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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 104951 to 105000:

  1. It's cooling
    Yooper, I agree with pretty much every point you make @ 74, but it is a strawman argument. To rebut me you would need to show how historic temp data encompasses the total Earth heat content. That is what this page is talking about and that is what my post was about. Nitpicking about what years of temp data the NAS has confidence in has nothing to do with my point that historical temp data doesn't encompass total Earth heat content.
  2. What should we do about climate change?
    kdkd, The discussion is pointless. You need to have some understanding of electricity generation system. Understand the overall picture first, then progress to lower levels of detail one you understand how the part you want to discuss links into the overall picture. Trying to discuss a partluclar item when you don't understand how it fits, or what effect (proportional contribution) it has on the overall system is simply a diversion. Please don't waste time on this. If you are genuinely interested you will do some research. You could start by going through the psosts on this thread, or you could go to Brave New Climate or you coluld take your own route. My suggestion is to read the authoritative reports not the nonsense on the media and Greenpeace type stuff.
  3. What should we do about climate change?
    PL #373 So do you have anything to say about demand management synergestic effects, and renewable generation site optimisation? Have you accounted for these in your conclusions? Can you show me where?
  4. What should we do about climate change?
    Michael sweet, I believe I have answered you, but perhaps you do not want to hear the message. I think this sums up your position: I also don't like to see all the eggs in one basket, but your nuclear proposal looks like a bad idea that should go to the end of the line. In otherwise, you are not prepared to do any objective research. I've provided sufficient on this thread to get you started if you are interested. If you are not, then so be it.
  5. What should we do about climate change?
    kdkd, I don't agree with your assertion that I have not challenged my own assumptions. You are not prepared to look at the links. There is too much background to get across to you in a blog field.
  6. Climate change from 40 million years ago shows climate sensitivity to CO2
    #34: "You take one location and say it is a reasonable representation of global effects." No, this is a global event. See Bohaty, cited in #35, who used OSDP cores; see Luciani et al 2010, who studied samples of Tethyan oceanic sediments now exposed in northeastern Italy.
  7. Climate change from 40 million years ago shows climate sensitivity to CO2
    Re: RSVP (27), Bodo (28, 25) To augment Bodo's excellent response to you, RSVP, at 28 above, remember that temps are a sum of forcings and feedbacks, of which CO2 is one (but the principal one). If CO2 levels spike, say due a methane clathrate/hydrate release as is theorized occurred during the PETM, then it would be reasonable to expect a temperature response of about 3 degrees per doubling of CO2 from baseline. But if that CO2 spike were accompanied by a lowering of TSI (as occurred during the Ordovician) and also some large volcanic aerosol releases in the tropics (where volcanoes have their greatest impact), than the global temperature response to CO2 will be more muted We know with certainty that CO2 is a greenhouse gas, that a certain increase in concentration will, other forcing and feedbacks remaining constant, drive a certain global temperature increase. Slow changes in Milankovich orbital cycles drive slow changes in temperatures, which can then change CO2 levels in response (an example of CO2 acting as a feedback to drive a limited secondary temperature increase). In this case, CO2 lags temps. How the modern era differs from past comps is this: we have injected an immense bolus of formerly sequestered (i.e., removed from the carbon cycle's closed budget) fossil-fuel derived CO2 back into circulation in the carbon cycle. So, despite a quiet sun with a flat TSI, despite some of the strongest La Nina's on record, global temps are up, Arctic ice area (and extant and volume) are down, Greenland, the WAIS and the EAIS are losing mass and sea levels are rising - all within ranges of predictions based upon the physics of greenhouse gases...CO2 in specific. In this case, CO2 is acting as a forcing to drive temperature increases, which then drive secondary CO2 releases which act as feedbacks; temps lag CO2 increases. As a result, the nearest analogue to the current spike in atmospheric CO2 levels is probably the PETM (which will be a worst-case scenario for us). If we continue BAU for long enough and spike temps high enough, the probability of a methane hydrate/clathrate release goes from a remote possibility to a probability. Hence the need to further study the PETM (per Bodo's question). The more we know about the PETM, the better able we may be to gauge how near the cliff's edge we actually are in this fog of lack of knowledge about climate response we are in. Given that, to say
    "it is clear that cart is in front of the horse, and neither are going anywhere"
     as RSVP says is specious and anything but helpful. The Yooper
  8. Compendium Maps: a visual summary of the climate debate
    May I suggest you make a similar Compendium Map of the specific claims supporting that humans are the cause of the present warming, and that it is leading to a problem of significant size. Note, I did not say show there is warming, and this is a problem, but that it is human caused. It would be best if these are falsifiable claims so they can be tested.
    Moderator Response: As far as the human attribution of the warming, please see the skeptic argument rebuttal It's Not Us - Intermediate.
  9. Climate change from 40 million years ago shows climate sensitivity to CO2
    32:"where you get 5 C as the temperature change." Since this figure is a stratigraphic record, time advances towards the present from bottom up. Below the MECO (yellow), the red is at 23C, during the MECO red is in excess of 28C. "if you start at the earlier time on the graph, the maximum increase in MECO is only about 2.5 C for the red " By the definition in this paper, the MECO is a short duration 'transient' event. Bohaty et al 2009 provide additional context: The identification of the δ18O excursion at sites in different geographic regions indicates that the climatic effects of this event were globally extensive. The total duration of the MECO event is estimated at ∼500 ka, with peak warming lasting <100 ka. Assuming minimal glaciation in the late middle Eocene, ∼4°–6°C total warming of both surface and deep waters is estimated during the MECO at the study sites. ... The synchroneity of deep-water acidification and globally extensive warming makes a persuasive argument that the MECO event was linked to a transient increase in atmospheric pCO2.
  10. Climate change from 40 million years ago shows climate sensitivity to CO2
    Another comment to John Cook: You take one location and say it is a reasonable representation of global effects. I won't dispute that, but it is weak. Now let us look at the Greenland ice core going back the last 10,000 years, and even back it up with an ocean floor core in the Sargasso sea. These (and other sources) show that the temperature was warmer several times and cooler several times by up to 2 C or more. The present temperature at these sites, which appears to be a natural recovery from a cool period called the little ice age, is actually slightly below the average peak for the last several thousand years. The speed of change was as high or higher for many of these variations. Yet the CO2 is indicated as constant to a narrow level. What do you propose as the cause of the variations, which make the present 150 year variation seem as typical? I would be glad to input the curves, but I am sure you have seen them.
  11. Climate change from 40 million years ago shows climate sensitivity to CO2
    #31, Bodo, I agree with your comment. 15 ppm per 1 C it is. Going back to the post by John Cook: John, I look at figure 1 and ask where you get 5 C as the temperature change. It appears the temperature and CO2 were going in opposite directions up to the beginning of MECO. Explain that. Also the 5 C assumes the red proxy case is the correct one, and the value was used at the low at the beginning of MECO and the high within it. However, if you start at the earlier time on the graph, the maximum increase in MECO is only about 2.5 C for the red and near zero for the purple proxy (based on the earlier maximum than MECO). In addition, there is a slow peak after MECO in CO2 but a dropping temperature. It clearly appears something happened, but the deduction shown is not a strong one.
  12. Climate change from 40 million years ago shows climate sensitivity to CO2
    @Iweinstein: For example the interglacial/glacial cycles, there you have enough time (5000 years ca.) and the feedback is about 15 ppm/K. Furthermore oceans were ventilated during that time, biological pump was more efficent during the glacials. Check also the Frank et al 2010 Nature paper. They state that there is only a limited time dependece of the co2 feedback.
  13. Climate change from 40 million years ago shows climate sensitivity to CO2
    #28, I am curious where you came up with the figure of 15 ppm CO2 caused by 1 C temperature increase. Consider that only the upper 10% or so of the ocean has time to respond to a 1 C temperature change in just 100 or so years. In a few thousand years, all of the ocean would be affected, so about 10 times the CO2 would be released. Actually, since the deep ocean is far colder than the surface, and since the solubility of CO2 is far higher in cold water, I expect even more than 10 times the CO2 would be released for a 1 C increase. You are welcome to try to refute this.
  14. Climate change from 40 million years ago shows climate sensitivity to CO2
    #25: "I havent heard of MECO " MECO shows up in literature as early as Bohaty and Zachos 2003 This isotopic event is designated as the middle Eocene climatic optimum, and is interpreted to represent a significant climatic reversal in the midst of middle to late Eocene deep-sea cooling. The lack of a significant negative carbon isotope excursion, as observed during the Paleocene–Eocene thermal maximum, and the gradual rate of high-latitude warming suggest that this event was not triggered by methane hydrate dissociation. Rather, a transient rise in pCO2 levels is suspected, possibly as a result of metamorphic decarbonation in the Himalayan orogen or increased ridge/arc volcanism during the late middle Eocene.
  15. Abraham reply to Monckton
    AWoL. You found Monckton's rebut 'pretty impressive'? I on the other hand, thought of a line by Shakespeare. I'd describe is as "... full of sound and fury, signifying nothing." If you find the scientists responses lacking in passion, perhaps it's because they are concerned primarily with precision, accuracy and facts. Remove the many colourful ad hominem attacks by Monckton in his rebut and you'll find that while it may have style, it's sorely lacking in substance.
  16. What should we do about climate change?
    Peter Lang #368 My hot water heater may not be an electricity generation system, but as it replaced an immersion heater, it certainly has a substantial impact on demand (reduced our household consumption by about one third). I'm concerned that your argument is geared towards confirming your assumptions. That is, you're aggressively arguing your case, without examining if the assumptions of your argument hold up to scrutiny. If you start making the assumption that some of the premises of your argument are incorrect, and use that to test the quality of your argument, then I'm going to be in a much better position to accept the veracity of your position. For example, what effect would a smart grid have on peak demand if 'discretionary' heating and cooling activities could be moderated through demand side management? What synergistic effects would this have if wind and solar sites were placed to reduce the problems of intermittency? And so on. Right now, I see you agressively defending your own argument with no evidence that you've challenged your own assumptions. Once the small scale safe nuclear stuff is clearly viable, and commercially available, I will be writing to my politicians by the way.
  17. Climate change from 40 million years ago shows climate sensitivity to CO2
    RSVP: The CO2 feedback (you increase the temperature 1°C, how much does CO2 rise?) is about 15 ppm/K. In MECO temperature increase was according to Bijl et al 2010 6°C or less, thus an increase of 2000 ppm or more is difficult to explain with CO2 outgassing as an feedback. Another point is that there are many different ways to estimate climate sensitivity, they ALL come up with about 3°C, read for example Knutti 2008
  18. Climate change from 40 million years ago shows climate sensitivity to CO2
    moderator #18 Thanks for your answer. michael sweet #20 Thanks for listening so keenly. Again, the stronger one assumes the coupling between CO2 and climate, the less change in CO2 level needed to affect climate (i.e., CO2 has great leverage)..., or the inverse; the weaker the coupling between CO2 and climate change, the more change in CO2 level needed to affect climate (i.e., CO2 has little leverage). This paradox makes it difficult to know with certainty that CO2 has any effect, because in the first case any correlation may be completely false, and in the second, if true, the coupling is weak and might as well be ignored. If, as has been stated, CO2 is released with higher temperature, it is clear that cart is in front of the horse, and neither are going anywhere.
  19. Climate change from 40 million years ago shows climate sensitivity to CO2
    As it seems this CO2 increase was even lager than PETM (about 700 ppm), and no knows source (but lower temperature increase)? Seems to be an interesting research topic ;-)
  20. Climate change from 40 million years ago shows climate sensitivity to CO2
    Very interesting paper! Perhaps you could add a few clarifying words about the CO2 increase. The fact that there was not a strong signal in carbon isotopes is stunning. The source of carbon must be an different as in PETM (probably methanhydrates). PS Does anyone know why reasearch focuses so much on PETM? I havent heard of MECO until a few minutes ,while PETM is discussed for a long time in journals?
  21. Sea level rise is exaggerated
    Re: Karamanski (103) Not accounting for an additional rise due to an unknown level of thermal expansion, if it all goes at some unknown point in the future, Greenland contains enough water to raise sea levels by 7.2 meters while Antarctica (WAIS + EAIS) has enough to raise sea levels by 61.1 meters for a total of 68.3 meters (224 feet). Dunno where you got those figures (not cited in my powerpoint of the same name), but that total amount is approximately the vertical interval between the lowest of the sea levels during glacial max and that if all the ice melted. Perhaps that is what they meant. As far as thermal expansion, my understanding is that per each 1 degree C of ocean temperature rise will be accompanied by 1 meter sea level rise just from thermal expansion. Unless memory is deserting me. The Yooper
  22. Sea level rise is exaggerated
    What is the maximum possible sea level rise if all of the glaciers and ice sheets melted, and how much sea level rise can we get from thermal expansion? I read in "Global Warming FOR DUMMIES" that the maximum possible sea level rise from global warming is 650ft(200m) is this correct?
  23. Climate change from 40 million years ago shows climate sensitivity to CO2
    Miekol: "The fossil fuels that was once living organisms had to get their CO2 from the atmosphere, so early on the atmosphere must have been loaded with CO2." Even at a basic level that is incorrect. You are confusing carbon with CO2. A lot of CO2 would have been sequestrated by life at the time and held as carbon. As a poster pointed out you need to understand the carbon cycle. Apart from that, the faint young Sun and the CO2 thermostat would have taken care of long term CO2 effects and levels over hundreds of thousands of years.
  24. Compendium Maps: a visual summary of the climate debate
    Here are databases of climate research literature in a similar map format. Scroll down to 'Research Front Map'; there are four sub-topics mapped out. Another interesting feature is the Top 20 list. A few years back AAPT published 'famous physicist' and 'famous astronomer' trading cards; maybe someone can do climate scientists based on these lists.
  25. Climate change from 40 million years ago shows climate sensitivity to CO2
    From the article:
    During MECO warming, atmospheric CO2 increased to between 6,400 to 15,000 ppm.
    This statement misled me too. There is a peak in the algae estimates band in the CO2 graph at about 15000ppmv alright, but the red trend line seems to meander between 2000 - 3000ppmv as The Skeptical Chymist points out. It certainly never goes much above 4000ppmv.
  26. Climate change from 40 million years ago shows climate sensitivity to CO2
    #21: "this paper only measures the change in sea temperature at one site" The Eocene climate is quite well-researched. For further reading, here is a database of recent papers.
  27. The Skeptical Chymist at 22:17 PM on 6 November 2010
    Climate change from 40 million years ago shows climate sensitivity to CO2
    Re the increase in C02. Although this isn't my field I take it that C02 changes were found by measuring carbon isotopes in algae. The carbon isotopes showed a clear change demonstrating a large increase in C02, but the difficulty is in trying to convert this into actual C02 concentrations. How much the carbon isotopes change is apparently also dependent on phosphate concentration, so if you know the phosphate concentration you can get a more accurate determination of what the C02 change was. Their attempts to do this are shown in the light and dark grey bands in figure 1 above. By adding in more information they improved their phosphate concentration estimation and were able to get a better estimate of C02 increase (dark grey band which has lower uncertainty). This suggested a "rise in pCO2 by 2000 to 3000 ppmv" which is 2 to 3 times the baseline C02 of 600 and 1600 ppmv. @10 HM. AFAIK polar amplification is at least partially driven by the ice albedo feedback which didn't exist at this time (it was an ice free world). You are correct in noting that this paper only measures the change in sea temperature at one site, however as noted in the paper these results are consistent with previous measurements of the temperature change at this time from other sites
  28. What should we do about climate change?
    Peter Lang, Since you have not responded to my question about subsidies for wind in Texas I presume that you could find no subsidies. These extensive installations have been put in by the free market and reduce CO2 emisions now, not at some future time. The electricity they generate is billed when it is used at market rates. They are primarily limited by a lack of transmission lines. I doubt that Texans are subsidizing wind as you imply, it is the center of the oil industry and Texans are known to be anti-green. You must provide documentation for your extraordinary claim of wind subsidy in Texas. I am still paying monthly for the unapproved nuclear plant. Since you have not responded to my question about reactor safety in third world undeveloped countries, despite me asking it three times, I conclude that you feel that it is unsafe to build reactors in the third world. How do you propose the third world reduce their CO2 emissions, since they can't safely use nuclear? Your claim about R&D for established industries compared to new technology is absurd. On this web site it is expected that claims will be supported by documentation beyond what the nuclear industry puts out to support their position. You have convinced me that the nuclear option is limited in its ability to provide safe electricity to the world for the near term. Perhaps we can have this discussion again in 20 years if thorium reactors actually work and have a safety record we can examine. I have seen many similar proposals from nuclear proponents in the past that did not work and am skeptical about thorium. I would like to see a proposal for waste storage beyond "leave it to our children to take care of". I also don't like to see all the eggs in one basket, but your nuclear proposal looks like a bad idea that should go to the end of the line.
  29. What should we do about climate change?
    kdkd, Since you live in southern NSW you may have heard of Queanbeyan, yes? This should be of interest. Seriously, you should gain a lot of understanding from it.
  30. What should we do about climate change?
    kdkd, I posted before I was complete. Personally given the imperative to decarbonise, I'm wary of any solution that suggests putting more than half of the eggs into one basket :) Fair point. But surely that should lead you to do all you can to remove the blocks and imposts against nuclear. [don't forget wae presently have 80% of our eggs in the coal basket in Australia and 76% of our eggs in the nuclear basket in France. So I don't think this is a vaild point. I believe our requirements are: 1. security/reliability of supply 2. least cost 3. health, safety and environmental
  31. What should we do about climate change?
    kdkd, Well I have a solar thermal plant on my roof in southern New South Wales (an evacuated tube solar hot water system), That is not a solar thermal electricity generating plant. Not the same at all. Try this indicating that not everything has to be about electricity generation in order to reduce demand from the grid. The above link applies here too and also see David Mackay's 'Plan C' (see links on previous page) Next, once we add externalities, which demonstrate that fossil fuel technologies and renewables are of similar costs before we've realised economies of scale and technological advances relating to renewable technologies. Not even close. See my previous comment as to why you cannot directly compare the costs of electricity from intermittent generators with dispatchable generators.
  32. Climate change from 40 million years ago shows climate sensitivity to CO2
    RSVP, As you have been told numerous times before, for the climate to change there has to be a reason. Fireflys don't count. If orbital changes cause temperature changes, as has happened many times in the past, then CO2 rises as a feedback. If temperature goes down CO2 goes down. You appear to be deliberately asking stupid questions that you have been told the answer many times before. Read the basics before you post more questions that everyone knows the answer to.
  33. What should we do about climate change?
    PL #365 Well I have a solar thermal plant on my roof in southern New South Wales (an evacuated tube solar hot water system), and I can assure you that while it's not nearly as effective between the March and September equinoxes as it is for the other 6 months of the year, it's certainly no dud during that time. If it's cloudy for a week in winter we have to put the booster on for a couple of hours once every few days. Its winter effectiveness could be fixed by increasing the number of collectors by about 20%. Once you get to lattitudes more polar than say Tasmania, then winter effectiveness will be a serious problem. I see that CSIRO are currently commercialising domestic air conditioning technology based on solar-thermal and evaporative cooling principles, indicating that not everything has to be about electricity generation in order to reduce demand from the grid. Next, once we add externalities, which demonstrate that fossil fuel technologies and renewables are of similar costs before we've realised economies of scale and technological advances relating to renewable technologies. Nuclear on the face of it appears cheaper than both (including externalities), although the capital costs are very high in this case. The safety issues seem to be being addressed, but "safe non-proliferative nuclear" seems to be a couple of years off yet (although I could be wrong). The posts I've seen from you have generally tended towards you producing arguments aimed at confirming your assumptions. I'd like to see you producing an argument aimed at testing your assumptions, so that you can test the rigour of your point of view. Personally given the imperative to decarbonise, I'm wary of any solution that suggests putting more than half of the eggs into one basket :)
  34. What should we do about climate change?
    We interrupt your regularly scheduled fiction for a brief foray into reality: Solar Energy Generating Systems (SEGS) is the name of the largest solar power facility in the world (though there are more than a dozen larger ones now in development). It first began generating electricity in 1984 and was completed in 1991... without the 'massive' subsidies (for 'massive' read, "vastly smaller than fossil fuel subsidies") currently available. It has an installed capacity of 354 MW and has been providing stable baseload power (despite this supposedly being impossible for solar) at competitive prices (despite THIS supposedly being impossible for solar) while also generating a profit (again, supposedly impossible) since the very beginning. SEGS is 20+ year old technology and thus uses natural gas as backup when sunlight is dim; which results in about 10% of the power generated by the plant coming from natural gas vs 90% from sunlight... contrary to claims that solar power actually requires the installation of MORE fossil fuel power than would be required without the solar power. Which are, of course, so mind-numbingly ridiculous that it is difficult to imagine how anyone can take them seriously. This concludes our brief foray into the real world and things which actually exist. We now return you to your regularly scheduled nonsense about how technology will never improve to the point where such things (that have been around for 20+ years) would ever be possible. Have a nice day.
  35. What should we do about climate change?
    kdkd, There is an enormous amount of background to cover. I'd suggest you start at the beginning of this thread, read the rational posts and also read the links. There is a lot here. I have observed that most people who have commented on this thread have been constrained by their deeply held personal beliefs and have not been prepared to do objective research. So I am a bit jaundiced to start with. I wonder if you will be different. Will you do the objective research to discover about this important subject for cutting the worlds CO2 emissions from fossil fuel use? The current cost of solar thermal - in day time only and mostly in summer (it is next to useless in winter) - is about $225/MWh. USDOE has a goal to try to get solar thermal capable of baseload generation by 2030. NEEDS has a projection to get solar thermal to be able to provide 24 hour power by 2020. That is it is hoped it will be able to supply one day of full power by 2020; but this does not mean baseload capable because baseload would mean it could generate throughout long periods of overcast weather, dust storms, etc). The point to understand is the cost of energy from solar and wind cannot be compared with cost of energy from fossil fuels or nuclear without including the costs of the back up generators. The same applies to the externalities. In short, intermittent renewables have application for remote sites (but very expensive) and can make a small contribution to the grid. Anymore than a small contribution increases the cost of electricity from the grid substantially (I cannot quantify 'substantially' without defining many assumptions and constraints). We all agree it would be ideal to include more of the externalities in the cost of energy. And we have been progressively including more, mostly by regulating the emissions. However there are offsetting costs too, and in reality we have to achieve the best balance. There is a cost to society of raising the cost of electricity. Just look at the people who do not have electricity and look how they live to understand the costs of making electricity more expensive. I argue electricity should be as cheap as we can possible make it. See previous comments to understand why. I also argue that we can have low-cost low-emission electricity. We are blocking that by the polices we impose and we have been imposing for the past 40 years or more. But to understand requires opening one's mind!
  36. Climate change from 40 million years ago shows climate sensitivity to CO2
    Considering the correlation assumed between CO2 and temperature, it would seem that the less CO2 changed as a function of warming, the greater its effect. This of course rests on the initial assumption that climate change is driven by CO2, and not (for instance) the fire fly population.
  37. Climate change from 40 million years ago shows climate sensitivity to CO2
    Just wondering if there a position amongst those who truely believe CO2 drives climate, as to what would happen to CO2 levels if it simply got warmer for some other reason??? Would CO2 levels remain the same, go up, go down, etc.
    Moderator Response: Under modern conditions, which are quite well understood, CO2 is considered to be the biggest control knob of global temperatures, but not the only one. The sum balance of all forcings and feedbacks (of which CO2 acts as both) determines global temperatures. In the situation you briefly posit, rising temps would then drive a methane/CO2 release to some degree, driving a further warming response (a self-limiting mechanism, overall). If you wish something more specific in response, please posit a physics-based mechanism for your thought experiment for the group to discuss.
  38. What should we do about climate change?
    PL #363 There's unnecessary sarcasm in your reply. I may have spelled megawatt hour incorrectly, and I haven't been following the comments here terribly slowly for the past couple of weeks, so I'm afraid I'm not across the detail of what you've been posting. Anyway I don't know much about the topic, but I'm pretty clear that economics is far too anthropocentric a discipline to be taken seriously ;). I'm of the view that we should account for externalities to the maximum extent possible. Particularly where human activities can have long term unintended consequences. Anyway, we've established that the real cost of coal is approximately greater than or equal to the real cost of wind. How does it stack up with solar? Bear in mind that solar probably has quite a lot of distance to go before price and storage capacity is optimised, and it could well be entirely appropriate to subsidise this until it can hold its own.
  39. What should we do about climate change?
    kdkd, Your sacrism is noted. I am just wondering why you didn't look it up yourself given that I've postred the link about a dozen times so far? Since you clearly know a lot about this subject, could you explain which externalities should be internalised and which should not, and how you suggest we should internalise them? Why haven't we managed to yet given that we've been working on this for the past30 years? You forgot to mention what is the cost to society of higher cost electricity? Also, for my benefit, could you please explain what is a MwH?
  40. What should we do about climate change?
    PL #359 (the funniest three digit number according to Douglas Adams fwiw). You need to quantify your statement, not just throw out assertions. Actually in this case I don't. I just needed to point out the hole in your argument. Which leads to #361 and thank you for doing some research. According to my calculations, from the main table on page 13, firstly the external costs of fossil fuel power is aproximately an order of magnitude greater than for the non-fossil technologies. The average external cost for coal is somewhere between €40 and €75 per MwH ($USD 55-105 per MwH). The average externalities for the other technologies (including nuclear) are going to be around 5-10% of this value, and gas is around 25% of the coal externality for reference. I have no particular nuclear axe to grind, but I'm quite keen on the idea of efficiency through distributed power generation, and not putting all of our eggs in one basket (with the proviso that we should decarbonise as quickly as possible). Again, thanks for doing some research :)
  41. What should we do about climate change?
    kdkd, Here is European data on the externalities for the different electricity generation technologies (see the two tables on page 13)
  42. What should we do about climate change?
    KR, I agree nuclear was heavily subsidised in the past. So were hydro and fossil fuels and renewables (and still are). But this doesn't change the fact that you have to make comparisons on a properly comparable basis. The link provided the annual subsidies by governments. Therefore, to obtain a proper comparison you need to divide the subsidies by the amount generated in that year. If you want to life time subsidies you need to get the life time subsidies and divide by the life time energy generated by the technology. A couple of other points. Much of the subsidies for nuclear were for military purposes not civil. The total subsidies would need to be split in the appropriate proportions if you want to compare lifetime subsidies. The other point is the figures in the link to not contain the major component of the renewables subsidies (see my previous comments on this, e.g. #353).
  43. What should we do about climate change?
    kdkd, You need to quantify your statement, not just throw out assertions. How much higher? You also need to factor in what is the cost to society of higher cost electricity.
  44. It's cooling
    Found this poking around on Kelly O'Day's site. Data through 10-26-2010. The chart can be found here. The Yooper
  45. It's cooling
    Re: erikbays (71, 73) Your claim was that:
    "According to the NAS even surface temperatures from proxies like tree rings are not that reliable earlier than about 500 years ago. But there is no way at all to get total ice volume or temps from specific layers of the ocean from the medieval warm period or earlier."
    This claim is addressed both in the linked post you were given as well as linked from there directly to this 161-page NAS document, 'Surface Temperature Reconstructions for the Last 2,000 Years'. I would direct your attention to FIGURE S-1 on p 17 and then these quotes from the summary on p 18:
    "It can be said with a high level of confidence that global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries."
     and
    "Less confidence can be placed in large-scale surface temperature reconstructions for the period from A.D. 900 to 1600."
     Less confidence does not mean unreliable or no confidence. Compare the confidence expressed in those two quotes to that in this (also from the summary on p 18):
    "Very little confidence can be assigned to statements concerning the hemispheric mean or global mean surface temperature prior to about A.D. 900 because of sparse data coverage and because the uncertainties associated with proxy data and the methods used to analyze and combine them are larger than during more recent time periods."
     So, the NAS has little confidence in surface temps prior to A.D. 900, and high confidence in temps post-1600 A.D., with temps 900 - 1600 A.D. falling somewhere in-between, confidence-wise. This, based on multiple, converging lines of evidence. Thus, the post you were directed to did indeed refute your claim. I believe that is why the Moderator directed you to the prior post. I'd recommend reading the entire NAS report. There's some good stuff in there. If your point was otherwise, I'd recommend re-phrasing it more narrowly & resubmitting it. Hope that helps. The Yooper
  46. What should we do about climate change?
    I will point out that nuclear power plants were heavily subsidized when first developed. It's a bit hard to compare the situation of a relatively mature technology (at least for once-through light water reactors) to wind farms that are still somewhat in development as major grid sources.
  47. What should we do about climate change?
    Peter Lang #353. "The LCOE for New coal plants is around $50/MWh and much lower for existing plants." This is with the externalities being given a value of $0/MWh. Once you price the externalities properly, this figure should be much higher. Not only CO2 emissions, but other forms of damage caused by mining itself.
  48. It's cooling
    So after my post @ 71 it says my statement is addressed on the hockey stick page. Yet the hockey stick page does not talk about total ice volume or total heat content. I think someone was missing the point of my comment.
  49. What should we do about climate change?
    Regarding the cost of electricity from nuclear and renewables http://www.iea.org/Textbase/npsum/ElecCost2010SUM.pdf IEA, “Projected Costs of Generating Electricity – 2010 Edition; Executive Summary” compares the Levelised Cost of Electricity (LCOE) in North America, Europe and Asia Pacific by generator technology. Note this comment: Neither does the study include other systemic effects such as the costs incurred for providing back-up for variable or intermittent (nondispatchable) renewable energies. For the calculation of the costs of coal‑fired power generation with carbon capture, only the costs of capture net of transmission and storage have been taken into account. In other words, the costs for wind (and other renewables) do not include the cost of back-up and the cost of Carbon Capture and storage is meaningless because it is for the capture part only and does not include the transmission and storage.
  50. Climate change from 40 million years ago shows climate sensitivity to CO2
    #14: Sorry if you found my replies harsh. Your earlier comment So what? So what nothing! didn't give me the impression you were 'still collating'. "ALL of the history of the planet must be factored into the discussion" Yes, that's called geology. Please check the prior articles 'CO2 was higher in the late Ordovician' and 'CO2 was higher in the past' for some context for your thinking. Be sure to recall that paleogeography is a controling factor in both oceanic circulation and the degree to which the planet can sustain glaciation; plate tectonic activity (or the relative lack thereof) produces both CO2 and aerosols; carbonate deposition in warm shallow water has the capacity to suck huge volumes of CO2 out of the atmosphere. Oh, and did I mention there weren't any flowering plants in the Ordovician?

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