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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 102301 to 102350:

  1. The human fingerprint in the seasons
    First, let me reiterate Sphaerica's very important point that if you accept a 40-60% water vapour feedback from increases in temperature, then you are logically committed to accepting that feedback as a result of the approx 1.2 degrees C per doubling of CO2. Given that, and given the degree of warming in the 20th century, accepting a strong water vapour feedback commits you to CO2 being the main driver of that warming. Second, if the watervapour feedback was a consequence of solar heating, it would not exhibit the same pattern as that resulting from greenhouse warming. In particular, direct solar heating would make days hotter than night, summers hotter than winter, and tropics hotter than the poles, while to a first approximation, the water vapour feedback would have the reverse effect. Because the initial forcing and feedback have effects opposite in sign, they would cancel each other out (to a first approximation), thus resulting in no signal. In contrast, a water vapour feedback to a green house forcing would reinforce the signal, consistent with the strong signal observed. Third, all though a water vapour feedback is identical to a first approximation, more detailed analysis reveals important differences. In particular, direct solar heating would result in a significant increase in humidity in the tropics, but not the poles. So the water vapour feedback induced from solar warming would also be stronger in the tropics than at the poles. In contrast, water vapour feedback from greenhouse forcing would be more evenly distributed, tending to reinforce the signal. So, stronger warming in the poles than tropics is a clear signal of an initial greenhouse forcing, irrespective of the additional signal from water vapour. Fourth, water vapour is largely confined to the troposphere, so the water vapour feedback will not result in stratospheric cooling. Consequently, for a solar forcing we would expect a warming stratosphere, and this signal would not be masked by a water vapour feedback. From a greenhouse forcing, we would expect a cooling stratosphere, with the signal not reinforced by water vapour feedback. The cooling stratosphere is the death knell to any theory that solar radiation has driven the twentieth century warming. Similar considerations show that the warming is not due to a reduction in aerosol albedo, nor due to a reduction in cloud albedo, nor due to variations in ocean heat content (ENSO, PDO, AMO).
  2. Stratospheric Cooling and Tropospheric Warming
    I don't know but I'll give it a swag based upon the definitions below which I ran across on the web. Note that there seems to be many definitions and I didn't explicity see the one that I am guessing at. Maybe it depends upon which layer you are talking about regardless of the chemistry or any other characteristic. Apparently atmospheres on all planets are layered and perhaps the first layer is the troposphere, second the stratosphere, third the mesosphere and fouth the thermosphere. By the way, a swag is a highly technical term. It means sophisticated wild ass guess. Bob Definitions .layer of the earth's atmosphere located above the troposphere and below the mesosphere. Definitions of mesosphere on the Web: •the atmospheric layer between the stratosphere and the thermosphere
  3. 2nd law of thermodynamics contradicts greenhouse theory
    damorbel, the law about equilibrium temperature uses only the energy that the object actually absorbs. Energy contained in photons that reflect off the object is excluded by that law. Think about it: Energy that the object did not absorb does not exist inside the object, and so cannot be emitted by the object. The object does not "need" to emit energy it never absorbed.
  4. We're heading into an ice age
    Looking at the graph of temperature in the past 420,000 years, one thing that strikes me is that although the current interglacial period appears as though it may be lengthier than some previous ones, it doesn't appear to have reached the same peak value as some of the previous one's, actually falling significantly short (at present). Of course 5 datasets isn't much to go on, and the earth has been around for many million years, not just 420,000 years. But who am I to argue?
  5. Renewable Baseload Energy
    Ned - well put. I've frequently expressed my opinion that increasing nuclear will be part of the forward energy mix. I suspect breeder reactors of some type (including thorium cycle) will be needed. But treating this issue as an Either/Or proposition, ignoring valid and honestly asked questions, pooh-poohing renewable data sources while using nuclear sources uncritically, and denigrating and insulting those you disagree with, well - that doesn't add to the discussion, or to my willingness to put up with such nonsense. Peter Lang - You've made some good points about relative costs. You've made some bad ones about site distribution of renewables and the backup load requirements of uncorrelated sites (if sufficiently uncorrelated sites are available in Australia, which I regard as an open question in the absence of a decent wind/solar survey). I just wish you would drop the arrogance. And actually add to the discussion with what information you have.
  6. Stratospheric Cooling and Tropospheric Warming
    Bob Guercio @93, I understood the stratosphere to be a region of the atmosphere characterised by an inverted lapse rate (it gets hotter with greater altitude) in which convection played almost no role in heat transfer, allowing strata of distinct temperatures to form. Based on the lapse rates observed on Venus, there is no such region on Venus. On the other hand, the article you link to, and several others I found by googling "Venus" "stratosphere" do in fact refer to Venus' stratosphere. So, are you and they using a different definition to mine, or am I missing something?
  7. The human fingerprint in the seasons
    Sphaerica #36 I think you spotted one more conflicting contrarian argument. And of course the "it´s the sun" reasoning lacks one key fact: sun´s irradiance has not been increasing for several decades, now. On the other hand, the increasing direct CO2 forcing can be calculated with established, century-old science.
  8. Berényi Péter at 01:37 AM on 4 December 2010
    We're heading into an ice age
    #143 Daniel Bailey at 00:14 AM on 4 December, 2010 Changes in CO2 and temps in the paleo record occurred much more slowly than what we are physically measuring today. We do not know that. At least the ice core record does not tell us anything about the swiftness of past changes. Or do you have other, undisclosed data sources to support your valiant claim? Here is the Historical CO2 Record from the Vostok Ice Core. As you can see the difference between Age of ice and Mean age of air in it is anywhere between 1879 and 6653 years (at depth 506.4 m and 3119.51 m respectively). Therefore it takes several millennia for carbon dioxide to get enclosed in Antarctic ice. With such a heavy smoothing the present spike or anything comparable to it is rendered invisible. In general it is a grave error to conclude from the fact you can't see an invisible thing that it does not exist either.
  9. 2nd law of thermodynamics contradicts greenhouse theory
    damorbel, I understand what you believe. I also know it is false. How you can not know it is false is a great mystery to me. If you fire identical lasers at a black iron plate and a mirror the black iron plate is going to get hotter than the mirror... no matter how long you wait. This is basic and obvious, because the mirror reflects more of the laser light and thus absorbs less energy than the black iron plate. Less incoming absorbed energy means a lower temperature at which the emitted radiation equals the incoming radiation (i.e. equilibrium point). The same is true of sunlight or any other radiation and any other matter it is striking. The lower the energy absorption rate the lower the final temperature of the object will be. Again, let's look at it mathematically; Incoming radiation: 100 units Object A reflectivity: 90% Object B reflectivity: 25% Object A reflects 90 units and absorbs 10. That 10 absorption heats up the object until it is emitting 10 units. At that point the 90 units reflected + 10 units emitted equals the 100 units incoming and the object is at equilibrium. Object B reflects 25 units and absorbs 75. That 75 absorption heats up the object until it is emitting 75 units. At that point the 25 units reflected + 75 units emitted equals the 100 units incoming and the object is at equilibrium. At equilibrium object A is emitting 10 units of energy and object B is emitting 75 units. Object B is thus much hotter than object A. Albedo has a direct and obvious impact on temperature.
  10. The human fingerprint in the seasons
    John, can you show what the summer's max temps are doing? What is the trend of the hottest days of the year? What is the prediction of AGW theory about the number of extreme hot days in the summer?
  11. Stratospheric Cooling and Tropospheric Warming
    The Ville @88, my understanding is that if the atmosphere were entirely transparent to radiation, all energy flows from or to it would take place at the surface. Therefore, it would warm until the energy flows from the surface to the lowermost layer of the atmosphere equalled the energy flows from that layer to the surface. That should be when the surface and the lower most layer have the same temperature. The rest of the atmosphere would derive its heat from the lowest layer, primarily by convection. That convection would establish the temperature profile at the adiabatic lapse rate. Hot air rising would still cool as it expands from reduced pressure, ensuring that the upper atmosphere (excluding the thermosphere) remained cooler than the lower atmosphere at all times. (The situation is a little more complex if we include heat transfer to the poles.) Even if a hot air parcel rose to the top of the atmosphere at a temperature above that defined by the lapse rate, it would prevent more heat transfers to the upper atmosphere by convection at its location, and gradually cool back to the adiabat by conduction and turbulent eddies. If such hot parcels of air were generated frequently enough, and cooled slowly enough, then the lapse rate could be less than the adiabat; except that even in this case it would be defined by the adiabat for periods of peak surface temperature. Again, please correct me where I am wrong.
  12. 2nd law of thermodynamics contradicts greenhouse theory
    Re #270 CBDunkerson you wrote:- "If albedo is irrelevant to temperature... why exactly is it that black asphalt gets hotter than white cement on sunny days? " You must not confuse 'rate of heating' with 'final temperature'. Highly absorptive materials heat up quickly because they absorb a large % of the incoming radiation. Switch the radiation off and they cool correspondingly quickly. Highly reflective materials (high albedo) heat up slowly and cool down slowly in the absence of input; an example of this is a thermos flask with its highly polished surfaces. In either case, black or shiny, the final temperature, after stabilisation from whatever the initial temperature was, will be the average of the fluctuating sunshine or whatever thermal input there is. You must see from this that, with a fluctuating radiation input, the temperature of the asphalt will fluctuate about the average temperature far more than the contents of the flask but both will have the same average temperature.
  13. The human fingerprint in the seasons
    I have to agree with HumanityRules' logic that any warming will increase water vapor, providing a strong, positive H2O GHG feedback in all cases, for all forcings which will give any warming of any sort a GHG signature. For this reason, it is difficult to apply the argument made by this post. Of course, to accept this logic, one must also accept net positive feedbacks and a higher climate sensitivity. You can't argue for this, and also argue that clouds will cause a negative feedback that will hold temperatures (and therefore H2O content) relatively constant. You also can't argue the line that atmospheric H2O content simply won't change with warming. But the correct statement should be that "solar forcing without any positive GHG feedbacks" would warm days more than nights and summers more than winters. This is of course a purely abstract statement, since any warming will introduce a positive H2O GHG feedback, and eventually a positive CO2 GHG feedback as well. It would also, I think, warm the troposphere but not the stratosphere (since the warming would not necessarily increase H2O content in the stratosphere, although that's now a "known question mark", as highlighted by Solomon 2010). But it is still a difference between CO2 and solar warming, in that CO2 will reach and actively cool the stratosphere (at least until solar warming introduces its own carbon feedbacks). So that argument stands as a distinction between CO2 and solar (or other) warming. So, in the end, one is again left with the question of what has caused the warming? AGW proponents say CO2 (which, for the record, is my stance). AGW deniers say that it is the sun, or cosmic rays, or seasonal Eurasian Leprechaun Farts, or just that we don't know, but it must be something other than CO2.
  14. The human fingerprint in the seasons
    Re: TOP (31)
    "Figure 1 shows green house warming started in 1980. Cool. "
     Why in the world would you make that conclusion? Are you just graph-mining? Or do you actually have a source for that opinion? I call a balk. The Yooper
  15. Stratospheric Cooling and Tropospheric Warming
    The Ville - 81 In addition to what you say about teaching, it sems that virtually everything in Physics depends upon ridiculously simple models. Bob
  16. The human fingerprint in the seasons
    Minor remark: The link to the data on the graph subtitles points to CRUTEM3v Northern Hemisphere, whereas the graph itself is CRUTEM3 global.
  17. It's a 1500 year cycle
    Re: cjshaker (22)
    "I think the bottom line is that climate modelers don't really understand the glacial cycle, nor how it really works."
     I have responded to this over here. The Yooper
  18. We're heading into an ice age
    Re: cjshaker This is a reply to your comment over on the 'It's a 1500 year cycle' thread: ---------------------------------------------------------------------------------------------------------- Re: cjshaker
    "I think the bottom line is that climate modelers don't really understand the glacial cycle, nor how it really works."
     And your source for that claim would be...? You may want to actually read up on models. Suggested starting points can be found here, here, here, here and here. The Yooper
  19. The human fingerprint in the seasons
    #31: "Greenhouse warming is primarily a land based effect. " Surely you would include the Arctic as a place where greenhouse warming is significant... that is the Arctic Ocean?
  20. Stratospheric Cooling and Tropospheric Warming
    Mighty Drunken - 90 In the steady state, which is what my blog was all about, there is not less IR energy reaching the stratosphere from below. The same amount of IR reaches the stratophere. However, the nature of this radiation is different. There is less in the frequency range that CO2 absorbs and more in the range that sails past the CO2 totally unaffected by it. Bob
  21. Stratospheric Cooling and Tropospheric Warming
    damorbel - 85 An editorial error on my part. I meant to say "Venus does have a stratosphere". http://adsabs.harvard.edu/abs/1983KosIs..21..205A
  22. The human fingerprint in the seasons
    Humanity Rules: "That means 40-60% of the warming trend from a doubling of CO2 comes from the water vapour feedback. 40-60% of the GHG fingerprint comes from water vapour. The water vapour effect is not specific to CO2 but is a consequence of a warming world. All things being equal, any process that warms the world is going to have this 40-60% water vapour feedback." That is a ridiculous over simplification. Insolation varies, when you reduce it, you reduce the energy. CO2 is present all the time and is a 'storage' mechanism. The two have different impacts on how they would effect water vapour production and retention. It is somewhat duplicitous to accuse John of over simplifying the issue, when you yourself make a faulty assumption.
  23. The human fingerprint in the seasons
    Figure 1 shows green house warming started in 1980. Cool. I wouldn't expect the tropics to necessarily warm as much in summer due to solar increases. After all if you look at the globe between the tropics you will see that you are dealing with predominantly water, not land. Greenhouse warming is primarily a land based effect. Oceans absorb almost all the solar radiation they receive and transport that heat via currents to other parts of the globe (very low albedo). Because oceans absorb almost all the heat they receive there is nothing re-radiated for CO2 to absorb. Heating of the air over the oceans is primarily driven by water temperature which is why the temperature record over the oceans is based on sea temperatures. Ocean heating due to solar activity extends to a depth of 50m-100m during the summer. This heat is not all available to heat the atmosphere immediately but is transported via various currents and usually northward and southward. So again, Figure 1 points to an effect possibly caused by a shift of some sort in ocean currents or the transport of heat from increased solar activity farther north. England is seeing this effect right now. Most of the big hurricane activity this fall was confined to the North Atlantic taking huge amounts of heat out of the Gulf Stream which warms England and northern Europe and makes it livable.
  24. We're heading into an ice age
    Re: cjshaker (142) From the literature I've read, the Vostok and Epica cores were sampled every 0.5 to 2 meters, depending upon the depth (I don't recall offhand the spacing intervals from Greenland cores). The final several hundred meters of the Vostok core was deemed unusable due to heat penetration upwelling from Lake Vostok lying underneath the borehole at that point. The larger sampling interval actually carries with it fewer questions about the resulting resolution, due to the spacing involved. More frequent sampling might yield more data, but the resulting data would not necessarily add anything new. Changes in CO2 and temps in the paleo record occurred much more slowly than what we are physically measuring today. The Yooper
  25. Mighty Drunken at 00:11 AM on 4 December 2010
    Stratospheric Cooling and Tropospheric Warming
    @Tom Curtis post 83 Looking at your post and some other explanations about stratospheric cooling I think your description is more accurate than the post. The dominating factor for the cooling is not less IR radiation reaching the stratosphere from below, but the increased emission by increasing CO2 concentration. The difference between fig. 2 and fig. 3 show the cooling effect from less IR coming from below can only be slight. Gavin's post at real climate does seems to suggest greater concentrations of greenhouse gases warm the atmosphere up to a certain altitude and above that they cool as the balance between absorption from the surface and emission into space changes, as convection dominates in the troposphere though you don't get to see this effect in the troposphere. My post is only my understanding and is probably wrong!
  26. Stratospheric Cooling and Tropospheric Warming
    Re: Bob Guercio You are very much correct, sir. While I am aware that pre-1970 (or so) CO2 was primarily a lag/feedback to temps, I was remiss in not taking the time to point that out in my comment above. I will add verbiage to that effect in my comment. Apologies for adding to your workload. :) The Yooper
  27. Stratospheric Cooling and Tropospheric Warming
    Tom Curtis: "To see this, consider a hypothetical planet whose atmosphere is completely transparent at all wavelengths of electromagnetic radiation. In this case, its surface temperature will be its temperature as measured from space, ie, its effective temperature. The temperature at any point in the atmosphere above the surface will be less than the effective temperature, and the temperature profile of the atmosphere will be defined by the adiabatic lapse rate up to the thermosphere. (Like Venus, see graphic in 80 above, it will have no stratosphere.)" Not quite correct. Although this is an interesting game. If the atmosphere were transparent to electromagnetic radiation, the only way of transporting energy would be by conduction and convection. The only lapse rate would be as a result of convection and you may very well have an 'inverse' lapse rate, eg. hotter at the top over time. In fact it would get hotter and hotter, because the atmosphere wouldn't be able to emit the accumulating energy to space. Transparency = no absorption or emission
  28. The human fingerprint in the seasons
    HR, I think the disconnect here is that you aren't considering the fact that feedbacks must perforce follow the same 'fingerprints' as the forcings which cause them. That is, if a solar forcing were causing increased Summer temperatures that would indeed result in a water vapor feedback effect... during the Summer. When Winter arrived and the impact of the solar forcing declined the water vapor feedback would follow suit. Ditto geography... if a solar forcing were causing accelerated equatorial warming then we would indeed see increased water vapor feedback... near the equator. Yes, there is always going to be some overlap and 'flow' of feedbacks, but they must always be most pronounced in the same conditions the forcing causing them is. The law of cause and effect still applies.
  29. Renewable Baseload Energy
    Re: Ned (315) Quality words, ably spoken and spot-on; bravo, sir! More comments such as yours are needed to help maintain the decorum and high level of discussion already found on most of this blog, but lacking to some degree on this thread. On the other thread, being of like mind with you, I reached out to Peter and attempted to find common ground with him...and was rebuffed. The Yooper
  30. The human fingerprint in the seasons
    27 Argus: "How come, then, a majority of this year's heat records are from the tropics?" Perhaps because annual events are not climate trends.
  31. 2nd law of thermodynamics contradicts greenhouse theory
    damorbel #270: "The idea that planetary temperature is affected by its albedo is quite mistaken." Your belief that you have any idea what you are talking about is quite mistaken. If albedo is irrelevant to temperature... why exactly is it that black asphalt gets hotter than white cement on sunny days? Or what magical property would be at work such that a planet with no atmosphere covered in white cement would be just as hot as an otherwise identical planet covered in black asphalt? That's the thing which gets me about nearly everything you say here... it isn't just that it is wrong, it is that any person capable of observing the world around them should know it is wrong. First you argue that a non-zero energy flow produces zero heating... now that reflection and absorption yield the same result. It's gibberish.
  32. Stratospheric Cooling and Tropospheric Warming
    Tom Curtis @83 " Therefore, I would have to conclude that stratospheric cooling with increased CO2 is primarilly due to increased efficiency at radiating away energy absorbed by ozone due to increased concentration of CO2. There would be a small additional boost due to reduced outgoing radiation of IR in the 15 micron (CO2) band; but that is ony a secondary cooling effect, and would have been a warming effect where it not for the presence of ozone in the stratosphere" vs my #79 "So are there two effects: 1) increased emission in the CO2 emissions bands increases thermal to radiative heat conversion and thereby reduces the temperature necessary to maintain overall heat balance AND 2) decreased absorption in the same spectrum because CO2 in the troposphere has already taken it out reduces the total heat input to the stratosphere " I think we are in agreement, so clearly we've both got something wrong ;-)
  33. Renewable Baseload Energy
    Peter Lang #292: "SEGS is a day time only plant." False. Didn't you read BP's post about how they are evil and dangerous because the heated fluid used to provide night time power caught fire once (though 0 people were harmed by this)? Seriously, if you guys are going to spread nonsense could it at least be consistent nonsense? Also: "This thread is about baseload. SCEGS is not baseload." Yes, it is. No other power plants are required to be 'on standby' to cover for them. They have natural gas power generation on site to make up for any shortfalls... but that's only 10% of total power generated.
  34. Renewable Baseload Energy
    Thank you, Ned. You've said what I would have, had I the wit (and the patience).
  35. Stratospheric Cooling and Tropospheric Warming
    Bob, neither Venus nor Mars have a stratosphere: But, contra damorbel, the absorber of shortwave radiation does not have to be O3 (or O2), as shown by the examples of Titan and the gass giants:
  36. Renewable Baseload Energy
    Peter Lang writes: ... the strong resistance to nuclear as is being expressed on the SkepticalScience web site ... I know from previous discussions that there are many of us on SkepticalScience who support nuclear power and who think that investments in nuclear power will need to be greatly expanded in the next few decades. So why aren't any of these people contributing to the discussion? I can only speculate, but here are three possible reasons: (1) Many of us support both nuclear power and renewables. My expectation is that reducing our use of fossil fuels will involve increased reliance on nuclear and hydro and solar and wind and geothermal and tidal power and biomass and ... well, you get the point. But you seem to be at least as motivated by the desire to attack renewables as by the desire to promote nuclear. Your approach, of pitting one against the other, is going to drive away those who support both. (2) On a more personal note, the aggressively combative style of many of your comments here may well to inhibit others from posting pro-nuclear comments (and almost certainly drives fence-sitters away from your position). You ignore and insult those who disagree with you, and convey the impression that you're not willing or able to objectively consider different sides to the debate. Your comments are riddled with absolutist language; there's no recognition of shades of gray or of the possibility that others might have any valid points whatsoever. Again, as someone who wants to build support for nuclear power (and other non-fossil sources) I know we need all the allies we can get. Intemperate outbursts -- like insulting comments about "Greenies" and repeated implications that your opponents are "irrational" -- don't help. I'm pro-nuclear, but I'm also a very committed environmentalist ... why should I participate in this thread when the main pro-nuclear poster is busily insulting people whom I identify with? (3) Although this thread is about energy sources, it's in the context of a site that is primarily focused on the science of climate change. Like others, I've gotten the impression that your knowledge of and interest in climate science is minimal to nonexistent. Your only purposes in posting here seem to be to (a) aggressively promote nuclear power, and (b) aggressively run down renewable energy (not necessarily in that order). This perception naturally further reduces people's interest in joining the discussion. Of course, this is all just one person's opinion ... but I would suggest taking some time to reflect on what you're trying to accomplish here and whether your efforts are likely to be effective in accomplishing that.
  37. The human fingerprint in the seasons
    20 Albatross I haven't had time to fully take in what Braganza is saying but the quote you pick out does highlight a problem I had noticed. Let's limit ourselves to just the most recent trend. Braganza seems to investigate two possible scenarios. 1) The warming is solely from human GHGs. or 2) The warming is solely from solar and volcanics. He then tries to see which best fits the observed trends. The problem I have is that those two options aren't the only possibilities. 2) would demand the position that CO2 increases have no possible role in temperature trends. Some sceptics might hold that position but many more hold a more nuanced position where they accept the role of CO2 as a GHG but are critical of the magnitude of that effect expressed by the IPCC. That would mean that a third possible option exists where the recent warming trend is in response to multiple forcing factors. Simply positing the two extreme positions and asking the question which one is the better fit does not fully investigate the problem. As I said before, but in respect to another issue, this is not an all or nothing problem. In fact your quote highlights the problem I have with John's presentation. In Braganza's words this is "consistent" with human GHGs not a fingerprint of it.
  38. Stratospheric Cooling and Tropospheric Warming
    Re #84 you wrote:- "Venus does have an atmosphere." What I wrote was:- "Venus has no stratosphere."
  39. Stratospheric Cooling and Tropospheric Warming
    damorbel - Venus does have an atmosphere. http://adsabs.harvard.edu/abs/1983KosIs..21..205A
  40. Stratospheric Cooling and Tropospheric Warming
    After carefull consideration, I believe the explanation of stratospheric cooling given in the original post is simply wrong. To see this, consider a hypothetical planet whose atmosphere is completely transparent at all wavelengths of electromagnetic radiation. In this case, its surface temperature will be its temperature as measured from space, ie, its effective temperature. The temperature at any point in the atmosphere above the surface will be less than the effective temperature, and the temperature profile of the atmosphere will be defined by the adiabatic lapse rate up to the thermosphere. (Like Venus, see graphic in 80 above, it will have no stratosphere.) Now, as we introduce CO2 into the atmosphere, what happens is that the altitude of the effective temperature gradually increases in height. As the temperature profile is still defined by the lapse rate, the temperatures at every altitude up to the thermosphere will also increase. Even if we exclude convection as a means of transfering energy in the atmosphere, and hence exclude the adiabatic lapse rate as a temperature profile, radiative transfer in an optically absorbing atmosphere will generate a lapse rate, indeed, typically a shallower (greater change in temperature for a given change in altitude) lapse rate than the adiabatic lapse rate. Therefore this reasoning should still hold. Looked at differently, and using Earth as our model, we need to consider that the effective altitude of radiation, ie, the average altitude from which radiation reaches space, lies several kilometers below the tropopause. Therefore most outgoing radiation at the tropopause reaches space, and the Beer-Lambert law is an appropriate approximation of the effect of changing CO2 concentrations in the stratosphere. Given that, then if we double the CO2 concentration we also double the amount of IR radiation absorbed by CO2 in the stratosphere. The amount of IR radiation outgoing from the tropopause will not itself double, but infact will slightly fall because the atmosphere is optically thick below the tropopause. Consequently, although the net radiation entering the stratosphere will fall in this scenario, the amount absorbed in the stratosphere will increase. Of course, the amount of IR radiation emitted at a given temperature will also double with doubling of CO2 in the stratosphere. The result is that, if the temperature of the stratospheric CO2 is less than the brightness temperature radiation emitted by CO2 in the troposphere, it will warm. If it is greater it will cool. Of course, had the temperature in the stratosphere followed the adiabatic lapse rate, it would have been less than that of the troposphere; and increasing CO2 would warm the stratosphere, all else being equal. But all else is not equal - the stratosphere is much hotter than the upper levels of the tropospere because of the absorption of UV radiation by ozone. Therefore, I would have to conclude that stratospheric cooling with increased CO2 is primarilly due to increased efficiency at radiating away energy absorbed by ozone due to increased concentration of CO2. There would be a small additional boost due to reduced outgoing radiation of IR in the 15 micron (CO2) band; but that is ony a secondary cooling effect, and would have been a warming effect where it not for the presence of ozone in the stratosphere. Having said all that, I now hope some one will knock some holes in my reasoning.
  41. Renewable Baseload Energy
    Ogemaniac, @ #303, “If we were to scale solar to about one hundred times what it is now, prices would likely fall more than half from where they are now. This would also be enough production capacity to replace every fossil fuel plant within a generation. The scale of this industry would be similar to that of the auto industry...certainly not impossible” Several points to make here. 1 You have posed some really big ifs. Do you want to wait in the hope that solar might be able to do the job sometime in the future? Do you want to continue to ban nuclear, or continue to put such onerous restrictions on it that it is uneconomic, so we delay another 20 years or so? Do you want to take the risk? Because that is what is happening as a result of the strong resistance to nuclear as is being expressed on the SkepticalScience web site and other web sites dominated by contributors with similar beliefs. 2 “Scaling solar to one hundred times rimes what it is now” would not make a dent in the amount of generating capacity we would need in 20 or 30 years time. It would be insignificant. 3 If you halved the cost of solar thermal that has sufficient storage to do what the ZCA2020 report assumed (which is totally insufficient anyway), the cost would still be about five times the cost of nuclear. Gemasolar (Spain) Generating Capacity = 17MW Storage = 15h Energy pa = 100,000MWh Cost (2009 €) = €230 million (200 Cost (2010 A$) = $395 million Cost per kW = $23,225/kW Cost per average kW = $34,587/kWy/y For comparison nuclear = $4,500/kWy/y So, the cost for Gemasolar with 15h storage (not baseload) is about 8 times higher than nuclear Halve the solar (and don’t reduce the cost of nuclear) and solar is still 4 times higher than nuclear. Reduce the cost of nuclear over the same period too, and solar would still be around 6 times higher than nuclear. Make solar thermal baseload capable and solar would be probably 20 times higher cost than nuclear (if it is even possible to do it, which I doubt) I am sure someone here will pull out some other figures from another plant. Please do but try to keep a sense of perspective. Differences between plants are not significant unless they are at least a factor of five lower cost per kWy/y, given the size of the discrepancy between solar an nuclear. Please provide the source of your figures, present the equivalent figures to those I’ve shown above and show how you calculated them. By the way, the new solar PV station recently commissioned at Windorah in Queensland cost $4.5 million for 130kW, 360MWh/a, = A$34,625/kW, = A$109,500/kWy/y. Key Point: Solar thermal is totally uneconomic, and probably can never be a viable baseload technology. Even if we halve the cost of solar thermal it is many time more costly than nuclear. If we could make it capable of baseload generation it will be many times more expensive still. This is why I say there is no realistic prospect of solar thermal being economically viable as a baseload technology. Sources: http://www.nrel.gov/csp/solarpaces/project_detail.cfm/projectID=40 http://europa.eu/rapid/pressReleasesAction.do?reference=BEI/09/224&type=HTML http://www.solarpaces.org/Tasks/Task1/Task%20I.pdf http://ecogeneration.com.au/news/windorah_solar_farm/011780/
  42. Stratospheric Cooling and Tropospheric Warming
    Daniel Bailey - 78 garythompson - 77 This graph does show a correlation between CO2 and temperature. However, it may not show the correlation that you want. In this graph, temperature changes occur a few hundred years before CO2 changes. CO2 does contribute to the temperature increase but as a feedback rather than a forcing. This is often used by contrarians to debunk the present day issue of CO2 causing the temperature to rise. Bob
  43. The human fingerprint in the seasons
    Quoting from top post: "Solar warming should result in the tropics warming faster than the poles. What we observe instead is the poles warming around 3 times faster than the equator." How come, then, a majority of this year's heat records are from the tropics?
  44. The question that skeptics don't want to ask about 'Climategate'
    Physics based models still make a host of assumptions? All models make a host of assumptions, including those written by the atmospheric particle modelers. Chris Shaker
  45. The question that skeptics don't want to ask about 'Climategate'
    "actually thoughtful": If we saw a temperature change that exceeded that from the historic glacial cycle, it'd be a lot easier to believe in AGW. So far, the global warming that we're seeing appears to be a natural part of the warm phase of the glacial cycle. We reached 4.5C warmer than today (1950) during the previous warming phase, 130,000 years ago. http://news.nationalgeographic.com/news/2007/07/070705-antarctica-ice.html Chris Shaker
  46. 2nd law of thermodynamics contradicts greenhouse theory
    Re #266 KR you wrote: "Photons don't have temperatures (cold, warm), they have energies." The temperature associated with photons comes from the Planck energy distribution, the peak of the curve tracks the Wien displacement law In the same way as a gas has a distribution of energies following the Maxwell-Boltzmann distribution according to its temperature; photon energy follows Planck's law. But, since the bulk gas has the average temperature of all the molecules, this also means that the individual (isolated) molecule has its own temperature. In the same way a photon also has its own temperature, related of course, to its energy. This goes further; a planet orbiting a star is immersed in photons emitted by the Sun, the number of photons intercepted by a planet is reduced by the inverse square law but this is the only reduction, making the equilibrium temperature of a planet a function only on the Sun's (photon) temperature and the planet's distance from the Sun. The idea that planetary temperature is affected by its albedo is quite mistaken.
  47. It's a 1500 year cycle
    My further comments are posted at We're heading into an ice age http://www.skepticalscience.com/argument.php?a=53 Chris Shaker
  48. We're heading into an ice age
    Thank you for the explanations about the graph. What you say makes sense. I think this implies that the cores are sampled for analysis every so many mm? Chris Shaker
  49. The human fingerprint in the seasons
    16 Daniel Bailey I guess a definition of a 'human fingerprint' would help. Maybe John (or you) could provide one? For me it means evidence that stands alone in identifying a human component and excludes all other possibilities. Without both of these it's just evidence that's consistent with CO2 warming. A discussion of whether there is or isn't a TSI trend will not get us any closer to understanding why this is a fingerprint. More back of the envelope calculations. Solar warming would contain a 40-60% GHG component from water vapour. What about IPCCs estimates of CO2 warming? 0-33% comes from albedo and other non-GHG warming forcings and feedbacks and 66-100% from the GHG component (about half that from the water vapour feedback the rest directly from human GHGs). Can John's graph differentiate between a 40-60% GHG warming signal and a 66-100% GHG signal? If it can't then it's not a fingerprint of human warming. As I said before, in John's written description of what a solar fingerprint will look like he seems to ignore feedback and focus solely on the direct effect from changes in TSI. DB you seem to be taking two steps forward. John introduces the mythical "solar fingerprint' to the the discussion. I'm only going with John's flow here. If there is a problem with considering a solar fingerprint then maybe you should direct your criticism toward him.
  50. Stratospheric Cooling and Tropospheric Warming
    Humanity Rules: "That in a nutshell seems to be the problem." Then I hope you are not a teacher. You don't go in guns blazing and teach someone who knows nothing about science, the complexity of a subject that only an experienced scientist knows. You start with simplicity and add complexity as the student has learnt the simpler principles. That applies just as much to climate science, as it does to carpentry, stonemasonery or welding.

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