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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 102851 to 102900:

  1. 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.
  2. 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.
  3. 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)
  4. 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.
  5. 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!
  6. 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.
  7. 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.
  8. 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?
  9. 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.
  10. 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
  11. 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.
  12. 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!
  13. 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!
  14. 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.
  15. 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.
  16. 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!
  17. 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!
  18. 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.
  19. 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
  20. 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
  21. 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
  22. 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.
  23. A basic overview of Antarctic ice
    72 Albatross You still prefer to ignore the V09 data and snipe instead?
  24. Renewable Baseload Energy
    actually thoughtfull - Can you repost that link to the cost estimates?
  25. 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).
  26. 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
  27. 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.
  28. 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.
  29. 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
  30. Renewable Baseload Energy
    Peter Lang - Even on a quick read, the critiques do have some serious points. The ZCA proposal seems to grossly underestimate power demands (it will take quite some time and regulatory/pricing impetus to change heating/cooling methods), transportation energy needs, and quite possibly the build costs of the solar plants. The ZCA schedule is completely unreasonable, but that's not as much of a cost issue. I found the wind comments a little thinner - there's certainly a decent amount of 1.4-1.5MW generator costing available for consideration - but still a ZCA underestimate. On the other hand, having looked at references such as Czisch (have you read this?), studying power availability using a large catchment basin, I think the wind availability numbers are really low. Not enough to overcome the optimism of the ZCA proposal, but still an underestimate. As Bern noted, renewables do appear to be able to supply baseline power, albeit at what may be a higher cost. Of course, business as usual will have an extremely high cost too, just not in terms of energy...
  31. Climate's changed before
    Sorry, this is a repeat of a post today, which I should have included with this topic, but placed under stratospheric cooling. My first blog--I haven't found such an interesting site before. I have reviewed some old posts and found one under "climate's changed before" with a question that I have also wondered, from jebjones42. It did not seem to have been addressed in any subsequent posts. "I'm curious. Do we know what caused the reversal in past warm periods in the Earth's history? What made it get cool again? Clearly, despite CO2 having a positive feedback loop, we didn't get runaway warming. We're not living on Venus. Even if we're headed for higher temps, rising sea levels, drought, mass extinctions, catastrophic loss of human life, etc. At some point won't it top out an head back to another ice age? What's prevented a runaway greenhouse effect in the past?" I am also interested in this question. Is it sun cycles and precession/sun obliquity, and is the prevailing thought that we will overwhelm these historical cyclical temp. changes ?
  32. Renewable Baseload Energy
    I'd go with KR's comment at #193, about the wind farms all being in the same wind pattern. If you look at the locations of the windfarms on that Landscape Guardians site (thanks for that link, Peter Lang!), you'll see that they're all on the south-east coast of Australia, and are all sited to pick up the winds coming off the southern ocean. Great place to put a wind farm, if you get paid a fixed amount per kWh irrespective of when it's produced. Not so great to put them all there if you're interested in producing something closer to a base-load profile - the correlation between sites along the southern coast of Australia is often going to be very positive, and dependent almost entirely upon the weather patterns at the time. On the other hand, that's where the greatest wind resource is, so a means of storing that power (or having fast-reacting backup that can fill in the gaps) would be great. As I understand it, that's more-or-less what the ZCA people are proposing with their solar thermal with storage. Cost is a different issue - and, while an important consideration as to whether 100% renewables is the way to go, it doesn't actually affect the question of whether renewables are *capable* of providing baseload. The answer to that question seems to be "yes". It may be very expensive to do so, and we may be far better off with a large contribution by nuclear, but just because it might be unacceptably expensive doesn't mean it's not possible. :-D BTW, I read an old post on Climate Progress earlier, linking to a study suggesting the annual cost due to climate change effects of "business as usual" will be something around $1.5 trillion by the middle of the century. Net present value of the next 80 years worth of climate change costs was something like $1,240 trillion. Scary numbers.
  33. Stratospheric Cooling and Tropospheric Warming
    This is a tough problem that I have long struggled to grasp and I thank you for trying to explain it and for provoking me to think about it some more. However, I can't help thinking that your model is a bit too simple to allow you to conclude that increasing CO2 is the only possible mechanism to explain stratospheric cooling. For one thing, I'm not sure that there even would be a stratosphere (ie with temperatures increasing with height) if there was no oxygen/ozone in the atmosphere as there is in your model. So it may not make sense to talk about a warmer lower atmosphere causing an even cooler upper atmosphere in such a simplified case. Also, I understand that other variations, in water vapour, volcanic aerosols, chlorofluorocarbons and methane concentrations, can cause temperature changes in the stratosphere. Having said that, I don't actually doubt that rising CO2 does result in a cooling stratosphere, I'm just struggling to understand how exactly and by how much. There's a helpful article by some German scientists here: They conclude: We now know that stratospheric cooling and tropospheric warming are intimately connected and that carbon dioxide plays a part in both processes. At present, however, our understanding of stratospheric cooling is not complete and further research has to be done. ....
  34. Stratospheric Cooling and Tropospheric Warming
    This is a nice simple model, explains the absorption for us non-experts. I have reviewed some old posts and found one under "climate's changed before" with a question that I have also wondered, from jebjones42. It did not seem to have been addressed in any subsequent posts. "I'm curious. Do we know what caused the reversal in past warm periods in the Earth's history? What made it get cool again? Clearly, despite CO2 having a positive feedback loop, we didn't get runaway warming. We're not living on Venus. Even if we're headed for higher temps, rising sea levels, drought, mass extinctions, catastrophic loss of human life, etc. At some point won't it top out an head back to another ice age? What's prevented a runaway greenhouse effect in the past?" I am also interested in this question. Is it sun cycles and precession/sun obliquity, and is the prevailing thought that we will overwhelm these historical cyclical temp. changes ? I apologize if I am posting this in the wrong place. I am new to blogging.
  35. Renewable Baseload Energy
    Peter Lang - I'm still running the numbers from the critiques, I'll comment when I have a better feel for them. As to site placement, unless there is large scale (national) oversight, I suspect that the individual power companies will not chose the best mix of sites, but rather load sites to the highest wind levels regardless of large scale correlation.
  36. Renewable Baseload Energy
    KR, You say "But even if the costs are off by a factor of two, even if the energy requirements are off by a factor of two." You clearly did not read the critique or else you did not understand it.
  37. Renewable Baseload Energy
    KR, If you are not prepared to look at the links that have been suggested to you, then there is little point in the discussion. The points you are making have been covvered manny many times elsewhere. None of it is new.
  38. Renewable Baseload Energy
    Peter Lang - Looking at Quokka's links, the proposal discussed includes 60% concentrating solar and 40% wind. This is already reducing correlation considerably. I'll also note that this proposal (I'm sure it's optimistic, no worries about that) estimates that when global concentrating solar (CSP) reaches 8-9GW the costs will drop below coal energy costs. This proposal alone has 42GW of CSP. The timeline critiques are quite reasonable - I cannot see action occurring on that schedule. But even if the costs are off by a factor of two, even if the energy requirements are off by a factor of two - this is one potential approach to reducing CO2 consumption.
  39. A basic overview of Antarctic ice
    Hi all, OK, so I have been to the NSIDC FTP site and downloaded some data for sea ice area over the Arctic and Antarctic for January and February (peak of Austral summer) and July through September (Boreal summer) for all years between 1979 and 2010. Daniel and Tamino have also looked at this, but since HR wants us all to be critical ;) Great post Daniel by the way. Some things to note off the bat-- nobody is dismissing the presence of Antarctic sea ice during the austral summer. What I think people have been unsuccessfully trying to communicate to the "skeptics"/contrarians here is the significance of the difference in the rate of change in the sea ice extent. The distribution of land mass is also important, but more about that later. Some numbers: In the Arctic in August and September the rate of loss has accelerated in recent years-- in fact, a quadratic fit provides a much superior fit to the data for July and August and September. But for ease of comparison I will refer only to trends derived using an OLS model. Here statistically significant is set at 95% (p-value < 0.05). Arctic sea ice area trends 1979-2010: January: about -37 000 km/decade (not statistically significant) February: about -34 000 km/decade (not statistically significant) July: about -330 000 km/decade (statistically significant, p-value = 0.000) August: about -390 000 km/decade (statistically significant, p-val =0.000) September: -429 000 km km/decade (statistically significant, p-val =0.000) Antarctic sea ice are trends 1979-2010: January: about +74 000 km/decade (not statistically significant, p-value = 0.219) February: about +75 000 km/decade (not statistically significant, p-value = 0.132) July: about +158 000 km/decade statistically significant, p-value = 0.02) August: about +100 000 km/decade (not statistically significant, p-val =0.072) September: about +100 000 km km/decade (not statistically significant, p-val =0.117) So hopefully this clarifies the point that Robert and others have been trying in vain to make-- the statistically significant and accelerating rate of loss of sea ice during the boreal summer far exceeds the small (statistically insignificant) increase of sea ice during the austral summer. During the boreal summer, the minimum Arctic sea ice area is currently around 3.2 million km^2, compared to 4.5 million km^2 in the early eighties (down 1.3 million km^2). By comparison, the Antarctic sea area minimum during the austral summer is currently around 2 million km^2, compared to 1.8 million km^2 in the early eighties (up 0.2 million km^2 and that trend is not statistically significant). Another issue that I alluded to earlier (here, but I was clearly being too subtle) is that the Arctic ocean is essentially surrounded by a continental land mass which heats up rapidly during the summer. In contrast, the Antarctic ice sheet is thousands of metres high and surrounded by a band of very strong westerlies which essentially isolate it. That is why, for now at least, there has been little polar amplification over most of the Antarctic (not to mention the complicating factor of ozone loss). In contrast, in part because of the albedo feedback, there has been very marked polar amplification of the Arctic. The loss of sea ice from the Arctic during the boreal summer is easily offsetting any gains in the Antarctic sea ice during the austral summer. It will be interesting to see how long it takes before the Antarctic sea ice starts responding to the warming en mass, right now decreases have mostly been regional.
  40. Renewable Baseload Energy
    KR, The best wind sites are selected. All of what you are talking about is well known. The investors and the regulator want the best sites. But I suggest you take a look at the costs. You cannot deal with this in the absence of cost. That is the crunch. 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 ore will not consider the cost of what they advocate.
  41. Renewable Baseload Energy
    Ogemaniac, "Economically competitive vs what? Subsidized-up-the-ying-yang fossil fuels, whose free public garbage dumping rights alone are worth something on the order of a trillion dollar per year?" It is renewables that are "Subsidized-up-the-ying-yang". 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). Regarding the cost of externailites, why don't you provide actual figures instead of adjectives. Read this and get a handle on the actual value of externalities: http://www.externe.info/externpr.pdf Look at the tables at the top and bottom of page 13. The point is that even when the externailities are included, renewables are still many times higher cost that fossil fuels or the other (unmentionable) baseload electricity generation technology. You should also taske into consideration what is the real cost to society of higher cost energy. Have a long hard think about that!!
  42. Renewable Baseload Energy
    Peter Lang - I would be very interested in a wind correlation study for Australia. That would prove or disprove any possibility of reliable power by splitting generation between different regions. Not knowing Australian wind patterns, might it possible that this region is covered by the same strong trade winds? The study I referred to here indicated correlations as low as 0.3 for Australian sites only 375km separation (small by the measures proposed) - if you chose sites in different wind patterns.
  43. Renewable Baseload Energy
    KR, You said: "First, what you want is negative correlation between wind sites." I agree. But that is not what happens in practice over areas of over a thousand km east west as is demonstrated in the Australian National Grid and other large grids. @ 184 I said: "This grid demonstrates high correlation of wind power output." That is, high positive correlation, the opposite of high negative correlation. I thought I was sufficently clear. Solar and wind cannot provide baseload generation at a cost that is anywhhere near viable. Furthermore, they are unlikely to ever be the case. US DOE hasd a goal for solar thermal with energy storage to be able to provide "baseload" generation by 2030. But the costs would appear to be enormous. The costs of providing 24 hour power (as long as there is not more than 1 day of overcast weather in a row and no dust storms) are reasonably estimated in Quokka's first link in post #175.
  44. A basic overview of Antarctic ice
    #70: "Bad data analysis is ..." Here are some key points about the data analysis in Velicogna: For both the Greenland and Antarctica ice sheets, we found that Radj^2 is larger when we use a quadratic fit, i.e., the data are better modeled by a linear increase in mass loss than with a constant mass loss. To verify that the improvement obtained with the quadratic model is significant we used an F-test. The F-test show that the improvement obtained with the quadratic fit is statistical significant at a very high confidence level (99%). Note that if we use the unfiltered GRACE time series instead of the smoothed one, the Radj^2 values drop by 2% and 16% for Greenland and Antarctica, respectively. This illustrates the importance of removing the seasonal variability in the trend estimates. The improvement is much larger for Antarctica than for Greenland. So it doesn't sound 'bad'. But I guess I would accept HR's nitpick: Why wasn't the quadratic function used shown in the paper? That way the 'acceleration' could be determined directly. But here is some 'hedging': The Antarctic filtered data also suggest a slight change in trend around the end of year 2006. It appears that the long term variability could be described by two linear trends, one for the period 2002–2006 and the second during 2006–2009. ... We fitted two straight continuous lines through the data, i.e., connected in the middle. We find that the Radj^2 for the two lines regression model is 0.97, the same than for the quadratic model So to answer HR in #55: It appears that breaking the data into two segments is not arbitrary, nor is it necessarily 'bad'. My key take-away: GRACE supports a flat rejection of the skeptic claim that Antarctica is gaining ice.
  45. The Inconvenient Skeptic at 15:01 PM on 1 December 2010
    Stratospheric Cooling and Tropospheric Warming
    Bob, I agree in keeping it simple for this. It would be interesting to see what would happen with the temperature profile with the model. I tinkered with the one in the link and didn't see anything that would generate a temp profile as a response. I am curious about the convection only model. Nitrogen would have to dissipate heat at the top, but I am curious as the method. Say a planet with nitrogen density comparable to Venus. What would happen there? I don't know, but I am thinking about that model. That is why I ask. Hope to see more like this one.
  46. A basic overview of Antarctic ice
    HR, yes, at least we can agree that your analysis of the V09 data is a distraction.
  47. A basic overview of Antarctic ice
    HumanityRules: Rather than trying to get to the heart of "skeptics" mental state why not try looking at the data critically. The comment you objected to wasn't directed at you specifically. Sorry that wasn't clear. As for your other comment, I've been looking at the data critically since the late 1980s. Please don't make the mistake of assuming that people have not been critical until they've embraced whatever species of "skepticism" you favor.
  48. Stratospheric Cooling and Tropospheric Warming
    Thanks John, It is a completely artificial and impossible situation. However, my objective was to make it understandable and to do that I had to keep it very simple. Also, the nitrogen is not necessary. People understand parts per million but the concept of an equivalent CO2 vapor pressure to that of 100 ppm and 1000 ppm would have made it more complicated. I read other explanations on the Internet explaining this but I could not understand any of them. It drove me crazy and then I had one of those Eureka moments when I realized what was going on. It is really not explainable without considering the absorption spectrum. I suppose for simplicity, I cannot allow convective transfer:):) Bob
  49. The Inconvenient Skeptic at 14:31 PM on 1 December 2010
    Stratospheric Cooling and Tropospheric Warming
    Nice article here. I have been looking at this issue as well recently. One thing I would argue is that the tropopause would be much less defined (or possibly not exist) in this situation. The tropopause on Earth is impacted by water vapor and in this case water vapor would not be an issue. As the density of the atmosphere dropped, less energy would be needed to cause a comparable amount of temperature increase. I really don't see how the tropopause would develop in this situation unless full saturation was reached. It is an interesting situation. Also. Curious if you have run a model with just nitrogen. The atmosphere would warm from convective transfer, but after that the model gets odd and I am still sorting through it. This is fun science. John Kehr The Inconvenient Skeptic
  50. Twice as much Canada, same warming climate
    GC - me too.

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