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Comments 110151 to 110200:

  1. The contradictory nature of global warming skepticism
    @Baz "If you run a bath of saline water and you add a teaspoon of sugar, you haven't 'sweetened' it - do you see?" Actually, you *have* sweetened it, in the sense you've made it a bit sweeter. "Sweet" is not a binary state, i.e. sweet/non-sweet. Sweetness, like the pH value, is a continuum. So if I put a little bit of sugar in my spaghetti sauce, I'm sweetening it, even though it'll still be more salty than sweet. Similarly, if you're lowering the pH, you're making it more acidic (i.e. you're increasing the number of hydrogen ions), even though it's still a base. Again, if you have an alternative to the scientifically-accepted term "acidification," please share it with us. "However, I wanted to try and stop something which I've witnessed seems to happen on AGW forums so often." Nice way to show your bias here. Putting words into soemone else's mouth is much more prevalent on anti-AGW forums than on a scientifically-oriented site such as this one. The fact you feel this is mostly a feature of AGW forums illustrates selective bias. Try to be more objective. "I DO NOT accept that there is sufficient evidence to show that we WILL get warming as a result of our emissions." Well, let me use your rhetorical tactic and as you how much (and which) evidence would convince you that increased CO2 will increase the warming? Right now, it appears you simply don't *want* to consider evidence that supports AGW theory. "Each time we're treated to 'Scientists say that the effect could see millions die' " Do you have repeated examples of such claims? It seems to me you're engaging in hyperbole, here. How about the claims made by contrarians that transitioning away from fossil fuels would cause millions to die? Are you also skeptical of these? "I do not see how we can state that positive feedbacks will occur to dramatically warm the planet, when we don't understand - and cannot adequately model - the climate system" The fact is we understand it better than you seem to believe. That's why GCM predictions, by and large, have been confirmed by observation. "We don't swallow "we're doomed"." Don't say "we." You're only speaking for yourself, here. "Having seen Hansen's Scenarios we know he got it wrong. Admit it!" Really? Care to provide some evidence? "Sometimes, listening to scientists, it's remarkably like listening to politicians. Now that's a sad state of affairs, isn't it? Science has always been riddled with egos and personality, now we've thrown dependent-grants into it." When all else fails, attack the integrity of scientists, right? There's no indication that grants are dependent on a research's outcome. Additionally, since you claim scientists are ego-driven, then if someone was making false claims other reputable scientists would quickly show how he's wrong. Yet, we have a near-consensus...how could that be? I'm sorry, but your arguments aren't convincing, nor did you adequately respond to the (polite) counter-arguments you've been presented with. You have to approach this in a more rational manner, which means you first have to accept that changing your belief about AGW based on a five-year period is an irrational decision.
  2. The contradictory nature of global warming skepticism
    archiesteel, my response was on the polar bear thread basically that hunting 10% of a bear population per year makes all other hypothetical threats moot. My main point for bringing it up is giving a complete (not one-sided) depiction of the problem.
  3. The contradictory nature of global warming skepticism
    Baz, Thanks for the clairification. As I can't put all the comments on one page here, it's too hard to search all yours for precisely what you said, but it was along the lines of: "I stopped believing in AGW when the blue line went down", followed by "fair enough, but I still don't accept AGW" which I read as not accepting continued warming was compatible with the temperature data. So to be clear: 1) You do accept that the earth is warming and that the surface temperature record supports this 2) You don't accept that the earth will continue to warm In order for these not to be in contradiction (the point of the article) you need to 1) Reconcile the current warming with something other than an anthropogenic source 2) Predict that the alternative source of heat has or is about to stop. I'd love to hear your response ! VTG
  4. The contradictory nature of global warming skepticism
    @Eric: you have still to provide concrete evidence that hunting represents a bigger threat to the global polar bear population than climate change. Hunting also doesn't explain why polar bears are venturing further south - into brown bear territory - than they've done before. In fact, it doesn't make sense that bears would risk getting closer to such an existential threat if that was the case.
  5. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Speaking of the heat content of the lithosphere… Check out: “Using Underground Clues to Determine Past Atmospheric Heat” posted yesterday (Sep 13) on Science Daily. http://www.sciencedaily.com/releases/2010/08/100831095138.htm
  6. Why positive feedback doesn't necessarily lead to runaway warming
    39, TimTheToolMan: - Case 1: Sea ice covers an area of ocean. The Sun's rays come down, bounce off into the sky. To excellent approximation, none of the energy is absorbed by the ice, nor is the reflected light absorbed by the atmosphere. Therefore, all that sunlight contributes essentially 0 to the radiant energy budget. - Case 2: Sea ice is gone, so that same area is now bare ocean. The Sun's rays come down, and, to excellent approximation, are completely absorbed by the water. a) This increases the water temperature a bit, causing it to radiate Infrared (IR) radiation a bit more than before. The radiation of the IR will bring the water's temperature down a bit - but not lower than what it was before the radiation hit: absorbing radiation cannot lower temperature. Therefore, some of that solar heat will be retained in the water, and some will be radiated as IR back to the atmosphere. b) The IR radiated back to the atmosphere will head upwards, but because of greenhouse gases, it will not stream outward as the visible light did, but be bounced around in the atmosphere. The rate of IR escape will not be as high as the rate of IR generation, so there will be a heat build-up. In summary: - When there is ice on the water, the sunlight makes no contribution to heating or cooling the ocean. - When there is no ice on the water, a portion of the sunlight's energy is absorbed and retained in the water, and the rest escapes to the atmosphere; of the escaped energy, some of it escapes to space and some of it is bounced back (resulting in heating). The "blanketing" capability of the ice becomes interesting if you think there is some reason that the water under the ice is going to be WARMER than the air, on the average. In either case, as CBDunkerson pointed out, this article is not a calculation of the actual climate sensitivity, but a demonstration of a mathematical principle: a system with positive feedback can demonstrate naturally self-limiting behavior, it can go for significant amplification without "running for the fences".
  7. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Albatross 220, Better yet... the NRC create a special committee to delve into this entire ball-of-wax.
  8. Why positive feedback doesn't necessarily lead to runaway warming
    40, Michael Le Page: In the case you mention, the fact that heat radiation increases with temperature will put a lid on the temperature EVENTUALLY, but would not stop a runaway in all cases: As CBDunkerson pointed out, there actually has been a runaway in the case of Venus. Likewise, in the classic case of the sound amplifier, the output of which is fed into the input microphone, there is an ULTIMATE limit based on such constraints as maximum available power; however, these constraints don't have any effect until the system has gone into full squealing mode, due to the positive feedback. They then limit the volume of the squealing. This particular case, discussed in more detail in the Advanced version, shows that there can be a feedback that is ALWAYS positive, yet which is self-limiting. This case, as therein shown, also differs from that of the amplifier with constant gain less than 1: In that case, the output signal itself decreases to zero, rather than stabilizing. By the way: the power of a blackbody radiator goes like (Temperature)^4; it is not exponential in the Temperature.
  9. The contradictory nature of global warming skepticism
    #161 Baz at 00:17 AM on 15 September, 2010 I've seen a lot of "we're doomed" in my life, and the only thing that really concerns me is an asteroid hit, nothing else. Why, a supervolcano comes close. It happens more often and can hit hard.
  10. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    VTG, Great idea. I would take it further, A post from NODC and another from PMEL (i.e., groups who obtained different trends in the data between 2004 and 2008/9. Or someone with a good understanding of OHC and the earth's energy budget. For example, Dr. Tremberth or Dr. Palmer. As far as I can tell, Dr. Trenberth does quite a bit of outreach, but he is of course ridiculously busy.
  11. Video update on Arctic sea ice in 2010
    HR, I am sure glad that we have you with all your experience to tell us that Dr. Barbers last 25 years in the arctic were wasted. You sure saw through him! Maybe we should get someone who really knows what is going on, like Goddard or Watts, to tell us about the arctic. For the record, how many years have you spent on an icebreaker in the Arctic? At some point we have to trust that the experts are telling us what they are observing. It serves no purpose to suggest that someone as experienced and respected as Dr. Barber would tell us something, at a major science convention, that is not well backed by on the ground data. The data is there if you want to look. He did not present the data here because it was a summary for an informed audience.
  12. The contradictory nature of global warming skepticism
    You make excellent points though...but one small nit pick, it is Hansen. JMurphy, I'm beginning to think "concern troll".
  13. The contradictory nature of global warming skepticism
    Baz, More off-topic comments. This thread is about "The contradictory nature of global warming skepticism". Re Hansen's predictions being wrong. I'm afraid that assessment (made on contrarian pseudo-science blogs) has been shown to be wrong. Early projections by Manabe et al. (1992) and Hansen (1988) have been shown to be remarkably good given the knowledge, fairly limited sophistication of the models at the time, and assumptions that had to be made about GHG emissions. Dr. Gavin Schmidt at RealClimate concluded: "My assessment is that the model results were as consistent with the real world over this period as could possibly be expected and are therefore a useful demonstration of the model’s consistency with the real world. Thus when asked whether any climate model forecasts ahead of time have proven accurate, this comes as close as you get." You can read more about Hansen's projection for yourself here at SS, or at RealClimate. As for ocean acidification, I'm afraid whatever you might believe is the correct terminology is irrelevant. Like I said before, but which you seem to have ignored, for better or worse, that is the term the EXPERTS use....deal with it. If you have an issue email NOAA-PMEL, WHOI, Scripps etc. Even better, write a paper in a peer-reviewed journal making your case why they are wrong. I could address a bunch of other misguided comments that you have (about uncertainty and internal climate modes, for example), but that would ALSO be off topic. Please go to the appropriate thread for each of your arguments--you will see that your concerns and "arguments" have been addressed before. Thanks.
  14. The contradictory nature of global warming skepticism
    Baz wrote : "We don't swallow "we're doomed". Having seen Hansen's Scenarios we know he got it wrong. Admit it! Sometimes, listening to scientists, it's remarkably like listening to politicians. Now that's a sad state of affairs, isn't it? Science has always been riddled with egos and personality, now we've thrown dependent-grants into it." You really are going through all the tactics of the so-called skeptics, aren't you ? First you claim to have been a "believer". Then you claim to have stopped 'believing' because of a 5 year period of...well, something that made sense to you - you still haven't explained anything about the reasons, beyond generalisations. Then you claim to be here to see what the "believers' think - forgetting that you claim that you used to be one, of course. Now you identify yourself with the common people or something : "WE don't...", "WE know...". Plus, you make a claim about Hanson (one of the bogeymen to the so-called skeptics), without trying to explain what it is you are trying to claim. Finally you equate scientists with politicians, so you can belittle them in comparison, and you bring in the old chestnut of all that lovely money being wasted on grants to the scientists who believe - who are producing studies only so they can get rich quick and join in that great big conspiracy. You are busted. Oh, and to help you out with your difficulty over acknowledging ocean-acidification, perhaps you might like to attend this, where all will be explained : A consortium of institutions and organizations from Monterey, California has successfully bid to host the third symposium on The Ocean in a High-CO2 World in autumn 2012. The symposium aims to attract more than 300 of the world’s leading scientists to discuss the impacts of ocean acidification on marine organisms, ecosystems, and biogeochemical cycles. It will also cover socio-economic consequences of ocean acidification, including policy and management implications. The symposium is sponsored by the Scientific Committee on Oceanic Research (SCOR), Intergovernmental Oceanographic Commission (IOC) of UNESCO, and International Geosphere-Biosphere Programme (IGBP), which selected the Monterey consortium from eight bids to host the meeting. The international Planning Committee is led by Prof. Dr. Ulf Riebesell of the Leibniz Institute of Marine Sciences (Germany), and the local organization is led by Dr. Jim Barry of Monterey Bay Aquarium Research Institute and supported by a consortium of institutions. The symposium is the third in a series and will build on the successes of the Paris and Monaco symposia in 2004 and 2008, respectively. The Paris meeting was seminal in identifying the magnitude of ocean acidification for marine ecosystems and the outcomes of the Monaco symposium, focusing on the advances in knowledge of the affects on marine organisms, also made an impact on a broader audience through a Summary for Policymakers and the Monaco Declaration. Hang on, the UN are involved : must be a conspiracy, right ?
  15. Video update on Arctic sea ice in 2010
    HR, Come one. PIOMAS is used by the US Navy (to mention but one agency which has cited it), that alone is a pretty big endorsement. The model has also been validated (and performed well) against ICESAT, and once CROSAT-2 comes online later this fall, there will be even more validation points. Last year the "skeptics" were mocking Barber, well it turns out that the ice was indeed "rotten". Barber made transects on the ship HR, that is not one data point as you suggest. From the UofM website: "In September 2009 Barber and others went to various points in the southern Beaufort Sea aboard the research vessel (NGCC) Amundsen. They discovered the multiyear sea icescape was not as ubiquitous as it appeared in satellite remote sensing data." As you will have seen in the video, they have also flown transects using a helicopter with a boom equipped with a radar to measure ice parameters.
  16. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    @ Radar 30331, Are you stating in post #216 that Dr. Pielke's simplifying assumption about the heat content of the lower ocean levels not increassing during the 2004-2009 period is nothing more than a "caveat"?
  17. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    @ Radar 30331 Lest there be any confusion about the meaning of the second sentence of my post #205… It reads: “Even Dr. Pielke admits that this key assumption can neither be proved or disproved because the requisite database simply does not exist.” The phrase, “the requisite database simply does not exist” refers specifically to the lack of data sufficient to compute the heat content of the lower ocean layers for the tome period 2004-2009.
  18. The contradictory nature of global warming skepticism
    Hello all. As I said before, you'll have to be patient on replies as I get precious little time to 'play'. However, I wanted to try and stop something which I've witnessed seems to happen on AGW forums so often. Please stop saying things that I haven't said! VeryTallGuy does it again above. Where VTG, do I say that I "do not accept the world is warming"? Let me state yet again, I DO NOT accept that there is sufficient evidence to show that we WILL get warming as a result of our emissions. I have even stated that I accept the physics behind it(!), and at NO POINT do I say that I do not accept the world is warming. Please people, read someone's posting before writing. I do not see how we can state that positive feedbacks will occur to dramatically warm the planet, when we don't understand - and cannot adequately model - the climate system. Please understand that I'm not trying to frustrate or argue a 'sceptic' point, I'm saying that as we don't understand the system then modelling and analysis is little good. I lean toward ocean circulation patterns determining our climate, and look forward to see what changes in the PDO/AMO bring in the next 20 years. Trueofvoice. Sorry, but I do not accept that at all, not one bit. Read conclusions on scientific papers and they are littered with "we believe". Science is rife with "we believe". actuallythoughtful. In order to win over people like me it's necessary to be realistic. I'm middle-aged, and I've seen a few scare stories come and go. Each time we're treated to 'Scientists say that the effect could see millions die' - that effect never happens! It's incumbent upon scientists to be truthful, to let journalists know the truth without putting any emphasis on the worst-case scenario. I agree that's very difficult (having been a journalist many years ago). The ridiculous comments that have been made about the Arctic is classic. kdkd 154, no offence taken. Shallow thinking maybe, but I can reasonably analyse and decide. As I say above, I've seen a lot of "we're doomed" in my life, and the only thing that really concerns me is an asteroid hit, nothing else. Even massive population is workable. Albatross, re: acidify. If you run a bath of saline water and you add a teaspoon of sugar, you haven't 'sweetened' it - do you see? On the wider issue (and the subject of this thread) this is what turns the public off. You should not use terms, nor scare stories, that are just not applicable. The whole idea of AGW is suffering from this. Tell us the most likely, tell us the truth about computer models, tell us the incomprehensibility of the climate system. THAT we can understand. We don't swallow "we're doomed". Having seen Hansen's Scenarios we know he got it wrong. Admit it! Sometimes, listening to scientists, it's remarkably like listening to politicians. Now that's a sad state of affairs, isn't it? Science has always been riddled with egos and personality, now we've thrown dependent-grants into it. But to return to my point to you, stop callig it ocean-acidification - IT ISN'T! Will return when I can.
  19. Why positive feedback doesn't necessarily lead to runaway warming
    TimTheToolMan, why exactly should an article explaining the mathematical proof against claims that 'positive feedback would lead to runaway warming' need to cite every imaginable feedback effect? They are immaterial to the issue at hand. Michael Le Page, when the article refers to diminishing returns it is in reference to a constant 'feedback multiplier' less than one being mathematically incapable of producing a runaway effect. You seem to instead be referring to cases where the 'feedback multiplier' itself decreases over time. That is an additional reason that positive feedback would not inherently lead to a runaway effect. Also, while heat output will increase to maintain equilibrium with heat input this doesn't really prevent runaway warming... look to Venus as an example.
  20. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    @ Radar30331, As they say, “The devil is in the details.” What have Hansen, Steig, Lyman, postulated about the heat content of the ocean system?
  21. Why positive feedback doesn't necessarily lead to runaway warming
    I think this answer needs revising. The fundamental reason why positive feedbacks do not produce runaway warming is that the hotter the earth gets, the more heat it emits. Put another way, the hotter the earth gets, the faster it cools. The amount of infrared radiation emitted by Earth increases exponentially with temperature, so in simple terms, as long as some infrared can escape from the atmosphere, at some point heat loss overtakes heat gain. Yes, some positive feedbacks are diminishing - CO2 has less and less effect the more there is of it, for instance - but I don't think all positive feedbacks are diminishing.
  22. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Re: Badgersouth "The 'accuracy' of Pielke's postulate will therefore likely never be proven or disproven." This goes back to what I said originally, that IMO posters here are being too picky in expecting him to include caveats that you wouldn't insist on in the top line of consensus AGW abstracts. If Pielke can't make conclusive statements because "the requisite database simply does not exist" then Hansen, Steig, Lyman or whomever can't do so either right?
  23. Why positive feedback doesn't necessarily lead to runaway warming
    Regarding : "For example: The Earth heats up, and some of the sea ice near the poles melts. Now bare water is exposed to the sun's rays, and absorbs more light than did the previous ice cover; so the planet heats up a little more." Why is it that the negative feedback of the open ocean radiating heat is never mentioned? Ice makes a very effective blanket. If you're going to offer an "unbiased" opinion on feedbacks then at least mention them all for your examples.
  24. A detailed look at climate sensitivity
    Berényi Péter, I am and was sure you know the problems quite well and that you're well aware that it does not have "immediate consequences either on numerical integration of these beasts ..." so widely used in many fields. For the same reason, I think that writing of that mathematical problem was just to make noise and confuse people.
  25. A detailed look at climate sensitivity
    #49 Riccardo at 07:07 AM on 14 September, 2010 the millenium prize problem has a completely different goal than "simply" solve the Navier–Stokes equations I think I was clear enough. Re-read please. That problem is about the very existence of well-behaved solutions, which is of course different from actually solving the equations. It does not have immediate consequences either on numerical integration of these beasts which is relied upon heavily by GCMs. However, any step forward in this specific area of research would advance our general understanding of structures behind turbulent phenomena and that could be useful in climate modeling as well. In 3D flows a considerable portion of energy is being pushed to ever smaller scale features. This energy is thermalized eventually, but the road leading there is rather bumpy. The dissipation process is not uniform, on intermediate scales even focusing phenomena can develop giving birth to such extreme events as rainbands or tornadoes spawned from the eyewall of hurricanes making landfall. Therefore some rather tricky context-dependent statistics is required for the parametrization of sub-grid phenomena, one that is neither measured properly, nor can it be derived from first principles due to lack of understanding. BTW, I have found an essay which is highly relevant in this context. Bulletin of the American Meteorological Society Volume 86, Issue 11 (November 2005) pp. 1609–1614. DOI: 10.1175/BAMS-86-11-1609 The Gap between Simulation and Understanding in Climate Modeling Isaac M. Held "Should we strive to construct climate models of lasting value? Or should we accept as inevitable the obsolescence of our models as computer power increases?"
  26. Polar bear numbers are increasing
    Heh, that should have been 'polar bear numbers are INcreasing' in the second sentence of the post above. Oi!
  27. Polar bear numbers are increasing
    Eric, the article above references a USGS study from 2006 which looked at only a few regions and specifically at habitat loss. These were sufficient to disprove the false claim that 'polar bear numbers are decreasing'. Adding in information about hunting would be irrelevant to the issue of climate change and misleading given that hunting losses can be recovered IF the habitat can support more bears. As to 'density dependence'... bears go where the food is. When there's no ice in some regions you're naturally going to get bears relocating towards areas that DO have ice. Until recently that included the Davis Strait region. So now you've got alot of bears there and not enough food for them... but even less food back in the areas they came from. The whole 'the population has grown over the past 30 years' bit is also a red herring because 30 years ago polar bears were on the brink of extinction due to there having been no hunting controls at all. The fact that numbers recovered so quickly once hunting limits were put in place shows that hunting is a manageable issue. Loss of habitat is not. As the available food supply dwindles so does the total number of bears. That is an inevitable and obvious dynamic.
  28. Jupiter is warming
    One place the deniers never mention when they take these off world trips ........ Venus. Can't be pointing out a planet with a 92 % CO2 atmosphere, and a 900 F surface temperature.
  29. Video update on Arctic sea ice in 2010
    HR, there were several articles on Barber's expedition last year and information about previous ice conditions. They should still be easily accessible from Google News or even in the 'mainstream media' links here. Why not go read up rather than jumping directly to unfounded allegations? The idea that it is somehow 'not new' or 'unimportant' that ships can go at nearly full power through supposed pack ice is also just silly on its face. Barber's point was that the satellites estimates were showing incorrect results for that area... which was proved by direct observation. The claim that PIOMAS is not widely used is, if anything, even more bizarre. How many times have YOU seen it brought up? Dozens? Hundreds? NSIDC refers to it frequently. It is all over the climate blogs. Even the (false) claim that 'only Zhang' references it would make it 'widely used' given Zhang's extensive connections with the rest of the 'arctic science community'.
  30. Why positive feedback doesn't necessarily lead to runaway warming
    Found the following: "In the past, photosystem II (PSII) was considered a key weak link (Enami et al. 1994) but damage to PSII only occurs at high temperatures, often above 45 °C (Yamane et al. 1998)." So photosynthesis will weaken considerably in temperatures of over 45 degrees, just to set some limits to the tolerance of the ecosystems in the world. And of course if there's a cool season (like in India), annual plants will grow OK in the cool season.
  31. What about that skeptic argument that Jupiter is warming?
    I'm really enjoying these 'Basic Version' entries. Keep it up!!!!!!!!!!! rmp
    Moderator Response: [Graham] why thank you Sir. You are clearly a man of excellent judgement :)
  32. Why positive feedback doesn't necessarily lead to runaway warming
    nealjking, no argument there, 70 degrees C (global average) will change most of earth uninhabitable for all eukarya (higher life). I probably should try to track the whole RUBISCO response curve somewhere before continuing.
  33. Why positive feedback doesn't necessarily lead to runaway warming
    jyyh, If you are talking about 70 degrees C, we are no longer dealing with climate change. We are talking about planet change.
  34. The contradictory nature of global warming skepticism
    archiesteel (#116) The roughly 200 polar bears killed (out of about 2000 around Baffin Bay) is in the link on the polar bear thread. About 100 were permitted (from another source), the rest poached.
  35. Why positive feedback doesn't necessarily lead to runaway warming
    Another article possible future scientists, doing research on plants' response on GW, will need: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.2001.00668.x/abstract Note that the response curves end on 40 degrees Centigrade. I would have liked them to continue up to 70 degrees which is about the limit simpler plant enzymes will work. As I said above, bacteria can work at higher temperatures, which is (I guess) the reason it took so long for Eukarya to develop (if one takes evolution for granted).
  36. Positive feedback means runaway warming
    I am uncomfortable about the soda pop analogy for CO2 in seawater. The naysayers get confused by this and cone up with all kinds of wrong arguments based on it. The ocean is not saturated with CO2. It would be better to describe the temperature dependance if the distribution coefficient. But even that would be wrong because I am not sure that the system is in equilibrium.
  37. Why positive feedback doesn't necessarily lead to runaway warming
    29, jyyh: I agree with you about the rate of temperature change and its ecological impact: I've done some simple estimates to show that an 0.1-deg-C increase in global average temperature would push ecosystems 15 km poleward; or about 10 m upward (geography & topography cooperating, of course). (This is another one of Hansen's favorite points, as well.) At current rates, that's quite a bit of distance for a tree to move in 10 years! A more refined look at just the borders of the tropical zone seems to lead to another factor of 3 or more for its rate of expansion.
  38. Why positive feedback doesn't necessarily lead to runaway warming
    18, Chris Colose: - With regard to carbon-cycle sensitivity: I was thinking of fossil-fuel-based CO2 as an initial input, and the additional CO2 from out-gassing as being part of the system response. This was one reason I didn't discuss the case (in the Advanced version) of a 100% dollop of CO2, which would have invited direct comparison with the usual 2X-CO2 climate sensitivity. - In general, the calculation should not be taken too seriously, as it is intended as a demonstration of self-limiting positive feedback, and not really as a model for CO2 in the atmosphere. The main point was to show that the concept of diminishing returns, in the case of positive feedback, was not just a case of "special pleading". - I will be very interested to see the discussion you & Rasmus post on feedbacks.
  39. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    VTG - are you volunteering?.
  40. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Albatross and (Moderator) following from this thread an authoritative post on the OHC analysis would be really interesting. Can you suggest someone who might be prepared to do that ?
  41. Video update on Arctic sea ice in 2010
    5.gpwayne Zhang - Many but widely used suggests, well, widely used by the arctic science community. I'm still looking for evidence of that. As good as it is, and it's probably the closest thing to climate science porn, does Prof Barber's reportage represent anything more than one data point?
  42. Why positive feedback doesn't necessarily lead to runaway warming
    ClimateWatcher: The evaluation of the overall feedback for global warming is an active area of research, and will certainly not be resolved here. The main intent of the post was to make the point that a system can have positive feedback without having an exponential blow-out.
  43. Why positive feedback doesn't necessarily lead to runaway warming
    6, John Cook: Thanks for stepping in. This is my first post in SkS, so I forgot that I have certain responsibilities for my "children". 1 & 8, beam me up scotty: Yes, I was also surprised that Hansen had made that remark. Riccardo and Chris Colose have dealt with the substance of that question already. My impression (formed in large part by some explication, by Chris Colose, on this topic in the RealClimate site; and largely reproduced above at 18) is that Hansen was discussing what could happen if a lot of things go very bad; so, kind of a corner condition. On the other hand, Stephen Hawking and James Lovelock have taken a more apocalyptic stance: My impression is that the science is not with them on this point. 25, MattJ: If you look at the Advanced version (link at the bottom of the posting), you can find an explicit discussion of the "classic" positive-feedback scenario (the squealing sound system), and the difference to the model of the carbon-cycle feedbacks.
  44. Why positive feedback doesn't necessarily lead to runaway warming
    Putting this up here as an example of what sort of research can be done on, of the heat stresses in natural systems, maybe someone will experiment with higher increases in surface absorption of heat (what was the greenhouse wattage on the surface again? (Further note: the experiment should include producing the higher humidity to the experiment location as well (not really easy to do)): http://www.springerlink.com/content/ebcg4kx5e13q5mdj/
  45. The contradictory nature of global warming skepticism
    Baz, I put some time into answering your question quantitatively and with a thought through argument. Your response was "that's fair enough" but you continue to say you do not accept the world is warming. This is contradictory, UNLESS you also share your rationale why. If you're not prepared to do that, then you are trolling - simply putting up provocative questions in order to elicit a response, without having the respect to engage. So please, show you are not trolling, and given the answers myself and others have provided on your specific question as to how long the temperature record would need to show a falling trend, tell us not just THAT you disagree but WHY you do.
  46. Video update on Arctic sea ice in 2010
    Hey, the loss of ice is nowhere near as scary as that bloke singing...truly worrying! HR - predictable response. Now tell us how many citations Zhang has.
  47. The contradictory nature of global warming skepticism
    @Trueofvoice: "We accept AGW theory because of the overwhelming empirical evidence which validates the theory. We do not believe in it." Very well put.
  48. Climate change: Water vapor makes for a wet argument
    scaddenp at 07:13 AM, if you have been looking at the BOM site, checking the terrestrial minimum temperatures that we have been discussing, you would have seen that as a rule it is always the same, every day, at every station, including those in Queensland and Northern Territory, the terrestrial minimum is nearly always lower than the station minimum temperature, and only on the odd occasion is it otherwise. Apart from those odd occasions the only difference is by how what magnitude lower is the terrestrial minimum. I assume by your post that you haven't been checking the data as it is updated daily and so are merely speculating. Unless you understand what is actually occurring in the real world then how can you be so sure that you are applying the correct physics principles. The data from these BOM stations is most relevant because this particular theory of back radiation applies over both land and the oceans, the only difference being that the data being collected from these stations is happening under more easily controlled conditions on an ongoing basis and from a well distributed network covering a wide variety of conditions allowing greater analysis. With your understanding of basic physics and studying of the text books, I was hoping that you might be able to correlate what is being measured on a daily basis with the physics theory that applies, so perhaps dispense with the speculation and put forward some credible explanation.
  49. Video update on Arctic sea ice in 2010
    HR He's being doing Arctic sea ice for 25 years. If he's not been in that particular area before ..... it's because he couldn't get there by ship before. Be honest, would you want to land a helicopter on that surface?
  50. actually thoughtful at 14:51 PM on 14 September 2010
    The contradictory nature of global warming skepticism
    Matt J Excellent post. Beyond the logic and the structured argument, another useful system for understanding why people choose to believe what they feel, rather than accept what the evidence tells them, is Myers-Briggs (M-B). According to M-B, only 16% of humanity is of the type they call "rationals" - for good reason. So those 16% are willing/able to look at the facts and come to logical conclusions. The other 86% MAY come to the logical conclusion, but they probably won't come to it using strict logical analysis. About half will use their feeling - even to decide scientific questions (perhaps Baz is in this category?). For the other half, the issue itself doesn't matter - only how it impacts their life. So you can see that just structuring a logical, fact based argument doesn't get you very far (16% BEST case). One also has to appeal to feelings - "how will you feel when there is no polar bear habitat left?" and to practical concerns - "how will it affect you when all of lower Manhattan is under water?" Hopefully the idea comes through my terrible examples above. Sadly, logic alone won't sway the masses. And the vast majority of the climate scientists are M-B rationals - and they literally don't know any other way to interact with the world. Witness the frustration of trying to communicate with Baz on this site. Tom PS - kudos to Daniel Bailey and pbjamm - Baz I hope you will use the opportunity to actually learn. Get beyond feelings and beliefs and begin to understand the science. We would all like for AGW to be a disproved theory - but if you come at it scientifically - it is very hard to see a path out from under AGW - other than changing human behavour.

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