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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 94851 to 94900:

  1. Meet The Denominator
    I would have to say that I actually did learn a thing or two about Google Scholar from Poptech in this process. Not an easy pill to swallow but I accept it. But Poptech has yet to learn the lesson that I was teaching in that numbers require context. Poptech's position is somewhat like a guy running down the street screaming, "I've got $850!!" quickly followed but a creditor with a bill for $85,000.
  2. Meet The Denominator
    "You seem confused in that you believe you or anyone else here has any remote ability to teach me anything. I find that humorous." I find it very very sad. By your own admission you are not a climatologist but a computer dork like myself*. There are, at least on occasion, actual climatologists and experts who show up on this site to share their knowledge. If you think they can not teach you anything about this subject then you are deluded. * not exactly like me since I am eager to learn
  3. Hockey Stick Own Goal
    #15: You are using a 133month smoothing, when one was discussing about about the divergence POST 2000's. So what you just did was that hid the divergence with smoothing. How does it look like when looked more closely, HadCRUT vs GIStemp since 1995: What you also stated that why should "polar amplification be ignored". GISTEMP HAS NO MORE DATA IN THE ARCTIC THAN ANYONE ELSE! They just interpolate it. Interpolating DOES NOT mean they have more data or that it would be more accurate. There is also LESS multidecadal dynamics in GIStemp, clearly visible when comparing detrended data: (both graphs end in 2003 so the recent decline in HadCRUT isnt shown here) I wonder if that is because Model E cannot reproduce the 1910-1940 warming and the 1940-1970 decline.
    Moderator Response: [DB] Last warning: please refrain from using all-caps. Thanks!
  4. Hockey Stick Own Goal
    HR @54, Hegerl 2007 notes that: "Consistent with earlier results (Hegerl et al. 2003), a response to solar forcing cannot be robustly distinguished. This can be due to either the climate response to solar forcing being small, or to low-frequency variations in solar forcing being different from estimates used here. The latter is quite possible given large uncertainties in these reconstructions (Lean et al. 2002)." In fact, Hegerl produces the most coherent results, ie, with climate sensitivity of solar and GHG forcings being the same, if solar forcings are half that of the estimates which he used. With solar forcings only 1/4 of that which he used, the sensitivity of GHG and solar forcings will still be very close, within limits of error. In other words, more recent reconstructions of solar variability make sensitivities fit better with the AGW picture, not worse. Having said that, this is an area with room for substantial refinement as shown by the significant differences in scaling factors for different temperature reconstructions.
  5. Hockey Stick Own Goal
    This nonsense of "dana1981" is driving me crazy! The Ljungqvist proxy data ends in 1999. So THERE IS almost NO missing incline in the proxy data itself. What you must do is compare proxies of today (or the 90's if you wish) against MWP. Yes, the recent rise in temperatures do not seem as strong as in the temperature records, but HEY ITS PROXY DATA it is LESS accurate. Same "missing inclines" would be in the MWP as well. And according to the proxy-data there is no significant difference between MWP and today. Period. Ljungqvist also states that: ”a very cautious interpretation of the level of warmth since AD 1990 compared to that of the peak warming during the Roman Warm Period and the Medieval Warm Period is strongly suggested.” So what you have done here isnt a "very cautious interpretation". Instead you have used Mannian smoothing techniques on top of the apples-to-oranges comparison. How do I know that? Because your graphs show almost 1degC increase from the mid 1900's when properly smoothed data shows this, less than 0,45degC increase: The original reconstruction looks like this: http://i54.tinypic.com/11wd2r5.png Why dont you respect the author and his data, and instead make your own "versions" of it, without reading the actual paper and without respecting the original author? And BTW, warmer MWP does NOT mean "higher sensitivity". That is bullshit. Or where is it proven, that climate changes ONLY due to external forcings? What warmer MWP means, is that temperatures can oscillate not in only 30 year periods but also in multicentennial periods, without having an actual external forcing.
    Moderator Response: [Daniel Bailey] Please refrain from the use of all caps; also, please moderate the personal nature of your comments. Focus on the science - not the person. Thanks!
  6. Dikran Marsupial at 02:28 AM on 24 February 2011
    Meet The Denominator
    Poptech wrote "You seem confused in that you believe you or anyone else here has any remote ability to teach me anything." Poptech, please go and read up on the Dunning-Kruger effect. I would agree that nobody is able to teach you anything, but only because you are apparently unwilling to learn, judging from the comment above, largely becuase you have an unrealistic view of your own ability. I think the above quote is one of the most shocking and absurd things I have seen from a "skeptic" on a climate blog, and a great pity.
  7. It's not us
    Julian Flood - Having read and puzzled over your post, I have a question for you. When you state "No, we cause some of it, that is all the mass balance argument allows you to say", is that because not all of the CO2 molecules come from our emissions? Certainly there is continuing exchange of CO2 with the biosphere, with the ocean, etc. If so, yes - lots of the atmospheric CO2 comes/goes without our interaction, even though that's irrelevant to the current discussion. Or (as we have been emphasizing), are you stating that the atmospheric CO2 would be rising without our (well known) contributions? That would be an error. Without our emissions CO2 levels would be dropping - we are wholly responsible for the current increases in atmospheric CO2 levels, which equal half our emissions. The rest is being absorbed by nature. Without our emissions, which without other sources or sinks would cause a >4ppm/year increase? CO2 levels would drop from current values, as CO2 worth ~2ppm/year of our emissions is currently being absorbed by natural sinks. With our emissions? Rising at >2ppm/year. While we are not responsible for every molecule of CO2 out there, we are completely responsible for the current rise in CO2 levels, the change. It doesn't matter if the sum of sources and sinks is 5x our throughput, 10x, or 100x - we're responsible for the current difference between the source/sink levels.
  8. It's not us
    Currently all of the annual rise in CO2 is caused by man. Since nature absorbs about 1/2 of our annual emissions, one can stretch the word "cause" to say that the rise is caused by the lack of nature's ability to absorb all of our emissions. Part of the lack is due to warming oceans. But our current CO2 causes that warming (averaged over decades to smooth natural variations). A footnote: natural warming following the LIA is the cause of a small part of the historical rise in CO2 (e.g. from 280 to 285 or something similar). But using the common meaning of "cause", man currently causes all of the annual rise in CO2.
  9. Meet The Denominator
    Poptech - "You seem confused in that you believe you or anyone else here has any remote ability to teach me anything..." This is, perhaps, the saddest statement I have ever read on this website. Personally, it's my aim to be learning until the day I die - from children, from the experienced, from fools, and from geniuses. "Learning, n. The kind of ignorance distinguishing the studious." - Ambrose Bierce
  10. Meet The Denominator
    709 ... and ... you completely (and not for the first time) missed the point. You say "I am well aware how the process works." but that wasn't the point. I was referring to your 'work', not the papers in your list. You clearly are not working within science bounds nor within the review process. That is what we are trying to teach you; but, as you say, you don't seem to have the ability to learn. 2/10 to they guy who programmed your AI engine.
  11. Meet The Denominator
    Poppy... This "You seem confused in that you believe you or anyone else here has any remote ability to teach me anything." is clearly not true! your loss.
  12. Prudent Path Week
    Re: Ann (45) Every now and then I'm struck by an observation one of our commenters makes. With regard to "skeptics", Ann makes this observation:
    "...if your understanding of the climate is zero."
    Obviously Ann is not applying this to everyone posting here. Legitimate seekers of knowledge become obvious in short order; the obverse as well. It should be painfully obvious to readership which parties comes here in good faith to learn...and which do not (have any intentions to learn). Thanks, Ann, for saying something more eloquently than I could. The Yooper
  13. Prudent Path Week
    I wonder how far AGW proponents should get involved in the whole “unprecedented” discussion. It is a side issue, and while deniers are losing every argument, they are winning the battle, if only by wasting precious time. Even if it can unquestionably proven that current global temperatures are higher than during the MWP, I’m sure they will come up with some other, earlier period in history when the earth used to be warmer. This is a game that can continue forever. The earth is 4,5 billion years old and has had – some pretty extreme climates, to say the least. In the past the earth has been a giant snow ball with an average temperature of -50 degrees. It has also been a molten ball of lava, with a 1200 degrees surface temperature. So no matter how hot it is going to get on earth, it is never going to be “unprecedented”. While your argumentation about the incompatibility of large temperature changes and low climate sensitivity is correct, I don’t think it addresses the underlying assumption of the “unprecedented” argument used by skeptics. What is this “unprecedented” claim really about and why does it appear so often in skeptical arguments ? As far as I can tell, the implied argumentation behind it is: “If I can prove that in the past the earth was warmer than today due to natural causes, the present warming might be due to natural causes as well, and there is nothing to worry about.” This is actually a valid reasoning if your understanding of the climate is zero. When lacking any other information, it is a crude way to determine if the current climate still falls within a range that can be considered as “normal”. So it is a perfectly reasonable thing to do if you don’t have the information, but it is irrational behavior if you do have more detailed information at your disposal, which you choose to ignore. Climate science takes into account all available information to explain all climate changes, past or present, warming or cooling. If we can explain and predict all climate changes of the past and the present, by means of all the known forcings (human and natural) and feedbacks, this means we understand the climate and also have a pretty good idea of how it is going to evolve. Scientists have to fit the pieces of the puzzle together and check if there are any missing pieces, any holes in our understanding (e.g. warming or cooling that cannot be explained by the current theories). And as it appears the puzzle cannot be made complete without taking the role of CO2 into account. No skeptical theory exists that is able to successfully explain and predict past and current climate changes, leaving CO2 out of the equation. I’m sorry if this all sounds too obvious, but I think many people just don’t know these things.
  14. Dikran Marsupial at 00:37 AM on 24 February 2011
    It's not us
    Julian@43, Can you explain why it would be informative to exclude some natural source and lump the remainder of the natural carbon cycle together with anthropogenic emissions? We all know that some parts of the carbon cycle are sources and some sinks. WHat is important is whether CO2 levels would be rising if not for anthropogenic emissions, and the answer is quite clearly "no, they would be falling" (which we know because the net effect of the natural environment as a whole is to absorb about half our emissions). Given that CO2 levels would now be falling if we were to cut our emissions to zero, it seems odd to suggest we are not 100% responsible for the current rise. Try giving a specific example, giving values for all natural and anthropogenic sources and sinks, where the annual rise is less than anthropogenic emissions and where the natural environment is a net source. You will find that you are unable to do so, but the attempt will probably demonstrate to you why the mass balance argument is correct. "No, we cause some of it, that is all the mass balance argument allows you to say." It should be obvious that you are missing something here, given that we don't actually need the mass balance argument (or the assumption of conservation of mass) to know that we are the cause of at least some of the observed increase; we already know that simply because our emissions vastly exceed our uptake. It should be no surprise then that the addtion of a constraint (conservation of mass) allows us to make a stronger argument. I have repeatedly explained that you don't need to know the value of individual fluxes to know that the natural environment as a whole is a net sink. If you shared a bank account with your partner and always put in $100 a month more than you spent, but observed your monthly balance only increased by $50 a month, you would know your partner was a net sink (to the tune of $50 a month) without needing to know where he/she spent the money, or how much he/she spent in total or how much he/she deposited each month. The mass balance argument is essententially analogeous.
  15. Hockey Stick Own Goal
    HumanityRules, in 1998 Mann and company published the first attempt at a multi-proxy paleo-temperature reconstruction. They used new methods of combining proxy data sets and statistical analysis and smoothing in the attempt to develop a coherent picture... and they slathered disclaimers about the uncertainty of the methodology and the limits of the data sets all over it. They put a large error range on the data. In short, they did the best they could with an entirely new process and disclosed such. That's perfectly good science. Yes, the results they said could contain errors in fact did contain errors... but within the bounds of the error bars they estimated. That they (and others) have now produced more detailed results with smaller error bars based on more extensive data and more refined statistical analysis is the natural progression of science. You keep asking if Mann 98 is 'the same' as Mann 2008... apparently not realizing that "yes" is a perfectly defensible answer in the sense that the possible paleo-temperature range shown in the 2008 paper is within the constraints of the possible paleo-temperature range from the 1998 paper. It defines a narrower range and a longer time period, but nothing in the Mann 2008 (or Ljungqvist 2010 for that matter) results contradicts the Mann 1998 results. In short, the latest research from all sides says that the results of Mann 1998 were correct. Your argument is essentially the equivalent of saying that Newton performed 'junk science' because his instrumentation was not precise enough to measure the acceleration due to gravity as accurately as we can now.
  16. It's not us
    Sorry for the long pause, I got rather busy and dropped the ball. At one stage I thought the mass balance argument would allow us to say something about changes in sources and sinks, but further thought led to more doubts. quote Do you agree that the mass balance argument demonstrates that the natural environment is a net sink? If not, can you explain why? unquote The mass balance argument demonstrates that sources are greater than sinks. However, because it does not attribute any numbers to any of the many sinks and sources, it is unable to distinguish between a change in either: for example, see my painstaking plod through the equations above. If you take any source X larger than 14 Gt out of the equations and lump all other sources together as 'natural plus human' then the proponents of the mass balance argument say that all the extra CO2 must be caused by X. This seems to be an error. If sources are in balance and then two sources, X and anthropogenic, increase then all you can say is that some of the increase is caused by fossil fuel burning. If you have no size for X then all you can say is that X+anthropogenic is greater than the sinks by at least 14 Gt. The sinks have increased by enough to absorb (X+anthropogenic) - 14Gt. quote If the CO2 increase was larger than our emissions, then there would be plenty room for discussion as to which part of that CO2 rise was due to us. But it's not - it's much less than our emissions. We cause all of the rise in CO2. unquote No, we cause some of it, that is all the mass balance argument allows you to say. quote Julian Flood wrote : "Argument from absence is a new one on me." I haven't come across any papers that demonstrate that the Theory of Evolution is false : is that an "argument from absence" or a demonstration of the facts ? unquote I have seen elsewhere the conflation of those who ask questions about aspects of climate science with those who e.g. deny evolution, tobacco causes cancer, round Earth etc. It has never, in my experience, been helpful That's my best shot -- we are obviously talking past each other and I am missing some hidden subtlety in your posts which makes things clear to others but not to me. I have seen a post by Lubos Motl where he states that he is sure that the CO2 increase is anthropogenic. I think I'll go and ask him. Thank you all for an illuminating discussion.
  17. Smoking, cancer and global warming
    I like your expositions on the logic (and lack thereof) of different lines of argument a lot. They are very helpful tools for laypeople to make sense out of debates on complex issues.
  18. Hockey Stick Own Goal
    http://wattsupwiththat.com/2010/09/28/loehle-vindication/#comment-493590 "I have noted in the post that there are a lot of (indirect) references to Mann et al. (1999) – the so-called “Hockey Stick Graph”. It is science history now. Any references to temperature reconstructions by Michael E. Mann should be to his 2008 and 2009 temperature reconstructions. They actually show an even warmer Medieval Warm Period than I do. I don’t think it is fair to refer to an outdated work (from 1999) when we have newer and better. As was shown in an earlier post today, my new reconstruction is practically identical with Mann et al. (2008) after c. AD 900. The same is true with Moberg et al. (2005). My reconstruction is also very similar to Loehle (2007) in shape although his reconstructed amplitude is larger." Fredrik Charpentier Ljungqvist
  19. Meet The Denominator
    701 Poppy: Poppy, dearest... Let me educate you. Real science actually involves a lot of review and improvement; clarification, removing week (even if not, provably wrong) data, adding strong data, qualifying data, comparing with sister arguments etc. This is part of the real meaning of peer review. What a lot of people don't understand is that it isn't just that someone has read a paper, maybe corrected some typos and said 'yay' or 'Neigh'. Normally results are discussed with colleagues, at conference, in pre-prints, by email etc. way before publication. At the last hurdle the editor and reviewers will send back comments which may require more work, input, removal of information, consideration of related work and so on... maybe for several iterations before the paper is accepted. By far the majority of good science publications have been through this. Most researchers are masochistic; They repeatedly bare their chest to the slings and arrows of criticism, knowing that this will improve their output... if they take note and improve. And you will notice that the comment policy of this site follows that - discussion should be on the post, in the posts thread etc. People who do sciency work (i.e. the output look similar to real science, but the processes are broken) don't really understand this. Instead, like here, they take every criticism as being something to be shot down rather than learned from. You've been told that often enough and don't seem to understand it... maybe your programmer will get on the case? Shall I rise a trouble-ticket?
  20. Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
    Albatross, The anti-correlation between climate sensitivity and aerosol forcing in climate models, as discussed by e.g. Knutti (2008) is interesting. His argument is that it makes sense to see such a correlation, as the observed temps are a major quantity that the models are supposed to simulate, so naturally, the models are optimized for such a simulation. It relates a bit to the extent which, and how models are "tuned" though. I'm not an expert on climate modeling, and find this a difficult topic to opine about. In the process modeling that I've done it makes sense to try to optimze the simulation within physically realistic boundaries of the tunable parameters. In a physics based model the similation is heavily constrained anyway (at least in my experience). You then chose the set of parameters that gives the best simulation. If different sets of paramaters give equally good results, the uncertainty of which parameter values are best increases. Note though that the indirect effect was missing from most modesl used in this study. An important point (as I also tried to make in this post) is that climate sensitivity is more constrained by other data than by the instrumental temp record, so this correlation is no reason to distrust the climate sensitivity estimates. Within the uncertainties of both cliamte sensitivity and aerosol forcing, the picture together with observed temp increase is coherent (see Dana's "case study" post on Lindzen as linked from this post).
  21. Hockey Stick Own Goal
    So Dana on the issue of climate sensitivity I wonder if you've got anything to say about solar forcing over this time period? You seem to suggest we just drop a more variable temperature reconstruction (like ljundquist) into Hegerl-like study and get higher climate sensitivity. But if we accept that science evolves then we have to see that our understanding of solar forcing has changed. More recent estimates of TSI changes from the MM to present are 2-4 times lower than the earlier Lean estimates that were used in Hegerl. Going with the logic of saying newer estimates are better estimates (obviously not always true) then climate sensitivity isn't just high it's rocketing into the stratosphere. Combine the more variable temp records, such as Ljundquist, with the less variable solar forcings of STEINHILBER ET AL 2009 and others (see his table 1) and you have climate sensitivities that are so high as to contradict much of our understanding of 20th C temperature change. You get into the realms of the fanastic. Is it true that climate sensitivity can be so high as to be not just problematic to our future or inconsistent skeptics but also problematic to the wider AGW theory? The issue was summed up for me in a Nature review by Foukal1 Frohlich Spruit and Wigley. Obviously the science has moved on even from 2006 but they include the following line towards the end. "Overall, we can find no evidence for solar luminosity variations of sufficient amplitude to drive significant climate variations on centennial, millennial and even million-year timescales."
  22. A Swift Kick in the Ice
    I'm not an expect on this either: The reason for warming at the poles so strong: The temperatures are much colder at the poles, and this actually puts the black body radiation curves peak closer to CO2's absorption band. So the CO2 driven greenhouse effect occurs more strongly near the surface. --- Is this correct?
    Moderator Response: [Daniel Bailey] This is discussed both here at SkS and here by Serreze et al 2009.
  23. Smoking, cancer and global warming
    rjacobsen0 - thanks for the reference. I had a look, but it's only a summary, and I tried to check out the data sources. What I found is that over the past century, there has been increased precipitation in some areas, and decreases in others. For example, the contiguous USA has seen an increase of about 6% over the past 100 years, but tropical areas (Asia,) Southern Africa, and the Mediterranean have experienced a decrease. It's also significant that cities have experienced increased precipitation due to the urban heat island effect (increased heat leads to local upward air movement, so more thunderstorms). This effect should be deducted, as it will confound the null hypothesis if urban data is included. However, it seems that "globally, there has been no statistically significant overall trend over the past century". While there's lots of models that suggest this could happen, I can't find much actual data to back it up. Gruber and Levizzani http://cics.umd.edu/~yin/GPCP//ASSESSMENT/assessment.html have a fairly comprehensive report on this covering the past 30 years, and show no significant global change in precipitation.
  24. Smoking, cancer and global warming
    @ rjacobsen0 There was also another article in Nature, though it only examined one specific flood event (http://www.nature.com/nature/journal/v470/n7334/full/nature09762.html) Real Climate had a good write up on both papers (http://www.realclimate.org/index.php/archives/2011/02/going-to-extremes/)
  25. Smoking, cancer and global warming
    I can't provide definitive data for all weather disasters, but an article came out just last week in Nature (http://www.nature.com/nature/journal/v470/n7334/full/nature09763.html) called "Human contribution to more-intense precipitation extremes" which links heavy rains to human-induced increases in greenhouse gases.
  26. Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
    Chemist1, if you want to take things one step at a time, then why you keep posting new claims when you haven't still answered the responses to your old claims?
  27. Hockey Stick Own Goal
    52 Tom Curtis You're trying to drive the discussion done an avenue that is very quickly going to be moderated as OT. Dropping this line is obvious to all reasonable people, just because I recognize this doesn't mean I'm running away from the arguement. I agree with Dana the implications of this work are more interesting than just point scoring. You're moral stance and all the fluff around M&M is irrelevant to the science. Is Mann 98 the same as Mann 2008, moberg and the rest? NO it is not, you seem unable to accept that. If you accept this we can move on. Essentially that was the point of my initially post but fine ignore that and stick to you're moral indignation.
    Moderator Response: [Daniel Bailey] Since you're still on the subject of Mann, even after many excellent comments from others trying to help you, please see CBDunkerson's response to you on that subject at number 56 below.
  28. Hockey Stick Own Goal
    HR @51, as an "alarmist" I am regularly accused of desiring genocide, of faking experiments in order to continue gaining funding, or of being a shill paid for by the Labor Party to spread false opinions. Let me assure you, "alarmist" is no insult compared to the way deniers regularly slander those who actually accept the evidence of climate science. After all, I have looked at the evidence, and as a result I am alarmed, and with good reason. You, on the other hand, plainly do not like being called a "denier". You think it "does nothing for further understanding". If I saw in your comments any hint of an attempt at understanding, that would concern me; and I would not call you a denier. As it is, I do not see such a hint. I have given you an opportunity to show that you are not just a denier. I have plainly shown that M&M's attacks on Mann at Climate Audit are unprincipled, and an attack on science rather than an attempt to advance it. You earlier endorsed that attack. Well, disendorse it. Clearly state that you consider M&M's one sided critiques and political machinations, not to mention their various outright slanders, to be unacceptable. Because you cannot both endorse their methods and not be a denier. Further, there is no inconsistency between MBH 98 and 99 containing statistical errors which only result in a 0.05 degree C variation in their result, and their containing a limited data set which does not provide as good a result as modern studies with their much larger data sets. M&M's critique was focussed on (as is seen) almost irrelevant statistical issues. On the other hand, MBH were up front about the limitations of their data set, but it was the best available at the time. Finally, I am sure you want to drop this line. After all, your comments have been thoroughly exposed as being based on, and apparently designed to foster, misunderstandings and misinformation. But if this were a principled withdrawal from this line, you would acknowledge your error.
  29. Smoking, cancer and global warming
    I think I get the point the author is trying to make, and yes, it is an important point, but I think he is making it unreasonably difficult for himself to make this point when he says, "Not Humphrey Bogart, not “King” Cole, not the guy down the street. No one definitely ever died from smoking." Please, please think of a better way to put this.
  30. Smoking, cancer and global warming
    Do we have actual evidence that the frequency of extreme, or the magnitude, has increased? We need to allow for the improved detection, reporting, and documentation during the last couple of hundred years. For the past 60 years, I remember a constant stream of weather related extremes. The Australian Scientific Authority CSIRO has stated " No significant global trends have been detected in the frequency of tropical cyclones to date, and no significant trends in the total numbers of tropical cyclones, or in the occurrence of the most intense tropical cyclone, have been found in the Australian region." There was the Great Blizzard of 1888 in USA, and the 1900 drought in India which killed about 1 million people, and the Yellow River Flood in China in 1887 which also killed over 1 million people. There was the cyclone in Cape York Australia in 1899 where 400 people died. Can you provide some definitive data to substantiate an increase in natural weather disasters. I like to have a strong data base before I depend on this type of argument.
  31. Hockey Stick Own Goal
    #47 Tom Curtis You really should drop the denier language it does nothing for furthering understanding. I really wanted to drop this line as Dana said and move on to the implications of the work but you seem to want to take it back to step 1. So can we nail this? I thought we'd all agreed that Mann had moved on from his earlier estimates to much more variable one's? That Ljundquist is like Mann 2008 not Mann 1998. You can't do this while at the same time thinking Mann 1998 is essentially OK (give or take 0.05oC). Wahl and Ammann (2007) seems to be in opposition to Mann's own self realisation as described here earlier by some of you're fellow alarmists (yep I'm dropping to your level here).
  32. Hockey Stick Own Goal
    Dana @45, Point taken-- I think someone is trying to derail the thread, the findings are just too inconvenient. You really do seem to have a knack for hitting the nail on the head ;) The 'skeptics' just do not see that they cannot have it both ways-- one cannot argue for a warmer MWP and at the same time argue that climate sensitivity is low.
  33. Hockey Stick Own Goal
    "o if I talk about early Mann reconstructions I'm stuck in the past, If IPCC 2007 refers to early Mann reconstructions it's...... Ah yes I see your logic now." I dont think so. Can you see the difference between presenting an old reconstruction as if it was the current state of "AGW thinking" (the pseudo-skeptic tactic discussed), and presenting a history of reconstructions showing the effect of different proxies and methodologies leading to a convergence of evidence? You might also like to read the accompanying text to see if IPCC is "stuck in the past".
  34. Meet The Denominator
    Poptech - X, Y, Z are cited many times - Excellent! That means they're not trash. And I'm glad you see a value in citations. Some of those citations will, of course, disagree with the conclusions of those papers; that's the fate of all papers that are actually discussed. And these many pieces of science, discussed, hashed over, considered, accepted or abandoned, make up the consensus view. Which takes us right back to what the consensus is. 97% of those working in the field (a higher number than those outside the field, who don't look at the data) say it's AGW. Disagree? Then write your own paper(s) - present a theory that encompasses all the data indicating a human contribution to the climate, that accounts for the various data we have (ocean heating, tropospheric warming, stratospheric cooling, rapid temperature changes over the last 100 years, radiative physics of greenhouse gases, etc.). Convince the consensus. Enough said - I'm out of this thread.
  35. Hockey Stick Own Goal
    HR @46, as previously indicated, they did include a discussion of Lamb, whose graph was included in IPCC 1990: "Lamb (1965) seems to have been the first to coin the phrase ‘Medieval Warm Epoch’ or ‘Little Optimum’ to describe the totality of multiple strands of evidence principally drawn from western Europe, for a period of widespread and generally warmer temperatures which he put at between AD 1000 and 1200 (Lamb, 1982). It is important to note that Lamb also considered the warmest conditions to have occurred at different times in different areas: between 950 and 1200 in European Russia and Greenland, but somewhat later, between 1150 and 1300 (though with notable warmth also in the later 900s) in most of Europe (Lamb, 1977). Much of the evidence used by Lamb was drawn from a very diverse mixture of sources such as historical information, evidence of treeline and vegetation changes, or records of the cultivation of cereals and vines. He also drew inferences from very preliminary analyses of some Greenland ice core data and European tree ring records. Much of this evidence was difficult to interpret in terms of accurate quantitative temperature influences. Much was not precisely dated, representing physical or biological systems that involve complex lags between forcing and response, as is the case for vegetation and glacier changes. Lamb’s analyses also predate any formal statistical calibration of much of the evidence he considered. He concluded that ‘High Medieval’ temperatures were probably 1.0°C to 2.0°C above early 20th-century levels at various European locations (Lamb, 1977; Bradley et al., 2003a)." It was not appropriate to include it on the spaghetti graph because (for the highlighted reasons) it was not a comparable reconstruction.
  36. Hockey Stick Own Goal
    Humanity Rules is now in denial about whether or not he is a denier. He wrote (@18): "So can we just nail this. The reconstructions that were so critically used by the IPCC are these earlier Mann reconstructions and if you are now accepting Fig1 as the correct reconstructions then it looks like the critics were right to highlight this problem. So would you be supportive of ClimateAudits attempts to highlight this problem early on?" The IPCC wrote (AR4): "McIntyre and McKitrick (2003) reported that they were unable to replicate the results of Mann et al. (1998). Wahl and Ammann (2007) showed that this was a consequence of differences in the way McIntyre and McKitrick (2003) had implemented the method of Mann et al. (1998) and that the original reconstruction could be closely duplicated using the original proxy data. McIntyre and McKitrick (2005a,b) raised further concerns about the details of the Mann et al. (1998) method, principally relating to the independent verification of the reconstruction against 19th-century instrumental temperature data and to the extraction of the dominant modes of variability present in a network of western North American tree ring chronologies, using Principal Components Analysis. The latter may have some theoretical foundation, but Wahl and Amman (2006) also show that the impact on the amplitude of the final reconstruction is very small (~0.05°C; for further discussion of these issues see also Huybers, 2005; McIntyre and McKitrick, 2005c,d; von Storch and Zorita, 2005)." So, of M&M's criticisms, one is based on an incorrect implementation. Further, even if methods are applied to the data which avoid the issue entirely, MBH's reconstruction still emerges from the data. And the other statistical issues raised by M&M only result in a 0.05 degree distortion of the result. So, does HR really want to stand by Climate Audit's efforts to raise this mammoth problem of a potential 0.05 degree distortion in MBH's results? Does he further want to stand by their insistence that IPCC 1990 better reflected reality? Does he further want to stand by their "audit technique" that takes a potential distortion in a scientific graph of 0.05 degrees C to Congress, but ignores as irrelevant any potential flaws in IPCC 1990 (which is again reproduced without critical scrutiny in the Wegman report)? Does he want scientific scrutiny to be, like the practise of M&M, entirely based on whether they like or dislike the political consequences of the science? If he does not want to stand by any of these, but instead wishes to withdraw his question @18 as ill conceived, well then perhaps he does not deserve the denier label.
  37. Hockey Stick Own Goal
    39 scaddenp So if I talk about early Mann reconstructions I'm stuck in the past, If IPCC 2007 refers to early Mann reconstructions it's...... Ah yes I see your logic now. 40 muoncounter Hey they dropped the early 1990 estimate why not drop Mann 1999? The National Academy of Science had already questioned the result in 2006. I understand science evolves, it really just a question why the IPCC was so slow to end it's love affair with early Mann. "BTW, that's another figure showing at least 1 degree of warming since 1910." In the instrumental record not in paleo's, right?
  38. Hockey Stick Own Goal
    Several commenters here seem to be missing the point and taking the discussion off topic. The point is that we would be better off if the original hockey stick were correct. It would mean that, as the "skeptics" require, climate sensitivity might be low. As reconstructions have progressed, yes, they now have less of a 'hockey stick' shape. That is a point against "skepticism". The "skeptics" seem so eager to score a point against Mann or the IPCC or whoever that they don't realize they're scoring major points against themselves. Hence the article title.
  39. Hockey Stick Own Goal
    Further to Muoncounter @40, the IPCC AR4 even discuss Lamb's reconstruction (the basis of IPCC 1990) in box 6.4 Because the IPCC is trying to advance understanding of the science, it clearly tries to show how we got from our prior state of understanding to our current state of understanding. It acknowledges the past without being stuck in it. In constrast, M@M were still pushing a reconstruction made without using any statistical techniques in the 1960s (IPCC 1990) in 2005, and WUWT was still pushing it in 2010.
  40. Hockey Stick Own Goal
    HR, If you don't want people to think that you are in denial about AGW, stop behaving like someone who is in denial. Going by your posts on this thread it is becoming increasingly difficult to give you the benefit of the doubt.
  41. Hockey Stick Own Goal
    HR, The figure that you posted was from the IPCC assessment in 2001. Go here. Now AR4 was released in 2007, and the figure shown in the link shows 12 paleo reconstructions published between 1998 and 2006. MBH99 is in there, as is Moberg et al. (2005). Now AR5 will no doubt include Lungqvist (2010), as well as Mann et al. (2008, 2009) and any other recent reconstructions worth merit. This is really not difficult. Again I have to wonder whether you actually took the time to read Dana's post. The reconstruction under discussion here, in this post, was Ljungqvist, which shows that recent N. Hemisphere land temps. are running higher than during the MWP. Yet you insist on arguing a strawman about earlier reconstructions, that really smacks of desperation. Do you accept Ljungqvist (2010) as a reliable reconstruction? Other 'skeptics' do.
  42. Hockey Stick Own Goal
    38 Tom Curtis Gosh that was painfull but you know what Tom I think we all agree except I'm still 'denier' of course.
  43. Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
    Sigh, moderator, sorry if I was not clear. I will post in the appropriate thread. I will say this though, these topics are interconnected and not so compartmentalized.
    Moderator Response: [DB] You are welcome to then post a stub comment here with a link inviting interested readers to continue the discussion on those other threads. Most commenters here are well experienced at following thread jumps such as that.
  44. Hockey Stick Own Goal
    HR: "these early Mann recocstructions are there in the 2007 IPCC report." Among other, more up-to-date reconstructions: -- Chap 6 Paleoclimate, Figure 6-10b Perhaps showing that our understanding has evolved. That's what science does. BTW, that's another figure showing at least 1 degree of warming since 1910.
  45. Hockey Stick Own Goal
    "is the IPCC that's stuck in the past?" I dont understand. What part of the AR4 WG1 paleoclimate chapter suggests to you that the IPCC are stuck in the past?
  46. Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
    Albatross, 62: I an saying a Lindzen gets aerosols mostly right The claim I am making is the science supports Lindzen's main arguments. I am also stating some additional information, potentially expanding upon the aerosol discussion.
  47. Hockey Stick Own Goal
    Further to Marcus @27 and scaddenp @29, Lundqvist has this to say about the difference between his and Mann's reconstruction: "Our temperature reconstruction agrees well with the reconstructions by Moberg et al. (2005)and Mann et al. (2008) with regard to the amplitude of the variability as well as the timing of warm and cold periods, except for the period c. AD 300–800, despite significant differences in both data coverage and methodology." My emphasis, obviously. Unlike deniers around the world, it is note worthy that Lundqvist has noticed that Mann and the "hockey team" have moved on. Because they want actual reconstructions, not just political talking points, they have used better data and techniques as they have become available, so that now Mann et al (2008) actually shows the most variability of the three reconstructions (and Lundqvist the least).
  48. Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
    Chemist @60, You really do not have to feel like you have to talk posters through the science. I'm expecting G&T...... This thread is about Linden and others' getting the science of aerosol forcing wrong.
  49. Hockey Stick Own Goal
    30 muoncounter at 14:15 PM on 23 February, 2011 Albatross, "Why do some people insist on being stuck in circa 2000? " Muon, agian these early Mann recocstructions are there in the 2007 IPCC report. Sorry for the repetition but is it me or the IPCC that's stuck in the past? And if it's both then which is more important and which is the one you should be getting most agitated about?
  50. Hockey Stick Own Goal
    "Once again fellow posters in general, I did my homework, and see that the data is not so factual or well evidenced... " ....and once again, we're expected to simply take your word for it, as you've failed to provide any *proof* of your statements. Seriously, you "skeptics" seem to expect others to take a lot on *faith*, don't you?

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