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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 68301 to 68350:

  1. Climate sensitivity is low
    RW1 - Two items. First: The appropriate numbers for TOA forcing with feedbacks given a 3°C climate sensitivity is ~10 W/m^2, resulting in the aforementioned 3°C rise in surface temperatures due to changes in total Earth emissivity and the surface temperature required to emit another 10 W/m^2 at TOA. Your numbers are wrong. Second: I wrote my most recent post for the general public, the readers of this thread. You have not shown any indications that you recognize evidence contrary to your preconceptions. As per the Debunking Handbook, Worldview Backfire , "...outreaches should be directed towards the undecided majority rather than the unswayable minority."
  2. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Richard Arrett - I would take other posters comments even a bit further. The theory (not hypothesis) of forcings and climate change fully explains current conditions and changes within acknowledged uncertainties - uncertainties which are constantly reducing with ongoing research. "Skeptical" hypotheses fail to explain the data, and tend to add up to kettle logic: a mass of contradictory partial explanations, a logical fallacy at best, deception or self-delusion at worst. They certainly do not represent a functional description of the world around us, a useful handle on what is happening, let alone a description of what influences are present (or accessible to us). As such they are, quite frankly, a waste of time.
    Response:

    [DB] Fixed link.

  3. Galactic cosmic rays: Backing the wrong horse
    scaddenp, I have biases (what I consider intuition) like you say in 105 towards (among other things) low sensitivity, but that's another thread. I also realize that I'm not going to make the perfect case for any of these skeptic arguments, there are people with more knowledge about the topics. But I'll accept your complement for this topic.
  4. Plimer vs Plimer: a one man contradiction
    Glenn @ 36 A good point, well made, sir. I must admit to seeing myself in the group of people who did not regard book learning as relevant to real life, until the day I was working to find the best power transmission solution for a client and found that if I'd paid closer attention in school to quadradics I'd have saved myself half a day's work and instead would have managed with just couple of minutes of calculations. For me that was a character building experience and led to a rethink about many of my old opinions. Certainly a reading of Howard's biography reveals an individaul who is primarily driven by ideology rather than altering his views in the face of emergent evidence. There again, rigidly adhering to one's policy is seen as political strength. Anything else will attract terms like back-fliper and flip-floper.
  5. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Richard, I am not a scientist, but I flatter myself that I am a true sceptic who forms a view based on evidence, not opinion. I read and understand as much as I can, but there is a great deal which is inaccessible to me because I don't know the math, or physics, or chemistry, or whatever. When I strike that problem, I have to decide whether the reported results are plausible and often that involves me deciding if previous results from the same source have been plausible. The problem with the climate denier camp is that they are not offering me any plausible alternative to the science I have been able to digest. If you want to convince people like me, you need to do more than say "I do not need to come up with an alternative theory": on the contrary, for people like me, you need to come up with a weight of plausible evidence demonstrating where the AGW evidence is flawed.
  6. Climate sensitivity is low
    RW1 - I don't think anyone knows how to help you. People go so far and then you seem to point blank refuse to get it. "I dont understand". Left to a 14 year girl to do your homework IIRC at one point. It seems you believe one thing and when an argument takes you to the point when that belief is challenged, then you shut down. It still seems to me that you are stuck in the "back radiation cant warm the surface" mindset, and discussion cant go forward till you get that.
  7. Galactic cosmic rays: Backing the wrong horse
    Okay, Eric, and you once again impress as being the honest skeptic.
  8. (Fahrenheit) 451 ppm
    Tom Curtis: Having followed this comment thread from the get-go, I believe skept fr ‘s posts suggest that he/she is a disciple of Bjorn Lomberg.
  9. Galactic cosmic rays: Backing the wrong horse
    Thanks for the replies. Sphaerica, GCR can't be easily modeled but like you say that's not permanent. Other factors like solar UV will eventually get better modeling too. Perhaps after that we will start to understand weather variations better (though not likely predict). Muoncounter those Forbush decreases are minimal in number but we are in a relatively low GCR period so the decreases may not be as effective since we in an interglacial with relatively less GCR to begin with. Skywatcher, I agree that Mercurio's paper has a lot to be undesired. I thought the 140k year chart (fig 13) was sufficient for a study, but instead of analyzing that in depth, he put in enough ideas for 10 more studies. I think muoncounteri is right that the effects are too minimal to be of consequence to climate over short time periods, certainly including temperatures in 2100. The remaining issue IMO is glacial (mostly high GCR) to interglacial (consistently low GCR) differences since those affect studies that require knowing how each quasi-stable state is produced. It seems to me that Mercurio section 13 was a good start to that, then he goes on in section 14 to talk about global warming "hysteria" and I am forced to toss the whole paper.
  10. Ocean Acidification: Corrosive waters arrive in the Bering Sea
    No worries John, any constructive criticism to improve my writing can only be a good thing. Duly noted and taken on-board.
  11. Ocean Acidification: Corrosive waters arrive in the Bering Sea
    Rob Painting: I also believe that an introductory paragraph to a technical document such as your article should include the major take-away point(s) of the article.
  12. Ocean Acidification: Corrosive waters arrive in the Bering Sea
    Rob Painting: Your initial paragraph includes the following sentence: "Well, this is one of three blog posts that continue in that vein." I did not know this sentence meant this article is the first of a three part series until I read the bottom tag. You might have been referring to two other existing blog posts in the above sentence. This matter is insignificant in the scheme of things, but I just wanted to explain my rationale for my comment.
  13. (Fahrenheit) 451 ppm
    skept.fr @87:
    "But here it is, we have the faaaaamous 2K/450ppm target, at least 9 years of bureaucratic diplomacy open to all the lobby influences. Bravo!"
    Are you suggesting, perhaps, that we should adopt Hansen's scientifically supported target of 350 ppmv? No, of course not. A caveat that Hansen may be right goes in the wrong direction for you, and is consequently ignored. If you had paid any attention to it, you would not be so sarcastic about a 450 ppmv target. Your sarcasm, however, captures perfectly how one sided your skepticism is.
  14. Ocean Acidification: Corrosive waters arrive in the Bering Sea
    For information about three additional specific impacts of ocean acidification, check out: “AGU Fall Meeting: the (pH) lowdown on ocean acidification” posted on Environmental Research Letter’s Environmental Research Web. To access this informative article, click here.
  15. (Fahrenheit) 451 ppm
    skept.fr @83, I am very disturbed by your repeated attempt to position the various authors and comentors at Skeptical Science as being insufficiently skeptical. It calls into question the bona fides of your entire discussion. It seems to me that what is missing from your discussion is two crucial perspectives. The first is simply time. It takes time to transition from a high carbon to a low or zero carbon economy. With the best will in the world it could not be done in less than twenty years, and ideally it would be phased in over 40 to 50 years (ie, through the natural cycle of replacement of obsolete power plants). Anything faster incurs significant increased costs. Given that a thirty year transition to a low carbon economy already commits us to around a trillion tonnes of cumulative emissions, and hence to a 50% probability of a 2 degree C rise over the preindustrial average, that already represents a problem. There are of course, caveats. We may get lucky and climate sensitivity may be in the lower half of the IPCC range, in which case we may have 40 rather than 30 years to make that transition. Of course, an equally important caveat which you neglect entirely is that the climate sensitivity may be in the upper half of the IPCC range, meaning that even with our best efforts we are looking at 2.5 to 3 degree increases. In other words, the risk we face with determined action against climate change is that we are already to late to stop a change in climate which will significantly reduce future agricultural productivity. As it happens, we are not making our best efforts. The world as a whole has reluctantly agreed that they should talk about making an agreement that they will consider signing in 6 years and which will come into effect in 9 years. In the meantime several major emitters (including the second, third and fourth largest) will accept no significant reduction targets, nor even significant carbon intensity targets. That means we are facing 10 years of increasing growth of emissions, which means that by 2020, to meet the 2 degree C target that is considered safe, we will not have 20 years in which to act, but 10 or less. What that means in practical terms is that instead of a 1-3 degree probable warming range, we are now looking at a 2 to 4 degree warming range if an effective agreement is implemented in 2020, an assumption that requires rampant optimism. In other words we are already on target for probable levels of warming that even you acknowledge as dangerous. If you like analogies, we are in a car approaching a solid looking wall. We do not know if the wall is far enough away for us to break in time or not. Nor do we know if it is solid enough that our car will be completely destroyed, or merely severely damaged. Our response, in the face of this uncertainty has been to step on the accelerator. The second perspective you appear to lack is that the current policy response is well below that recommended by all the various balanced studies that look at exactly this issue and which show that on balance, mitigation preserves a higher proportion of future economic growth than does adaption alone. Current policy response is behind the curve of recommended action, based on all the caveats. It is not ahead of it. So while you can glibly quote Schneider about the nature of scientific skepticism, it is you who are ignoring the caveats that should be on your position, rather than we that are ignoring those on ours. I have not seen any caveats from you about the likely effects of rising fossil fuel prices (especially petroleum products)in the near future. On your logic, which with I agree, that represents a massive risk to the welfare of future generations. It is, however, a risk that is significantly reduced by a transition to a low carbon economy. Nor have I seen your caveats about the relative importance of energy to well being (or is that thesis sacrosanct for you, and beyond disputation). I agree that energy is important for development, but that is not a tautology. Finally, your "caveats" on renewable energy have a catastrophic strain that is unsupportable. The standard of economic well being in 1950's USA was very high even by current world standards. Yet it was sustained at an energy cost far below that of the current economy. Given known economics of commercial solar and wind power stations, that standard of living could certainly be maintain that 1950's standard of living. Remember, the dispute about renewables is not whether they can produce commercial power, but whether they can produce enough to maintain current, Western standards of living. If they fail at that, they do not maintain nothing, but a standard 5 or 10% lower than current Western standards. While not ideal, an increase of third world standards of living only to the level of 1950's USA, and a (slow) retreat of Western standards to that level is no catastrophe. In light of this, you are failing to see the caveats implicit in the positions of your debating partners only because you have not placed appropriate caveats on your own objections.
  16. Climate sensitivity is low
    KR, You're very good at 'explaining' things to me and making declarations I'm wrong, but this is not offering anything to the discussion here or on the other thread.
    Response:

    [DB] Actually, KR and others have more than amply explained things to you, including the specific points where you stray from accepted understandings into error. 

    Thus, it is your intransigence (amounting to agenda) that is standing in the way of the discussions.

  17. 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.
  18. 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?
  19. 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?
  20. 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.
  21. 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.
  22. (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).

  23. 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"
  24. 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.
  25. Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
    Sorry - I meant Dave123 #21.
  26. 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.
  27. 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.
  28. 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?
  29. Clouds provide negative feedback
    Well that is the physics whether you can understand it or not.
  30. 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.
  31. 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?
  32. 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.
  33. 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.
  34. 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.
  35. 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.
  36. 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.
  37. 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'.
  38. 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.
  39. (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.
  40. 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 ;)
  41. 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.
  42. 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?
  43. (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.
  44. 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.
  45. 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.
  46. 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.
  47. (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...
  48. 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!
  49. 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."
  50. 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.

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