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Comments 104251 to 104300:

  1. forensicscience at 07:12 AM on 16 November 2010
    Naomi Oreskes' Merchants of Doubt Australian tour
    Re #18, I cant see what that has to do with ACC. We burn 30 billion barrels of oil per annum (4.5 billion tonnes) so its hardly an issue now is it?
  2. Naomi Oreskes' Merchants of Doubt Australian tour
    Re: DBailey (18) There is some merit in what you say about networking, physical presence, etc. given our current lifestyles and expectations . This is precisely the question - who will begin to implement and to demonstrate the lifestyle changes we need? And when? A tour such as this would have been improbable 50 years ago, and virtually impossible 75 years ago. (I expect that sometime in the not-too-distant future, it will again become very unusual, unless we find much greener air transport.) A book would still sell (or not), based on recommendations by friends, local advertising, intrinsic worth of the contents, etc. People would not expect personal meetings/glad-handing - this is Madison Avenue creating the norm in our current (unthinking) world. Inter-continental networking in the past was done by snail-mail. People networked based on their ideas, on paper. Today we have e-mail and Skype - much more accessible. The expectation of personal presence for networking is in large part a consequence of easy air travel. We have to revise our "normal" expectations in this "post-normal" world. Live tele-presenting is still somewhat unusual. It could be advertised positively, as low-impact communication with the author. Emphasis on the Skype Q&A...pose your own questions live! As to the question of how many converts Dr. Oreskes' personal presence will bring on board, I wonder to what extent she will be preaching to, and meeting with, the "converted", as opposed to the doubters, or the deniers. Entrance and exit polling at the presentations might be an interesting study. Re: RHoneycutt (20) Right now, there are lots of vegetables available. The shortage of vegetables (and flights to Oz) are in the future. I am just trying to suggest that we can start to demonstrate that people can live quite happily and healthily while eating a lot less meat.
  3. Naomi Oreskes' Merchants of Doubt Australian tour
    All the comments of "walk the walk" in relation to people using carbon emitting forms of transportation is a bit like telling someone they should become a vegetarian at a time where there are few vegetables available. Yes. Let's move toward solutions. Yes, use reasonable low carbon options where available as they become available. But let's not kid ourselves that it's currently possible to be productive in the quest to reduce CO2 by eschewing all carbon based transportation.
  4. Naomi Oreskes' Merchants of Doubt Australian tour
    #10 @humanityrules What's your problem with "AGW isn't true because I like Oreos ... AGW is true because (a large list of real causes behind an AGW that is true)"? Why your "There seems to be no logic in this comment. What have clouds got to do with DDT? Guilt by association???" looks like it works with an "is" in the assertion you criticize instead of the "isn't" that is indeed written? Why don't you explain it again -including the original "isn't"-?
  5. Solving Global Warming - Not Easy, But Not Too Hard
    actually thoughtfull: "How many of us are using renewable energy right now?" I use a green electricity tariff (i'm all electric). I have managed to reduce my energy consumption by about 60% by just doing a few simple things which haven't had a big impact to the quality of life. I would have solar heating panels if it weren't for the big tree in the neighbours garden that blocks the Sun, also cost is an issue for me right now. actually thoughtfull: "Electricity is 20% of the energy consumed. Because of the coal in the mix, it accounts for 1/3 of the carbon emissions." Yeah but in the UK, coal is 30% of the electricity mix which equates to 60% of the electricity emissions. In the US coal is something like 70% of generation capacity so must be something like 90% of electricity emissions. The other point is that electricity is likely to be the main source and means of conveying energy, so it may not be the majority chunk now, but it certainly will be in the future.
  6. Naomi Oreskes' Merchants of Doubt Australian tour
    Another example of mixed messages was the Copenhagen meeting a year ago. 1200 limousines (a negligible number of them electric or hybrid) were used. The prominent guests used 140 private jet planes to get there, in addition to all the regular airplanes that transported the 15000 guests and journalists. We can only dream about the buffés with caviar and lobster and so on. Of course the top guys want to live in their usual luxury even if it is a climate meeting.
  7. Naomi Oreskes' Merchants of Doubt Australian tour
    Re: KeenOn350 (17) Appreciate the perspectives and the personal experiences with green telepresenting. But do not underestimate the power of networking and physical presence that in-person tours such as Dr. Oreskes is performing now have. Much interaction goes on behind the scenes that also has value, interaction that would not occur in a green tour. If a physical tour, such as is being undertaken, gets the job done then I'm OK with that. For there are many who would not attend such a program without a live speaker present. And if the glad-handing at a book-signing is what it takes to convince someone, then I'm OK with that, too. The Yooper
  8. Economic Impacts of Carbon Pricing
    "When a price is put on carbon emissions [government sells allowances], it creates a revenue stream." True. "The funds which are generated from the carbon price can be distributed in any number of ways – usually through reductions in other taxes, investment in research and development of 'green' technologies, funding of energy efficiency programs, etc." Not necessarily. The money can also be wasted, here is a libertarian response http://townhall.com/columnists/RobertMurphy/2009/05/02/the_cost_of_cap_and_trade/page/full/
  9. Are ice sheet losses overestimated?
    This is an excellent article. Not being a glacialogist, it really makes it much clearer to me what is behind all these estimates and explains well the bases of differences. Thanks! It also makes it clear how hard it is to do science in the current atmosphere of hypervigilism (and hyperhypism) we are in. As described in this article, the Wu paper becomes a call for better GPS coverage in central Greenland, which is a good thing if you want to lay out priorities in future efforts. However, the way it has been spun in some blogs (and by some on this site) you'd think it was the nail in the coffin of scientific credibility regarding climate change rather than part of a real debate about how best to quantify what is universally acknowledged to be a decline in ice mass on Greenland. It must be difficult knowing that something you will publish for perfectly good objective scientific reasons might get picked up by the vortex of public debate, stripped of all scientific context and flung back at you with amazing force and some new originally untended political bias. How can we protect scientific debate from this kind of distortion?
  10. Economic Impacts of Carbon Pricing
    Here's a different way of visualizing the costs of cap-and-trade that shows just how small they really are: http://akwag.blogspot.com/2009/09/visualizing-costs-of-cap-and-trade.html
  11. Naomi Oreskes' Merchants of Doubt Australian tour
    Let me preface these observations by saying that I have seen several video presentations by Dr. Oreskes on the Web, and admire her work. Nevertheless, I feel there is something to question about this tour. A few months ago, our community green group put on a presentation of the film No Impact Man, followed by a Q & A session with Colin Beavan. The Q & A was done by Skype, and worked very well. We had personal interaction with Colin, we could see him on the big screen, even though he was not physically present. Environmental impact - very low! Results - very satisfactory. Information exchange - just as good as it would have been by personal travel. I fully realize that individual efforts to reduce carbon footprint/climate impact (CFL or LED bulbs, driving a small car, cycling more, etc.) will be insufficient to curb climate disruption. However, I believe that such efforts are necessary, along with more sweeping measures on regional, national, and international scales. Partly it is a question of changing attitudes, and reinforcing that change It is unfortunate that the IPCC reports, and the general community of those addressing the problem of CO2 emissions, refer to the danger of "BAU" (Business as usual). In reality, the danger derives from "LAU" - Living as usual - which more expressly includes the fact that we must change our lifestyle practises, as well as our practises at work. I find it ironic that Naomi Oreskes is flying half way around the world, and then all over Oz, to do something that could just as well be done from her home, with perhaps a minor inconvenience due to time zones. I find it ironic that such organizations as the presenters ( Climate Change Research Centre, The Global Change Institute, The Monash Sustainability Institute, The Melbourne Sustainable Society Institute) have invited her to do this. This is sustainable? This is change? Or is this unthinking BAU/LAU which could easily be changed to a more sustainable format? One factor that we must include in any effort to combat climate disruption is better use of our amazing modern technology. People purporting to be concerned about climate impacts must begin to walk the walk - talk is not enough - and do so in obvious ways which make a public demonstration of the changes we can implement easily. Is it worth the impact to have Dr. Oreskes flying all over, so that a few people can actually shake her hand, and get a personally autographed copy of her book? ------- A small final point - in her all her major video presentations on the web, Dr. Oreskes is drinking bottled water. Another unnecessary modern convenience with disproportionately high impact. Check out The Story of Bottled Water. I do hope the presenters at these sessions will at least provide her with a glass of tap water, or a re-usable water bottle filled with tap water, instead of the pre-bottled stuff, especially if she will be on a video which will then be widely seen. ------ Enjoy the tour - but consider the alternatives....
  12. Ice-Free Arctic
    James Hansen is well known for saying that controlling black carbon is one of the lowest hanging fruits in controlling AGW. For those who claim the IPCC goes only after CO2 this is a clear counter example of scientists trying to identify the cheapest fixes to go after first. That said, even with black carbon controlled, without controlling CO2 the ice will all melt out. We need to control as many sources of warming as possible.
  13. Naomi Oreskes' Merchants of Doubt Australian tour
    Just a comment to HumanityRules #10: (BTW Argus you seem to be falling for the same fallacy with your linking of Nazism and Communism. These are both historically specific movements, both require critiques independant of each other.) What you are referring to here is not my opinion; it is part of a quoted example of a faulty argument, borrowed from: en.wikipedia.org/wiki/Guilt_by_association
  14. Ice-Free Arctic
    #68: "The particulate load that China adds daily to the Arctic" #70: "The teleconnection between Chinese soot and Arctic melt is undeniable." That this soot largely originates in the burning of coal is proof that anthropogenic input is real and of significant, measurable magnitude. If this soot is moving to the Arctic, so are the exhaust gases which are produced with the soot. To verify this conclusion, look at the significantly higher average annual CO2 concentrations in the Arctic: compare BRW, ALT, ICE, OSM, PAL, MBC, ZEP to MLO. Further verification comes from Fisher et al 2010, who traced combustion gases via CO (monoxide) monitoring using data from both aircraft and the AIRS satellite: We find that Asian anthropogenic emissions are the dominant source of Arctic CO pollution everywhere except in surface air where European anthropogenic emissions are of similar importance. So if soot, then CO and CO2. And that is melting Arctic ice.
  15. Naomi Oreskes' Merchants of Doubt Australian tour
    Re: jsam (12) In HR's defense, he did not fire the opening salvo needed to invoke the Godwin rule. He was, however, caught in the resulting firefight. The Yooper
  16. How significance tests are misused in climate science
    Re: HumanityRules (43) We all have bad days; I certainly still have my share. :) Of course, just how bad is a matter of degree; how often, a matter of conjecture (speaking of my bad days, no-one else's). ;) The Yooper
  17. Naomi Oreskes' Merchants of Doubt Australian tour
    Argus, #8 This is a case of inductive logic ... X had used standard argument A and standard B in denial of demonstrable scientific propositions several times before. Inductively, X is also wrong about P (global warming) and this has been shown to be the case. The point is that argument A and tactic B are used continuously and repeated ad nauseam in and by the popular media, even after they have been refuted scientifically. In a way, that is part of tactic B. X, in fact, left the realm of science long ago, and entered the realm of the patron saint of marketing, P.T.Barnum. Barnum said "There is a sucker born every minute". In the Barnum world, every unprincipled tactic is justified to gain the desired result. This may be stronger than the way Oreskes puts it, but it is my interpretation. X may even have passed away, but his/ her successors, the Legion of X, are repeating his/ her arguments and tactics. Inductive logic tells us that X (or his/her Legion of Successors) are wrong but will be successful for a while. The point is how long will their tactics of delay postpone the inevitable?
  18. How significance tests are misused in climate science
    32.Daniel Bailey We are discussing n=1 papers here but I accept your criticism, I over-stated the point. We're all capable of mistakes, as Maartens work suggests. Maarten(n=1) I don't suppose you want comment to what extent you agree or disagree with the statements contained in this link?
  19. Naomi Oreskes' Merchants of Doubt Australian tour
    By Godwin's Law HumanityRules has lost the argument. See http://en.wikipedia.org/wiki/Godwin's_law. More seriously, the book is worth reading. There are also some very good, if long (60 minute) Youtube clips. Real skeptics have, of course, viewed those before posting. On the other hand when person X tells fibs A and then B it is perfectly reasonable to question whether his statement C is a fib or not. Skeptics note trends.
  20. Naomi Oreskes' Merchants of Doubt Australian tour
    Re: HumanityRules (10) Much of what the moderator had to say in this response to Argus above also applies to you as well. I suggest you read the book and then form an opinion of it. That would be the skeptical thing to do. The Yooper
  21. Dikran Marsupial at 00:58 AM on 16 November 2010
    How significance tests are misused in climate science
    Hi Maarten, I fully agree the p-value can't be used to draw a fully objective conclusion; it is a subjective choice to disregard the null hypothesis based on a convention/tradition amongst frequentist statisticians (Occam's razor being a large part of the motivation) - nothing more (I checked with a frequentist colleague before I wrote that ;o). The distinction between rejecting and negating the null hypothesis is the key to the point I was making. Essentially we need to employ a form of words that emphasises the fact that we are chosing (not to) accept the null hypothesis, rather than that we have established that it is (not) true. When I was taught stats, that was the motivation given for saying "we reject the null hypothesis" rather than a positive statement about the alternative hypothesis or claiming that the null hypothesis is false. Essentially rejecting implies a choice, rather than a rational necessity. In short - I agree! BTW, the p-value fallacy doesn't just appear in science, I have seen this error made in statistical methodology papers I have reviewed. It certainly isn't limited to climatology!
  22. Naomi Oreskes' Merchants of Doubt Australian tour
    Response to 4.Argus In an attempt to refute Argus' accusation of guilt by association you immediately repeat the idea. "Her point is that the people who are skepticial towards AGW are the same people who used the same arguments against other areas of scientific consensus." You cannot right off all skeptics as Fred Singers, you lose credibility by suggesting such a thing. It would be like me suggesting all climate scientist have the same agenda driven position as James Hansen. Taking the details here at face value Singer essentially seems to be an anti-state libitarian who is oppposed to regulation against industry, it seems like the only thing that links all these issues. Not all skeptics are coming from this position, I know this for a fact. Even if this is true it's still only right that Singers ideas are engaged, it shouldn't be so difficult if "AGW is true". People ultimately have the right to dissent no matter how unpleasant (or pleasant) they are. But then I'm an old-fashioned democrat. "AGW isn't true because the skeptic arguments are similar to skeptic arguments against DDT, etc." There seems to be no logic in this comment. What have clouds got to do with DDT? Guilt by association??? (BTW Argus you seem to be falling for the same fallacy with your linking of Nazism and Communism. These are both historically specific movements, both require critiques independant of each other.)
  23. How significance tests are misused in climate science
    Re: Maarten Ambaum Thank you for taking the time to shed some light on your paper. It's appreciated. The Yooper
  24. How significance tests are misused in climate science
    Dear Dikran (Re post 39) Perhaps I misunderstand you and Tamino, but a low p-value cannot objectively be used to reject a null-hypothesis; it simply does not contain the required information to do so. I formalize this in my paper, if you like to know more. On the other hand, a high p-value indicates that the presented evidence is easily consistent with the null hypothesis. This is not evidence that the null-hypothesis is true; the evidence could also be consistent with the alternative hypothesis. A significance test simply contains no information either way. Using Occam's razor we can then conclude that there is no evidence for our hypothesis, so we better stick with the null-hypothesis. It is Occam's razor that makes the argument here, not the significance test. Maarten
  25. Dikran Marsupial at 00:01 AM on 16 November 2010
    How significance tests are misused in climate science
    The terminology used in reporting the results of statistical tests is indeed a thorny issue. Taminos comment that "it merely negates the null hypothesis.", would have been O.K. if he had instead written "is enough for us to reject the null hypothesis". The difference, while subtle, is very important; "negating" the null hypothesis is a statement that the null hypothesis is false, while "rejecting" the null hypothesis is merely a statement that we have made a subjective (if perhaps very reasonable) choice not to believe the null hypothesis based on the evidence - but stops well short of saying that it is false. Essentially it is only a convention that we "reject" the null hypothesis if the p-value falls below some critical value (which is also a subjective choice) - nothing more. The two phrases we should use would be something along the lines of "we can reject the null hypothesis" or "we are unable to reject the null hypothesis" - the frequentist test doesn't really give a basis to make any statement about the alternative hypothesis (note the alternative hypothesis doesn't actually appear in the frequentist test - so perhaps that isn't surprising!).
  26. Economic Impacts of Carbon Pricing
    Very good topic, btw. About time.
  27. Economic Impacts of Carbon Pricing
    Ok, now a derogatory comment on my own country, Brazil. Back-of-the-envelope bill: stop deforestation now, effectively cutting down 1994 emissions by some 20-30% immediately, with very marginal impacts to national GDP (logging in the Amazon is about 0.07% of the national GDP). Here's our emission inventory. Unfortunately in Portuguese, but the wrap-up graph on the last page is understandable with minimal google translating work.
  28. The Skeptical Chymist at 23:54 PM on 15 November 2010
    Are ice sheet losses overestimated?
    Thanks for a well explained post Robert. Solving these sorts of "mysteries" is part of the reason us science geeks enjoy science.
  29. Naomi Oreskes' Merchants of Doubt Australian tour
    Argus, I think the larger argument is that just as these efforts at attacking science and confusing the public had some success in past incidents (tobacco, asbestos, evolution, et cetera) so to are they in part responsible for the 'debate' over global warming. This site includes dozens of examples of 'skeptic' arguments which are provably clearly false... doubt has been created by the same deceptive tactics used in the past attacks on science Oreskes and Conway identify. No, that does not mean that all 'skeptics' are being deliberately deceptive or that all 'skeptic' arguments are wrong. However, it does mean that the discussion has been poisoned by deliberate misinformation. Which logically should lead everyone interested in the truth to want to identify provably false arguments and shut them out so we can deal with these issues from a foundation of reality.
  30. Naomi Oreskes' Merchants of Doubt Australian tour
    Thanks, tobyjoice: "What can you deduce from the foregoing?: - Most likely that I should not trust Mr X, and now I do not have to read that book. But are all "the people who are skeptical" wrong because Mr X (and Y and Z) is wrong? And are all "the people who are skepticial towards AGW" today, "the same people who used the same arguments against other areas of scientific consensus" ?
  31. Miriam O'Brien (Sou) at 22:44 PM on 15 November 2010
    Naomi Oreskes' Merchants of Doubt Australian tour
    I haven't read the book yet, but listened to Dr Oreskes on the ABC today. One of the points she made was that this tiny group of people appeared to be in it for ideological reasons rather than for monetary gain. They appear to be some sort of anarchists (my interpretation not Oreskes) and against any government guidance let alone intergovernmental cooperation or intervention. The other point was that they used their scientific qualifications and position of influence to try to boost their credibility. However none of them are specialists in the areas they criticised. In effect they are just Joe Bloggs. In fact it's worse, because they are peddling falsehoods, whereas Joe Bloggs knows that smoking tobacco carries high health risks, the earth is warming and the climate is changing.
  32. How significance tests are misused in climate science
    PS: I would like to highlight Tom Dayton's excellent contribution (no 16, above - I don't know how to include internal links - sorry). I agree very much with what he says. But may I just add that significance tests are perhaps not as innocent as he makes them out to be. Indeed, they are usually only a small part of the evidence, but I have been involved in discussions where an important part of the argument was whether a certain link, as measured by linear correlation, was "significant" (in the statistical meaning). This was very much an instance of explorative data analysis, where some link was posited, with only tenuous indications this link should be there, and where significance tests were an important part of the argument. Interestingly, that claimed link has now become part of mainstream climate literature (I am referring to "annular modes" which appear to indicate a connection between Atlantic and Pacific pressure patterns) and a large number of people have by now stopped to worry whether this implied link is really present. This is a feature of significance tests in general: perhaps many people do not mean to say that a low p-value is evidence for their hypothesis, but by publishing the low p-value along with phrases such as, "this or that effect is significant at the 95% level" certainly seems to imply that that want to use these statistics as positive evidence at face value.
  33. Dikran Marsupial at 22:26 PM on 15 November 2010
    How significance tests are misused in climate science
    Eric L @ 18 I strongly disagree that scientists should not bother with Bayesian statistics, especially in the case of statistical significance tests. There is rather more to Bayesianism than Bayes rule (which is a fundamental law of probability whether Bayesian or frequentist); the very definition of what a probability actually is, is an argument in favour of the Bayesian framework in this case. The problem with frequentist approach to statistical significance tests is that they fundamentally cannot assign a probability to the truth of a hypothesis, because a hypothesis is either true or it isn't, its truth is not a random variable and has no long run frequency (the frequentist definition of a probability). Unfortunately the probability of the alternative hypothesis being true is exactly what we want to know! Fortunately the Bayesian definition of probability is based on the state of knowledge regarding the truth of a proposition, so the Bayesian framework can directly assign a probability to the truth of a hypothesis. Generally in science it is best to carefully formulate the question you want to ask, and then choose a method that is capable of giving a direct answer to that question. As such the Bayesian approach is perfectly respectable, if not preferable. The frequentist approach can only give an indirect answer, telling you the likelihood of the observations assuming the null hypothesis is true, and leaving it up to you to decide what to conclude from that. Most of the problems with frequentist statistical tests lie in mistaking the indirect answer to the key question for a direct (Bayesian) one. The Bayesian approach is more than a means of aggregating evidence; one of the most important benefits of the Bayesian approach is that it gives mechanism to properly incorporate the fact that you know you don't know something, by assigning a non- or minimally-informative prior on it and marginalising it out of the analysis. For instance, if you want to model the impacts of climate change, it is incorrect to assume we know the exact value of climate sensitivity (for instance by picking the maximum likelihood value), instead we should integrate it out by computing an average of the impacts for each value of climate sensitivity weighted by its plausibility according to what we do know. "When do Bayesian statistics matter? When the prior probability is extreme (very likely or very unlikely). So if the chance of a woman your age has breast cancer is 1 in 1000, and mammograms have a 1 in 100 false positive rate, and you had one done as part of a routine checkup and it came back positive, Bayesian statistics tells us that chances are you don't have cancer." In this case, the Bayesian result exactly coincides with that from the frequentist approach. The only difference is that the Bayesian approach allows you to formulate the question in terms of an individual patient, rather than a randomly selected member of some population with the same test results. "Bayesian statistics that combining your result with the prior gives you 99% confidence and, presto! a statistically significant publishable result! Of course not." Indeed not! Bayesian conclusions are only as strong as the priors used, if you could show the priors were unreasonable then you could reject the result of the test (and the paper). If you can't question the prior, you are logically forced to accept the result of the test. The good thing about the Bayesian approach is that the priors are explicitly stated. If you disagree with the use of priors on the hypothesis, you could always use a "significance test" based on Bayes factors instead, where the priors (on the hypotheses) do not appear in the analysis. "And if someone else finds further evidence and publishes a paper showing P(M5|N), well now that Bayesian analysis you did in your paper to get P(N|M1..M4) is out of date." That is equally true of any frequentist analysis - if your information changes, your view on the truth of the hypothesis should also change, whatever form of analysis you choose. "But that calculation of P(M4|N) stands, and will forever be useful as a piece of the evidence used to assess P(N)." That is only correct if M4 is independent of M1-M3 & M5 (otherwise it is the so-called Naive Bayes approach), which in the case of climate change is rather unlikely as rising levels of atmospheric carbon dioxide are posited to be a causal factor for a great many phenomena. "And in this analogy we can't perfectly do the Bayesian calculation because we don't really know what fraction of the population has cancer" This is incorrect, the whole point of the Bayesian formulation is that it allows your to deal rationally with the fact that you don't know something, or that you have imperfect knowledge of somthing. You choose a prior distribution that captures what you do and don't know about it and marginalise. The perfect Bayesian calculation reflects the consequences of that uncertainty. ", except for what we infer through these tests." This is incorrect, the operational priors are estimated from epidemiological studies, not just from diagnostic tests followed by biopsies. "But you don't subject patients to tests that tell 1 in 5 healthy people they have cancer" Neither a competent Bayesian nor frequentist statisticians would do so. Eric L. @19: I agree there, however given sufficient data it is similarly virtually always possible to get a statistically significant result even if the effect size is negligible, which is the flip side to the same coin. A common criticism of frequentist statistical tests is that we almost always know from prior knowledge that the null hypothesis is false from the outset. For instance with temperature trends, do we really think the trend is actually exactly zero? Anyway the differences between the two frameworks is a fascinating topic in its own right, you need a really solid understanding of both frameworks to know which tool to use for which job.
  34. How significance tests are misused in climate science
    Dear All, Thank you all for your reactions to my post. I hope you don't mind it if stick my oar in in some of the topics you raised. If I have overlooked something, please let me know. Sorry for the somewhat rambling response here ... Re post 1, and the pirate-global mean temperature correlation: Alexandre is of course right to say that we need statistics and physics to make any progress. What I am highlighting, though, is not that specific issue (which is serious and important in itself). I am highlighting that significance tests are used to give certain statistical results higher "credibility" than others, based on a largely spurious test. So it is the selection of statistical results that I am objecting to, not the statistical results per se. Some posts (specifically Steve L) refer to the frequentist vs Bayesian discussion. This is interesting in itself, but in my paper I am simply applying Bayes' equation, which also a frequentists would accept as indisputable. The difference comes in the interpretation of the meaning of these probabilities. Indeed, significance tests have a clear frequentist flavour, while hypothesis tests have a much more Bayesian flavour. I think it is hard to escape that scientific hypotheses naturally fit a Bayesian framework. Nonetheless, I think the distinction between Bayesian and frequentist interpretations is largely irrelevant to the discussion at hand. Several posts point out that scientists should know about this and also that climate science should not be singled out. Indeed, in my paper I point to more general references which highlight the misuse of significance tests in a wide spectrum of fields (medicine, economics, sociology, psychology, biology, ...) In fact, I suspect that your average research psychologist knows more about the pitfalls of significance tests than the climate scientist. In those more "softer" fields, people have had to mainly rely on statistics from the start and therefore needed to know how to use statistics from day one. In those fields, many people have pointed this problem out (and it still seems to persist). Climate science has always been a subfield of physics, where significance tests are largely irrelevant. I bet that most physicists (by training, I am a theoretical physicist myself) didn't get a stats course in their curriculum! However, these days more and more geographical thinking seems to enter the field of climate science with the resulting lack of rigour and physical underpinning. Many climate scientists have become geographers of their model worlds! Also, the point I am making is not new: many people are aware of the problems with significance tests, and many people have pointed it out before (although most practitioners probably believe that climate scientists would know better). It boggles the mind that the error keeps on being propagated - surely an interesting question for a psychologist or sociologist to get their teeth into. I do have an opinion about why this may be, but that would make this post even longer. Regarding the somewhat rambling posts about 75% of papers being misleading in part. I claim that 75% of papers (in my own paper I clearly state that this is based just 1 (one) sample and make no claim regarding its statistical significance!) make a technical misuse of significance tests: they use it to select or highlight certain statistical results in favour of others. Perhaps I should write a post where I discuss what significance tests can be used for (largely for debunking fake hypotheses, but even this is an application with its own pitfalls). However, this is generally not how significance tests are presented in the literature. The latter of course follows from the fact that very few scientists would publish negative results (in fact, they would probably have a hard time to get it past the reviewers). Some people, including John Cook himself, pointed me to a post by Tamino. Tamino also highlights some further points from my original paper. Let me just add two little comments to Tamino's interesting post: Tamino states that "I’ve certainly struggled to emphasize to colleagues that a highly significant statistical result does not prove that one’s hypothesis is true, it merely negates the null hypothesis." This is again the error of the transposed conditional: a low p-value does not negate the null-hypothesis, it just indicates that our statistical result would be unlikely in case the null-hypothesis were true. It is remarkable how easily we can stray into this error. Tamino also seems to indicate that the p-value does provide useful quantitative information. I cannot find any evidence in his post of this. Yes, the p-value is quantitative, but its usefulness is never really made clear. The p-value is perhaps an indication of the signal-to-noise ratio; a high p-value means that it will be difficult to see any evidence of any claimed effect. A low p-value indicates very little really: we want to study the validity of some hypothesis assuming it is false; some attempt at a reductio ad absurdum proof of your hypothesis - unfortunately it is not quite that ...
  35. Solving Global Warming - Not Easy, But Not Too Hard
    archiesteel #144 I said, "which is in turn tied directly to natural chemical energy." then you said, "So is Religion. So is making stuff up. So it trolling. What is your point? " The point is clear. If something itnt profitable, it will ultimately affect the bottom line. Get the bottom line low enough and you wont have chemicals (food) to even get out of bed. Or do you run on batteries? Actually, even that would be chemical.
  36. Jacob Bock Axelsen at 22:04 PM on 15 November 2010
    Economic Impacts of Carbon Pricing
    @Dana Thanks for your efforts. You might be interested in reading the report from the Danish Climate Commission (it is also in English). www.klimakommissionen.dk
  37. Solving Global Warming - Not Easy, But Not Too Hard
    Actually Thoughtful #147 "How many of us are using renewable energy right now?" I just threw another log in the fireplace.
  38. Berényi Péter at 21:37 PM on 15 November 2010
    Ice-Free Arctic
    #17 Camburn at 05:16 AM on 8 November, 2010 And not least, is the tremendous amount of soot that China spews that lands in the Arctic. Yes. Here is an intercomparison of Annual total number of hours of Reduced Visibility observed at the Hong Kong Observatory and Annual Minimum Sea Ice Extent in the Arctic (reversed scale). The teleconnection between Chinese soot and Arctic melt is undeniable. Let me note it is possible to burn coal with no soot output while it is impossible to burn it without producing CO2. Eliminating black carbon emissions is not even prohibitively expensive. It is routinely done in Europe and to a somewhat lesser extent in the US of A. Some background material: JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 110, D04204, 2005 doi:10.1029/2004JD005296 Distant origins of Arctic black carbon: A Goddard Institute for Space Studies ModelE experiment Dorothy Koch and James Hansen "The (former) Soviet Union (FSU) was implicated as a major source of Arctic haze in many studies. Novakov et al. [2003] found that black carbon emissions from the FSU in the late 1990s was less than 1/4 their peak levels of 1980. European emissions are also about 1/3 their levels in the 1970s. However China and India have doubled their BC emissions since the late 1970s. Thus BC emissions are more heavily weighted toward south Asia than they were in the 1970s and 1980s, when many of the Arctic haze studies took place."
  39. Naomi Oreskes' Merchants of Doubt Australian tour
    Argus, #4 The book goes more like this: X makes argument A and uses tactic B against scientific proposition M X makes argument A and uses tactic B against scientific proposition N X makes argument A and uses tactic B against scientific proposition O M could be "acid rain", N could be "nuclear winter", O could be "tobacco smoking increases cancer risk" or "the ozone hole" ... And so on ... X has been demonstrated to be wrong in each case, but the use of argument A and tactic B have been invaluable in confusing the public, influencing key politicians and delaying corrective action. This has been worth $billions to important interests. X has been handsomely remunerated for his/ her work in propagating argument A and using tactic B. Now, X is using argument A and tactic B against P, which is global warming. What can you deduce from the foregoing?
  40. Economic Impacts of Carbon Pricing
    I hope I may be allowed to make an observation on Camburn's posts above. If he/she wants to take it further, I suggest moving the discussion to Extreme weather isn't caused by global warming. Camburn wrote : "Russian heat wave: Black Swan Event not related to GAWG. So says Dr. Martin P. Hoerling of NOAA." As usual, things are not quite as simple as some would have us believe : As we learn from our 2010 experience what a sustained heat wave of +5ºC to+10ºC implies for human health, water resources, and agricultural productivity, a more meaningful appreciation for the potential consequences of the projected climate changes will emerge. It is clear that the random occurrence of a summertime block in the presence of the projected changes in future surface temperature would produce heat waves materially more severe than the 2010 event. The Russian Heat Wave of 2010 - Dr. Martin Hoerling As for Camburn's second link (HERE in translation), it is a collection of stories and reports, without any comparative data whatsover. Would anyone rely on this rather than something like the previous NOAA report ?
  41. Naomi Oreskes' Merchants of Doubt Australian tour
    I read both books this year. Schneider's modelling predicted a "nuclear autumn" that was somewhat less disastrous than the "nuclear winter" predictions. Schneider (and many others - Oreskes quotes Kerry Emanuel in her book) thought Sagan had jumped a gun by going public with the "nuclear winter" scenario in news publications before the science was fully tested. Oreskes does not deal with Schneider's part in the controversy, but is critical of Sagan for "violating scientific norms". Her presentation has the dispute on two levels - firstly, the science, and then, how it was publicized. On the science, she emphasizes that "scientists broadly agreed that a nuclear war would lead to significant secondary climatic effects". It was at the conclusion that deniers took aim.
  42. Naomi Oreskes' Merchants of Doubt Australian tour
    Her book appears to be an example of using the method: 'Guilt by association as an ad hominem fallacy' (wikipedia): If you are skeptic towards the AGW hypothesis, you are just like those people who did not believe that acid rain, DDT, CFCs and smoking was dangerous. Also, because the arguments used in global warming skepticism look similar to those false ones used against DDT or whatever, consequently AGW must be true. Quote: ''Guilt by association can sometimes also be a type of ad hominem fallacy, if the argument attacks a person because of the similarity between the views of someone making an argument and other proponents of the argument. This form of the argument is as follows: A makes claim P. Bs also make claim P. Therefore, A is a B. Example I: Social justice is a philosophy shared by Nazis and Communists, therefore churches that teach social justice are equivalent to Marxists and Fascists.''
    Response: You probably should read the book before posting such criticisms. Her book doesn't make that argument at all. Her point is that the people who are skepticial towards AGW are the same people who used the same arguments against other areas of scientific consensus. It's not 'Guilt by association' if you're talking about the same person.

    AGW isn't true because the skeptic arguments are similar to skeptic arguments against DDT, etc. AGW is true because of the multiple lines of evidence. Scientists built a consensus on smoking, acid rain and ozone depletion by gradually accumulating multiple lines of evidence painting a single, consistent picture. Similarly, scientists have built up many lines of evidence that humans are causing global warming. And when the evidence is so strong, the only way to refute it is the diversional and rhetorical techniques employed by the Merchants of Doubt.

    But Naomi Oreskes and Erik Conway explain it a lot better than I do and in much greater detail, so I'd recommend reading their book.
  43. Economic Impacts of Carbon Pricing
    #6 @Robert Way Whatever you had in mind when you asked, costs in terms of relinquished GDP growth are in table 1. As the initial "and" let you deduct, my answer was intended for Camburn (#1) who seems to be arguing "something must be done but not in this very moment" by comparing something recurrent -annual- with some one time cost depicted as abruptly incurred. This new argument is the way to get a new ten-year delay and it is the expected response to this site's 'moving into solutions' new approach. So, I expect more of this kind: A comparing a function and it's derivative in an argument, B pointing that fact and C asking B 'so, what's the function then?'.
  44. Naomi Oreskes' Merchants of Doubt Australian tour
    "When scientists calculated that nuclear war would cause a devastating nuclear winter, the same group of scientists sought to cast doubt not only on the science but on the entire scientific establishment." Just an aside: Steve Schneider, in his 'Science as a Contact Sport', argues that Sagan's case for a nuclear winter wasn't as scientifically certain as Sagan was making out. He also points out you hardly need the nuclear winter argument to conclude that global nuclear war is a bad idea. He bought it up in the book to make clear that we have to follow the science at all costs. I haven't read Merchants of Doubt, so I don't know what Oreskes argues (or indeed if Sagan is the 'nuclear winter' proponent) but thought it worth mentioning.
  45. Naomi Oreskes' Merchants of Doubt Australian tour
    Read the book. Highly recommended. There are several videos on You Tube featuring Naomi Oreskes e.g. http://www.youtube.com/watch?v=2T4UF_Rmlio
  46. CO2 limits will harm the economy
    Not much of a problem. Massive new bureaucracy? I don't think so. Taxes are one thing modern governments have lots of experience with - income taxes, goods & services, excise, import duties - all well established, ho-hum, routine procedures. Hand over the legislation and the public servants will just do the same as they've always done. Heavy industry, light industry, any industry? All you have to do is organise import duties to match homegrown production taxes so that it won't matter where the stuff is produced, the same imposts will go on.
  47. Naomi Oreskes' Merchants of Doubt Australian tour
    Rats. Adelaide's fully booked. Someone'd better do a video.
    Response: Hmm, I didn't even think to book, I was just going to turn up (slaps forehead). Thanks for the tip!
  48. CO2 limits will harm the economy
    Do these analysis consider the global industry transfer- it may destroy the last bit of heavy industry in the US and send it somewhere they have no problem polluting much more- let alone other effects of that ? How about the cost the massive new bureacracy for this tax- I admit less than that for a carbon trading scheme? Even more disasterous for somewhere like Australia and no net benefit on carbon dioxide output.
  49. Are ice sheet losses overestimated?
    Thanks for the hard work, Robert! Will take me a while to digest and internalize. The Yooper
  50. Climate cherry pickers: cooling oceans
    Re: Camburn (30, 32) One more thing: Robert Way takes a very insightful look into the GRACE issue here. Topical, timely, worth the read. The Yooper

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