule as KE. The fact that Eli mentions a book on quantum mechanics in his introduction does not excuse him for ignoring it in the relevant parts, if as you say he fully realises that his diagrams are comic book then he should say so.
  46. Is CO2 a pollutant?
    suibhne Your thought experiment is ill-posed, and I can't discern any meaning from it. It isn't a matter of a tracing around a single photon and studying its "time delay", suibhne. It's a question of energy flows. Take this diagram as a simple illustration. windows.ucar.edu/.../earth_rad_budget_kiehl_trenberth_1997_big.gif Without greenhouse gases in the atmosphere, that back-radiation term would not be there. If you increase the concentration of greenhouse gases, the outgoing longwave radiation term would decrease, and the system would have to warm up over time until the two terms going out to space again balanced the incoming term (here, 342 W/m^2).
  47. Visual depictions of CO2 levels and CO2 emissions
    RSVP & guinganbresil, 'infrared radiation' covers a huge range of EM wavelengths. Your statements above about whether IR radiation is increasing or decreasing are faulty due to overgeneralizing; Wavelengths of infrared absorbed by GHGs have shown decreased amounts escaping the atmosphere and increased amounts radiating down to the surface. Other wavelengths of infrared have increased both in amounts escaping and warming the surface.
  48. It's the sun
    In answer to response. There is nothing to show that greenhouse gasses caused global warming except that co2 has increased concurrently with the warming. The increase in sunspot numbers during the same period could have been totally responsible. Greenhouse gasses are an over simplified solution to a complex climate phenomenon and again seems to ignore the effects of the oceans interaction.
    Response: There is nothing to show that greenhouse gasses caused global warming

    I suggest you read through the empirical evidence for an enhanced greenhouse effect. Satellites find less infrared radiation escaping at CO2 wavelengths. Surface measurements find more infrared radiation returning back to Earth at CO2 wavelengths. This is experimental evidence for a direct causal link between increased CO2 and a build-up of heat in our climate.

    I also suggest you read the article above. Sunspot numbers have shown a long term declining trend during the last few decades of global warming.
  49. Is CO2 a pollutant?
    Suibhne, you seem to be forgetting the existence of all matter OTHER than GHGs. As in... some of that IR radiation which is absorbed and re-emitted by GHGs then goes back down to the lands and oceans of the planet. Making them warmer. Ditto non greenhouse gases. Poof... away goes the 'speed of light' objection. We are literally talking about the difference between 'up' and 'down' here. Solar radiation passes through the atmosphere and heats the planet. The planet gives off infrared radiation... which travels UP and escapes into space... UNLESS it is absorbed by GHGs and emitted back DOWN towards the planet. Carrot eater correctly noted that this infrared energy can also interact with non greenhouse gases in the atmosphere... but that's true regardless of which direction the radiation is traveling. The central point is that some of the energy which was going up and away into space gets re-directed back down and remains here on Earth. The more energy that happens to the warmer the planet gets.
  50. The Dunning-Kruger effect and the climate debate
    TOP, 87: "I already had a grasp of the basic principles that those folks were using and haven't seen a compelling argument for the kinds of actions being proposed to combat it. Sorry, I still stick to my principles. " Then prove that you have understood it. For example by refuting the estimated 3 degC increase per CO2 doubling. Otherwise, you just provide strong indications that you haven't - that may be another example of the effect discussed in the post. The basic action, reduction of CO2 emissions, may be too simple for your taste. NOT doing that, will give some, by now, fairly well predictable effects. The biggest uncertainty is the exact time scale.

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