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Comments 102601 to 102650:

  1. Renewable Baseload Energy
    Peter Lang #292: "SEGS is a day time only plant." False. Didn't you read BP's post about how they are evil and dangerous because the heated fluid used to provide night time power caught fire once (though 0 people were harmed by this)? Seriously, if you guys are going to spread nonsense could it at least be consistent nonsense? Also: "This thread is about baseload. SCEGS is not baseload." Yes, it is. No other power plants are required to be 'on standby' to cover for them. They have natural gas power generation on site to make up for any shortfalls... but that's only 10% of total power generated.
  2. Renewable Baseload Energy
    Thank you, Ned. You've said what I would have, had I the wit (and the patience).
  3. Stratospheric Cooling and Tropospheric Warming
    Bob, neither Venus nor Mars have a stratosphere: But, contra damorbel, the absorber of shortwave radiation does not have to be O3 (or O2), as shown by the examples of Titan and the gass giants:
  4. Renewable Baseload Energy
    Peter Lang writes: ... the strong resistance to nuclear as is being expressed on the SkepticalScience web site ... I know from previous discussions that there are many of us on SkepticalScience who support nuclear power and who think that investments in nuclear power will need to be greatly expanded in the next few decades. So why aren't any of these people contributing to the discussion? I can only speculate, but here are three possible reasons: (1) Many of us support both nuclear power and renewables. My expectation is that reducing our use of fossil fuels will involve increased reliance on nuclear and hydro and solar and wind and geothermal and tidal power and biomass and ... well, you get the point. But you seem to be at least as motivated by the desire to attack renewables as by the desire to promote nuclear. Your approach, of pitting one against the other, is going to drive away those who support both. (2) On a more personal note, the aggressively combative style of many of your comments here may well to inhibit others from posting pro-nuclear comments (and almost certainly drives fence-sitters away from your position). You ignore and insult those who disagree with you, and convey the impression that you're not willing or able to objectively consider different sides to the debate. Your comments are riddled with absolutist language; there's no recognition of shades of gray or of the possibility that others might have any valid points whatsoever. Again, as someone who wants to build support for nuclear power (and other non-fossil sources) I know we need all the allies we can get. Intemperate outbursts -- like insulting comments about "Greenies" and repeated implications that your opponents are "irrational" -- don't help. I'm pro-nuclear, but I'm also a very committed environmentalist ... why should I participate in this thread when the main pro-nuclear poster is busily insulting people whom I identify with? (3) Although this thread is about energy sources, it's in the context of a site that is primarily focused on the science of climate change. Like others, I've gotten the impression that your knowledge of and interest in climate science is minimal to nonexistent. Your only purposes in posting here seem to be to (a) aggressively promote nuclear power, and (b) aggressively run down renewable energy (not necessarily in that order). This perception naturally further reduces people's interest in joining the discussion. Of course, this is all just one person's opinion ... but I would suggest taking some time to reflect on what you're trying to accomplish here and whether your efforts are likely to be effective in accomplishing that.
  5. The human fingerprint in the seasons
    20 Albatross I haven't had time to fully take in what Braganza is saying but the quote you pick out does highlight a problem I had noticed. Let's limit ourselves to just the most recent trend. Braganza seems to investigate two possible scenarios. 1) The warming is solely from human GHGs. or 2) The warming is solely from solar and volcanics. He then tries to see which best fits the observed trends. The problem I have is that those two options aren't the only possibilities. 2) would demand the position that CO2 increases have no possible role in temperature trends. Some sceptics might hold that position but many more hold a more nuanced position where they accept the role of CO2 as a GHG but are critical of the magnitude of that effect expressed by the IPCC. That would mean that a third possible option exists where the recent warming trend is in response to multiple forcing factors. Simply positing the two extreme positions and asking the question which one is the better fit does not fully investigate the problem. As I said before, but in respect to another issue, this is not an all or nothing problem. In fact your quote highlights the problem I have with John's presentation. In Braganza's words this is "consistent" with human GHGs not a fingerprint of it.
  6. Stratospheric Cooling and Tropospheric Warming
    Re #84 you wrote:- "Venus does have an atmosphere." What I wrote was:- "Venus has no stratosphere."
  7. Stratospheric Cooling and Tropospheric Warming
    damorbel - Venus does have an atmosphere. http://adsabs.harvard.edu/abs/1983KosIs..21..205A
  8. Stratospheric Cooling and Tropospheric Warming
    After carefull consideration, I believe the explanation of stratospheric cooling given in the original post is simply wrong. To see this, consider a hypothetical planet whose atmosphere is completely transparent at all wavelengths of electromagnetic radiation. In this case, its surface temperature will be its temperature as measured from space, ie, its effective temperature. The temperature at any point in the atmosphere above the surface will be less than the effective temperature, and the temperature profile of the atmosphere will be defined by the adiabatic lapse rate up to the thermosphere. (Like Venus, see graphic in 80 above, it will have no stratosphere.) Now, as we introduce CO2 into the atmosphere, what happens is that the altitude of the effective temperature gradually increases in height. As the temperature profile is still defined by the lapse rate, the temperatures at every altitude up to the thermosphere will also increase. Even if we exclude convection as a means of transfering energy in the atmosphere, and hence exclude the adiabatic lapse rate as a temperature profile, radiative transfer in an optically absorbing atmosphere will generate a lapse rate, indeed, typically a shallower (greater change in temperature for a given change in altitude) lapse rate than the adiabatic lapse rate. Therefore this reasoning should still hold. Looked at differently, and using Earth as our model, we need to consider that the effective altitude of radiation, ie, the average altitude from which radiation reaches space, lies several kilometers below the tropopause. Therefore most outgoing radiation at the tropopause reaches space, and the Beer-Lambert law is an appropriate approximation of the effect of changing CO2 concentrations in the stratosphere. Given that, then if we double the CO2 concentration we also double the amount of IR radiation absorbed by CO2 in the stratosphere. The amount of IR radiation outgoing from the tropopause will not itself double, but infact will slightly fall because the atmosphere is optically thick below the tropopause. Consequently, although the net radiation entering the stratosphere will fall in this scenario, the amount absorbed in the stratosphere will increase. Of course, the amount of IR radiation emitted at a given temperature will also double with doubling of CO2 in the stratosphere. The result is that, if the temperature of the stratospheric CO2 is less than the brightness temperature radiation emitted by CO2 in the troposphere, it will warm. If it is greater it will cool. Of course, had the temperature in the stratosphere followed the adiabatic lapse rate, it would have been less than that of the troposphere; and increasing CO2 would warm the stratosphere, all else being equal. But all else is not equal - the stratosphere is much hotter than the upper levels of the tropospere because of the absorption of UV radiation by ozone. Therefore, I would have to conclude that stratospheric cooling with increased CO2 is primarilly due to increased efficiency at radiating away energy absorbed by ozone due to increased concentration of CO2. There would be a small additional boost due to reduced outgoing radiation of IR in the 15 micron (CO2) band; but that is ony a secondary cooling effect, and would have been a warming effect where it not for the presence of ozone in the stratosphere. Having said all that, I now hope some one will knock some holes in my reasoning.
  9. Renewable Baseload Energy
    Ogemaniac, @ #303, “If we were to scale solar to about one hundred times what it is now, prices would likely fall more than half from where they are now. This would also be enough production capacity to replace every fossil fuel plant within a generation. The scale of this industry would be similar to that of the auto industry...certainly not impossible” Several points to make here. 1 You have posed some really big ifs. Do you want to wait in the hope that solar might be able to do the job sometime in the future? Do you want to continue to ban nuclear, or continue to put such onerous restrictions on it that it is uneconomic, so we delay another 20 years or so? Do you want to take the risk? Because that is what is happening as a result of the strong resistance to nuclear as is being expressed on the SkepticalScience web site and other web sites dominated by contributors with similar beliefs. 2 “Scaling solar to one hundred times rimes what it is now” would not make a dent in the amount of generating capacity we would need in 20 or 30 years time. It would be insignificant. 3 If you halved the cost of solar thermal that has sufficient storage to do what the ZCA2020 report assumed (which is totally insufficient anyway), the cost would still be about five times the cost of nuclear. Gemasolar (Spain) Generating Capacity = 17MW Storage = 15h Energy pa = 100,000MWh Cost (2009 €) = €230 million (200 Cost (2010 A$) = $395 million Cost per kW = $23,225/kW Cost per average kW = $34,587/kWy/y For comparison nuclear = $4,500/kWy/y So, the cost for Gemasolar with 15h storage (not baseload) is about 8 times higher than nuclear Halve the solar (and don’t reduce the cost of nuclear) and solar is still 4 times higher than nuclear. Reduce the cost of nuclear over the same period too, and solar would still be around 6 times higher than nuclear. Make solar thermal baseload capable and solar would be probably 20 times higher cost than nuclear (if it is even possible to do it, which I doubt) I am sure someone here will pull out some other figures from another plant. Please do but try to keep a sense of perspective. Differences between plants are not significant unless they are at least a factor of five lower cost per kWy/y, given the size of the discrepancy between solar an nuclear. Please provide the source of your figures, present the equivalent figures to those I’ve shown above and show how you calculated them. By the way, the new solar PV station recently commissioned at Windorah in Queensland cost $4.5 million for 130kW, 360MWh/a, = A$34,625/kW, = A$109,500/kWy/y. Key Point: Solar thermal is totally uneconomic, and probably can never be a viable baseload technology. Even if we halve the cost of solar thermal it is many time more costly than nuclear. If we could make it capable of baseload generation it will be many times more expensive still. This is why I say there is no realistic prospect of solar thermal being economically viable as a baseload technology. Sources: http://www.nrel.gov/csp/solarpaces/project_detail.cfm/projectID=40 http://europa.eu/rapid/pressReleasesAction.do?reference=BEI/09/224&type=HTML http://www.solarpaces.org/Tasks/Task1/Task%20I.pdf http://ecogeneration.com.au/news/windorah_solar_farm/011780/
  10. Stratospheric Cooling and Tropospheric Warming
    Daniel Bailey - 78 garythompson - 77 This graph does show a correlation between CO2 and temperature. However, it may not show the correlation that you want. In this graph, temperature changes occur a few hundred years before CO2 changes. CO2 does contribute to the temperature increase but as a feedback rather than a forcing. This is often used by contrarians to debunk the present day issue of CO2 causing the temperature to rise. Bob
  11. The human fingerprint in the seasons
    Quoting from top post: "Solar warming should result in the tropics warming faster than the poles. What we observe instead is the poles warming around 3 times faster than the equator." How come, then, a majority of this year's heat records are from the tropics?
  12. The question that skeptics don't want to ask about 'Climategate'
    Physics based models still make a host of assumptions? All models make a host of assumptions, including those written by the atmospheric particle modelers. Chris Shaker
  13. The question that skeptics don't want to ask about 'Climategate'
    "actually thoughtful": If we saw a temperature change that exceeded that from the historic glacial cycle, it'd be a lot easier to believe in AGW. So far, the global warming that we're seeing appears to be a natural part of the warm phase of the glacial cycle. We reached 4.5C warmer than today (1950) during the previous warming phase, 130,000 years ago. http://news.nationalgeographic.com/news/2007/07/070705-antarctica-ice.html Chris Shaker
  14. 2nd law of thermodynamics contradicts greenhouse theory
    Re #266 KR you wrote: "Photons don't have temperatures (cold, warm), they have energies." The temperature associated with photons comes from the Planck energy distribution, the peak of the curve tracks the Wien displacement law In the same way as a gas has a distribution of energies following the Maxwell-Boltzmann distribution according to its temperature; photon energy follows Planck's law. But, since the bulk gas has the average temperature of all the molecules, this also means that the individual (isolated) molecule has its own temperature. In the same way a photon also has its own temperature, related of course, to its energy. This goes further; a planet orbiting a star is immersed in photons emitted by the Sun, the number of photons intercepted by a planet is reduced by the inverse square law but this is the only reduction, making the equilibrium temperature of a planet a function only on the Sun's (photon) temperature and the planet's distance from the Sun. The idea that planetary temperature is affected by its albedo is quite mistaken.
  15. It's a 1500 year cycle
    My further comments are posted at We're heading into an ice age http://www.skepticalscience.com/argument.php?a=53 Chris Shaker
  16. We're heading into an ice age
    Thank you for the explanations about the graph. What you say makes sense. I think this implies that the cores are sampled for analysis every so many mm? Chris Shaker
  17. The human fingerprint in the seasons
    16 Daniel Bailey I guess a definition of a 'human fingerprint' would help. Maybe John (or you) could provide one? For me it means evidence that stands alone in identifying a human component and excludes all other possibilities. Without both of these it's just evidence that's consistent with CO2 warming. A discussion of whether there is or isn't a TSI trend will not get us any closer to understanding why this is a fingerprint. More back of the envelope calculations. Solar warming would contain a 40-60% GHG component from water vapour. What about IPCCs estimates of CO2 warming? 0-33% comes from albedo and other non-GHG warming forcings and feedbacks and 66-100% from the GHG component (about half that from the water vapour feedback the rest directly from human GHGs). Can John's graph differentiate between a 40-60% GHG warming signal and a 66-100% GHG signal? If it can't then it's not a fingerprint of human warming. As I said before, in John's written description of what a solar fingerprint will look like he seems to ignore feedback and focus solely on the direct effect from changes in TSI. DB you seem to be taking two steps forward. John introduces the mythical "solar fingerprint' to the the discussion. I'm only going with John's flow here. If there is a problem with considering a solar fingerprint then maybe you should direct your criticism toward him.
  18. Stratospheric Cooling and Tropospheric Warming
    Humanity Rules: "That in a nutshell seems to be the problem." Then I hope you are not a teacher. You don't go in guns blazing and teach someone who knows nothing about science, the complexity of a subject that only an experienced scientist knows. You start with simplicity and add complexity as the student has learnt the simpler principles. That applies just as much to climate science, as it does to carpentry, stonemasonery or welding.
  19. We're heading into an ice age
    scaddenp said at 07:05 AM on 23 March, 2010 "I hate to be reiterating an old point but its all about rate. The transition into and out of ice age is extremely slow by human terms. (around 10,000 years). The rate of warming we are creating is by comparison very fast. Rates of change that overwhelm species capacity to adapt are the danger." It seems that these claims are incorrect. Natural systems have caused huge and rapid temperature change in the recent past. http://www.scientificamerican.com/article.cfm?id=ice-core-reveals-how-quickly-climate-can-change "Following this abrupt shift, as much as 20 degrees Fahrenheit (10 degrees Celsius) of warming occurred over the subsequent decades—a change that ultimately resulted in at least 33 feet (10 meters) of sea-level rise as the ice melted on Greenland." http://www.sciencedaily.com/releases/2008/06/080619142112.htm "The ice core showed the Northern Hemisphere briefly emerged from the last ice age some 14,700 years ago with a 22-degree-Fahrenheit spike in just 50 years, then plunged back into icy conditions before abruptly warming again about 11,700 years ago. Startlingly, the Greenland ice core evidence showed that a massive "reorganization" of atmospheric circulation in the Northern Hemisphere coincided with each temperature spurt, with each reorganization taking just one or two years, said the study authors." Note that the Woolly Mammoth, giant sloth, and Sabre tooth tiger went extinct during one of the most recent temperature excursions, only 12,900 years ago. Chris Shaker
  20. The human fingerprint in the seasons
    Daniel Baily #16 "all other forcings have been flat or declining " Correction. Albedo has changed. Human waste heat has only been increasing. Urban heat islands are unfortunately real. Waste heat is real energy, over and above that provided by the sun. (i.e., unlike the flash-in-the-pan diurnal greenhouse effect.)
    Moderator Response: [Daniel Bailey] Please do not reprise the waste heat discussion here. 356 comments on that topic and counting; if you feel you have something to add that shows waste heat amounts to more than 1% of GHG forcings, go back to that thread and comment on it there. UHI has been thoroughly debunked and rebunked, both here at SkS and by Tamino, to mention but two places. Use the search function to find the most appropriate UHI thread. Waste heat and UHI comments are off-topic on this thread.
  21. Renewable Baseload Energy
    scaddenp, I should have explained for others that a small proportion of wind power with a large proportion of hydro generating and storage capacity can work because when the wind is blowing the water stored in the reservoir (stored potential energy) is saved because the hydro generators are turned down when the wind is blowing. When the wind power decreases the hydro power is turned up to meet the demand. In short, wind power avoids using stored hydro energy. Whether this is economic or not, is another question. It can be, in some situations, just! In New Zealand you, like Australia, have a ban on (unprintable), so we have no way of knowing if your generating system is the least cost option.
  22. Renewable Baseload Energy
    scaddenp, I agree that wind can make an economically viable contribution where it is matched with large hydro generating capacity. This is the case in Denmark/Norway, New Zealand, China, Brazil and parts of Canada (although they are beginning to realise that it is not economically viable at all even with huge baseload hydro generating capacity).
  23. Renewable Baseload Energy
    People, This discussion is silly. The questions posed in the lead article have been answered - and supported in previous posts. Read back through the posts and the links provided. 1. Yes, baseload generators are essential. (about 75% of our electricity demand is baseload). 2. No. Non-hydro renewables cannot provide a significant proportion of baseload generation (except where there is volcanic geothermal) 3. There is little likelihood that non-hydro renewables (and volcanic geothermal) will ever be commercially viable (at the scale required to make a significant contribution). All the sources to substantiate these statements are provided in earlier posts.
  24. It's a 1500 year cycle
    The numbers I see for temperature increase caused by man claimed by the IPCC is about .7C. We reached 4.5C higher during the previous glacial cycle. I think the bottom line is that climate modelers don't really understand the glacial cycle, nor how it really works. Chris Shaker
  25. Stratospheric Cooling and Tropospheric Warming
    Re #40/41 Bob Guercio you wrote:- "the fictitious planet that I am using is a physical impossibility" You don't need to imagine a fictitious planet to see that O2 is essential for a 'stratosphere effect'. Venus has no stratosphere, the image below is a temperature profile of the Venusian atmosphere from 30km to 100km. (the lower part contains various extrapolations to the surface, further, you can open the image in another application to get a better quality). The green/red horizontal lines 2/3 up on the left are at 50-60km altitude and a pressure detween 1000 and 2000mB - thus the profile is similar in pressure terms to Earth.
  26. The human fingerprint in the seasons
    I like this post showing strong data supporting the AGW argument. Do the people arguing WV claim that the sun evaporates more water in the summer and then wind blows it to the other hemisphere so that it is warmer in winter? The WV would rain out on the way. WV would enhance solar warming during the summer but not during the winter. This is the opposite of CO2 warming that is observed. Can the WV people clarify the mechanism whereby WV causes warming similar to CO2 which is always present in the atmosphere. Please provide a link to a detailed argument that supports your claims.
  27. Renewable Baseload Energy
    muoncounter @392 and referring to my post #297. You are correct in that my statement in #297 is loose and not correct. I should not have said the "consumer pays" 5 to 20 times more for electricity from renewable generators. What I should have said is that the distributor must pay a higher price for electricity for renewables. The LCOE (cost) of electricity is 5 to 20 times higher from renewable generators than from conventional power stations. The cost must be recouped by the power station so, over time, on average, the wholesale price paid by the distributor must be at least that much higher for electricity generated by renewable energy generators than by conventional power stations. The distributors higher cost must be passed on, with profit and all the other costs, to the consumer as a higher price. I hope this clarifies my too brief statement that you so rightly picked up on :)
  28. Renewable Baseload Energy
    Ogemanic, "Solar has been tracking right along this path the last several years, and prices are lower than ever." I see. (sarcasm alert) In that case, why did the cost of solar generated electricity in the USA increase 30% beteween 2009 and 2010 (part of an ongoing upward trend), and why did the cost of Solar Tres / Gemasloar (Spain) increase by 250% from 2005 to 2009? Furthermore, why did the NEEDS analysis project that costs would fall by about 30% (from memory) between 2007 and 2010, yet they have increase by over 100% (in real terms). You might also apply your argument of decreasing cost with increasing roll outs to the unprintable technology. Once we get over the fear factor and remove the impediments in the western democracies, the cost will reduce for this technologuy too. China is now building it NPP's for $1,500/kW in 52 months. Ogemanic, I do no what you are getting at, but it is based on the price of solar panels not the full cost of commercial scale solar power stations (200 - 1000MW) with 24 hour generating capability including through prolonged periods of overcast weather and short winter days.
  29. It's a 1500 year cycle
    I don't have any idea where the 1500 year cycle claims come from. I take exception to the claim that "Ancient natural cycles are irrelevant for attributing recent global warming to humans." Chris Shaker
  30. Renewable Baseload Energy
    Peter, Your claim that renewables must currently generate 24/7 in order to supply 24/7 in the future is absurd. Why should we build expensive storage today when it will not be needed for decades? Demonstration plants have shown that it is possible to store the energy. It is currently not stored because storage is not needed with the current grid. Solar plants generate power during peak demand, why would they store the energy to sell later at a lower price? When you make absurd claims like this no-one listens to what you say and it makes nuclear proponents look bad. I have moved further away from nuclear due to your arguments. If your arguments are the best nuclear can do, nuclear is not worth much. You have made your point numerous times on this thread that you think that renewables cannot supply baseload. You have not provided convincing arguments or links to peer reviewed studies. I suggest you stop posting more of the same, the rest of us know what you think and disagree. If you try to link a new study every time you post you will contribute much more to the discussion. If you cannot link to a new study, you are just repeating yourself and wasting everyone elses time. I am still paying monthly for an unapproved nuclear plant which will not generate electricity for at least 10 years. If nuclear is so good why do I have to subsidize it for 10 years? I pay for renewables only when I get the electricity. We agree that wind generates GWhrs of electricity, without subsidy, economically in Texas using wind. We agree that nuclear cannot be used in much of the developing world. You have made no suggestions of how to deal with the nuclear waste. You are a proponent of thorium reactors that have not yet been built and cannot contribute to electricity generation for at least 20 years. I am not convinced by your repeated rants. Post on the what should we do about renewable energy thread that you previously hijacked for nuclear discussion if you want to continue the debate, not here. I notice that you have stopped responding to the questions raised there. Do you find them impossible to answer?
  31. Renewable Baseload Energy
    muoncounter, scaddenp is correct. The relationship between cost and price is extremely complex. For example, in the Australia system coal generated electricity may be around $30/MWh but the price bid ranges from -$1,000 to +$12,500/MWh. The price changes rapidly and by very large amounts. That is the wholesale price. The retail price includes the transmissions and grid operating costs, distribution, retail operating costs (including managing and paying the fees for mandated renewable energy, profit, etc. Price is extremely complicated. Better to stick with Levelised Cost of Electricity (LCOE).
  32. Renewable Baseload Energy
    scaddenp, Yes, France is required by EU requlations to build 20% renewable by 2020 (or something like that) despite it already having near zero emission electricity. France is required to buy electricity from the renewables first (obviously - otherwise they wouldn't be built). That shows how dumb all this renewable energy advocacy is. I'm with you regarding dumping subsidies and market distortions. I argue to dump all subsidies, all regulations that favour one technology over another, all tax breaks and remove all market distortions. Once that has been done, and not until it has been done, then consider what else needs to be done. However, I expect if that is done properly, there may be no need to do much more because low emissions electricity would be cheaper than fossil fuel generation and would become even cheaper as time progresses. If we do need to give some extra shove then, as a first step, I favour regulating emissions for new generators, with the increasingly restrictive emissions requirements being phased in between now and 2025. For existing generators I'd advise them they will have to meet increasingly stringent emissions rates from a date to be determined. Once the G20 countries reach agreement on a way to price emissions then we would, of course, be part of that international agreement.
  33. The human fingerprint in the seasons
    The final sentence of the article reads … What we observe instead is the poles warming around 3 times faster than the equator. I have read that Canadian/Alaskan temps have risen by 5C, a lot more than 3 times the increase at the equator – or does the “3 times” refer to Antarctic temp increase rather than Arctic? Can anyone refer me to material which explains difference between average global temps and polar arctic temps please.
    Moderator Response: [Daniel Bailey] This post by Ned covers much of that. The use of Arctic-only stations relative to the global datasets shows the ongoing polar amplification present in the Arctic.
  34. Stratospheric Cooling and Tropospheric Warming
    Sphaerica 71 "it could/would still be a net emitter in the end, but just with a smaller differential, and with some IR redirected back to the surface." I wouldn't dispute this, but if it is true, why do we need to consider the troposphere at all, as in the original post? Surely if CO2 is always a net emitter, then adding it will always reduce the temperature, regardless of what spectrum of radiation comes up from the troposphere? Your explanation was also my original understanding of statospheric cooling - that CO2 made the stratosphere more efficient at radiating than a blackbody by converting thermal energy to radiation at the absorption bands. To maintain the same overall emission, the temperature drops. But Bob's post says it's a whole lot more complex than that. Actually, as I write the last paragraph, maybe that's it - the internal radiative emission from the stratosphere (as opposed to mere transmission of ground level or troposheric radiative heat) actually falls because of reduced tropospheric tranmission in the CO2 absorption band. So are there two effects: 1) increased emission in the CO2 emissions bands increases thermal to radiative heat conversion and thereby reduces the temperature necessary to maintain overall heat balance AND 2) decreased absorption in the same spectrum because CO2 in the troposphere has already taken it out reduces the total heat input to the stratosphere
  35. Stratospheric Cooling and Tropospheric Warming
    Re: garythompson (77) Try this: (BTW, the zero-year baseline is 1950) Source here. Note that there exists much more than mere charts establishing a link between rising CO2 levels and rising temperatures. ----------------------------------------------------------------------------------------- [ - Edit - : In the graph I supplied, temperature changes occur a few hundred years before CO2 changes. CO2 does contribute to the temperature increase but as a feedback rather than a forcing. CO2 can act as a forcing (and has, post-1970 or so), but it's effects as documented in the paleo-record have been as a feedback to temperatures. The biggest exception to this is the PETM, which (unfortunately) is beginning to look more and more like the best comp for the modern era. Time will tell. - End Edit - ] ----------------------------------------------------------------------------------------- The Yooper
  36. Miriam O'Brien (Sou) at 17:09 PM on 3 December 2010
    The human fingerprint in the seasons
    Not at all, Albatross :) BTW, with regard to water vapour. Some of what goes up must come down. Water comes down more quickly than CO2. And where I live we've been getting a whole heap of it coming down - unseasonally so and in unusual torrents and record breaking amounts. This follows a record long and hot drought. All this weird weather signals a changing climate.
  37. Stratospheric Cooling and Tropospheric Warming
    where can i find a long term graph of the troposphere temperatures and data showing that its temperature increase is correlated with increased CO2 in the atmosphere? the following link doesn't show it so there must be some other data that is validating this thesis. and by the way, i enjoyed this post, well done.
  38. The human fingerprint in the seasons
    Sout @9, You are quite right. Hope you don’t mind if I elaborate a bit on what you said. We are increasing CO2 (a GHG), as a result the planet is experiencing a net energy imbalance (e.g., Murphy et al.2009) which is causing warming of the oceans and atmosphere. Warming of oceans is increasing WV in the atmosphere (e.g., Dessler et al. 2010), and the air can hold more WV as it warms, one result is an acceleration of the hydrological cycle (e.g., Syed et al. 2010). Another result is that higher WV (a powerful GHG) is causing a positive feedback which is further enhancing the warming that we humans have kicked off. To summarize: From Braganza et al. (2004): “ Observed linear trends over 1950–1999 in all the indices except the hemispheric temperature contrast are significantly larger than simulated changes due to internal variability or natural (solar and volcanic aerosol) forcings and are consistent with simulated changes due to anthropogenic (greenhouse gas and sulfate aerosol) forcing.” And “It is found that anthropogenic forcing accounts for almost all of the observed changes in surface temperature during 1946–1995”. From Dessler et al. (2010): “All of the other reanalyses show that decadal warming is accompanied by increases in mid and upper tropospheric specific humidity.” Anyway, sadly the point of this post has clearly been lost on some readers. Did they even read the post and references therein? John Cook and Braganza et al. 2003, 2004 have laid out their reasoning very clearly and this final sentence of John’s post sums things up: “All these pieces of evidence paint a consistent picture - greenhouse gases, not the sun, are driving global warming” Now do any of the resident “skeptics” take issue with that statement? I think not, they would rather argue this WV strawman that they have created.
  39. The human fingerprint in the seasons
    I'm Glad to hear that both John and HR acknowledge that water vapor is a positive feedback though. It is good to see when individuals who are skeptical join the scientific consensus.
  40. The human fingerprint in the seasons
    Couple Questions for John and HR, Is the theory that a solar (For example) perturbation is what is causing the initial temperature increase which then results in a positive feedback from water vapor causing the GHG signature to be present in the post 1975 warming? I don't buy it. I think this graph is very good because it shows that initially summers were warming quicker than winters and that as the effect of CO2 increased so did the rate of winter warming when compared to summer. That makes sense based upon what we already know which is that the early warming of the 20th century was solar induced mostly (I say oceans too but I digress) but that the late century warmth has a large anthropogenic component. What we have is a theory, early warming natural, late warming anthropogenic which we can then compare to the data, summers warm more than winters early, winters warm more than summers late. We also know that with increasing CO2 it was predicted that winters warm more than summers. For me its a pretty strong case. There's not really a need to always choose the 2nd or 3rd best theory when the evidence suggests theory #1 is well substantiated. Secondly I ask, wouldn't the initial solar warming being most prominent in summer counteract much of the winter warming caused by your GHG feedback?
  41. Renewable Baseload Energy
    muoncounter, I would have to say that retail electric cost isnt entirely correlated to generation cost, especially with the layers of subsidies that apply in US.
  42. The human fingerprint in the seasons
    TIS - if climate models work the way you seem to believe they do, then can you find me an example from ANY of the 15 or so models where the Antarctic is behaving like the Arctic? On the other hand, SH is most definitely warming. Why do think 0.25SW/m2/100year (max) has more effect than 3.7W/m2/100 year? Do you believe that energy received at the surface is an inconsequential factor in global climate?
    Moderator Response: Use italic or bold instead of all-caps, please.
  43. The human fingerprint in the seasons
    Re: HumanityRules (14) We know CO2 is rising; all other forcings have been flat or declining (source here). We know the increasing CO2 comes from us. Because increasing levels of atmospheric CO2 drives temperatures up, and the increased CO2 is shown isotopically to be of human origin, ergo: human fingerprint. Off road, stuck-in-sand, spinning-wheels. The Yooper
  44. Renewable Baseload Energy
    Peter: You said: "Moore's Law does not apply. These are very high cost systems with long life times and so turn over and learning takes decades." Moore's Law may not apply, but the laws of scaling do. In developing technologies, the rough rule of thumb is that a doubling of production lowers costs by 15%. Solar has been tracking right along this path the last several years, and prices are lower than ever. If we were to scale solar to about one hundred times what it is now, prices would likely fall more than half from where they are now. This would also be enough production capacity to replace every every fossil fuel plant within a generation. The scale of this industry would be similar to that of the auto industry...certainly not impossible.
  45. The human fingerprint in the seasons
    Re: The Inconvenient Skeptic (12)
    "Why isn't the Antarctic warming in its winter in the same manner as the Arctic if the cause is CO2"
     You present a logical fallacy. Comparing the Arctic, an ice-covered ocean surrounded by landmasses, with the Antarctic, a glaciated continent over 2 miles high: apples and oranges. A question to you: Why, exactly, would anyone expect the Antarctic to warm similarly to the Arctic? The Yooper
  46. The human fingerprint in the seasons
    11 Daniel Bailey We could argue about solar variation but that would be going OT and is for another thread. The contention in John's argument is GHG fingerprint = human fingerprint That seems wrong. The suggestion that the solar fingerprint will not contain a GHG component is wrong. The question is whether identifying a GHG fingerprint means you've identified a human fingerprint. The problem I have is to call this a fingerprint of human warming it should stand alone, that would be the nature of a fingerprint in this context. As you demonstrate it's only through bring in other arguments that you can make this stand up. This isn't a pedantic arguement. Part of the strength of the AGW arguement is the heaps of independant arguements that point to CO2. I think this and the previous human fingerprint point to a warming trend not a human warming trend. Back on the road, DB.
  47. Philippe Chantreau at 15:21 PM on 3 December 2010
    The human fingerprint in the seasons
    Both poles should be showing the same behavior" Why? I don't believe that at all. The poles are very different, so are the oceanic circulations around them. I think that they actually should not be showing the same behavior.
  48. It's a 1500 year cycle
    cjshaker - please see comments to you on this at We're heading into an ice age where this comments belong (the ice cycle is not a 1500 year cycle).
  49. The Inconvenient Skeptic at 15:10 PM on 3 December 2010
    The human fingerprint in the seasons
    There are a couple of problems with this article. There is no time when the Earth is in winter or in summer. By showing only part of the Earth it is certainly possible to miss what is happening as a whole. I do agree that the NH is the main driver of the Earth's climate. I have shown that here. The basis is a Jones paper in 1999 that shows that the NH winter and summer drives the global average as shown here. The global temperature shows that the anomaly in the Dec-Feb time frame has gone up more than in the June-August time frame. This isn't a surprise as Antarctica has not shown the winter warming that the Arctic region has in its winter. But that is a problem. Why isn't the Antarctic warming in its winter in the same manner as the Arctic if the cause is CO2. Both poles should be showing the same behavior, but they are not. So while I agree that Dec-Feb are showing more warming than Jun-Aug, the answer is not as simple as CO2. The current orbital obliquity trend should also be favoring warming Dec-Feb as the NH receives slightly more insolation during those months. That would also correlate to cooling Antarctic trend is also observed. John Kehr The Inconvenient Skeptic
  50. The human fingerprint in the seasons
    Re: HumanityRules (10)
    "My suggestion is that solar warming will contain a sizable GHG component because of the role of water vapour."
     Per this link, there has been no increase in TSI in the past 32 years and thus, no solar-driven warming over that period. It's not the sun, yet temps still rising. Water vapor would be a feedback, so it can't drive itself up via driving up temps. Ran outta road, HR. The Yooper

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