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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 101701 to 101750:

  1. A Cloudy Outlook for Low Climate Sensitivity
    muoncounter #105 - by "current pace" I was referring to an accelerating, not linear increase. For example see the upper IPCC emissions scenarios, which are what we're currently on pace with.
  2. Steven Sullivan at 04:16 AM on 9 December 2010
    Phil Jones says no global warming since 1995
    John, Tamino's 'How Long' post seems to have vaporized. But he has another, more recent, one that treats the Phil Jones quote http://tamino.wordpress.com/2010/11/11/hey-david-whitehouse-why-is-the-sky-green/
  3. Stratospheric Cooling and Tropospheric Warming
    Tom Curtis at 02:05 "Convection doesn't work in the stratosphere because the temperature increases with altitude in the Stratosphere, not because of the low density." As i understand it, convection stops working in the upper troposphere, because radiative transfer moves energy to quickly, preventing a build up/heating of a layer above that above it, the inversion between the troposphere and the stratosphere would prevent convection. But it is the result of the opacity reaching a level where radiation is the dominant means of energy transport... and the opacity is the result of the decreasing pressure. obviously higher up in the stratosphere convection once again plays a role, from the O3 absorption. Interesting points. Particularly about number two.
  4. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    Spiff... I think Alley's brilliance is as a teacher. You have to know he's used exactly that same demonstration ("my bald spot") with 100's if not 1000's of the students he works with. Even the wording he uses is wonderful. "Your brightness is the sun..." Makes listeners feel good about themselves. You have to remember Rohrabacher is not the audience when Alley is speaking to him. He is merely the antagonist in the forum. What is important is that people hear Alley teach the antagonist the error in his thinking. Therefore, it's not Alley's job to convert Rohrabacher, it's his job to teach the broader audience by politely responding to Rohrabacher's misinterpretations. I try to use exactly this thinking when I engage climate change deniers on various forums. I try to be polite. (I really do try!) I try not to make it a personal goal to convert the person I'm talking to. But I try, to the best of my abilities, use that denier as a way to teach the broader reading audience what I've learned about the science of climate change. Science that I have primarily learned here at SkS.
  5. Stratospheric Cooling and Tropospheric Warming
    VTG @185, from trial and error, I have figured out that it only adjusts the ground temperature. It uses several standard temperature profiles, which you choose by selecting "tropical" etc. It doesn't calculate the temperature at all. Rather, it determines the radiation out given a specific temperature profile and atmospheric composition. If you read the paperwork, you will see that the version available at David Archer's site is one from the early 1990's. I don't know the capabilities of more recent models. If you want to calculate equilibrium temperatures, you should probably use the NCAR model at the same site. I have not played with it very much, so I cannot advise you except for two caveats: it also is an obsolete model, and it does not handle cloud albedo well, giving non-physical results for significant change in cloud cover. Regarding convection, as convection operates in the mesosphere, presumably it would also operate in the stratosphere without the inversion. You may find these lecture notes a usefull summary of basic facts about the upper levels of the atmosphere.
  6. Renewable Baseload Energy
    Quokka, this source from Nebraska (the first hit on google) says 14% of electricity in houses is used for hot water. Solar hot water heaters are currently installed in many places. They are usable in all locations in Australia and most of the USA. That would greatly exceed the 3% you want in post 381. China is reported to be installing a lot of solar hot water. Where I live (Florida)solar pool heaters are the most cost effective method, and save even more energy. Your absolute arguments fall flat. A combination of methods will always outperform a single method.
  7. The Scientific Guide to Global Warming Skepticism
    I like the fact that it has lots of graphics.
  8. Stratospheric Cooling and Tropospheric Warming
    Tom @183 On Modtran, that's what I assumed - I tried adjusting the ground temperature in exactly the way you suggest, but it doesn't affect the atmospheric profile. If not by thermal equilibrium, how does it calculate the temperature gradient through the atmosphere and why doesn't CO2 concentration change the temperature profile at all? On radiative vs convective heat transfer - I'd thought about the inversion limiting convection as well but I'd also assumed that the reduction in density would be sufficient to significantly reduce heat transfer by turbulent mixing. Thank you for your time btw, I've learned a lot. Now, those pics, the red line is effectively the total stratospheric emission I think: 20km altitude, looking up, 100ppm CO2, total emission 6.6 W/m2 And again with 1000ppm, total emission 11.0 W/m2 You can clearly see the increase in stratospheric emissions as CO2 rises. Ergo in equilibrium you'd expect T to decrease.
  9. The Scientific Guide to Global Warming Skepticism
    This is a great summary and presentation of the data. You have done a terrific job of putting it all together. I like the clean look and easy to read summaries.
  10. Stratospheric Cooling and Tropospheric Warming
    VeryTallGuy @181, that is the first explanation in a nutshell, except ... My quibble is with (2). Convection doesn't work in the stratosphere because the temperature increases with altitude in the Stratosphere, not because of the low density. Also, Bob's second explanation is also a significant, if possibly transient effect.
  11. How Jo Nova doesn't get the tropospheric hot spot
    Gee, I think I understand how Jo Nova got it so wrong. Let's see... satellites have trouble reflecting what the models predict. So the sat data must be wrong. Weather ballons are wrong too. But the wind, steady reliable, proves the models supporting AGW are right. Furthermore, when the sat and ballons don't support the models, they also don't detract from AGW theory. But when ANY data is ...what was the term? "adjusted for" well, then it does support the models and hence support the theory of AGW. Yep, I've got it. How could Jo Nova get it so wrong?
  12. Stratospheric Cooling and Tropospheric Warming
    VeryTallGuy @179, Modtran is a radiative transfer model only. That means it calculates the emission and transmission for various atmospheric conditions, but does not adjust those conditions to establish equilibrium. In the version at David Archer's site, you can make a partial equilibrium adjustment for outgoing radiation by adjusting the ground temperature offset until the Iout matches the original value. However, it only adjusts ground temperature so it is not entirely accurate, and cannot (by that means) adjust for equilibrium in the stratosphere.
  13. Spaceman Spiff at 01:49 AM on 9 December 2010
    How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    Many kudos go to Alley for trying, but I find the piece to be depressing. Rohrabacher gets to spout off tired disinformation and falsehoods as facts that Alley needs to answer for (while constantly admitting he himself knows nothing about which he speaks!). Pat Michaels of the Cato institute gets to serve as an "equal" counterweight to Alley, as if....OMG.
  14. Arkadiusz Semczyszak at 01:41 AM on 9 December 2010
    A Cloudy Outlook for Low Climate Sensitivity
    Under are comments authors to this paper: Boyce et al., 2010.: “But their numbers have dwindled since the dawn of the 20th century, with unknown consequences for ocean ecosystems and the planet's carbon cycle., … the global population of phytoplankton has fallen about 40 percent since 1950., That translates to an annual drop of about 1 percent of the average plankton population between 1899 and 2008., It's very disturbing to think about the potential implications of a century-long decline of the base of the food chain ..., They include disruption to the marine food web and effects on the world's carbon cycle., Phytoplankton productivity is the base of the food web, and all life in the sea depends on it., In addition to consuming CO2, phytoplankton can influence how much heat is absorbed by the world's oceans, and some species emit sulfate molecules that promote cloud formation.
  15. The Scientific Guide to Global Warming Skepticism
    @ Albatross: I have an iphone 3Gs and it comes through fine as PDF via the Safari viewer, not sure about 3G, but most people should be able to see it without problem..
  16. Stratospheric Cooling and Tropospheric Warming
    Bob @180 Yes, I think that's more accurate. Tom @ 180 has put forward what seems to me like a pretty solid case that you need an external heat source (ie UV absorption) to effect cooling with higher CO2.
  17. Stratospheric Cooling and Tropospheric Warming
    Tom Curtis Ah, yes, I realise now that the total power output of the CO2 is limited by it's temperature ie it can't emit more than the equivalent blackbody in its emission bands. So your argument goes that unless there is another factor heating the stratosphere, to raise the CO2 temperature, then CO2 will actually absorb more CO2 from the troposphere than it will emit. In which case, how about this for a really simple explanation: 1) The stratosphere is heated by UV absorption in the ozone layer. 2) Due to low density, radiative heat transfer rather than convective heat transfer dominates. 3) At a given temperature, emissivity of the stratosphere increases as CO2 concentration increases, and at given CO2 conc, total IR emission from the stratosphere increases with temperature. 4) Therefore the temperature must fall to compensate if CO2 rises to keep the overall heat balance satisfied. The issue of the spectrum of IR coming up from the troposphere is then pretty much irrelevant I think?
  18. The Scientific Guide to Global Warming Skepticism
    This guide is simply superlative. Excellent work John & contributors!
  19. Stratospheric Cooling and Tropospheric Warming
    Very Tall Guy 179 Most of your comments are about my writing and I'm going to digest them and change my writeup if necessary. Regarding this comment: "Energy also causes CO2 molecules to vibrate but although this vibration is related to the energy content of CO2, it is not related to the temperature of the gaseous mixture." I think it would have been more accurate to say ""Energy also causes CO2 molecules to vibrate but although this vibration is related to the energy content of CO2, the temperature is not a function of this vibrational energy. The temperature is only a function of the translational K.E." Does this take care of your issue? Bob
  20. Human CO2 is a tiny % of CO2 emissions
    Yeah, most people here know the glass greenhouse analogy isn't great. But it actually works in this case. To answer your question, kdfv, if you insist on the 10m-thick slabs of glass analogy, think of CO2 as the thin line of caulk that seals up the cracks between those slabs. :-)
  21. Human CO2 is a tiny % of CO2 emissions
    Re: kdfv (79) Greenhouses warm by preventing convection (glass barrier). CO2 and the other non-condensable GHG's work by slowing the loss of radiated energy at the top of the atmosphere (TOA) through back-radiation which warms the lower layers of the atmosphere nearer to the ground and cools the mid-to upper layers of the atmosphere, like the stratosphere and the mesosphere. Hope that helps. The Yooper
  22. Stratospheric Cooling and Tropospheric Warming
    OK, I think I've got a good way to show this, although I've also found some more of my own limitations. I've had a play with the MODTRAN model interface available online: http://geoflop.uchicago.edu/forecast/docs/Projects/modtran.html and tried the following. I used the defaults (tropical, no clouds, zero ground offset temperature. I ran the model with 100ppm CO2, altitude 20km (ie at the tropopause), looking UP (ie at stratospheric emissions coming back) then again with 1000ppm. The results are striking. The increase in emissivity is clearly visible, and total IR from the stratosphere increases from 6.6W/m2 to 11.0W/m2. What I don't understand is that the model produces the same temperature profile at both concs, but this clearly shows that for increased CO2 and constant temperature, IR emission increases, ergo in order to maintain heat balance you'd expect the temperature to reduce. Someone who understands MODTRAN better can probably get the temperature profile to work properly too. Bob - this sort of graphical output, once correct, could be used to very effectively demonstrate the effect of CO2 in the stratosphere, I think. Apologies, my html isn't up to pasting the graphics straight in here.
    Moderator Response: [Daniel Bailey] 1. First type this symbol: < 2. Next, type: img width="500" src="http://image_url/" 3. Replace the URL in Double Quotes "" with the actual URL intended 4. A common error is to have an extra / at the end of the URL; this can be avoided by using the preview function. Should work for you now
  23. Water vapor is the most powerful greenhouse gas
    A few thoughts on the above post... A comparison is made stating that CO2 is an external forcing and water vapour is a result of temperature. This is is misleading, since CO2 levels in the atmosphere can be affected by temperature (for example oceans) while water vapour is added to the atmosphere by power plants and other industry. Therefore are they actually similar in the source for both gases - both affected by temparature and man made sources. The overall point of the article to state that water vapour warming will amplify CO2 warming is misleading, since there is nothing special about the CO2 warming. A natural sun-inducing warming would have similar effects on water vapour. So it is dangerous to state without qualification that 'Water vapour is also the dominant positive feedback in our climate system and amplifies any warming caused by changes in atmospheric CO2. This positive feedback is why climate is so sensitive to CO2 warming.' It could just as easily read 'This postive feedback is why climate is so sensitive to sun warming'. With this in mind, it leads me to ask why such postive feedbacks inherent in the atmosphere have not lead to runway global warming in the past from any naturally induced changes. The reference to Kiehl 1997 shows the clouds also reflect some sunlight back into space (diagram on page 10). Why is this negative feedback not discussed?
    Moderator Response: I fixed your extraneous line breaks. Please use the Preview button before using the Submit button. Clouds are not water vapor; they are condensed water. This post is about water vapor. See the post Positive feedback means runaway warming.
  24. Human CO2 is a tiny % of CO2 emissions
    If the atmospheric water vapour is equal to 10m spread around the world and co2 is equal to 6mm how does the temperature in a greenhouse alter when 10m of glass is increased by 6mm?
  25. Stratospheric Cooling and Tropospheric Warming
    VeryTallGuy @177, I have thought something similar in the past. Your suggestion is not correct, though, because absorptivity increases with emissivity, so that if you double stratospheric CO2, you double the amount of IR from tropospheric CO2 absorbed. You also double the the amount emitted. Obviously, if the stratospheric CO2 is warmer than the tropospheric, doubling both absorption and emmission will result in a larger increase of emission, thus cooling the stratospheric CO2. If the stratospheric CO2 is cooler, doubling both will result in a greater increase in absorption, thus cooling the stratospheric CO2. In the respective cases, the CO2 was warming (cooling) the stratosphere already, and just does so at an increased rate.
  26. The Scientific Guide to Global Warming Skepticism
    [standing ovation for John's work] Already blogged on my site: Doc alert: The Scientific Guide to Global Warming Skepticism
    Response: Thanks Lou, the post is much appreciated (but for the record, I am definitely defatigable).
  27. Stratospheric Cooling and Tropospheric Warming
    Bob @173, you asked for nit-picking so here goes. "The former dominates" Are you sure - I'd like to see a figure put on this to judge it personally. "Energy also causes CO2 molecules to vibrate but although this vibration is related to the energy content of CO2, it is not related to the temperature of the gaseous mixture." If (big if) I have understood correctly, then this isn't quite right. As temperature rises, a larger proportion of CO2 molecules will enter the higher vibrational states and preferentially emit IR in those frequencies. And this is the mechanism by which stratospheric cooling happens - conversion of thermal energy to IR by CO2. So whilst temperature does not measure vibrational energy, increased temperature does cause more CO2 molecules to enter excited states and hence emit IR. (I think)(Tom makes a similar point @176) "IR radiation contains energy and in the absence of matter, this radiation will continue to travel indefinitely. In this situation, there is no temperature because there is no matter." I think this is just confusing - all it amounts to is saying that vacuum has no temperature, and light can travel through it. Can you just cut this para? "These molecules will then collide with other molecules of either N2 or CO2 and some of the K.E. of these particles will be transferred to the CO2 resulting in excited CO2 molecules and a lowered stratospheric temperature. All entities, including atoms and molecules, prefer the unexcited state to the excite state. Therefore, these excited CO2 molecules will emit IR radiation which, in the rarefied stratosphere, will simply be radiated out of the stratosphere. The net result is a lower stratospheric temperature. This does not happen in the troposphere because, due to higher pressures and shorter distances between particles, any emitted radiation gets absorbed by another nearby CO2 molecule." A suggestion to simplify: "Due to the lower density of the stratosphere, IR is less likely to be reabsorbed, and more likely to escape either to space or back to the troposphere. With increased CO2 concentration, IR emission increases in the part of the spectrum where CO2 dominates. Thermal emissions in the rest of the spectrum must reduce to maintain overall equilibrium, which results in a lower temperature to maintain the heat balance." Tom Curtis @176 "where it not for Ozone being a net absorber of energy in the stratosphere, CO2 would not be a net emitter of energy in the stratosphere. And it is only by being a net emitter that CO2 can cool." I think this may be incorrect. I think that CO2 will increase the emissivity of the stratosphere regardless of ozone and therefore decrease the temperature. However, without Ozone, the temperature of the stratosphere would be much lower, as the UV energy absorbed by Ozone would then be transmitted. The relative effect of extra CO2 would, though, I think reduce the temperature still further. And I'd just like to emphasise I'm no expert in this and could be very much mistaken in my analysis. Interesting to try and understand though.
  28. The Scientific Guide to Global Warming Skepticism
    Brilliant!
  29. We're heading into an ice age
    NQoA wrote: "if accumulated CO2 is causing the globe to warm, then - by the AWG logic - 2008 through 2010 would be below 2007." That's not any 'AGW logic' I've ever heard of. First, sea ice extent is a measure of ice area and how spread out the ice is. The 2007 value was noted at the time to have been in part caused by wind conditions causing the ice to mass up in a small area (which 'skeptics' took as an excuse to ignore it). Now we've had three subsequent years where we haven't seen winds pack the ice into such a small area but the extent has been nearly as low in two of them, because there is now less ice... as we can see from looking at ice volume values, which have continued to drop each year since 2007. Second, there is something called weather which can cause large fluctuations in all kinds of climate readings. The Arctic winds contributing to the low extent in 2007 are one example. In this case the volume (aka 'actual amount') of Arctic sea ice has declined each of the past few years... but if it were to tick up for a few years that wouldn't be contrary to AGW in any way. Just expected natural variation.
  30. The human fingerprint in the seasons
    Norman, as I said somewhere further up in this thread... it is true that various climate feedbacks would take place regardless of what the forcing was. However, it is not true that the feedbacks would be exactly the same. For instance, your claims about water vapor and polar albedo (aka Arctic amplification) feedbacks are demonstrably incorrect. When atmospheric CO2 levels increase they do so globally. The CO2 level goes up for the entire planet and thus the rate of infrared radiation escape goes down. Further, this is a year round phenomenon... the CO2 level only fluctuates slightly during the year, much less than the cumulative increase we have observed (indeed, the annual rate of increase is now about equal in magnitude to the annual fluctuation). As such it causes increased water vapor and increased surface warming worldwide and year round... obviously with large fluctuations for weather events. A solar forcing on the other hand would be geographically and seasonally localized. If it were exactly equal in total magnitude to a CO2 forcing most of that energy would be located in the tropics and during Summer. Thus, while Arctic amplification would still occur it would be much less pronounced because a much smaller proportion of the forcing is at work in the Arctic. Ditto water vapor. It would increase more in the tropics, but less for the rest of the world... resulting in an even more pronounced tropical warming signal over that of the Arctic. Likewise we wouldn't see the accelerated Winter warming that we have with CO2 because a solar forcing would be concentrated in the Summer months. Feedbacks can only respond to forcings when and where they occur. This is inescapable. Thus, you can't have a strong Winter feedback from a Summer forcing... nor a strong Arctic feedback from a tropical forcing.
  31. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    jg - that is a superb piece of work, it's bookmarked for future use! I saw the Alley testimony a few weeks ago, and was disturbed by the dreadful way the Republican ignored his answers and kept repeating the most tired old talking points. I agree with archiesteel that Alley should have straightforwardly called out the Mars canard, but I guess he's caught in a hard place where he has to be polite and reasonable with his answers, yet the questioner does not have to be polite (and ignored/spoke over the answers when the got near being utterly inconvenient truths). But the more opportunity that Richard Alley gets to communicate, then the better for all of us, he is fantastic at getting the science across. Alley's CO2 control knob AGU talk should be standard learning material.
  32. The Scientific Guide to Global Warming Skepticism
    Thunderbirds Are Go Push it out there people. G
  33. The Scientific Guide to Global Warming Skepticism
    Absolutely fantastic. Certainly a lot of work but absolutely fantastic. Bob
    Response: Bob, if we do an extended version, we will of course have to explain why greenhouse warming causes the stratosphere to cool. Fortunately you've softened that subject up for us :-)
  34. The human fingerprint in the seasons
    #146 Albatross, "That all said, I have no idea what your speaking to polar amplification of the Arctic has to do with the original post..." The conclusion of the original 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. All these pieces of evidence paint a consistent picture - greenhouse gases, not the sun, are driving global warming." The article on polar amplification suggests that warm poles relative to tropics does not appear related to either GHG or solar forcing. It is a unique phenomena based upon another climate factor.
  35. Eric (skeptic) at 21:52 PM on 8 December 2010
    It's cosmic rays
    #25 muoncounter, thanks for transferring my comment to a more appropriate thread. As I tried to explain in the other thread, I am not "chasing" anything, only mentioning a few of the causes of variations in sensitivity that are not in any paleo studies or current era models. Dana shows the non-match to 30 years of temperature in his threads and John shows recent non-match above as well. So the CO2 warming theory holds well for 30 years of precise GCR data and warming data. GCR is a much more variable effect both with clouds as above, and SSW http://www.appmath.columbia.edu/ssws/index.php and other effects. Those effects come and go and may balance out over time. They won't explain any inexorable monotonic warming or cooling because of their measured variability and because their effects are nonlinear and indirect through cloud and weather pattern changes. Events like SSW are modulated by solar activity but celestial in origin so their source is unpredictable but their intensity will be more or less diminished by higher solar activity. The most interesting aspect is the effect on climate sensitivity, not direct warming or cooling. A blocking event such as created by SSW or by other mechanisms will tend to diminish the water vapor feedback part of sensitivity. Another aligned effect is what Mizimi mentions in #10 above, that the water vapor feedback is diminished by CGR cloud formation. It is not an energy effect as correctly pointed out in #12, but it is an important change in sensitivity. A long term change in solar activity and thus GCR flux is a very important consideration in potential paleo and model analysis. Part of the higher sensitivity to CO2 warming measured in the late 20th century may be due to solar activity which diminished both the intensity of SSW events and the low clouds from GCR. Likewise part of the recent decrease in sensitivity may be be explained with solar activity decreases. This last paragraph is speculative, and I welcome critiques and counter evidence.
  36. We're heading into an ice age
    NQoA @162, it is very easy to look up Doran's paper and see that it was 75 of 77 climatologists actively publishing in climatology that answered yes. So that would be 97.4% of that restricted sample. Or are you, perhaps trying to suggest it was only 75 out of the surveyed climatolotists that answered yes? That is certainly what you asserted, but it is false. In fact, of around 157 climatologists surveyed, around 138, or 88% answered yes to that question. Further, 2580 of all respondants (82%) answered yes to question 2. Even if we inflate the figures from the Oregon petition to allow for the effect of responce rates, we still have 97% of scientist who actually know the science of climate change support the basic veracity of the IPCC reports, while apparently, around 0.3% are very ill informed.
  37. The Scientific Guide to Global Warming Skepticism
    A really clear document. I assumne there's no restrictions ( apart from correctly attributing the material) if I print off and give away a few copies
    Response: The Guide has a Creative Commons licence (see the second page of the PDF) so you're welcome to copy the material and distribute.
  38. It's the sun
    Norman @746, you ought to read your sources more carefully. Specifically, from your link above,
    "If you look at the total atmospheric column, from your head on up to the top of the atmosphere, this solar proton event depleted less than one percent of the total ozone in the Northern Hemisphere."
    A 1% reduction of NH ozone (less from the SH) would represent at most a 1% reduction of incoming UV energy, and a 0.25% reduction in temperature. To put that into perspective, chlorofluorocarbons reduced stratospheric ozone by about 30%, an effect which contributes around 30% of the observed cooling of the stratosphere. As the event causing this reduction was episodic (the one observed being the third largest in 30 years) and as the Ozone recovers between episodes, it is doubtfull that such events would compensate for the warming effect in the stratosphere of increased insolation. They certainly would not reverse that effect and give as large a cooling as has been observed.
  39. The human fingerprint in the seasons
    TOP, You hit my nonsense meter with this one, "...because the ocean re-radiates almost nil energy via radiation." Wrong. Please look up the definition of black body and Stefan-Boltzmann. Sea water is a reasonably good approximation of a black body; therefore it radiates energy quite well.
  40. We're heading into an ice age
    NQoA Do you mean that you think that global warming means that every year should show a progressive increase or decrease in each indicator? And that any indicator not showing such a response in any year shows that the globe is not warming?
  41. Renewable Baseload Energy
    380 swieder Load following or spinning reserve capabilities of nuclear do not seem to attract a lot of public attention. Most likely because it's not an issue in many grids where nuclear is 20%-30% or less. As I am not a nuclear engineer, I can only go on what I read from credible sources. It seems to me that if there is an issue with material fatigue or deformation, it's severity or lack of severity is likely to be dependent on specific reactor designs. There is continuous research into the materials science of the hostile environment of reactor cores so I would be a bit surprised if this problem, if it really exists, has not been solved or cannot be solved. I note that Areva state that their current reactor designs load follow at constant temperature which is important not only to the core, but piping, heat exchangers, turbines and such like. Can Nuclear Power Be Flexible? discusses some of the engineering and economic issues. I think this could be an important issue in the future in the context of grid integration with wind. You may be able to get a more substantive answer by posting a question on bravenewclimate.com or a couple of the other nuclear blogs. I quite agree that external costs should be factored in, and also agree that CCS is probably a bit of a dud. Estimates of the external costs of various generation technologies including nuclear are provided here: EU External Costs for Electricity and Transport
  42. Renewable Baseload Energy
    379 Archiesteel 1. I posted both IEA and DOE/EIA estimates of LCOE for nuclear which are at least comparable to and probably lower than wind (the cheapest renewable). Nuclear is undoubtedly cheaper in east and south Asia. Impossible to overstate the importance of this. But it doesn't end there - nuclear displaces coal directly because it is baseload and dispatchable. This makes nuke generated electricity more valuable than wind generation both from an economic and emissions reduction standpoint. 2. Distributed power generation by consumers-producers on a scale and time frame to make a serious impact on emissions is a fantasy. Not only do PV panels need to drop in price a lot, but storage needs to drop in price by a lot. Installation and maintenance costs are not likely to go down. There is a reason things are done on an industrial scale - it's cheaper. I had a glance at the German PV performance for December. It's shockingly poor. Germany has about 15GW of nominal PV capacity. The maximum output at any time of the day on the best day was 0.7GW. On the worst day just 0.2GW. The capacity factor must be somewhere between 1% and 2%. Now think about storage requirements. Most of the world are not loopy survivalists living in the Arizona desert and are not interested in paying for that sort of lifestyle. I challenge anybody who thinks micro generation will make a serious dent into emissions to present a decently constructed scenario where say 3% of the worlds electricity could be feasibly produced by this mean by 2020. 3. It is quite wrong to assume that R&D funding will solve all engineering problems. Why is battery technology progress so painfully slow? Because you can only store so much energy in chemical bonds - the same reason so much fossil fuel is burned for energy. Progress will come but there are underlying hard physical limitations. Same is true for solar and wind - the energy density is low and this will ultimately place a bottom line under the cost for wind and solar CSP. Same is also true for mechanical energy storage such as compressed air, flywheels etc. Nuclear IS different because the binding energy of the nucleus is huge in comparison. No question that some serious engineering is required to realize the potential - but the potential is there, and there is a huge gulf between current implementation and physical limits. 4.There are multiple reasons for the back and forth, but the main reason is ultimately the agitation for the banning of nuclear power and/or the efforts to be as obstructionist as possible where new nuclear is proposed or being built. In my book this is the height of irresponsibility towards climate. There is also a lot of nonsense willfully spread. In discussion of climate science, nonsense is jumped on rapidly from a great hight and rightly so. In discussion of energy, it seems that just about anything goes. Not good enough. 5. My future projection. Sometime towards the end of this decade, when it becomes obvious that non-hydro renewables are not cutting it, there will be a rush to nuclear for reasons of low emissions and energy security. Asian nations will be the biggest suppliers together with Russia and France. And yes I do get involved in discussions other than nuclear. I've had far too many brawls with climate deniers - but not here. While confronting the deniers is important, clarity about energy is just as, or perhaps more important. There are of course ideologically motivated tea party type kooks who will never be persuaded, but there are a significant number of climate deniers that can be made to change their tune if they are convinced that there is road to a low emissions future that is not energy poor.
  43. Renewable Baseload Energy
    @quokka # 378 I had the impression you could technially elude a bit on the fact of the cycle limitation of NPP - is this something discussed seriously in pro-N circles? And if load follow operation is not something regular for NPP (e.g. limited to cycle number of 1000 or such), it is not valid to use it as an argument for nucelar. Regarding the cost: i fully agree with you tht the cheapest source is preferably, but i dont agree that this points to coal/nuclear or oil: considering all externalized cost for detremental effects of (coal, oil, nucler for) mining, transport, enrichment, storage, pollution during production etc. I strongly believe that todays energy is simply to cheap and that those "expensive" renewable can match them in case these cost are considered. Societies worldwide are paying for these external cost every single day. One important point in my mind regarding cost speaks for renewable in any case: the cost for electricity (power) will rise anyway, with or without one-time large investments for renewable now. But the cost for renewable will always only get less due to maturity, they will not increase. No cost decrease for coal, oil, nuclear are expected as far as i know, it will only get more costly with CCS or better environmental standards or safety standards.
  44. NQuestofApollo at 18:30 PM on 8 December 2010
    We're heading into an ice age
    Muoncounter (132): If "Artic sea ice falls to third-lowest extent", that means there were at least two extents that were greater. Here is the chart from the link that you sent - please notice that 2007 is the lowest point and 2008 - 2010 show a greater sea ice extent. While I stand corrected on one point: the increase has been for only two of the last three years; the main point remains: if accumulated CO2 is causing the globe to warm, then - by the AWG logic - 2008 through 2010 would be below 2007.
  45. NQuestofApollo at 18:29 PM on 8 December 2010
    We're heading into an ice age
    To Rob (127) - I have to ask: did you even read Doran's 2009 document? Exactly 75 climatologist agreed - NOT with your Orwellian claim that climate scientists believe that "climate change is real", what fool ever said it isn't? - but, that "human activity is a significant contributing factor in changing mean global temperatures". (do you understand the distinction?) Since you are the master of percentages, just what percentage of ALL climatologist would this be?
  46. NQuestofApollo at 18:29 PM on 8 December 2010
    We're heading into an ice age
    My second main point was questioning whether CO2 leads or follows global warming. To this point, Rob and Daniel were direct: CO2 leads global warming because it's basic physics. Okay - lets talk "physics". Anthropogenic CO2 emissions are about 30 Gtons per year . Total CO2 emissions are about 250 Gtons per year (for this, I estimated a consistent 2% per year increase) - making man responsible for about 12% of all CO2 emissions world wide (this includes CO2 sink effects). The impact CO2 has on GHE is, at its upper limit, about 26%. That means that anthropogenic CO2 emissions - WORLD WIDE - have, at most, a 3.12% impact on the green house effect. And for that, I should be hysterical? The problem here is that the most influential GHG is water vapor (since you all seem to trust the IPCC implicitly, please see their First Assessment Report by Working Group I). By the logic of suppressing GHGs, should we stop cooking and boiling water? Sound ridiculous? That is how I feel about CO2 emissions causing globe disasters. I've stated my reasons. I've tried to give reasonable supporting documents to the reasons for my doubts about AGW. We may have to just agree to disagree.
    Moderator Response: The point about human CO2 emissions being a small percentage of the total is addressed here.
    The point about CO2 lagging temperature is addressed here.
    The point about water vapor being the most dominant GHG is addressed here.

    In the future, please review the List of Skeptic Arguments before posting and place your individual arguments in the appropriate thread (ideally after reading what the post has to say). This will ensure that your points will be readily available to anyone reviewing the discussion of the relevant subject.

    Per the comment policy of this site, any future off-topic posts will be deleted.
  47. NQuestofApollo at 18:26 PM on 8 December 2010
    We're heading into an ice age
    Regarding lines 127-136 (sorry for the delayed response - life got in the way) To JMurphy in particular, I appreciate the time you spent providing all of those links. And, I have to apologize, as it appears that I may have been unclear in the main points of my previous post. My points were only: 1. to questioning the quality of the scientists and 2. questioning CO2 impact on temperature Your links to the hockey stick issue don't change the fact that two different sets of data were concatenated. AGW promoters find this acceptable, the rest of us do not. I'd like to discuss the urban heat effect, but fear we would just talk past each other. Daniel stated that GHG effect of CO2 is "not seriously questioned by any competent scientist anywhere". The only purpose in sending the link to the Petition Project was to show that over 31,000 scientists - surely some of whom must be "competent scientist" somewhere - provided a detailed explanation for their disagreement with AGW. I also took issue with his definition of "competent scientist" and provided links to support my position. It wasn't my intention to open a direct discussion on the petition project or climategate, but to offer those issues as causing legitimate doubt. JMurphy - most of your links regarding the IPCC back up what I said - the IPCC either lied or "misread" data. Furthermore, that happened because their reports were NOT peer viewed. Further promoting my point that they are not an entirely reliable source. That IPCC link represents meager 831 scientists. Additionally, my concerns remain about the quality of the scientists behind the IPCC. The IPCC states that their procedures provide for the InterAcademy Council to "assemble an international panel of experts". Now, you may trust that their basis of selection is unbiased and only considers the credentials of those selected, but I do not. Item 7 of this report gives me pause for concern on that topic as well.
  48. Stratospheric Cooling and Tropospheric Warming
    Bob, I have two points, and I will start with your second explanation first. Below is an image of the outgoing emmissions spectra over the Sahara, the Mediterainian, and over Antarctica: You will notice the small spike at the center of the CO2 absorption/emmision pattern in each case. That spike represents emissions by stratospheric CO2, which being warmer than stropospheric CO2, has a higher brightness temperature. The important point to notice is that the spike is confined to the center of the CO2 absorption/emmision band. Looking at your figure 2 brought my attention to the fact that the majority of excess absorption in the troposphere with increased CO2 takes place on the wings of the band, not at the center. It appears from your figure 2 that there is no reduction in CO2 absorption at the center of the band. But because it is at the center of the band where stratospheric CO2 emits and absorbs, it follows that the reduction in IR on the wings of the band will have no tendency to cool the stratosphere. Clearly, in the non-equilibrium state, adding extra CO2 will reduce the brightness temperature at the center of the CO2 band as well as at the wings, and will consequently reduce stratospheric temperatures. But as the troposphere achieves radiative equilibrium, it may be that the loss of IR radiation on the wings of the band undercompensates for, exactly compensates for, or over compensates for the increased emmisions outside that band due to increased surface temperature. In the first case, the equilibrium brightness temperature at the center of the CO2 band will be less than it was before introducing more CO2, thus cooling the stratosphere. In the second, it will have no effect; and in the third it will slightly warm the stratosphere. As to which case will actually apply, you will have to ask an expert; and it may be the models insufficiently clarify the situation. For practical purposes though, it appears that the cooling of the stratosphere due to the second method is a temporary effect, which declines to close to zero as the atmosphere achieves radiative equilibrium. (As an aside,the emission spectrum for Antarctica is especially interesting; showing, as it does, that the tropospheric CO2 was warmer than the surface. In the situation at the time of this observation, the effect of CO2 in the atmosphere would have been to cool the surface of Antarctica, rather than to warm it. ;) ) On to the first method: Where you say, "... this vibration is related to the energy content of CO2, it is not related to the temperature of the gaseous mixture", this is not strictly correct. The energy stored as vibration is not measured by the temperature, but there is an equilibrium relationship between the heat stored as molecular vibrations and the temperature of the gass. The actual relationship varies from gas to gas, and depends of the degrees of freedom of their vibrational modes. Because the relationship between heat stored as vibration, and heat stored as translation energy, adding more CO2 at the same temperature will not cool a gass (ignoring considerations of pressure and volume), for the added CO2 will have the same proportion of energy stored as internal vibrations. Adding a cooler or warmer amount of CO2 will, of course, temporarilly cool or warm the stratosphere, but the stratosphere will quickly return to equilibrium. What is happening in any gass is that the energy stored as vibration interacts with, and seeks to achieve equilibrium with two sources of energy. The first is the energy from collisions within the gass, which is a function of temperature. The second is the radiant energy it emits (which is a function of its temperature) and recieves (which is a function of the temperature of the source of the radiation it captures). If the temperature of the gas is less than the temperature of source of its radiant energy, its the energy it radiates will be less than that which it recieves, increasing its vibrational energy. This excess will then be passed onto the ambient gass, increasing its temperature. If the radiant energy it recieves has a lower "temperature" than the ambient gass, its will emit more energy than it recieves, draining its pool of vibrational energy. This shortfall will then be made up by collisions with other gass molecules, cooling the ambient gass. Applying this to your model, and assuming all energy transfers are radiant, the effect is that the stratospheric gass will reach an equilibrium temperature equal to the brigtness temperature of the tropospheric CO2. If the stratosphere were cooler than that, than the stratospheric CO2 would be a net absorber of radiant energy, thus warming the stratosphere. If it were warmer, the CO2 would be a net emitter, thus cooling the stratosphere. (In reality, the temperature would be determined by convection and the adiabatic lapse rate, which would dominate at stratospheric altitudes were it not for a major source of radiant energy to those levels.) So, once again, I come back to Ozone. where it not for Ozone being a net absorber of energy in the stratosphere, CO2 would not be a net emitter of energy in the stratosphere. And it is only by being a net emitter that CO2 can cool.
  49. The human fingerprint in the seasons
    Norman @141, Regarding warming rates for polar amplification. You need to keep a couple of factors in mind regarding the the paper by Chylek et al. (2009) that you cited. They, understandably, have access to a few, widely separated stations, and they have consequently greatly underestimated the rate of warming north of 70 N after 1980, especially during the winter months. Using ECMWF-interim data, Screen and Simmonds (2010) found warming of 1.9 C/decade in DJF for areas north of 70 N between 1989 and 2008, compared to 0.58 C/decade for the same area area and season (from 1980-2008) in Chylek et al. (2009). That is a huge difference. We are now clearly dealing with a very different beast than was the case back in the 1910-1940 window. Interestingly, the rate of warming during the winter determined by Chylek et al, for areas north of 70 N was 1.63 C between 1910-1940-- that value is very similar to the rate of warming obtained by Screen and Simmonds for the same season. One has to wonder why Chylek et al's analysis grossly underestimates the post 1980 warming-- did they perhaps use different stations for the two periods? Something does not add up. Also note that, according to Chylek, the rate of warming for the globe (from NASA GISTEMP data) between 1980 and 2008 was almost double (~0.20 C/decade) that observed between 1910 and 1940 (~0.10 C/decade), despite a slight decrease in insolation during after 1980. So Monckton should now be convinced that AGW is real (referring to his entertaining conversation with a Guardian reporter at Cancun)....but I digress. Be careful of confusing regional regimes and internal climate modes with drivers of global climate. That all said, I have no idea what your speaking to polar amplification of the Arctic has to do with the original post...
  50. The Scientific Guide to Global Warming Skepticism
    It's Christmas come early! Thanks, John!

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