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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 60901 to 60950:

  1. HadCRUT3: Cool or Uncool?
    WRT my #4, something is not quite right. I'd expect the WWII temperature hump to be more pronounced in the land than the sea, but that is not the case.
  2. HadCRUT3: Cool or Uncool?
    I need to move on to other things, but it seems to me that deciding on a grid model, any grid model, presents its own challenges and shortcomings. I'm thinking that it should be possible to use an alternate method. I have one in mind where each station contributes a measurement that is weighted according to the distance from the station. Not sure how to explain the math, but I visualise it as a globe with a calculated height above it (false surface map/tent) where the height above the 'sphere' represents the temperature (or temperature anomaly). How much any station contributes its measurement to the temperature value any given point on the surface is a function of how close it is to that point, and how much other stations are also contributing their measurements to that point. Total weights for all stations at any give point is always scaled to 1. Once you have the contour of the surface defined, you can integrate over it any way you like, grid it out, whatever. Sounds complicated, but it would not be that difficult to program.
  3. HadCRUT3: Cool or Uncool?
    Hmm, that spike in land percentage around WWII happens to coincide with the hump in the temperature record. I suspect the hump is a little exaggerated. Relative to GISTEMP, it is. Thanks Kevin, Now I'm thinking about the 5 degree grid. When it comes to the global averaging, and 5 degree cells are not all the some size, the math to weigh a fixed surface area size equally becomes complicated. IMO, you'd have to weigh surface area equally if you are talking about a global surface temperature average.
  4. HadCRUT3: Cool or Uncool?
    Chris: Yes, you are right about circulation being a critical factor in the slow warming of the oceans; i.e. you have to heat a lot more water because it keeps changing over. HadCRUT3 uses a fixed 5 degree grid. That also means that the high latitude cells are smaller than the equatorial cells, so you actually need a higher density of stations at high latitudes to achieve the same coverage. The common anomaly method used in CRUTEM3 also means that they lose stations as they go away from the baseline period (1961-1990).
  5. HadCRUT3: Cool or Uncool?
    Nice job explaining the problem of making sure that a sample represents the population. Pretty simple coverage here, for sure, but there are entire courses on avoiding sampling bias. "How do you know your random sample is really random?" and so forth; so, good for this venue. Question regarding: "...as would be expected given the higher heat capacity of water." I'm thinking that the temperature difference would have more to do with the fact that water tends to circulate to depth more than land does; so, you get the same energy distributed over more mass. On land, there is less "buffering" because the surface warms, and it takes a long time for the energy to equilibrate to much depth. Water cp ~= 4.2 (J/(g·K) Silicate rock ~= 0.75 (J/(g·K) but rock is about 3 times more dense; so, the difference per volume is about 2x. So, yeah, a given volume of water has about twice the heat capacity. But, I'm still thinking it has more to do with circulation because if you put rocks in a bucket of water, they all come to the same temperature in not much time. "Land coverage in the HadCRUT3v record has been declining over the past 50 years." Really? I could see them making use of a different set of stations, for various reasons, but I would expect them to grid it out so that the actual land surface area coverage did not decrease. Oh, I think I get it. They like to pretend that areas with poor coverage do not exist (at least for the calculations) and the sea surface coverage has been increasing relative to land surface. Ah, alarm bells just went off on my sampling bias detector. Double counting the coastal cells does not really improve the situation either. Nice bit of showing that stratified populations need to be sampled independently, their means calculated independently, and then trend and other analysis performed.
  6. Dikran Marsupial at 02:55 AM on 28 March 2012
    The Skeptical Science temperature trend calculator
    Barry, following on from what Daniel says, the "normal circumstances" for statistical significance tests include the period you are looking at being randomly chosen. In this case the period is not randomly chosen, the question that Phil Jones was asked was loaded by having a cherry picked start/end date, which biases the test towards the desired result. "Warmists" could similarly bias the test by starting the period in say 2000, and the fact that they don't (other than to show why cherry picking is a bad thing) shows who is seeking the truth and who isn't! ;o) IIRC Phil Jones actually gave a very straight answer to the question (no it isn't significant, but it is very close to being significant and that you need more data to be able to expect to reach significance). I suspect that much of the misunderstanding is due to some sceptics having only a rather limited understanding of what significance tests actually mean. Unfortunately they are not straightforward and are widely misunderstood in the science, and even amongst statisticians! ISTR reading a paper where the authors had performed a survey of statistics students understanding of the p-value, and compared that with the answers given by their professors. A substantial majority of the professors failed to get all five/six questions right (I would have got one of them wrong as well). So if you struggle with statistical significance, take heart from the fact that we all do, including statisticians! ;o)
  7. New research from last week 12/2012
    Ari: I love your intro!
  8. New research from last week 12/2012
    @Kevin C #18: Dumb questions: What the heck is the half-life of a scientific journal? How is it determined? By whom?
  9. HadCRUT3: Cool or Uncool?
    Once again, a great job of explaining for the scientifically challenged.
  10. New research from last week 12/2012
    ISI Web of Knowledge give the following for Journal of Atmospheric and Solar-Terrestrial Physics: Cites: 4788 Impact: 1.579 5 year impact: 1.610 Immediacty: 0.298 Articles: 298 Half life: 8.7 I don't know much about the numbers, and I understand they vary by field. 'Environment Research Letters' has an impact of ~3, but a half life of only 2.4 years. 'Solar Physics' has an impact of ~3.3, and a half life > 10 years.
  11. New research from last week 12/2012
    Ari, it is straightforward for the hockey schtick blogger. Lindzen says that cloud cover makes things cooler and this is what happened in (parts of) Europe. Therefore, Lindzen's low climate sensitivty estimates are truthy. Past time I hunted down some more papers for your site. :-)
  12. New research from last week 12/2012
    Sorry, clicked "submit" by mistake. This series is a great way to keep up with upcoming research. Thanks, Ari!
  13. New research from last week 12/2012
    Can species spread fast enough to keep up with climate change? It's not the first time I see a paper showing problems with species having trouble shifting poleward fast enough. Some guys try to argue that species can adapt to AGW. Come on! it's too fast for a lot of species to move fast enough, let alone evolve to adapt! This "new research" series is a great way to keep up
  14. Daniel Bailey at 01:14 AM on 28 March 2012
    The Skeptical Science temperature trend calculator
    Barry, my takeaway from Santer is that a 17-year minimum length of time series is the minimum under "normal" circumstances. As Tamino and others have shown, under optimal conditions, a shorter time series may return a series surviving significance testing, but only after rigorously controlling for exogenous factors to minimize spurious noise. HTH.
  15. The Skeptical Science temperature trend calculator
    Kevin - thanks for a straight answer. It seems I can make use of the tool in a limited way after all. I'll keep plodding. It seems that one were best to avoid making bold statements on trends that border on being statistically/not statistically significant. A bit more data, a few more months in this case, can undo your assertion. I liked Robert Grumbine's Jan 2009 post (one of a series) on minimum periods to usefully determine global temp trends (20 - 30 years). Santer et al (17 year minimum) and Tamino (and I think Rahmstorf in a 2007/8 paper on the most recent 17-year temp trend) have indicated that less than a couple of decades is sufficient to get a statistically significant trend, but it appears that these are unfortunate suggestions to have advanced in the popular debate. At 17 years to present, NOAA, HadCRUt, RSS and UAH all fail statistical significance (using the SkS tool - I think!). A theme that keeps popping up for me as a reader is the problem of balancing completeness with making things accessible to a lay audience. The 17-year thing (which is now cited in the skeptiverse), and Jones' latter comment on statistical significance in the HadCRUt record being achieved, which was made into a post here, are good examples. It seems to me that the message can be pushed harder than the facts when they are oversimplifed. Bookmarked this page and look forward to making use of the great new gadget. Thanks be to the creators.
  16. Cornelius Breadbasket at 00:35 AM on 28 March 2012
    Peter Hadfield Letter to Chris Monckton
    I have followed Monckton's progress from the time that he was the designer of a mathematical puzzle in the 1980s (the Eternity Puzzle). Before then he was a ‘parliament botherer’. Very good friends of mine was a civil servant in the Thatcher government and has related how Monckton would turn up unannounced, and assume a position of authority within a department when no authority was given. Monckton is superb with words – an excellent speaker with a formidable lexicon. He has a phenomenal grasp of both mathematics and human nature. He is a showman – a master of reading the subtle signals in a crowd so that he can give them what they want to hear. In this way, Monckton appeals very much to an older generation, those who do not want to believe that the climate has been changed by human activity. He gives them relief from guilt and permission to continue their lives without what they may perceive to be a threat to their hard-earned lifestyles. However, Monckton is quite obviously not a figure to be ridiculed and ignored. He has presented to (and misled) the US Congress on (two?) occasions. He is deputy leader of UKIP, a political party here that aims to separate the UK from the EU. He is a popular speaker all over the world with a dangerous message. He is – as one commentator has suggested – the epitome of a demagogue. There is always one thing that is overlooked about Monckton that fascinates me. His illness. A friend of mine is a doctor who watched a video of Monckton with me. She guessed without knowing that he suffered from Graves disease, both because of his eyes and his personality. This seems to be considered unworthy to mention. I can understand that we should be fair to him because he is not guilty of causing his hyperthyroidism – and because it is a horrible complaint that he obvious bears with fortitude. However, I can’t see why, when the stakes are so high, that we have to ignore that thyroid disorders are usually accompanied by mental illness and symptoms such as Histrionic Personality Disorder which results in the need to be the centre of attention . At the risk of invoking Godwin’s law – Hitler suffered brain damage from gassing in the trenches during the First World War. I wonder if he would have been quite so popular if more people had known. I wonder how history will judge us for sweeping Monckton’s illness under the carpet.
  17. New research from last week 12/2012
    The Kilifarska paper that stratospheric ozone is the most important driver of planetary climate seems bizarre. It is the latest offering in the cosmic ray theory of planetary climate, and is already hailed on one denialist blog, especially as it predicts imminent cooling. I notice that Tamino at Open Mind has scant respect for the Journal of Atmospheric and Solar-Terrestrial Physics, which he describes as "sinking further and further into disrepute", though he is discussing a different paper. http://tamino.wordpress.com/2012/03/22/mathturbation-king/
  18. Dikran Marsupial at 23:46 PM on 27 March 2012
    New research from last week 12/2012
    @martin, that journal has also published a couple of rather questionable papers by Scafetta. I suspect they need to attract more reviewers with a solid grounding in climatology and/or statistics. It is possible that they have a good reputation in other areas of solar physics, but it seems to me that they have a bit of a problem when it comes to climate related work. As a statistician, I am rather sceptical about concluding that 75% of temperature variations being due to a factor that had previously not been thought of as of great importance, based on a statistical model, especially a non-linear one. However I haven't read the paper, so I can't comment further, other than to say that extraordinary claims require extraordinary evidence.
  19. New research from last week 12/2012
    Biosphere responses to climate change is such a complex field. Everything is so interrelated in ways we do not always understand. The Hiddink et al paper is in their words an optimistic analysis, and yet it is still very worrying. There will be unexpected surprises. You would expect that seals that occupy a similar niche would all be affected the same. But the Weddell Seal may end up worse off the quickest, because Orcas have a strong preference for Weddell's. Robert Pittman and John Durban (NOAA) have documented some interesting behavior.
  20. New research from last week 12/2012
    Re - Climate Sensitivity and Ozone Does anybody know anything regarding the reputation of the Journal of Atmospheric and Solar-Terrestrial Physics? That paper also mentions galactic rays and that makes me quite skeptical.
  21. New research from last week 12/2012
    CBDunkerson you should value yourself more, just add facts and logic and stuff and publish your ideas. :)
  22. New research from last week 12/2012
    Hmmmmmm... Trenberth 2012: "The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question." Dunkerson 2011: "The whole question 'what caused weather event XYZ' is inherently flawed." Trenberth 2012: "All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be." Dunkerson 2011: "Thus, it could be reasonably said that ALL weather we see now is due to global warming. It is all an aspect of the current climate, which has been changed by AGW." Ok, that's it Trenberth! I'm calling you out for putting my crazy blog comment ideas into a peer reviewed scientific paper, and backed up with facts and logic and stuff! How could you do that to me? How am I supposed to maintain a reputation if you go around making my inane ramblings seem valid?! Tis a sad day. :[
  23. New research from last week 12/2012
    Just spotted this by Rahmstorf and Coumou: http://www.pik-potsdam.de/news/press-releases/wetterrekorde-als-folge-des-klimawandels-ein-spiel-mit-gezinkten-wurfeln The past decade has been one of unprecedented weather extremes. Scientists of the Potsdam Institute for Climate Impact Research (PIK) in Germany argue that the high incidence of extremes is not merely accidental. From the many single events a pattern emerges. At least for extreme rainfall and heat waves the link with human-caused global warming is clear, the scientists show in a new analysis of scientific evidence in the journal Nature Climate Change. Less clear is the link between warming and storms, despite the observed increase in the intensity of hurricanes.
  24. The Skeptical Science temperature trend calculator
    Oh yes, Nick's explanation (Jones was using AR(1)) seems more plausible than Lucia's (Jones was using annual averages), given the wide use of AR(1) in the field.
  25. Dikran Marsupial at 21:43 PM on 27 March 2012
    The Skeptical Science temperature trend calculator
    @barry, essentially if you can draw an horizontal line within the "error bars" covering the whole period of the trend, then it isn't statistically significant (as a flat trend is consistent with the data). Regarding Phil Jones' comment, the trend under discussion was hovering about the boundary between "significant" and "not significant", so small changes in the way the calculation is performed is likely to change the result. I want to congratulate Kevin C on an excellent job, the trend calculator gives a very good indication of the uncertainties, and is definitely more accessible to a non-statistical audience than explaining what statistical significance actually means (and more importantly, what it doesn't mean).
  26. The Skeptical Science temperature trend calculator
    I did a study of Phil Jones observation here (near the end). I think he's right. Significance goes down as you take account of autocorrelation. I found that if you don't allow for it, the trend of Hadcrut3 since 1995 is highly significant (t-stat of 5). But if you allow for AR(1) dependence, it comes down to 2.1, just marginally significant. As noted in Foster and Rahmstorf, AR(1) isn't quite good enough. I tried AR(2), which brought it down to just below significance. But most people think AR(1) is reasonable, and I think that's probably what he used. And I think that measure did cross the line somewhere during 2010/11.
  27. The Skeptical Science temperature trend calculator
    Barry: I agree, the uncertainties calculated by this method do not support Phil Jones' claim that HadCRUT3v snuck into statistical significance from 1995 part way through 2011. If I remember correctly, Lucia performed a very critical analysis of Jones' claim over at the blackboard. I think she deduced that his claim was based on calculating annual means, and then calculating the simple OLS trend and uncertainty on the annual means. That is a rather more crude way of dealing with autocorrelation, and while much better than using OLS on the monthly data, it still tends to underestimate the uncertainty a bit. Therefore, to my best understanding Jones' claim was wrong. (Caveats: estimating the autocorrelation is also noisy, and Tamino's method may not be optimal. I'm interested to see where Nick Stokes goes with this - he is certainly in Tamino's league when it comes to statistics.) As to what is going on with HadCRUT3 - there will be another post along shortly!
  28. Peter Hadfield Letter to Chris Monckton
    Long time lurker; first time poster. jimb, you wrote: "I have been wondering if Monckton, when he gets back to his hotel room after the applause has died down, feels even slightly embarrassed by the quality of the audience he attracts." I don't think he is at all embarrassed. I think he is a classic narcissist who (a) believes all he writes, (b) loves and needs the adulation, (c) realizes he is onto a very good thing: someone who will pay his way, audiences who love him because he supports the status quo they want, a network of deniers who support him and to whom he in turn can offer support. If he ever doubted that what he writes is nonsense, that cognitive dissonance is easily overcome by all the support he gets from adoring audiences--"they love me so I must be right!" His debate with Peter Hadfield is done and Anthony Watts has cemented that. He will just steer clear of any real debate; Tim Lambert got to him on stage, but he's the only one, AFAIK. I get a kick out of some of his nonsense: you've just gotta laugh at his pompous claim that he and others are trying to get U of C. shut down, but his audience would love (and obvious did love) him making such a threat. The only thing that could deflate his circus tent is if he libels someone with one of his outrageous ad homs and someone takes legal action.
  29. The Skeptical Science temperature trend calculator
    Barry @11, the null hypothesis is not that there is no trend. Actually, I don't like the term "null hypothesis" because it is as misunderstood and abused as the term "falsification", and generally when it pops up in argument, the "null hypothesis" always turns out to be the hypothesis that the person arguing wants to be true. In general, it is far better, and far more transparent to be good Popperian's and simply state whether or not the test results may falsify the hypothesis being tested. ("May" because approx 1 in 20 tests will fail the test of statistical significance even if the hypothesis is true. Seizing on just one example of this and saying, "look the theory has been falsified" simply demonstrates that you do not understand falsification.) Whatever the time frame, the trend is statistically significant if its two sigma (95%) confidence interval does not include a given test condition. So, if we want to say that the trend is positive, that passes the test of statistical significance if and only if no trend line within the two sigma confidence interval is negative. If we want to claim the medium term temperature trend of approximately 0.17 oC/decade has ended, that claim is statistically significant if and only if the trend of 0.17 oC/decade does not lie within the two sigma confidence interval. If we want to say the purported IPCC predicted trend of 0.2 oC/decade has been falsified, that claim is statistically significant if and only if the trend of 0.2 oC/decade lies outside the two sigma confidence interval. The two sigma confidence interval for the trend from 1995 to 2012 using the HadCRUT3 data is -0.048 to 0.21 oC/decade. Therefore, the claim that the temperature trend over that interval is not flat, the claim that it has changed from the ongoing trend, and the claim that it has falsified the IPCC predicted trend are all not statistically significant. Fake "skeptics" often want to treat the truth of the first of these claims as a proof that the other two are false. At the best, they are trying to draw attention to that fact while scrupulously not explaining that it is in no way evidence that the other two claims are false (which is disingenuous). As it stands, the lack of statistically significant warming from 1995 to 2012 as measured by HadCRUT3 is no more evidence that the long term trend has ended than was the lack of statistically significant warming from 1981-1998 on the same measure. And of course, Foster and Rahmstorf show quite conclusively that the underlying trend does in fact continue.
  30. New research from last week 12/2012
    jyyh, skywatcher I picked up a 1.2m satellite dish 15 years ago and covered the matt white surface with aluminium foil. The LNB holder was an aluminium ring supported by 4 struts coming out of the face of the dish, and the dish had a small hole at the centre that could be used to accurately align with the sun through the LNB ring. The power of this thing was awesome. Holding a large log at the focus just caused it to spontaneously char in under a second and fill the garden with smoke - lots of it. (I resisted the temptation to test with my hand!) I couldn't measure the temperature, but estimated about 1kW/cm² density - Wolfram Alpha wasn't much help in converting this to °C. Having set it up, I coated the bottom of a pan with soot from a candle, held it at the focus for about 1-2 minutes and made a cup of tea with it... My first home-made fusion-powered cup of tea, and it tasted wonderful! :-) There must be millions of discarded satellite dishes around the world just waiting to be converted and shipped off to Africa to help reduce deforestation. I have some ideas for improving its efficiency in focussing and capture... something for a rainy^H^H^H^H^H sunny day. Alas I don't have the dish any more, ex-wife threw it out :(
  31. The Skeptical Science temperature trend calculator
    Thanks, Tom. I know you meant to say Phil Jones. :-) Still don't know if or how I can use the SkS temp trend calculator to determine if a trend is statistically significant or not. Your reply only confused me more. I didn't mean to make hay out of the Jones/1995 thing, but while we're here... Laypeople like myself rely primarily on a coherent narrative. The skeptical camp don't offer a whole bunch of that, so it is particularly striking when mainstream commentary seems to deviate. Prima facie evidence is that 17 years is a good minimum time period to establish a robust climatc trend. (If that is too simple-minded, then mainstream commenters may have contributed to that understanding by heralding the result as a way of dismissing the memes about shorter-term trends) Being a failry avid follower of the debate, I've long been aware of the lack of polar coverage in the HadCRUt set (currently being replaced with version 4), the perils of cherry-picking, and the noisier satellite data. IIRC, Santer determined the 17 year minimum using the noisier TLT satellite data, so your concern about avoiding RSS and UAH may not apply? On the one hand I've got the 17-year minimum for statistical significance that should apply comfortably to surface temperature data, and on the other an uncertainty interval that is larger than the trend estimate, suggesting (to my stats-starved brain) the null hypothesis (of a flat trend) is not rejected for the HadCRUt3 data. This has implications for the Phil Jones/1995 trend narrative as exposited by the mainstream camp. If I have to refer to a longer-term trend to get the picture, as you say, how do I now read the recommendation of Santer et al that 17 years is a standard minimum to get a robust climatic trend? Somewhere along the road here I have failed to learn (most likely), or the description on how to read the significance values is not quite clear enough in the top post. In any event, I'm all eyes for a better education.
  32. Ari Jokimäki at 17:57 PM on 27 March 2012
    New research from last week 12/2012
    Well, that's just wrong. Decreasing cloud cover is (generally) a positive feedback to warming. If it would support Lindzen's hypothesis (assuming it's the Iris hypothesis we are talking about), then the cloud cover would increase during warming and therefore resisting the warming. Here of course the situation is a bit complicated as there is an area of decreasing cloud cover and an area of increasing cloud cover. However, we see that in areas of warming, cloud cover has decreased (which causes warming effect) and in areas of cooling cloud cover has increased (which causes cooling effect). Now, if we extrapolate this situation to global context (which is not necessarily a good idea) where the whole globe is on average a warming area, then we see that globally this would mean that cloud cover is decreasing which would cause a positive feedback to global warming. Observations of global cloud cover, by the way, show either constant or decreasing global cloud cover (edited to add: in the long term, that is).
  33. New research from last week 12/2012
    On the European cloud cover/temperature paper...
    "...In response, the summer temperatures increased in the areas of total cloud cover decrease, and stalled or declined in the areas of cloud cover increase..."
    How long will it take for a skeptical blogger to extrapolate this result to the globe, claiming it verifies Lindzen's hypotheses? No time at all. That post mentions SkS endorsing the notion of a runaway greenhouse effect on Earth. The delusion is strong in this one.
  34. The Skeptical Science temperature trend calculator
    barry @13:42, I believe that when Steve Jones claimed statistical significance, he did not allow for the auto-correlation of temperatures, and hence understated it. He was also talking about the 1995-2011 interval, which is closer to significant, and probably is "significant" if you ignore auto-correlation (which means precisely nothing except that he was accurately reporting on an inaccurate measure). Of course, reporting on just HadCRUT3 is a kind of cherry picking, as is simply reporting statistical significance or lack of it. There are three major temperature indices, whose trends from 1995-2012 lie in the following ranges: HadCRUT3 : -0.048 to 0.21 oC/decade NOAA: -0.017 to 0.213 oC/decade GISTEMP: 0.01 to 0.25 oC/decade So, even if we had nothing but HadCRUT3, we would have to conclude that the underlying trend is as likely to be 0.21 oC/decade as -0.048, and more likely to be 0.16 oC/decade than to be 0 oC/decade. That hardly supports denier claims that the temperature (understood as the underlying trend) is flat. What is more, it is not the only evidence we have on the underlying trend from 1995-2012, even just using HadCRUT3. For example, the trend from 1975-2012 lies in the range 0.121 to 0.203 oC/decade. Because of the overlap, that indicates is prima facie evidence that the underlying trend from 1995 to 2012 lies in the same interval, evidence that has not been "defeated" (to use a technical term from epistemology) by more recent data. Further, because we have three indices, absent compelling reason to think one of them flawed we should weight each of them equally. Doing so gives a trend range of 0.012 to 0.224. In other words, going on the total range of the data, the warming has been statistically significant over that period. (Please note that I am excluding the satellite indices from this comparison because they are much more effected by ENSO events. As a result they are much noisier data and have a much longer interval before we can expect statistically significant trends to emerge. As such they are not strictly comparable for this purpose. If you used an ENSO corrected version of the indices, all five should be used for this sort of comparison.) Of course, the kicker is that one of the three indices is known to have significant flaws, and despite the fantasies of the fake "skeptics", that one it HadCRUT3. With the release of information about the forthcoming HadCRUT4, it becomes clear that the lack of Arctic stations in HadCRUT3 has biased the index low. Kevin C has two forthcoming posts on other known features of HadCRUT3 which bias the trend low.
  35. New research from last week 12/2012
    jyyh, you might like this link to a segment I saw on a British science program, Bang Goes the Theory: Jem Melts Rock Using Sunshine. A ~1m parabolic mirror (IIRC from a big searchlight or something) can reach temperatures of ~3500C at the focus! So a much smaller mirror will reach 450C. Makes me wonder what temperature would be at the focus of my 8" telescope mirror in sunlight.
  36. New research from last week 12/2012
    Fig 1. in gives some indication of how much biochar could be in the soil: http://www.sswm.info/sites/default/files/reference_attachments/LEHMANN%20and%20RONDON%202006%20Bio%20Char%20Soil%20Management.pdf but this is for tropical (I'm assuming quite deep) soils, does someone know of a similar study made on temperate or boreal soils?
  37. 2012 SkS Weekly Digest #12
    Fixed linkage http://climateprogress.net/item/the-crisis-of-civilization.html
  38. 2012 SkS Weekly Digest #12
    Must watch THE CRISIS OF CIVILIZATION http://climateprogress.net/item/the-crisis-of-civilization.html
  39. An Open Letter to the Future
    SS - I believe the moderator may be pinging you for repeating earlier statement but without any supporting evidence. Scientific skepticism would require that you cite some published papers to support the idea that models are good enough, etc. Instead you repeated statements that you would know were untrue if you had looked at the science. At the moment, it does not appear that your opinion is based on science. As to what would happen next, if everyone accepted your defeatism, then the evidence indicates that more people will die than if we took action, and future generations will pay a higher cost than if we mitigated emissions. Excuse us if we prefer to advocate for some action instead.
  40. An Open Letter to the Future
    I don't understand people like ScientificSkeptic who seem to think that AGW is only a problem if it results in catastrophe such as mass extinctions. I live in a fairly northern location, in a transition between boreal forest and prairie ecozones. With a couple degrees of warming, perhaps conditions might improve for certain agricultural crops hereabouts, but not for forestry. Even with a longer growing season, the luvisolic soils that have developed under forest cover on glacial till simply will not grow wheat like the chernozemic soils that developed on the lacustrine deposits of glacial Lake Agassiz. Winters aren't cold enough to kill the Mountain Pine Beetle larvae anymore, and it's looking as though that epidemic is likely to expand from the lodgepole pine forests of B.C. and Alberta into the Jack pine of Saskatchewan and possibly eventually across Canada's boreal region as far as Newfoundland and Labrador. Forestry workers aren't generally seen as tree-huggers but many of them are concerned.
  41. An Open Letter to the Future
    ScientificSkeptic, you just need to be a little more careful and precise. You just made what appears to be a general claim: "The science is dubious." The fundamental science of the theory of AGW is anything but dubious. We've known about the possibility of AGW almost as long as we've had a directly-recorded temperature record. What exactly do you find dubious? Is it the modelling? If so, take it to one of the models threads. Put up or shut up. I happen to agree with you that there are problems on the horizon that are at least as big as AGW. Peak oil and peak water are two. Yet the situation is much more complicated than that; the synergy between the dominant mode of production, its resulting culture, peak oil, peak water, AGW, and the rapidly growing population is describable only in broad terms. It is clear, though, that AGW is a problem that will make all other problems much worse. If it were happening in a managed economy, with a well-informed democracy and a culture of trust, then I would say, "This is not a problem. We will see the danger and work out the best solutions." We're living in conditions that are the reverse of those listed. The economic mode determines the interests of the people. The democracy is generally clueless (name your country). Trust is not a cultural feature of the current economic mode. Interestingly, and perhaps fortunately (eventually), the solutions to the big problems are isomorphic to a large degree. Fix the moral failure of forcing ten billions to fight for food/energy over the next century, and we can hardly end up failing to address AGW. Problems and solutions are tied too closely together. However, if we don't do something about AGW now, the changes that occur (shifting weather patterns, biosphere adaptation problems, infrastructure replacement, the decline of the ocean as a food source, etc.) will drain resources--resources that could be used to fund education, research, and development to provide the technological miracle that will allow us to continue with unfettered economic growth and to avoid having the grand (and probably rather bloody) change in consciousness. In other words, the longer we wait to address any of the big problems, the more difficult it gets to address any of the big problems.
  42. New research from last week 12/2012
    Since the forum is down I'll put this in here: http://news.rice.edu/2012/03/22/cooking-better-biochar-study-improves-recipe-for-soil-additive/ Apparently 450C is enough to get some proper biochar, presumably they've checked for most common organic toxins, and found those destroyed in this temperature. How large a paraboloid mirror can produce a temperature like that?
  43. New research from last week 12/2012
    A recalibration of an ensemble of global climate models using observations over 28 years provides a scenario independent relationship and yields about 2°C change in annual mean global surface temperature above present as the most likely global temperature threshold for September sea ice to disappear If I read it correctly, then they predict September ice to disappear when transient climate response reaches 2K. That may happen sometimes by the end of this century, which is a rough estimate of BAU given transient climate sensitivity in the same ballpark of 2K. That's in contradiction to the observational predictions, that we may see ice-free Arctic sometimes in 2020-2030, or even as soon as 2015 by some sources, as it is accelerating. I don't have access to full text to check their claim or verify that my undesrtanding of their conclusion is correct. Can anyone shed some light on it?
  44. An Open Letter to the Future
    Scientific Skeptic, I wonder if the people in Queensland, Texas, Russia, Pakistan and Thailand (amongst many others) that have been impacted directly by large floods, droughts and heatwaves, of a type known to be exacerbated by AGW, think that these are just a "... woolly prediction about what might happen in 100, 200, x000 years time ..."? Hansen et al 2011, document the observed increase in extremes of heat. Fancy a 3-sigma heat event whose odds of occurrence in any one location have increased 100-fold (from ~0.13% to ~10%)... are ya feelin' lucky, punk?
  45. The Skeptical Science temperature trend calculator
    I'm sure I'm not the only know-little in the climate debates who has been looking for a way to glean statistical significance of a trend without taking a stats course. But I'm still not sure how or if I can use this tool to do that. As I was fiddling about trying to understand the variables, I ran the tool for HadCRUt global temp data from 1995 to 2012 - 17 years minimum, and with interest in the 1995 trend per the 'controversy' following phil Jones' comments of a few years ago. Trend: 0.081 ±0.129 °C/decade (2σ) β=0.0081091 σw=0.0016822 ν=14.770 σc=σw√ν=0.0064651 As far as I can read it - just looking at the first line - no trend is evident due to the uncertainty being larger than the estimate. I'm probably wrong in several ways, I'm sure - but if not then HadCRUt shows no trend for a period that skeptics are latching onto as the 'alarmist approved', gold-standard minimum time period for statistical significance in the global temp records. Whatever the case, this is a bit confusing (to me) considering Phil Jones more recent comment on the trend, with more data available, being both positive statistically significant. If an expert has time and interest in educating the maths idiots out here, a post of examples using some of the popular time frames and showing how statistical significance is gleaned from the tool, would be great. For example; showing how the HadCRUt trend from 1995 shifted from 'just barely' statistically signficant to statistical significance a la Phil Jones' comments; showing why the trend from 1998 is not statistically significant but the trend from 1988 is. And maybe showing what happens to the significance variables around the 17-year mark. Do I need to take a course, or can a complete noob use this tool to declare a trend is or isn't statistically signficant?
  46. Peter Hadfield Letter to Chris Monckton
    #46: SkS has some comment on Dessler's 2011 paper that deals with Lindzen and Choi here and also in a little more detail here. As for "it hasn't warmed as much as expected recently", Foster and Rahmstorf 2011 show that it has warmed just as much as expected, given recent solar and ENSO variations and the ongoing GHG forcing increase. The 2000s were also hotter than expected given the decadal trend through the 1970s, 1980s and 1990s. Convincing the general public is a different matter - new temperature records will go a long way to dealing with your #1 IMHO, and #2 is largely irrelevant as LC11 is a poor, debunked paper at variance with a mountain of evidence. New temperature records look distinctly possible in the next few years, largely dependant on ENSO, and are virtually certain after a few years regardless with the continuing rise in forcing. I don't think all this is that much about debating type fora anyway. That people like Monckton continue speaking rubbish shows you don't need evidence to claim to have a debate. But there's so little hard evidence to support any of the various mutually contradictory skeptical stances, they are finding it increasingly hard to support pretty much any points. This is leading to increased infighting and marginalisation amongst skeptics as they try and decide which points to follow.
  47. An Open Letter to the Future
    @Tom Curtis #39: Well said! Suggest that you transform it into a blog post article -- perhaps titled, "Open Letter to a 'Climate Skeptic.'"
  48. An Open Letter to the Future
    scientificskeptic @35 shows in two phrases why he is not being skeptical:
    "If our best models cannot accurately tell us the weather Friday week, how can we believe ones that tell us we'll be drowning in a hundred years time?"
    The impossibility of accurate short term prediction of weather is a result of weather being chaotic. This is encapsulated in the so called butterfly effect, ie, that the weather is chaotic so that a flap of a butterfly's wing can cause a hurricane. However, while apparently believing that so small effect can have such large consequences, the self named "ScientificSkeptic" believes that we can double the CO2 in the atmosphere with negligible consequences. If AGW deniers truly believed that climate was as chaotic as weather, they would by violently opposed to any perturbation of climate, right down to stratospheric air traffic. In fact, what they actually believe as demonstrated by their practice is that climate is fundamentally predictable, and fundamentally stable. So stable, in fact that you can double or even triple CO2 content and the effects will scarcely differ from natural variability, which they assume to be low over the medium and even long term (in historical terms). Reference to the unpredictability of weather in a climate debate shows only that the referrer has not thought out the logical implication of their claims - that they are feeding us sound bites, not reasons.
    "The main point is how we adapt as a species. Going on our past record, we're pretty good at it."
    A similar point can be made about the self named "ScientificSkeptic's" main refrain. His argument depends on the assumption that humans are ultimately adaptable so that adapting to a four degree plus increase in global temperature will not be a problem; but also on the claim that we will be unable to adapt to any means taken to avoid such an increase. Again, he does not follow through his claims with reasoning to ensure consistency. If adapting to a $200 US$ per tonne carbon tax, for example will have significantly harmful effects (as he wants to claim) then adapting to a four degree plus temperature increase must logically also be capable of resulting in significant harm. Given that, he owes us reasons why he thinks one to be more harmful than the other, but no reason is given. What he has in fact done is provided us with slogans in lieu of thought. Because they are slogans, he feels no need to apply them consistently. And because they are slogans, they are empty verbage serving no greater purpose then to identify which camp he is in. Sadly, you rarely find better from any self named AGW "skeptic". It is because of this that they have to call themselves "skeptics", because nobody else would based on their reasoning.
  49. An Open Letter to the Future
    SS#35: " Earth's atmosphere and the conditions that have resulted at ground level have always changed, albeit at a geological timescale rather than one of a rolling live news feed." Exactly. The changes we now see are neither geologic nor natural. That they are visible and widespread should disturb you. Now try to focus on specifics rather than vague generalities which sum to 'it will all be ok.'
  50. 2012 SkS Weekly Digest #12
    @Kate #1: Lucky for us, Interpol doesn't charge for investigating crimes.

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