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Comments 102601 to 102650:

102601. Bob Guercio at 01:39 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Let me add something to all this. The following passage came from: http://www.atmosphere.mpg.de/enid/20c.html _________________________________________________________________ Cooling due to the greenhouse effect The second effect is more complicated. Greenhouse gases (CO2, O3, CFC) absorb infra-red radiation from the surface of the Earth and trap the heat in the troposphere. If this absorption is really strong, the greenhouse gas blocks most of the outgoing infra-red radiation close to the Earth's surface. This means that only a small amount of outgoing infra-red radiation reaches carbon dioxide in the upper troposphere and the lower stratosphere. On the other hand, carbon dioxide emits heat radiation, which is lost from the stratosphere into space. In the stratosphere, this emission of heat becomes larger than the energy received from below by absorption and, as a result, there is a net energy loss from the stratosphere and a resulting cooling. Other greenhouse gases, such as ozone and chlorofluorocarbons (CFC's), have a weaker impact because their concentrations in the troposphere are smaller. They do not entirely block the whole radiation in their wavelength regime so some reaches the stratosphere where it can be absorbed and, as a consequence, heat this region of the atmosphere. _________________________________________________________________ This passage absolutely drove me crazy because I didn't understand it. I now understand it because I know that it is only part of the story. What bothered me was with regard to what happens after the earth heats up and reaches a steady state with a higher tropospheric temperature. Of course, this presumes stabilization of greenhouse gases but nevertheless, in the steady state the same amount of IR energy is going to be entering the stratosphere as before the CO2 concentration increased which caused the temperature to increase. This is necessary because conservation of energy requires that the solar energy entering the troposphere from the sun must equal the IR energy leaving the troposphere since the solar energy entering did not change. If the same amount of IR energy is entering the stratosphere from the troposphere, why doesn't the temperature of the stratosphere return to what it was before all this started. The reason is that more of this energy is in the atmospheric window which does not react with CO2 and less is in the absorption band which does react with CO2. So less in the absorption band than before means less energy reacting with the CO2 and a permanent lowered temperature. The stratosphere is also cooler because of the thinning of the ozone layer but this is relatively easy to understand and is explained in the referenced website. Bob __________________
102602. Bob Guercio at 01:35 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Alexandre, That's because, in my opinion, they try to make it too simple. They made it so simple that all they did was "handwaving". I sent my thoughts to RealClimate for confirmation and here is the email that I received from Gavin. Gavin's comment would have made my simple model more complex so I stayed with the simple model. Bob mostly right. You miss two key facts. First, all GHGs emit as well as absorb, and whether you will get warming or cooling in a region depends on the ratio of the change in absorption and the change in emittence. Second, the troposphere has many IR absorbers, the stratosphere only two (CO2 and O3 - everything else is minor). So the impact of CO2 above the tropopause is amplified. Otherwise you are spot on! Gavin > Hi, > > I've searched for an explanation of the reason that the Stratosphere cools > due to Global Warming and have not found a satisfactory answer. There > does seem to be quite a bit of hand waving though. > > I think that I now understand it but would like the confirmation of a > professional. If my understanding is correct, I would like to write a > blog on this most misunderstood subject. > > Please confirm if this is correct. > > Thank you, > > Robert Guercio > > The earth radiates Infrared Radiation in accordance with Black Body > theory. Most of the IR energy absorbed by CO2 has wave numbers of > approximately 650 and 1050. There is CO2 in both the troposphere and the > stratosphere so frequencies associated with these wave numbers emanating > from the heated earth heat up both the troposphere and the stratosphere. > Frequencies of all other wave numbers simply sail on through without > effecting either layer. > > If there is more CO2 in the troposphere, more of a chunk of the spectrum > is going to be taken out around these two wave numbers in heating up the > troposphere. Therefore, there is less energy in these two IR bands to heat > up the CO2 in the stratosphere and thus the stratosphere cools. >
102603. Bob Guercio at 01:30 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Tarcisio, I kept it ridiculously simple in order to explain a concept. I thought about bringing ozone into it which is also responsible for stratospheric cooling but for a different reason which is easy to understand. Incoming solar radiation interacts with the ozone causing the stratosphere to heat up. The ozone has thinned recently so less solar energy is reacting with ozone, thus cooling the stratosphere. However, by bringing ozone into the picture, it gets more complicated. Bob
102604. Bob Guercio at 01:25 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Ville, This could be the case if the temperature was at absolute zero where the spectrum is being measured and total saturation occurred. However, were that to happen, hypothetically of course, the temperature of the planet would increase allowing more IR energy to be in the atmospheric window. The area under that curve would still be the same or that of the energy of the incoming solar radiation. Just a minor point for precision. The graphs we are talking about represent energy but the y axis is actually power/meter squared wavenumber. Bob
102605. Alexandre at 01:24 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Thanks Bob, this is a brave attempt to explain a surprisingly complex subject. As I understood it, the post is coherent with the simplified version of the explanation that can be found in the NOAA Global Warming FAQ: An enhanced greenhouse effect is expected to cause cooling in higher parts of the atmosphere because the increased "blanketing" effect in the lower atmosphere holds in more heat, allowing less to reach the upper atmosphere. I've seen other competent guys try to explain the concept before, with limited success: Gavin Schmidt at RealClimate and Science of Doom.
102606. Arkadiusz Semczyszak at 01:21 AM on 2 December 2010
        A basic overview of Antarctic ice
        At the well ..., it is worth - this very interesting discussion, supplemented about the significant facts. At the beginning: I recall that one of the objections against Rignot et al. 2008 was: “Corr and Vaughn report that volcanic activity beneath the Antarctic ice may have increased the flow rate of some of the region's largest glaciers.” In addition, I will add that Monaghan et al., 2008., write: “Annual Antarctic snowfall accumulation trends in the GCMs agree with observations during 1960–1999, and the sensitivity of snowfall accumulation to near-surface air temperature fluctuations is approximately the same as observed, about 5% K −1 . Thus if Antarctic temperatures rise as projected, snowfall increases may partially offset ice sheet mass loss by mitigating an additional 1 mm y −1 of global sea level rise by 2100.” Why have not increased snow in the Antarctic? „However, 20th century (1880–1999) annual Antarctic near-surface air temperature trends in the GCMs are about 2.5-to-5 times larger-than-observed [!], possibly due to the radiative impact of UNREALISTIC increases in water vapor.” Also missing in this discussion, reference is made to this latest work: van Ommen et al., 2010. Commenting on his work van Ommen said: “Over the past 30 years, the cores indicated there had been a significant increase in snowfall in that area [coastal East Antarctica] ...” "The snowfall increase we see in the last 30 years lies well outside the natural range recorded over the past 750 years," In paper writes: “A range of factors [drought - Australia, the increase in snowfall - Antarctica], such as natural variability and changes in land use, ocean temperatures and atmospheric circulation, have been implicated in this drought, but the ultimate cause and the relative importance of the various factors remain unclear.” For me, "unclear" is at the same time: whether the (eventual) decrease in Antarctic ice mass is a sign of warming, or maybe, rather, its absence?
102607. Tarcisio José D at 01:19 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Bob Guercio This post provides one deserves a true science because it does not translate or approaches the climatic reality of our planet's atmosphere to exclude of the study, the most important component, "steam". The water vapor is part of the mechanism of convective transport of heat from the sun. He is able to pierce the "blanket" of greenhouse gases, leading over 50% of heat to the top of the troposphere, above this "blanket called CO2." Change the heat from troposphere to the stratosphere See:
102608. Paul D at 01:13 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Actually oamoe, if you think about it. If the trough did go down to zero, it would mean no IR was escaping the planet. The graphs are of emissions, so if a part of the spectrum dropped to zero, then it would mean that part of the spectrum was being absorbed by the planet but never emitted, which wouldn't be very nice!
102609. muoncounter at 01:13 AM on 2 December 2010
        A basic overview of Antarctic ice
        #78: "Just because a trend line fits this short data set doesn't mean it contains any meaning." It the trend fits, it fits. The meaning is in the eye of the beholder. If you choose to disagree, fine. But then how do you take such meaning out of the 'blip', which is a far shorter time sample than the data presented by Velicogna. This is akin to the 'it hasn't warmed since 1998' nonsense. "this is a completely separate question" Not really, especially in a thread that starts off "Skeptic arguments that Antarctica is gaining ice". One thing these data do not show is a gain in ice. So your criticism must therefore be directed at those who make conclusions using no data whatsoever.
102610. Bob Guercio at 00:53 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Everything we are talking about except "Why the stratosphere is cooler" is explained in the videotaped course given by David Archer at http://geoflop.uchicago.edu/forecast/docs/lectures.html The two blackbody levels, band saturation, CO2 weathering is all there. I recommend it highly. I also recommend the book although it has quite few typos. Bob
102611. Bob Guercio at 00:44 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Oamoe, My understanding is that the bandwidth, if I could use this word, is not precisely defined. At 1000 ppm the width is wider than at 100 ppm and the center of these two bands with different bandwidths is saturated in both cases. Bob
102612. muoncounter at 00:44 AM on 2 December 2010
        Naomi Oreskes' Merchants of Doubt Australian tour
        #116: "the main contender is clouds moderated by sun's magnetic atmosphere?" I'm not sure what you mean, but this might be a more appropriate thread.
102613. Paul D at 00:42 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        oamoe: I assume you mean the trough should be at zero?? No. The trough bottoms out at an imaginary curve (not shown) that represents the temperature at the top of the atmosphere. Effectively you would have two upper and lower limit curves, the higher one represents T at ground level, the other T at the top of atmosphere. The spectrum curve (for someone observing the planet from space and looking down) will be something in between the two, depending on what gases you include, with chunks taken out at different wave lengths. It would have been useful if Bob had shown the upper (ground) and lower (TOA) limits.
102614. Bob Guercio at 00:39 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        CBDunkerson The frequencies of the IR in the atmospheric window do not react at all with CO2. It's like light going through glass. Yes. In one case you have extra energy in the atmospheric window (higher tropospheric temperature/lower stratospheric temperature) and in the other case you have extra energy in the absorption band (lower tropospheric temperature/higher stratospheric temperature). If you had IR energy only in the atmospheric window, it would not heat up the CO2 at all. Bob
102615. Berényi Péter at 00:15 AM on 2 December 2010
        2nd law of thermodynamics contradicts greenhouse theory
        #220 KR at 02:59 AM on 1 December, 2010 However, when you say that "...Earth is a system very far from thermodynamic equilibrium", I would like to point out that as far as we can tell (again from Trenberth 2009, although I'm sure there are slightly different estimates out there) the balance sheet is currently tipped only about 0.9 W/m^2 from dynamic equilibrium. If we can reduce or prevent further GHG emissions, we can reduce that imbalance, and the resulting shift in global temperatures. Thermodynamic equilibrium and steady state are very different concepts. Earth is not in thermodynamic equilibrium in any sense of the word, because its environment is not in thermal equilibrium. About one part in 184,801 of the skies around it has an effective temperature of 5777 K, while the rest is at 2.725 K. In first, second and third approximation there is only radiative coupling between Earth and its cosmic environment. In spite of the fact the Sun occupies only a tiny portion of the sky, due to the T⁴ dependence of thermal radiation flux, in excess of a hundred million times more radiative energy comes from it than from CMB (Cosmic Microwave Background). What you call dynamic equilibrium has nothing to do with thermal equilibrium proper, when entropy of the system is supposed to be at its maximum. Quite the contrary. The overall entropy content of the climate system (which includes at least the atmosphere and hydrosphere of Earth, probably the biosphere as well) is kept at the smallest possible value by continuously getting rid of the entropy produced inside the system (OLR has a much higher entropy flux than ASR). This low entropy state can only be maintained by working as hard as possible, that is, producing entropy at the highest possible rate (then radiating it away into outer space as soon as possible). This is what MEPP (Maximum Entropy Production Principle) is about. Obviously an energy balance has to hold in the long run and on average, otherwise sooner or later the system would enter some absolutely crazy state (contrary to observations). But this balance is best described by the concept of steady state, not as a dynamic equilibrium, because it's only too easy to mix up the latter one with thermal equilibrium. It is easy to show that whenever the climate system is in a MEP state, increasing the opacity of the atmosphere in thermal IR (that's what so called GHGs do) decreases rate of entropy production if all else is held unchanged. At the same time entropy content of the system goes up. That's what is described as warming, because warmer stuff has higher entropy in general. BTW, if the climate system were in some suboptimal state by having less IR opacity in the atmosphere than required by MEPP, adding GHGs would increase overall entropy production and decrease entropy content, hence temperature. Saying the addition of some more GHG causes warming is equivalent to insist current IR opacity is already at or above the value implied by MEPP. The fictitious value of 0.9 ± 0.15 W/m² TOA energy flux imbalance from Trenberth 2009 has nothing to do with reality. What is actually measured by ERBE and CERES satellites, is 6.4 W/m² (which is obviously wrong beyond repair). Therefore they apply all kinds of adjustments to the measured dataset so as to match computational model projections and this is how they arrive at the value which was assumed to be the correct one from start. The logic behind this exploit surely makes one's head spinning. J. Climate, 2008, 21, 2297–2312. doi: 10.1175/2007JCLI1935.1 The Annual Cycle of the Energy Budget. Part I: Global Mean and Land–Ocean Exchanges. Fasullo, John T., Kevin E. Trenberth J. Climate, 2008, 21, 2313–2325. doi: 10.1175/2007JCLI1936.1 The Annual Cycle of the Energy Budget. Part II: Meridional Structures and Poleward Transports. Fasullo, John T., Kevin E. Trenberth The only measurement having a chance to shed some light on the true value of energy imbalance at TOA is ARGO Ocean Heat Content data, and only after mid 2003, not before (because OHC measuring network before that date was far too sparse, with serious undersampling as a result). An energy imbalance of 0.9 W/m² is equivalent to a heat accumulation rate of 1.45×10²² J/annum. In seven years (between mid 2003 and mid 2010) it would be more than 10×10²² J. The NOAA/NODC figure above shows somewhat less than zero J went into the upper 700 m of oceans, so more than 10²³ J had to go somewhere else. But there is no place on Earth where such a huge quantity could possibly hide, therefore it is not hiding anywhere, but has left the terrestrial climate system by crossing TOA (as outgoing thermal radiation). In other words, there is no energy imbalance whatsoever, Trenberth's speculations are falsified along with the computational climate model calculations they were based on (which means Trenberth's famous "missing heat" is nowhere to be found at the moment, but it used to be in the oceans earlier, unobserved by the much less reliable XBT/MBT system, making steep parts of the NOAA/NODC OHC graph wanting). Present climate is as close to a steady state as it can possibly be. It is as simple as that. And now back to theory. The most lucid point to have is that Earth is not getting any heat from the Sun, just short wave EM radiation. This radiation is turned into heat when and if it is absorbed by either the atmosphere or the surface (accompanied by a huge increase in entropy). Concerning the effect of GHG addition, the "if all else is held unchanged" clause above is an all-important one. Of course there is no one there to hold things unchanged as some more CO₂ is added to the atmosphere, making it more opaque in a restricted thermal IR band. The real climate system has an astronomical number of degrees of freedom (vastly more than any computational climate model can possibly have), so it can adjust itself in any number of ways if a single parameter (like IR opacity in the 14-16 μm band) is changing. If CO₂ addition has decreased entropy production rate initially (that is, if the system was close to a MEP state), it will readjust itself to increase its entropy production rate if possible, but under no circumstances would readjustment decrease entropy production rate further. That is, there is a strong tendency to counteract climatic effects of CO₂, but MEPP would not allow any change which would amplify it. And indeed, that's what is observed. In the 7 years considered atmospheric carbon dioxide content went up from 376 ppmv to 390 ppmv, which is 5.3% of the radiative effect of a CO₂ doubling. Yet, it has induced neither "radiative imbalance" nor "heat accumulation" in the system, as it is indicated by actual measurements (as opposed to computational models).
102616. CBDunkerson at 00:05 AM on 2 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Bob, one thing which this doesn't explain (and I'm not entirely clear on) is why the extra energy in the atmospheric window doesn't result in the stratosphere maintaining the same temperature. That is, even though CO2 is blocking the passage of a band of IR energy the total energy in and out must be equal. So the same amount of energy is passing through the stratosphere (in each direction) with or without the CO2 there. So why is the stratosphere cooler? Because the bandwidth distribution has changed?
102617. Peter Lang at 23:59 PM on 1 December 2010
        Renewable Baseload Energy
        Talk about ideological - what is more ideological than anti-N and pro-renewables at any cost? I can't take much of the pro-renewables at any cost, anti- N ideological stuff when the advocacy is devoid of costs. I've pointed you to a number of links where you can compare costs on a comparable basis. If you are not prepared to try to get your head around this material then there is no point in continuing the discussion. You keep pulling out bits and pieces all of which are not on any sort of comparable basis. Come back with sensible, justifiable costings for a system that can produce the power demanded by modern society, and once you do you will understand why non-hydro renewables cannot do the job. And just before someone jumps in and says we are not concerned about cost I'll just add that renewables cannot do the job at any cost and are unlikely to ever be able to. But don't believe me, read the links I and Quokka hjave proivided today on the previous and this page. Over to you.
102618. oamoe at 23:57 PM on 1 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Regarding the change in spectra from 100 to 1000 ppm, the center bands in the CO2 spectrum appear to be saturated, with all of the change coming in the peripheral bands. If the central bands are saturated, what is going on with the scale on the y axis - shouldn't it drop to zero in the center of the spectrum?
102619. CBDunkerson at 23:46 PM on 1 December 2010
        2nd law of thermodynamics contradicts greenhouse theory
        damorbel #224: "Sunlight travels from a cold region of the atmosphere to a warmer one... indisputable fact."? Just what it says. The stratosphere is between the Sun and the troposphere. The stratosphere is colder than the troposphere. Ergo, for sunlight to reach the troposphere (and us to be able to see it) it passes from a colder area to a warmer one. Also: "The sunlight that passes through the atmosphere is not affected by it." Nonsense. In the same post you went off on an inexplicable tangent about sunlight causing ozone formation. That alone proves that sunlight is affected by the atmosphere. Also: "Oh, and the temperature at the stratopause is not that low, just about freezing, 0C." First, the stratopause is the boundary between the stratosphere and the mesosphere. Second, it is the warmest point throughout the mesosphere and stratosphere. Third, 0C is still significantly colder than the ~15C average surface temperature. Also in #237: "Whatever the configuration of the hot and cold bodies, the cold body will always absorb more photon energy (no. x E) from the hot body than the other way round." True... but here you finally admit that the 'hotter' body is absorbing photon energy from the colder one. Ergo, the hotter body must have more photon energy with the colder body than without it. Take the colder body away and the hotter is emitting the same amount of energy but not receiving any... ergo, it has less energy and is colder than it would have been with the colder body there. In other words, yes more energy flows from the warm surface of the Earth to the cooler sky than vice versa, but the IR photon energy flowing from the greenhouse gases in the atmosphere down to the surface means the surface is warmer than it would be without those gases.
102620. Ogemaniac at 23:07 PM on 1 December 2010
        Renewable Baseload Energy
        Peter: You say: "Try putting properly comparable figures on your assertions (per $/MWh; even better, take it a step further and provide $/MWh of energy that meets our demand for power quality)." You then send me to a link that shows that coal and oil (not natural gas) have externalities of around $.08 or so per kwh, which is much higher than the subsidies renewables receive. And that's not counting the $312 billion in *direct* subsidies they receive every year. http://www.economist.com/blogs/newsbook/2010/11/fossil-fuel_subsidies I am sorry, but $312 billion/year + $.08 kwh is both a ying and a yang.
102621. JMurphy at 23:04 PM on 1 December 2010
        Renewable Baseload Energy
        Peter Lang wrote : "When I see this sort of argument, I believe the people pushing it, and pushing CAGW, are not serious about CAGW. They are more interested in pushing their beliefs." Strange comment which needs some clarification. What do you believe CAGW means ? Who do you believe is "pushing CAGW" ? What "beliefs" do you believe those people are pushing ? Why is your belief better than what you believe other people believe, and why do you think the belief you are pushing is better than what you believe other people are pushing ?
102622. kdkd at 22:37 PM on 1 December 2010
        Renewable Baseload Energy
        I'm unable to take anything Peter Lang says seriously I'm afraid, as the last time he turned up on this site, and was asked perfectly reasonable questions, he asserted that "this discussion is pointless" and disappeared. So I get the strong impression that there's an ideologically driven agenda here which when challenged results in logically flawed asserstions which are not proper arguments. As always I'm happy to be corrected, but am still awaiting an answer to the question that I posed prior to the post at the link above.
102623. Louise at 22:34 PM on 1 December 2010
        Naomi Oreskes' Merchants of Doubt Australian tour
        cgp - You're question 'Are you worried that the current consensus cannot be falsified when we have the logic temperature rising it's global warming, temp cooling its weather' is answered elsewhere on this site - http://www.skepticalscience.com/global-cooling.htm Bottom line is, it's not cooling and there are at least ten different ways that this can be shown. Away from this site, http://www.realclimate.org/index.php/archives/2010/11/so-how-did-that-global-cooling-bet-work-out/ has a pretty good article on global cooling too.
102624. MarkR at 21:56 PM on 1 December 2010
        Stratospheric Cooling and Tropospheric Warming
        (4) reluctant skeptic: it depends on a number of things. Very long term changes can be understood pretty well in terms of things like the carbonate silicate cycle. In summary, 'short term' feedbacks seem to be net positive - if you warm Earth you get some melting ice and more water vapour and more heating etc, although it is diminishing returns so you don't get a runaway effect. But longer term changes can swing us back the other way: more CO2 in the air means it dissolves more quickly in the oceans and silicate rocks weather more quickly at higher temperatures too, so they suck down CO2 as well. As CO2 drops away, the positive feedbacks amplify this cooling: cooler air holds less water vapour and cooling lets ice expand again. It's a very complex picture and it's different at different timescales, but the carbonate-silicate cycle is a great explanation for lots of geological observations so it's a good place to start! (even if it's not particularly relevant on 'short' timescales like the past few hundred thousand years)
102625. Riccardo at 21:50 PM on 1 December 2010
        2nd law of thermodynamics contradicts greenhouse theory
        damorbel #238 any body may behave like a blackbody in a frequency range and not in others. In particular, the earth surface is very near a blackbody in the IR range of interest.
102626. damorbel at 21:40 PM on 1 December 2010
        2nd law of thermodynamics contradicts greenhouse theory
        Re 233 KR you wrote: "Emissivity of the ground is in the range of 0.96 to 0.99, with cloud albedo at 0.5 accounting for a combined emissivity (relative to a blackbody) of ~0.612" I could discuss the ground if you like but just think of the oceans which cover 70% of the planet. The oceans reflect light mostly by specular reflection but they do not reflect very much, that is why they generally look rather dark. Mostly the incoming sunlight energy is absorbed and causes evaporation of water, the heat from the Sun then goes into the atmosphere when condensation (rainfall!) takes place thus there is not much of a 'black body' factor in the transfer of heat from watery surfaces to the atmosphere. Water evaporation from land is also an important mechanism for heat transfer into the atmosphere. Including it as part of radiation from the surface like your truly amazing "Emissivity of the ground is in the range of 0.96 to 0.99" figures would appear to do, is definitely an odd way of calculating heat transfer. Even graphite and charcoal never get near these emissivities!
102627. damorbel at 21:21 PM on 1 December 2010
        2nd law of thermodynamics contradicts greenhouse theory
        Re 235 Tom Dayton you wrote: "Even a simple climate model indicates about a 1°C temperature change for 3.3% change in albedo" That is what is wrong with the climate models, they are based on the assumption that the Earth 'emits like a black body', an assumption I have seen many times. Not only is this assumption never justified it is self evidently incorrect because Earth reflects quite a portion of the incoming solar radiation, a portion that is called the albedo; so Earth can never be considered as 'a black body'! Worse still, this 'back body' assumption makes the planet's equilibrium temperature a function of its albedo which is simply not the case, there is nothing in modern physics that allows for such a conclusion. If you calculate the average temperature of any planet on the assumption that it is a black body then you will definitely get an erroneous temperature, unless of course it really is a black body. In the case of Earth this 'black body' assumption gives the average temperature as 255K when it should be 279K, a temperature that disposes with the GH effect entirely.
102628. damorbel at 21:02 PM on 1 December 2010
        2nd law of thermodynamics contradicts greenhouse theory
        Re 236 Tom Dayton you wrote: "What happens to the photons from sources cooler than the target?" All bodies (that emit and absorb radiation) exchange photons all the time. The photons from a hotter body have more energy E (because E = h x v = Planck's constant times frequency) the cooler body emits lower energy photons because the peak emission frequency is, according to Wien's law, a direct function of temperature. Do not forget that all thermal bodies (those with an identifiable temperature - not monochromatic etc. like a laser) emit a broad spectrum of frequencies according to Planck's law. It is just that the hotter body emits photons with a higher energy and higher number of photons also. Whatever the configuration of the hot and cold bodies, the cold body will always absorb more photon energy (no. x E) from the hot body than the other way round. Betwen the surface the atmosphere and deep space it goes like this: the surface emits photons at 288K, these are absorbed somewhere in the troposphere, primarily by H2O & CO2 at, let us say at an average temperature of 255K. All the time the H2O & CO2 are emitting photons at 255K and absorbing photons from deep space at 2.7K, not very many and with very low energy (E = h x v ), so the balance is by far in favour of the energy going into deep space. If that was all, the H2O & CO2 in the troposphere would cool down PDQ but do not forget that these two gases are kept at the same temperature as the N2 & O2 also present in the atmosphere as well as absorbing photons from the surface. As well as absorbing surface photons and emitting photons to deep space, H2O & CO2 emit and absorb photons to and from each other. The extent to which this happens depends on where they are in the atmosphere; in the lower troposphere they exchange photons with the surface; since the surface and the lower troposphere have only a small difference of temperature the net energy exchange is small, a vast number of photons but, on average, a very small energy difference. Higher up the balance shifts from the surface exchange as the % H2O & CO2 intermediate between the emission/absorption altitude increases from zero. Even higher up in the atmosphere the gas density becomes so low and the chance of a photon being reabsorbed becomes correspondingly low. For thin atmospheres many photons emitted by H2O & CO2 do not get reabsorbed by adjacent H2O & CO2 molecules, some are reabsorbed by the surface but others are absorbed by deep space. Because it is the net transfer of photon energy between objects that determines the energy transfer you should realise that radiative transfer on Earth from the surface into the atmosphere is only about 26W/m^2, small in comparison with the 78W/m^2 put in directly by the Sun the 80 W/m^2 from evaporation and 17W/m^2 by convection (numbers from Trenberth's diagram). This is the heat that is transferred to the H2O & CO2 by O2 & N2 in the upper atmosphere for subsequent radiative transfer into deep space.
102629. swieder at 20:41 PM on 1 December 2010
        Renewable Baseload Energy
        @quokka, #210 That is generally a valid point. For PV, i think one can use existing structures like roofs, so a lack of land or the need for land in that case i dont see. There are large installations as well on land which was of agricultural use before and this is recognized and countered. Also, land used with PV can (and is) be used as pasture for example. Regarding material, i think the cost and the life cycle assesments account for that already - and those numbers look good. For wind, the footprint is quite small, for materials the same argument as for PV holds. Regarding hydro, yes: land requirements are large for dams. CSP requires large amount of land but what kind of damage is exerted in the desert of Nevada or Spain? On the other hand it sounds a bit like pretending: shall we really compare the impact on ecosystems of coal, oil or uranium exploration? The whole point of letting rest the fossile in peace is actually the impact on our ecosystem, right?
102630. quokka at 20:26 PM on 1 December 2010
        Renewable Baseload Energy
        One reason energy density is very significant is the quantity of materials you need per unit of electricity generated. Where materials include concrete, steel, glass, plastic etc etc AND land. There is a very real correlation between environmental damage and quantity of materials. It is also why Moore's law is quite irrelevant - the miniaturization that underlies Moore's law is not pertinent to electricity generation from sources of low energy density. The land requirements of hydro and CSP are very damaging to ecosystems.
102631. swieder at 20:25 PM on 1 December 2010
        Renewable Baseload Energy
        #207 - comment "If world production of modules go from 9 GWp to 18 Gwp, you get 20% lower prices simply due to learning effects in production of this product." I should have been more accurate: it is not the world production, but the accumulated production of the good we talk of. The 9 and 18 were just arbirtrary numbers. Accumulated solar power is around 22 GWp produced until end of 2009 [1] while production rate in 2009 was around 12.3 GWp/year [2]. In that case, you'd get around 20% price decrease in less then 2 years. Found an comprehensive overview on various price experience curves [3]. [1] according to PV Magazine, news on 06. Sep 2010 [2] according to Photon international, April 2010 issue [3] The report on cost development of the european NEEDS project
102632. cgp at 19:57 PM on 1 December 2010
        Climate change from 40 million years ago shows climate sensitivity to CO2
        # 49 .... If you remove all the CO2, the climate will cool as 1/5th of IR absorption by the atmosphere is due to CO2 (that is well measured). That's not just by the absorption spectrum is it? Any account that co2 is 390ppm vs 30000 ppm water? On the topic of paleo-carbon control knobs, the enthusiast scientist Dr Alley has given the fantastic explanation why co2 lagging doesn't in fact disprove causality. The credit card, interest playing the carbon role, with support by debt as temperature. - axiom interest increases debt - observation debt increases lead to interest raised. Thus observation of a lagging event of a causal factor. (that debt is due to banks boosting the economy in a low wage environment is beside the point). Dr Alley has a problem with causality. I wonder if he studied quantum mechanics, that subject causes serious damage to rational minds. That interest rate had to have travelled forward in time like a positron.
102633. swieder at 19:28 PM on 1 December 2010
        Renewable Baseload Energy
        @Peter Lang, #205 "Why would you bet on something that has low energy density (much lower than fossil fuels) and is not viable now and never likely to be? Why not bet on the technology that has 20,000 time higher energy density, is proven, and has been proven for 50 odd years?" Energy density (per kg) does only matter if you want to transport something. It is not something relevant for decentralized, static energy production like what we talk about here. Look in the real world: nature showed us how with a conversion efficiency of only 1-3% (photosynthesis) all the energy wich finally ended up in coal, oil etc and even today in biomass (wood - which you burn), wind, water, sunlight was and is produced. So please dont explain that high energy density is a must for our energy production. It is a must for centralized power generation, that is true - but not for economic power generation per se. I personally think that fossile and even nuclear energy production is extremly inefficient methods compared to renewable - you have to look at the efficiency in terms of usable (output) energy versus used (input) energy, not only at your power plant efficienc versus (e.g.) PV or wind efficiency: lets take coal - your cooking oven needs to boil 1 l of water, ok? Per thermal energy of water (CH2O=4.187 kJ/(kg*K)), you need 0.097 kWh to achieve this. With a high 38% efficiency assumed for conversion of primary energy (coal) to end energy (electricity) and some losses (45% assumed) when actually boiling it, you need 0.46 kWh of primary energy. So finally 79% of your primary energy input is gone somewhere°, only 21% of it is used. This is because all used power plants today are basically a carnot-process, wasting roughly 2/3 of the energy to start with. If you want to achieve this with renewble, the primary energy input is 0.175kWh to get the 0.97 kWh in the water - so with same losses assumed (45%) to actually boil the water, you have used 55% of the primar energy harvested. Its 55% versus 21%. There is no trick in this calculation, it is just looking at the overall cycle. I have not even talked about the 156 g CO2 generated by the coal plant or the effort to actually get it out of the mine or transport it...gas looks a bit better (31% efficiency). For nuclear i have not calculated but the ~2/3 loss of your primary energy loss will be the efficiency killer as well. ° if you want to use the heat from the coal plant in a CHP configuration, the situation for the totally used energy goes up in general, but you can again compare it to a combination of renewable sources producing heat and electricity. And I am not aware that any nuclear CHP plant is operating or even thought of. PS: by the way, the denominator in your term ("density") is important (energy per what exactly?) - i can easily calculate an energy density - lets say - for silicon (in PV) which will blow your mind. But again: it is not relevant, it is just pulling wool over other people's eyes.
        Moderator Response: [Daniel Bailey] Please, everyone: nuclear is off-topic on this thread. If you wish to discuss nuclear, please go to the What-should-we-do-about-climate-change thread I linked above. Thank you!
102634. cgp at 19:20 PM on 1 December 2010
        Naomi Oreskes' Merchants of Doubt Australian tour
        Hi, just registered. I would like to bring the thread back on track with a couple of observations from two separate talks the writer gave on the book which I have not read. She states that a consensus was well established 1980's. OK fine, but what about today? Has nothing changed? Why for instance doe she not put the last decade data in the temperate graph that clearly shows the human signature? Has there not been a bit of action since then? Why does she only refer to sun irradiation when the main contender is clouds moderated by sun's magnetic atmosphere? One question I would ask if I managed to get into the audience is 'Are you worried that the current consensus cannot be falsified when we have the logic temperature rising it's global warming, temp cooling its weather'. Sorry one more and it is a biggie she states that no contrarian paper has been peer reviewed. Holy hell, surely this ends completely any debate, full stop.
        Moderator Response: [Daniel Bailey] Thanks for joining! For questions on consensus, go here. For questions about TSI and cloud effects, go here. For a listing of peer-reviewed papers on climate change, please go here. For other questions, please use the search function in the upper left of every page to search for the most appropriate thread and post it there. Someone will address it there. Thanks, and welcome!
102635. HumanityRules at 18:53 PM on 1 December 2010
        A basic overview of Antarctic ice
        73 muoncounter So you seem to approve of fitting trend lines to 7-8 years of data with obvious examples of inter-annual variability? Just because a trend line fits this short data set doesn't mean it contains any meaning. I'm not quite sure what we are meant to have confidence in? Chen has another analysis from 2009 which sheds more light on how what occured in 2006 is affecting the interpretation of this data set. ftp://ftp.csr.utexas.edu/pub/ggfc/papers/ngeo694.pdf "GRACE supports a flat rejection of the skeptic claim that Antarctica is gaining ice." I think this is a completely separate question and it depends on how GIA (or PGR) is handled. I'd direct you back to the link in #51 where EU scientist lay out why this is still a contentious issue for the mainstream.
102636. swieder at 18:46 PM on 1 December 2010
        Renewable Baseload Energy
        @SNRatio, #178 "So far, it seems to me that renewable technologies are more expensive to implement, but I don't know if the operating costs always have to be that high. I think we need quite a lot of operation data for full-scale systems to make safe judgments." I agree - there is this thing called "learning curve" and "experience curve" which applies to may products in modern (and old) world. Attributed to it is the price experience curve. This is valid for such different things as wind turbines, displays technology, transistors and many more. All of these have generated steady and predictable declines in the "price expereince curve" (PEC) and a "learning factor". The basic outcome for all of this is: with doubled production of a good (like a display, a turbine, or solar installation or other mass products), you get a predictable price decrease of X% - this X depends on the technology you investigate for. For solar modules for example, it is around 20%. Meaning: If world production of modules go from 9 GWp to 18 Gwp, you get 20% lower prices simply due to learning effects in production of this product. I think, renewables as a whole are just at the beginning of this learning curve, so it is to early to judge what the experience factor truly is. For mature technologies like combustion engines, coal plants and such, the factor is much much lower due to the fact they went down all the way of the learning curve already. At a certain point, the curve deflects and gets rather flat. Ultimately, the decline for the renewable cost curves should prove to be quite significant and therefore enable increased and widespread adoption of renewale technology for a variety of applications.
102637. Peter Lang at 18:40 PM on 1 December 2010
        Renewable Baseload Energy
        KR, Here are the cost estimates from peer reviewed litterature: http://bravenewclimate.com/2010/11/30/the-arithmetic-adds-up-to-nuclear/
        Moderator Response: [Daniel Bailey] Please, everyone: nuclear is off-topic on this thread. If you wish to discuss nuclear, please go to the What-should-we-do-about-climate-change thread. Thank you!
102638. Peter Lang at 18:38 PM on 1 December 2010
        Renewable Baseload Energy
        actually thoughtfull, More's Law does not apply. These are very high cost systems with long life times and so turn over and learning takes decades. The costs you quoted for energy for wind and unprintable are not comparable. Not printable is baseload and dispatchable (meaning it can be called up any time as needed by the energy market operator). That is not the case for wind. Here is a rough comparison on an equal basis: http://bravenewclimate.com/2010/04/05/pumped-hydro-system-cost/#comment-86108 The "Zero Carbon Australia - Stationary Energy Plan - Critique" provides a more thorough comparison. Grid storage is not unexplored. It is simply totally un economic. The link above covers this too. Placing a link between unprintable electricity generation technology and weapons is a furphy. Sorry. Waste of time even discussing it. Go to BraveNewClimate if you want to discuss that. "I think the short term answer is you have to do both (ANYTHING to get us off of coal!) - but this rational person is putting his long terms bets on technology that improves over time." Why would you bet on something that has low energy density (much lower than fossil fuels) and is not viable now and never likely to be? Why not bet on the technology that has 20,000 time higher energy density, is proven, and has been proven for 50 odd years? Why delay any longer. Saying "I am prepared to accept unprintable will have a role but I want to put my efforts into renewables" is in reality just a way to continue to block unprintable. This is what has been happening for the past 40 years. When I see this sort of argument, I believe the people pushing it, and pushing CAGW, are not serious about CAGW. They are more interested in pushing their beliefs. You talk about doubling. Have you thought of applying the same logic to unprintable. For 40 years development has been blocked in the western democracies. We are still using the technology that uses only 1% of the available energy in the fuel. Consider why you really prefer renewables. Is it rational or emotional? I know the answer, but can you recognise it?
        Moderator Response: [Daniel Bailey] For posterity, please define what it is you mean by CAGW. Thanks!
102639. adelady at 18:38 PM on 1 December 2010
        Climate's changed before
        Try this page . Some good stuff to start you off and some links that might help.
        Moderator Response: Indeed, that is probably the best place for any further discussion of positive feedbacks and "runaway" warming.
102640. Daniel Bailey at 18:35 PM on 1 December 2010
        Climate's changed before
        Re: reluctant skeptic (141) I've posted the answers to your questions over here where I first saw them. To make things easier, when you have questions, please use the search feature in the upper left portion of any page here. This will give you a narrowed choice of where to post your question. Just pick the one that seems most appropriate & post it there. If multiple questions, follow this procedure for each. It'll get easier the more you do it. The Yooper
102641. Bob Guercio at 18:27 PM on 1 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Interestingly, the article by the German scientist is what drove me crazy. He correctly explains why cooling of the stratosphere takes place and explains that heat is trapped in the troposphere. This is correct but suppose the CO2 level were to miraculously stabilize at 390 ppm. The earth would continue to heat up until the IR leaving the troposphere into the stratosphere was the same as before all this started. This has to be because of conservation of energy. The total solar energy coming into the troposphere from the sun must equal the total IR energy leaving the troposphere in the steady state. I asked the question "Why wouldn't the temperature of the stratosphere go back to what it was originally since the same amount of IR energy is leaving. The German scientist doesn't address this. The reason that it doesn't go back to the original temperature is that there is now more IR energy in the atmospheric window and less in the absorption band and only the energy in the absorption band can can react with the CO2 in the stratosphere and the absorption of IR by CO2 is what heats up the stratosphere. Less absorption means a lower temperature permanently. By the way, I wasn't concerned about the cooling due to thinning of the ozone layer because that is easy to understand. It's much more difficult to understand how CO2 causes cooling of the stratosphere. Is this making sense? I'm already thinking about revising this post into two very distinct parts. First, the steady state solution which my post addresses and second, getting to that steady state solution which I'm talking about here. Bob
102642. Daniel Bailey at 18:27 PM on 1 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Re: reluctant skeptic (4)

        "Do we know what caused the reversal in past warm periods in the Earth's history? What made it get cool again?"

        Off-topic, but deserving of an answer. Just ran across this brief, but apt, summary from Bob (Sphaerica) over on RC. Check it out. As far as the runaway effect, see here. As far as heading back to another ice age:

        "Our research shows why atmospheric CO2 will not return to pre-industrial levels after we stop burning fossil fuels. It shows that it if we use up all known fossil fuels it doesn't matter at what rate we burn them. The result would be the same if we burned them at present rates or at more moderate rates; we would still get the same eventual ice-age-prevention result. Ice ages occur around every 100,000 years as the pattern of Earth's orbit alters over time. Changes in the way the sun strikes the Earth allows for the growth of ice caps, plunging the Earth into an ice age. But it is not only variations in received sunlight that determine the descent into an ice age; levels of atmospheric CO2 are also important. Humanity has to date burnt about 300 Gt C of fossil fuels. This work suggests that even if only 1000 Gt C (gigatonnes of carbon) are eventually burnt (out of total reserves of about 4000 Gt C) then it is likely that the next ice age will be skipped. Burning all recoverable fossil fuels could lead to avoidance of the next five ice ages."

        Source here [Sorry, Bob, for going so far OT] The Yooper
102643. Michele at 18:23 PM on 1 December 2010
        Stratospheric Cooling and Tropospheric Warming
        Bob Thermal energy flows are determined by temperature gradients. In the atmosphere there are two sinks that collect the aforesaid flows to radiate them to space: the tropopause and the mesopause. If the atmosphere has to dispose of more energy it will have to increase the temperature of its sinks. Then no cooling of the stratosphere but warming of tropopause/mesopause and drop of the lapses rates in the whole atmosphere.
102644. HumanityRules at 18:13 PM on 1 December 2010
        A basic overview of Antarctic ice
        72 Albatross You still prefer to ignore the V09 data and snipe instead?
102645. KR at 17:29 PM on 1 December 2010
        Renewable Baseload Energy
        actually thoughtfull - Can you repost that link to the cost estimates?
102646. actually thoughtful at 17:18 PM on 1 December 2010
        Renewable Baseload Energy
        Peter Lang: "One problem is that many people have very little understanding of economics, costs, financing. It is impossible to have a rational discussion with people who want to talk about their beliefs and hopes but cannot or will not consider the cost of what they advocate." This is very true. But either side can make this case - I would argue the renewable folks have the better case. I presented DOE/EIA data that showed wind, coal and gas all between US$53 and US$55/unit, the unmentionable at $60/unit and solar PV at $100/unit (best current case). CSP was not in that particular analysis, but usually weighs in roughly equal to wind. We also have a "Moore's law" type phenomena where the more PV and CSP you do, the cheaper it gets (there will be limits to this). We also have the fact that grid storage remains unexplored. Pilot projects have already been successful (as opposed to "clean coal" - which doesn't exist anywhere, for any amount of money, on planet earth). Do you bet on the known technology with huge negatives (as we spend the weekend contemplating a rehash of the Korean war, only this time with nuclear weapons)? Or do we look ahead to different, better technology? I think the short term answer is you have to do both (ANYTHING to get us off of coal!) - but this rational person is putting his long terms bets on technology that improves over time. Or maybe you would be willing to give me a penny today, and then double it tomorrow, repeat each day for one year? How about for one month? (a month would only be 5.3 MILLION dollars!). The power of compound efficiency increases/cost reductions swings this one way in favor of renewables. And the real world experience of PV, CSP and wind prove this is no pie-in-the-sky, but our best possible future (OK, with a helping of the unmentionable power as well).
102647. Bob Guercio at 17:02 PM on 1 December 2010
        Stratospheric Cooling and Tropospheric Warming
        It's late at night and so much has been mentioned above but other things do cause cooling. The ozone layer has thinned out and ozone absorbs incoming solar energy which causes the stratosphere to warm up. As I understand it, ozone is responsible for the stratosphere and for the temperature inversion of the stratosphere. Since there is less ozone, less incoming solar radiation is being absorbed. Less solar energy being absorbed means that it is cooler. As I understand Venus, the runaway greenhouse effect on Venus was caused by evaporation of water. The sun then broke the water molecules apart and the hydrogen escaped into space. So the water is gone forever. I believe that CO2 was a feedback as it has been on earth for the past million or so years. Of course the contrarians use this to imply that CO2 is not a problem. This cannot happen on earth because earth's atmosphere is sufficiently cool such that water vapor condenses and rains back to earth. I'm saying a lot here but I must stress that I am very much an amateur at this and may not be totally correct. I'm also a bit tired and may not be writing very clearly. Bob
102648. Peter Lang at 16:47 PM on 1 December 2010
        Renewable Baseload Energy
        Bern, If we ignore cost, I guess anything is "possible". But I doubt you could get more than about 1 to 5% firm power if you had wind farms spread all over Australia. The problem is that the wind just doesn't blow much in the places where wind farms are not being built. Furthermore, the cot of transmission alone would be many time higher than the cost of simply using the unprintable technology. It is just plain silly. Regarding cost benefit of emissions reductions, the externality costs per MWh are included in the ExternE link I provided up thread. Numbers like $1,240 trillion are meaningless and probably come from a 'biased' researcher anyway. I wonder if this estimate of cost benefit may not be more realistic: http://johnhumphreys.com.au/2010/06/05/benefit-cost-analysis-for-the-ets/ What it really boils down to is that we should aim to cut emissions in the least cost way. If we keep hammering renewables and being anti-(unprintable), the vast majority of middle people are going to question the veracity of everything being advocated. Being economically irrational about how to cut emissions leads to questions about how rational and objective is the rest of the stuff being advocated by the groups with the same leanings. One doubt leads to another.
102649. Albatross at 16:30 PM on 1 December 2010
        A basic overview of Antarctic ice
        Daniel @75, To take your metaphor further, I heard someone the other day say that "skeptics" are now scraping the rust off the bottom of the barrel.
102650. Daniel Bailey at 16:18 PM on 1 December 2010
        A basic overview of Antarctic ice
        Thanks, Albatross! BTW, it appears the level of replies to a 'basic overview' have gotten pretty in-depth. It seems da bottom of da barrel is now being scraped, eh? (yes, that's UP humor) The Yooper

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