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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 68201 to 68250:

  1. Ocean Acidification: Corrosive waters arrive in the Bering Sea
    John Hartz - thanks. I only include the bullet-points for too-long posts, otherwise the takeaway points may be lost on readers. I don't think mentioning that this is one of 3 posts in the opening paragraph qualifies as oblique, but YMMV. Agnostic - "An interesting warning of the dangers to the fishing industry posed by Ocean Acidification – though arguably understated." Perhaps, but I'm kind of constrained by what the science has to say on this. The next post on ocean acidification (not one of the 3-part series), will hopefully shatter a bit of complacency on this topic. Ocean acidfication is fatal to (some) fish larvae.
  2. Clouds provide negative feedback
    RW1 - I have responded to your post on the far more appropriate Climate Sensitivity thread. Moderators - Might I suggest that discussions of total climate sensitivity are (while related) off-topic in a thread on the specific subject of cloud feedback?
  3. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Richard@31... You are clearly setting up strawman standards for things. There is a vast amount of medical evidence that people are unique and that statistical studies are inadequate for treating individuals....they predict population outcomes, not individuals. That's why we treat people with 5%$ odds or 1% odds or hopeless cases: because each individual is a cohort of 1. So no different that the earth. So much for "only one earth". But beyond that, you seem to think that there is something out there overriding the basic physics of the system. You seem to be operating in ignorance of all the work that has been done to exclude alternative possibilities...and even in a court of law, when we've ruled everything else out...the burden falls on skeptics to provide alternative hypotheses....not just imagine that there might be some. It's positively insulting to the people who've put this site together for you to suggest that warming has caused the CO2 levels to increase: You demonstrate you are seriously uninformed and uninterested in informing yourself. Prowl around this site- you'll find the explanations and original papers showing that the origins of atmospheric CO2 increases come from fossil fuel burning. You'll need to show where else CO2 could be coming from if NOT fossil fuels. You'll need to refute the mass balance requirement, once you read what that bit of logic is. Not to mention that once you hypothesize that the earth has warmed from something other than CO2 since 1850 you have assumed the burden of providing a physical mechanism for said warming. But that's why the burden is on the so-called skeptics. But then, were you denying warming has taken place?
  4. Climate sensitivity is low
    (Redirected from the Cloud Feedback thread here) RW1 - Quite frankly, this issue on total sensitivity has been explained to you, at length, in multiple threads here. You have yet to demonstrate any tendencies to incorporate the science you have been shown. For new readers: A doubling of CO2 would add 3.7 W/m^2 to the top of atmosphere (TOA) forcing of the climate. This should by all measures (and by that, I mean spectroscopic effects as integrated through the depth of the atmosphere - very basic physics) result in ~1.1°C warming directly. That works out to ~0.3°C/W/m^2. The 3°C warming estimated from numerous estimates is in the range of roughly 2-4.5°C, most likely estimate of 3°C, indicating a TOA forcing of roughly 10 W/m^2. That's an additional 6.3 W/m^2 forcing from feedbacks. CO2 represents roughly 1/3 of the current greenhouse effect - increases in water vapor will easily (well within the uncertainty ranges) account for the additional 2/3. In regards to cloud feedback (the change in forcing with temperature, not the initial value as RW1 emphasises), please read the opening post on that thread. The best estimates, best data, on that topic indicate that cloud feedback with temperature is slightly positive, with a range of uncertainty that does include (at low probability given the data) very slightly negative. Certainly not enough to overwhelm the increase in CO2 and temperature dependent absolute humidity.
  5. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Richard, please see the detailed explanation on Co2 lags temperature. (In short CO2 is both feedback (which further amplifies warming) and a forcing). This article is about whether there is a case against AGW in the peer-reviewed literature. It is best to discuss in the appropriate place (see the Arguments button on the top left.) If you dont, moderators will delete your posts for being off-topic. "So - what caused the .8 - .9 C warming since 1850, if not natural variability." GHGs mostly - (see here for actual breakdown) -it just takes time for full amount of warming to be realised but warming is immediate. If you want to argue for natural causes, then tell us what the natural forcing over that period was. Also, we can tell that the increased CO2 in atmosphere is not from warming - it has isotope signature of fossil fuel, not the signature you see in the ice bubbles. I strongly recommend you look over the arguments list to fix some misconceptions.
  6. (Fahrenheit) 451 ppm
    #84 KR But currently the 10 largest emitters (here, pg. 13) are in order China, the US, India, Russia, Japan, Germany, Iran, Canada, Korea, and the UK - together accounting for >65% of world emissions. Your count adds apple (USA, Japan) and orange (India, China), not all these countries have the same real GDP per capita! Look at Peters et al 2011 figure for a comparison of developed and developing country. And above all, loo at the curve, one linear and flat, the other exponential and up. By the way, here in Europe we accept our historical responsibility and we're committed to GHG cuts, even if there is no international agreement in this sense. Considering fossil fuel 'cheap' power depends on ignoring the real, total costs of fossil fuels - including the external costs. That is exactly what I say. And so, why we do not implement immediately a global carbon tax, that is what I called "pricing carbon externalities"? It is very easy to implement (directly on coal, gas and oil producers, or deforesters) and quite easy to adapt (part of the tax will help specifically low and medium GDP countries that will be more affected by higher prices). (-Snip-) Rather than throwing ones hands in the air, claiming (as you have) that limiting fossil fuel usage will crush developing nations? When South Africa open a mega coal plant in 2010, the point of its policymakers is clear : “To sustain the growth rates we need to create jobs, we have no choice but to build new generating capacity — relying on what, for now, remains our most abundant and affordable energy source: coal.” What you call "my" claim is just what South-African, Indian, Chinese and other climate-energy plans are claiming, the escape of poverty will not be sacrificed. For example in the Chinese's National Climate Change Program, you can read : In the development history of human beings, there is no precedent where a high per capita GDP is achieved with low per capita energy consumption. With its ongoing economic development, China will inevitably be confronted with growing energy consumption and CO2 emissions. (…) To place equal emphasis on both mitigation and adaptation. Mitigation and adaptation are integral components of the strategy to cope with climate change. For developing countries, mitigation is a long and arduous challenge while adaptation to climate change is a more present and imminent task. China will strengthen its policy guidance for energy conservation and energy structure optimization to make efforts to control its greenhouse gas emissions. Meanwhile, China will take practical measures to enhance its capacity to adapt to climate change via key projects for ecosystem protection, disaster prevention and reduction and other key infrastructure construction » So if you understand the diplomatic language, beside the fuzzy promises of future effort for decarbonization, it means : mitigation is not our priority. (-Snip-) I think renewable energy development can be a definite win-win scenario I already gave above the numbers from IPCC SRREN 2011 concerning real capacities of RE in 2050 according to the median estimate of energy-economy scenarios. So you have to be specific : in a 450 ppm target in 2050, RE are planned to likely produce something like 250EJ/y, half of what we need now for 7 billion (500 EJ), not to say what we will need tomorrow for 9 billion. If you personally think that RE will produce 500 EJ or 750 EJ in 2050, you’ve to explain why the majority of 164 IPPC scenarios does not produce at all such a quantity. (-Snip-) #85 Sphaerica Some people disagree with you, and say that you have failed to make a coherent point, therefore this entire web site dedicated to presenting and clarifying the science is disingenuous. You're right. I clearly doubt your skepticism.
    Response:

    [DB] Inflammatory, political and argumentative snipped.  Please acquaint yourself with the Comments Policy of this venue.  And do also please attempt to ameliorate the inflammatory tone. 

    Modeling that which you seek others to emulate is best (good advice to all).

  7. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Richard Arrett - no amount of scrambling and 'blimp-pointing' will hide the rather humongous self-contradiction of the fake-skeptics. One can't trundle out 'low sensitvity' and 'the climates always changing' and expect to be taken seriously. Can you explain to me how both these memes can be true? With reference to the relevant peer-reviewed literature would be nice. Otherwise it's just an assertion, like say......"Brad Pitt and Angelina Jolie came to my house for dinner last night"
  8. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Richard, You are almost correct. Given all the natural processes, initial CO2 response _USED_ to be to temperature. Feedbacks and other mechanisms muddle the waters after the initial response. Since the industrial revolution, unnatural causes (humans burning fossil fuels and emitting CO2/CH4 through farming and herding) have caused CO2 to lead this cycle by causing temperature rise. There is no evidence anywhere in the empirical and computational data that there is a "natural" forcing in play that causes the current warming. Search SKS and you will find multiple references, articles, explanations supporting what I just explained.
  9. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Sorry - I meant Dave123 #21.
  10. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Dave123 #23: Only if you have as many Earth's as people have moles. To bad we only have one data point.
  11. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Rob Painting @26: I thought that CO2 followed temperature by around 700 years. It seems to me that the ice core data shows that as the temperature rises, that temperature rise causes the CO2 to rise. Based on past evidence therefore, the natural warming which may have occurred since 1850 could be the cause of the higher CO2 levels.
  12. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Chris @20: I don't understand your reasoning. Are you not double counting the .8 - .9C? On the one hand we have warmed .8 to .9C, but you then add the .87C equilibrium warming on top of that "since it takes the earth many decades to come to equilibrium with the current forcing resulting from raised greenhouse gases". So - what caused the .8 - .9 C warming since 1850, if not natural variability. Is it not possible that we are at equilibrium warming, and that it just happened much faster than you assume is possible. Therefore the .87C is the .8 - .9C of warming since 1850. What that means is that we will only experience 1.3C of direct warming due to C02 by 2100 - and there is no indirect amplification feedback additional warming. Isn't that also consistent with the evidence?
  13. Clouds provide negative feedback
    Well that is the physics whether you can understand it or not.
  14. Ocean Acidification: Corrosive waters arrive in the Bering Sea
    An interesting warning of the dangers to the fishing industry posed by Ocean Acidification – though arguably understated. Analysis of ice cores shows that alkalinity is now lower than it has been for 600,000 years and is continuing to fall. The average pH of ocean surface water has fallen by 0.1 of a unit since the industrial revolution and by the end of this century is predicted to have fallen by 0.35 - 0.5 units. The rate at which pH is now falling is estimated to be over 100 times greater than at any time during the past 100,000 year. The problems are both the reduction of alkalinity (falling pH) and the speed with which it is happening. The former damages calcifying marine life, the latter gives it no time to adapt. The result: Serious damage the marine environment and adverse affects on the ability of crustaceans and fish to survive. As CO2 entering the atmosphere continues to rise, increasing amounts of the gas are dissolved by seawater. In colder waters CO2 is dissolved more readily and reacts with water to form carbonic acid. In both cases, rising quantities of CO2 pose serious and growing problems for calcifying marine animals such as algae, corals, plankton and molluscs, by reducing the concentration of calcites present in seawater. Pteropods (Thecosomata), a small snail form of plankton are particularly vulnerable to this change since they make their shells from Arogonite which is 50% more soluble in water than other calcites. Reduced presence of this material makes it more difficult for juvenile pteropods to secrete and maintain robust protective shells. This greatly increases their vulnerability. So serious is this problem that marine scientists predict that Pteropods are likely to become extinct within 40 years. Pteropods are present in all the oceans. Such a wide variety of fish depend on them as their main source of nourishment and consume them in such vast numbers that they have been appropriately described by Dr. Hoffmann (University of California) as ‘chips of the sea’. The danger (and it is a very real one) is that loss of pteropods will have an effect so adverse as to create a significant break in the marine food chain. Millions of humans depend on these fish, or other fish which prey on them, as their main, often their only source of protein. At the very least, extinction of the Pteropod will result in major depletion of commercial fish stocks and growing scarcity, even their total loss to those who depend on them most.
  15. We're heading into an ice age
    Phil/Tom, there's also this paper: Effect of the potential melting of the Greenland Ice Sheet on the Meridional Overturning Circulation and global climate in the future - Hu (2011). I always save copies of papers that interest me when I'm trawling the internet, and your discussion rang a few bells. The modelling shows that even high rates of Greenland icesheet melt over the coming centuries will only slow global warming by a few tenths of a degree. Hardly enough to start a new ice age. If only eh?
  16. Clouds provide negative feedback
    scaddenp, "That additional flux on the surface comes from increase in backradiation due to increased GHGs. It is that simple. This is not sloppy; it directly calculated from the RTEs." You disappoint me with your answer.
  17. Clouds provide negative feedback
    Well, many people have tried to educate on the physics without success, but as to this one: "There are really only two possible sources for this required energy flux into the surface, and that is either from the Sun via a reduced albedo or from increased atomspheric absorption (like from water vapor)." That additional flux on the surface comes from increase in backradiation due to increased GHGs. It is that simple. This is not sloppy; it directly calculated from the RTEs.
  18. 2nd law of thermodynamics contradicts greenhouse theory
    John Hartz @1185, I do not think merely presenting a view, however flawed, should be grounds for banning or deletion of posts. Continuous and repetitive presentation of the same point again and again should be grounds for deletion of further repetitions as of topic, but I do not believe TOP has reached that point, yet.
  19. We're heading into an ice age
    Randy Subers @248, you are missing the obvious point that well before the 50 K years the Greenland Ice Sheet will have melted away, as will the Arctic Sea Ice (much earlier). Therefore in 50 K years there will not be massive charges of melt water to slow the conveyor because there will be no melt water remaining from our entry into the anthropocene. Whether we could return to an ice age in 50,000 years depends critically on how much CO2 we emit in the coming 100 to 200 years. If we keep it below 1000 tonnes of carbon, then in 10,000 years CO2 levels may have declined enough so that Milankovitch cycles can restart the recent pattern of glacials and interglacials. Should we continue at business as usual, however, even 50 thousand years from now, CO2 levels may still be too high for that process to recommence.
  20. We're heading into an ice age
    Tom, this seems to back my view - current melting isnt going to do anything dramatic, especially not another ice age. From the release: "No one is predicting another ice age as a result of changes in the Atlantic overturning," said Willis. In short, worry about warming, not a coming ice age.
  21. Clouds provide negative feedback
    I'm a bit late on this. We all agree that clouds both cool by reflecting the Sun's energy and warm by 'blocking' or delaying the exit of surface emitted energy, but this is rather trival to the fundamental question of the net cloud feedback, is it not? The biggest problem is in the current climate, the net effect of clouds globally averaged is to cool by about 20 W/m^2, as is even acknowledged in papers claiming to show net positive cloud feedback (i.e. Dessler 2010), and is consistent with net negative feedback from clouds. This discrepancy would have to be explained in the context of strong net positive feedback from clouds on incremental warming, would it not? Not only is this not explained either by Dessler or anyone else to my knowledge, but without knowing physically why the net effect of clouds is to cool by 20 W/m^2 in the current climate, there is no way to know if the assessments of net positive feedback on incremental warming are accurate, let alone even physically possible. Ultimately, the fact that no one purporting evidence of net positive cloud feedback can explain this or even tries to explain it in light of the conclusions of their work, is rather telling to me how weak and unsubstantiated the case for net positive cloud feedback actually is. And while globally averaged, the water vapor concentration and water vapor feedback in response can further increase temperatures in a warmer world, it cannot be separated or isolated from the cloud feedback, as the two are constantly interacting together to maintain the current energy balance. This gets back to my point about the water vapor and cloud feedbacks already operating in a very dynamic manner in the current climate's globally averaged state from the forcing of the Sun. From this, let's look at the fundamental question of climate sensitivity, net feedback, etc. from the basic constraints dictated by conservation of energy. If the surface of the Earth is the warm by 3C, it must emit 406.6 W/m^2 from S-B (assuming an emissivity of 1 or very close to 1), which is +16.6 W/m^2 from the current global average of 390 W/m^2. Conservation of Energy dictates this +16.6 W/m^2 flux has to be entering the surface from the atmosphere on global average if it is to warm by 3C. There are really only two possible sources for this required energy flux into the surface, and that is either from the Sun via a reduced albedo or from increased atomspheric absorption (like from water vapor). If the current averaged state of the atmosphere is only going to provide +6 W/m^2 (+1.1C) from 2xCO2 (3.7 W/m^2 directly from the CO2 'forcing' and the remaining 2.3 W/m^2 from the current average opacity of the atmosphere; 3.7 W/m^2 x 0.62 = 2.3 W/m^2), where is the additional 10.6 W/m^2 needed for the 3C rise coming from? Can anyone explain and quantify the actual physics of how about a 1 C rise in temperature will change the atmosphere in a way that will further cause an additional 10.6 W/m^2 flux into the surface? If you think it will come primarily from increased water vapor, are you claiming that the water vapor absorption will increase by 10.6 W/m^2 from a 1 C rise in temperature (actually more than 10.6 W/m^2 because half of what's absorbed by the atmosphere escapes to space as part of the flux leaving at the TOA), and if so based on what data or physics? Or if you think the combined cloud feedback will cause a large portion of it, in what specific physical way? If by letting in more sunlight, how does increasing water vapor cause decreasing clouds or more transparent clouds? If by causing increased atmospheric absorption through more clouds, how is this specifically more than the incremental power reflected from the additional or thicker clouds? How is this rectified with the fact the net effect of clouds is to cool by about 20 W/m^2 in the current climate? In general there seems to be a lot of hand waving in regards to this fundamental question and answers to it tend to only be vague, generalized statements like "it comes from the all the feedbacks" or "from downward LW", etc. This kind of sloppy and incomplete scientific reasoning is not good enough. The required energy entering the surface for a 3C rise has to be coming from somewhere specific and from some specific physical process or combined processes that can be corroborated by some real, observable, quantifiable physics and data. I see mosly heuristic assumptions and more or less wild guessing dressed up as some kind of quasi 'best estimate' or 'educated guess'.
  22. Galactic cosmic rays: Backing the wrong horse
    Eric, GCR does not need to be added to anything, as there is still, despite many requests, no mechanism for how it would operate. Cute model pirate ships don't need to be added to the models either. Others have already said the mercurio is junk science and should not be relied upon, one last example is he does not suggest the primary hypothesis for the PDO, that it is simply the integrated result of ENSO (Newman et al 2003). You keep saying 'potential' this, 'possibly' that in relation to GCR, but the reality is there's nothing there to hang your hat on. Sphaerica has it right above.
  23. (Fahrenheit) 451 ppm
    KR-
    It unfortunately represents a redistribution of wealth away from some vested interests, who are spending rather large sums lobbying for Business As Usual...
    It needn't be that way,in my view,if those vested interests would throw their considerable capital investment power behind alternative energy development.That way they can immediately drop their disinformation campaign,and keep all that money that they are funneling to politicians and advocacy groups,and go full bore into a cleaner future,and a safer world for themselves,their children,and grandchildren,and be genuinely proud of the business that they are in,instead of having to manufacture artificial advocacy using deceitful tactics.
  24. We're heading into an ice age
    scaddenp @252, this press release from NASA details some of the latest research. In essence, models predict a slowing of the Atlantic Conveyor with increased melt water because fresh water is less dense than salty, and hence less prone to sink. Josh Willis has used buoy data and satellite data to show the Atlantic Conveyor sped up by 20% from 1993 to 2009, contradicting earlier ship-based data. There has been no statistically significant change from 2002-2009. The acceleration is attributed to a possible natural cycle. However, I would note that Greenland ice melt has primarily been in areas where it would feed the Labrador current. Further, because of the reducing volume of sea ice, it is not clear the more extensive summer melt back results in more fresh water being introduced to the Arctic Ocean. The point is that there are obvious complexities in this issue, not all of which I have covered (or are competent to cover). If you want to become up to date on the issue, this google scholar search will get you started ;)
  25. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    >You have the burden of proof wrong. No. This is science not law. What science is about is finding the model that best explains observation. >I don't have to provide an alternative to natural >variability because that is the null hypothesis. All variation in climate has causes. We have an excellent model of natural forcing changes that have caused climate change in the past. We can also see that these natural forcings should be cooling the climate if any when in fact we are warming. (see here. In fact, read the report so you actually know what the science says. "That is why you have the burden of showing that the warming spike we are currently in is due to CO2 and not the other causes (whatever caused the warming in 1100 AD or 3000 BC)." Our current climate theory has no problem accounting for these past warming event (did you know that?), but struggles to explain current warming without anthropogenic factors. Policy has to be informed by theory that works.
  26. Arctic sea ice has recovered
    Thanks, thats great. I am not sure I have a full understanding but it is certainly much clearer. I would just like to clarify that I have got your explanation right by puttting what you say into my own words. The PIOMAS model is designed to make estimates of ice volume by using measurements of ice thickness which have been taken by submarine. The model then adds estimates of the amount of ice it expects to find in other areas and from this it gives a trend. (I am not sure how these estimates are arrived at but I'm guessing it is complex and I am not too worried about this). These measurements are combined with satellite measurements of area covered from which we can determine volume. As well as measuring surface area, the satellite can also measure the amount of ice thickness in areas where it can be seen above sea level and from this it is possible to calculate total thickness in the way you have explained. Measurements of ice thickness is also taken using various other methods - drilled sample readings etc To check the accuracy of the PIOMAS estimates, ice thickness is checked in areas where it has not been checked previously by using the various methods we have already talked about. Results from these checks show that the estimates are pretty good but tend to have a bias towards overestimation of ice thickness. Just to add to this myself, it means that whenever we see these charts that show the rate of loss in ice volume, these are conservative estimations and the loss is probably greater than that shown. Is that about right?
  27. (Fahrenheit) 451 ppm
    83, skept.fr,
    But I think I have now a clearer idea of how skeptic is "Skeptical" Science.
    Let's see. Some people disagree with you, and say that you have failed to make a coherent point, therefore this entire web site dedicated to presenting and clarifying the science is disingenuous. Yes, that makes sense. And your agenda is now crystal clear to everyone.
  28. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    14 Sphaerica, --"maybe a simple question along the lines of 'did you consider this?'" Actually, I raised such a question in response to the Part 2 post. "...veiled...implications of impropriety and deceit" You might re-read the comments and re-examine your thinking that led to these bitter words.
  29. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Richard Arrett @ 19 - "If CS turns out to be 1.3C - that will imply there is no indirect amplification feedback." How exactly is that supposed to work given that we know that the Earth was both much warmer and cooler in the past? If, as the fake-skeptics claim, the Earth is so insensitive, why has the Earth's climate changed so much over long timescales? And why is there such a strong relationship between CO2 and global temperature? (see below) See that's the problem with fake-skeptics, their ideas are negated by observations, and don't make any sense. And worse yet, they continually contradict themselves. One minute the 'climate is always changing', the next 'climate sensitivity is low.' Why is it now, when humans are pumping vast quantities of a powerful greenhouse gas into the atmosphere, that some never before observed, and inexplicable in terms of the physics, low sensitivity is supposed to ride to our rescue? That is why fake-skeptics are summarily dismissed by the scientific community. We need to focus on facts, not wishful thinking and self contradictory fake-skeptics.
  30. Galactic cosmic rays: Backing the wrong horse
    Eric#103: "I am however still interested in GCR due to its potential modulation of water vapor feedback." As we've seen, the most recently published results consist of Dragic, Love 2011 and Laken, all reporting that this 'potential modulation' is either minimal, undetectable or non-existent.
  31. (Fahrenheit) 451 ppm
    skept.fr - Side note: I can understand being tired of a particular discussion, but I do not believe that excuses the rather snarky tone of your post. Yes, most increases are coming from developing nations. But currently the 10 largest emitters (here, pg. 13) are in order China, the US, India, Russia, Japan, Germany, Iran, Canada, Korea, and the UK - together accounting for >65% of world emissions. Action by these nations (most of which _cannot_ be considered to be 'developing nations') can have significant effects on the rate of climate change. China has some of the largest investments in renewables in the world. In the US wind and solar are the fastest growing segments of the energy market - hardly an indication of lacking economic viability. In regards to baseline power (somewhat off-topic here), I would suggest looking at (and commenting upon) the Can renewables provide baseload power thread, where this myth is discussed. Considering fossil fuel 'cheap' power depends on ignoring the real, total costs of fossil fuels - including the external costs. Costs that will be paid by all (including developing nations) regardless of your accounting. Developing nations are growing rapidly, and will be an increasing part of the issue - but not yet. Hmm... wouldn't it be a good idea to head the problem off, and work together to minimize the high growth developing nation energy use impact on climate change? Helping all to create new power systems, increasing power availability, that don't pollute? Rather than throwing ones hands in the air, claiming (as you have) that limiting fossil fuel usage will crush developing nations? I think renewable energy development can be a definite win-win scenario. It unfortunately represents a redistribution of wealth away from some vested interests, who are spending rather large sums lobbying for Business As Usual, along with ideological interests who feel that any regulation of even potential freedoms for the common good is untenable - the situation here, at least, in the US. From that come the 'skeptics', pushing inconsistent and contradictory hypotheses that don't account for the facts, and from that come things like RealClimate and SkS - where the facts are (as best they can be) discussed. --- And yes, I would agree with you that "Readers will appreciate how clearly my different points and concerns have been answered here". Although I expect that my opinion on their reactions will differ from yours...
  32. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    O.K. fair enough angliss. I guess this shows the rather subjective nature of the choices associated with these analyses! I read Jim Powell's top "article" to be a consideration of skeptic papers involving a "case against human-caused global warming", and "that denied or attempted to cast substantial doubt on human-caused global warming". You stated above that Douglass et al (2008) "suggested that the climate isn't warming....", which would (if true) certainly accord with Jim's criteria. However you now say (and I agree) that Douglass et al are actually suggesting that their (atrociously flawed!) analysis indicates it's not going to warm in the future as much as model projections suggest. Does that accord with Jim's criteria of "a case against human-caused global warming" etc? Debatable methinks. But it's a subjective consideration!
  33. Infrared Iris Never Bloomed
    From Reisman - ""Science is at its core about reproducibility." If the result is reproducible or replicated by multiple scientific organizations or scientists, then it is more acceptable than that which is not. Both Santer and Mann seemed to agree that the Iris Hypothesis did not stand up to scientific scrutiny."
  34. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Richard (#18) says "I don't have to provide an alternative to natural variability because that is the null hypothesis." oh dear... choose a scientifically-deficient "null hypothesis" and bob's your uncle - you can then simply reject everything that we know! However, the "null hypothesis" isn't the hypothesis based on completely discarding all our knowledge. In fact if one takes your "hypothesis" that warming since the mid 19th century (say) is due to "natural variability", then you have chosen a hypothesis that simply doesn't accord with the scientific evidence base.
  35. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Sphaerica (#14) - Odd, I thought I had specifically suggested to Jim that he add Douglass et al 2008 and got no response. I'm not trying to imply that Jim did anything on purpose, but rather point out that he may have accidentally filtered out papers like Douglass et al 2008 because of the way he designed his search parameters. FWIW, I'm not using "bias" in the colloquial sense here - I'm using it as I would in my day job as an EE: bias is a detectable and correctable error independent from random processes like noise. I apologize for not making that clearer in my initial post. Chris (#15) - I have read the paper, although admittedly not recently. On a quick skim of it, however, I found this in the summary: (The use of tropical tropospheric temperature trends as a metric for this test is important, as this region represents the CEL and provides a clear signature of the trajectory of the climate system under enhanced greenhouse forcing.) On the whole, the evidence indicates that model trends in the troposphere are very likely inconsistent with observations that indicate that, since 1979, there is no significant long-term amplification factor relative to the surface. If these results continue to be supported, then future projections of temperature change, as depicted in the present suite of climate models, are likely too high. Also: The last 25 years constitute a period of more complete and accurate observations and more realistic modelling efforts. Yet the models are seen to disagree with the observations. We suggest, therefore, that projections of future climate based on these models be viewed with much caution. IMO, this meets Jim's criteria as described in his first post. Regardless, I am sorry for not suggesting this paper's inclusion it back on Post 1, as doing so might have avoided any unpleasantness.
  36. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Richard...what **global** warming spike at 1100 AD? I'm only aware of regional high temperatures smeared out over a couple of hundred years. For that matter, all the hockey sticks I'm seeing for **global** temperatures don't show anything at 3000 BC either. ps... I'm sure not going to be around in 2100. Nor are my children likely to be. If I had grandchildren right now, it wouldn't be a good bet either. How do you plan to be around in 2100?
  37. Infrared Iris Never Bloomed
    FYI Dana, Lindzen begs to differ with your assessment, and has a powerpoint presentation with counterarguments for at least the early-2000s papers. The argument-counterargument volleys are over my head, at least as much of same as I want to devote to this. So, 2 Qs - First, what heuristic does the non-expert use in a situation like this? I think the answer is to ask: do unrelated scientists looking into your hypothesis think that the evidence from their research supports it? (If I'm the scientific bystander, and the hypothesis-holding scientist stands his ground, is there any other way I can go about forming an informed view?) And second, not using a heuristic, could someone please (of the expert ilk) address some of Lindzen's counterarguments, e.g. that Lin et al 2002 were "ignoring the fact that we were taking Ac(260) as a surrogate for all tropical upper cirrus, and instead asserting that the clouds defined by Ac(260) were essentially the only clouds we were considering.")
  38. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    @16. So what you're saying Richard is that you can't take initial boundary conditions in say 1970, run a suite of models through 2010 that show good correspondence to the real temperature trends and use the climate sensitivity coming out of that? That you can't use paleoclimate data to calculate prior climate sensitivity and apply those estimates to present conditions? What is "knowing" to you anyhow? You've got an unstated premise/bias in there that needs to be laid out. Do words like 95% confidence mean anything to you? Are there other areas of knowledge where calculations are done that you also require waiting for? I keep thinking of the mention of a mole on your skin in another post. The individual variability of cancer progression is large...so why should you trust the past clinical data and progression models?
  39. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    We've got lots of actual observations Richard (#16). For example, the earth has warmed by around 0.8-0.9 oC since the middle of the 19th century, while [CO2] has risen from around 286 ppm then to 389 ppm now. A climate sensitivity of 2 oC should then give an equilibrium warming of: ln(389/286)*2/ln(2) = 0.87 oC We know that we haven’t had the full warming from this enhancement of greenhouse gases, since it takes the earth many decades to come to equilibrium with the current forcing resulting from raised greenhouse gases. Likewise we know that a significant part of the warming from this enhancement of greenhouse gas levels has been offset by manmade atmospheric aerosols. On the other hand some of the warming is due to non-CO2 sources (man-made methane, nitrous oxides, tropospheric ozone, black carbon). Non greenhouse gas contributions to this warming (solar, volcanic) are known to be small. Overall, it’s rather unlikely, given the warming since the mid-19th century, that climate sensitivity is less than 2 oC. This is expanded on in more detail in Knutti and Hegerl, in Murphy et al. (2009), in Rind and Lean, 2008, in Hansen et al (2005), etc. etc. So the evidence simply doesn't support a climate sensitivity that is below 2 oC. The evidence in fact supports a climate sensitivity of around 3 oC at maximum (evidence-based) likelihood. It's silly to make arguments based on the premise of ignorance! In science we assess hypotheses on the basis of the evidence.
  40. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Dave123 @17: I guess we will have to agree to disagree on who has the burden of proof. Personally, I plan on measuring the average global temperature at 2100, and the sea level rise at 2100. Then we will have actual observations which we can use to determine the climate sensitivity. If CS turns out to be 1.3C - that will imply there is no indirect amplification feedback. If CS turns out to be 3C or higher - you are right. If CS turns out to be 2C or lower - skeptics are right.
  41. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    scaddenp #10: You have the burden of proof wrong. I don't have to provide an alternative to natural variability because that is the null hypothesis. What caused the warming spike around 1100 AD? What caused the warming spike around 3000 BC? The CO2 data (ice cores) tells us it couldn't have been caused by CO2 - because CO2 was constant at around 280 ppm for during both of those temperature spikes. That is why the null hypothesis is natural variability. That is why you have the burden of showing that the warming spike we are currently in is due to CO2 and not the other causes (whatever caused the warming in 1100 AD or 3000 BC).
  42. (Fahrenheit) 451 ppm
    #81 KR : OK, my apologies for the misinterpretation of your sentence : "And yet - you seem to repeatedly call for "go slow" approaches, to minimize economic shifts or disruption, to 'tone down' the urgency. This despite the (acknowledged) lead time required to shift energy production from fossil fuels." It sounds to me as if I was supposed to leave or silence all my doubts because of a urgency to act. But it was not your thought, so sorry. "given the observed intransigence of the fossil fuel industry and conservative politicians" No. Like the Sphaerica's "magnats", this is a typical misinterpretation of reality. Look at Peters et al 2011 article I already quoted, nearly all the increase of CO2 emissions since 1990 come from non-OECD countries who're escaping poverty. And so for the projected decades, as IEA WEO 2011 put it : "The dynamics of energy markets are increasingly determined by countries outside the OECD. Non-OECD countries account for 90% of population growth, 70% of the increase in economic output and 90% of energy demand growth over the period from 2010 to 2035." So even if the last 15 years US blockage to climate decision is a pity, partly due to lobbies, you should IMO leave this Western-centric view of the energy-climate problem for the future, because even US is henceforth a small part of this problem. (At least, carbon intensity of US economy made small progress, this is not at all the case when a poor country begins its development.) In real choices for developing countries, the problem is not the fossil fuel industry (not speaking of Western conservatives), it is the incapacity of wind and solar industries in their current technologies to provide the regular, large and if possible cheap basis for an energy infrastructure needed at a national scale. And also to provide fuel for transportation, of course. BRICs and other developing countries are not foolish, if non-fossil solutions were the most interesting for their energy mix, their would have chosen this way for a long time: no pollution, no dependency of foreign providers, no climate warming... # 82 Sphaerica : the French expression for your repeated claim is "procès d'intention", I don't know the English counterpart. I'm tired too. But I think I have now a clearer idea of how skeptic is "Skeptical" Science. Readers will appreciate how clearly my different points and concerns have been answered here.
  43. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    @12- "It has been" warmer/cooler "in the past when CO2 was 280 ppm". A. There is no such thing as "natural variability" in the sense that things move around with no recourse to a physical explanation....which is what I hear whenever someone on the "skeptic" side uses that phrase...unless they mean "it's too complicated for me to figure out, so you can't understand it either". B. Your statement is pointless unless you also hold all other variables constant... insolation, albedo etc. And you need to be clear on whether this is a stable or transient condition. Do you have that information? C. And for SkS you really ought to cite the dates, and the papers providing the temperature and CO2 information and other control information. Anything else just isn't up to standard. D. I submit that this data has been developed, presented in peer reviewed papers, and summarized and presented here on SkS. That in sum your statement that it has been warmer and or colder at 280 ppm, and implying that all other things are equal is in fact false because it has been shown all other things aren't equal. E. And if you have been immersed in this discussion through sites providing direct access to peer-reviewed literature...such as SkS and RealClimate you'd have to say that given the data on the table, for a skeptic to make a case they must refute it. The ball is in their court, the burden of proof is on them.
  44. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Sphaerica, #8: We don't actually know that. We know from physics that we should experience around 1.2C by 2100 from the direct effects of CO2 warming. However, what is in question is the amount of indirect feedback. There are lots of theories and projections - but no actual observations. So until we can actually measure temperature and/or sea level when 2100 rolls around, we don't actually know what the climate sensitivity number will be. It may be 3C or it may be 1C - we just don't know.
  45. Galactic cosmic rays: Backing the wrong horse
    106, Eric, Except GCR can't be added to the model physics because no one has demonstrated a working mechanism and defined the underlying physics needed to incorporate it into a model. By contrast we know the exact bands at which CO2 absorbs radiation, the emission times, the density throughout the atmosphere, the overlap with other gases, the resulting TOA emissions spectrum, the energy associated with each photon, and 80 bazillion other details that allow us to directly model the physics. For GCRs we have "hey, look, there was maybe sort of a correlation over a several million year time scale, given a window of tens of millions of years, give or take, and a questionable proxy for the strength of GCRs, and no correlation whatsoever in recent, hard, direct instrumental measurements." GCRs are a non-starter until someone does a lot more work and gets some positive results from it, and I don't expect that to happen for a decade at least, if ever. Including GCRs now might as well be accompanied by the well-considered effects of Eurasian Leprechaun Farts (ELFs, a well-known Christmas time seasonal impact).
  46. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    angliss (#9), that's simply incorrect. Nowhere in Douglass et al (2008) is it suggested "that the climate isn't warming because the analysis erroneously concludes that there's no evidence for tropical tropospheric warming". It's very easy to establish that fact - one simply has to read the paper! You seem to be arguing on the basis of an easily-established false premise. Douglass et al are very clear that they are addressing something rather specific. Santer et al (2005) determined that apparent differences in modeled and measured temperatures in the altitude-dependence of temperature trends in the tropical zone during the satellite era is not an indication that there is fundamental discrepency between models and measurements since the uncertainty in the latter overlaps with the variance in the models. Douglass et al's reanalysis purported to show that the uncertainties are actually sufficiently small that a strong statement about fundamental discrepencies in models and measurements in this subset of tropsopheric data can be made. Of course Douglass et al's analysis was pathetically flawed. But that's not the point. In the context of this thread, Douglass et al's analysis has nothing to say about whether the climate is warming or not, nor the origins of warming. In fact Douglass et al state completely explicitly that the climate is warming (see their Table 1) since they accept the very marked surface warming trends that are well established.
  47. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    angliss, Roger Gram, Do you think it might have been possible to simply post a comment saying "Hey, you missed one, what about the Douglass 2007 paper?" rather than: (a) Implying that Jim didn't try hard enough
    "If you want to list all the skeptic's papers, you need to look more carefully. "
    or (b) Implying that his entire method of locating papers was perhaps biased towards getting some sort of desired result
    "questions that need to be asked about why, and whether the methodology might be inadvertently biasing the results of the study"
    Hint: I'm sure Jim would gladly add this paper, and any others you find, to the list. I'd further point out that in part 1, Jim explicitly gave reasons for not including Klotzbach et al. (2009), which appears in many ways to be similar to the Douglas paper. Once again, maybe a simple question along the lines of "did you consider this?" would have served better than veiled (whether purposeful or not) implications of impropriety and deceit? Consider Jim's comment here, on part 1, which ends with the statement:
    I welcome suggestions for papers I missed, as Troy has done.
  48. Galactic cosmic rays: Backing the wrong horse
    Either the GCR needs to be added to model physics or it will have to be ignored. Very short term empirical analysis, although still requiring a model, should not need GCR included as we see from the Laken and other papers. For solar cycle sensitivity-based estimates, I don't see how GCR can be ignored if it has any role at all. For longer term empirical it probably needs to be in the model.
  49. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    #6 Utahn: The part which requires that skeptics have the burden of disproving AGW.
  50. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    #4 John Russell Again - this all depends on who has the burden of proof. It has been warmer in the past than it is currently, and CO2 was at around 280 ppm. It has been colder in the past than it is currently, and CO2 was at around 280 ppm. So, given that natural variability is the null hypothesis, don't you have the burden of showing why the current warming is due to CO2 and not to whatever caused prior warming spikes (while CO2 was at 280 ppm)? But to take a stab at answering your question, perhaps aerosols are an opposing forcing which are counteracting CO2.

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