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Comments 94601 to 94650:
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HumanityRules at 19:03 PM on 23 February 2011Hockey 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." -
StevenDobbs at 19:02 PM on 23 February 2011A 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? -
rhjames at 18:28 PM on 23 February 2011Smoking, 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. -
Dan Moutal at 18:03 PM on 23 February 2011Smoking, 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/) -
rjacobsen0 at 17:29 PM on 23 February 2011Smoking, 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. -
Ari Jokimäki at 17:12 PM on 23 February 2011Radiative 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? -
HumanityRules at 17:09 PM on 23 February 2011Hockey 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. -
Tom Curtis at 16:50 PM on 23 February 2011Hockey 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. -
MattJ at 16:39 PM on 23 February 2011Smoking, 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. -
rhjames at 16:32 PM on 23 February 2011Smoking, 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. -
HumanityRules at 16:20 PM on 23 February 2011Hockey 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). -
Albatross at 15:37 PM on 23 February 2011Hockey 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. -
scaddenp at 15:37 PM on 23 February 2011Hockey 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". -
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. -
Tom Curtis at 15:18 PM on 23 February 2011Hockey 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. -
Tom Curtis at 15:13 PM on 23 February 2011Hockey 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. -
HumanityRules at 15:06 PM on 23 February 2011Hockey 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? -
dana1981 at 14:59 PM on 23 February 2011Hockey 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. -
Tom Curtis at 14:56 PM on 23 February 2011Hockey 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. -
Albatross at 14:56 PM on 23 February 2011Hockey 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. -
Albatross at 14:54 PM on 23 February 2011Hockey 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. -
HumanityRules at 14:53 PM on 23 February 2011Hockey 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. -
Chemist1 at 14:45 PM on 23 February 2011Radiative 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. -
muoncounter at 14:44 PM on 23 February 2011Hockey 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.
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scaddenp at 14:43 PM on 23 February 2011Hockey 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? -
Chemist1 at 14:43 PM on 23 February 2011Radiative 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. -
Tom Curtis at 14:37 PM on 23 February 2011Hockey 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). -
Albatross at 14:33 PM on 23 February 2011Radiative 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. -
HumanityRules at 14:32 PM on 23 February 2011Hockey 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? -
Marcus at 14:30 PM on 23 February 2011Hockey 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? -
Marcus at 14:29 PM on 23 February 2011Hockey Stick Own Goal
"You should really learn to construct an argument without resorting to offense." I just tell it like I see it. If you take offense to being labeled for what you are & what you do, then the fault lies with you-not me. The IPCC then, as now, was relying on the best information to hand-namely Mann 98. As has already been pointed out to you (but you clearly choose to ignore) the IPCC, in 1990, was relying on an even more limited paleo-climate reconstruction using a proxy from central England. In spite of its imperfections, Mann was a considerable improvement on this, & the IPCC included it. The IPCC has since incorporated the much improved reconstructions that have come out more recently. So again, your arguments reveal more about your own lack of knowledge of the processes than anything about the IPCC. -
HumanityRules at 14:28 PM on 23 February 2011Hockey Stick Own Goal
31 Tom Curtis I'm unaware of the IPCC 1990 reconstruction but I'm happy to consign it to the dustbin of history along side Mann's early reconstructions if that'll more things along. -
Chemist1 at 14:24 PM on 23 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
Biblio to explain that would take a long time. I will merely explain why the first and second law are violated at a later date, but as promised I will provide the references regarding the IPCC flaws, and why the hockey stick is false. One step at a time folks.Moderator Response: [DB] Sigh. All of those topics are covered by other threads. Use-the-search-function-to-find-the-most-appropriate-thread-and-post-on-them-there. Comments posted on those topics here will be deleted. Thanks in advance for your helping SkS keep a clean house! -
muoncounter at 14:22 PM on 23 February 2011Hockey Stick Own Goal
HR: "No science" There are several graphs on this post showing between 0.8 and ~1.0 degrees of warming since circa 1910. Your statement suggests you believe all of them are wrong. Sounds like you're the one preaching 'no science'. -
Meet The Denominator
Poptech KR - "The thing is, Poptech, citations are the 'vote' of people in the field, indicating what is relevant, meaningful, and worth consideration. It's like a jury - trial by a body of your peers." "It is still subjective and does not determine if a paper is scientifically valid." What it does is show the judgement of those in the field, those who study the data, the effects, the interactions, who understand the topic. Subjective? Certainly. The best judges available? Most definitely. If a paper isn't cited, it has failed to impress the most qualified audience possible. And a lack of citations is the fate of most bad papers. -
Chemist1 at 14:21 PM on 23 February 2011Hockey 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...Moderator Response: [muoncounter] I'm sorry, I have no idea what this comment means. Homework? Data? Evidence? -
Tom Curtis at 14:18 PM on 23 February 2011Hockey Stick Own Goal
HR 23, of course the 0.3 degree difference in variation between MBH and Moberg, and the 0.4 degree difference between MBH and Lundqvist is important. That is why climate scientists have not rested on their laurels and continue to refine the reconstructions. What is puzzling is why deniers cannot recognize that the 0.5 difference between IPCC 1990 and Lundqvist. (Note, the variation of Lundqvist compared to MBH, IPCC 1990 and Moberg 2005 is greatly exagerated because of the higher resolution smoothing used.) -
muoncounter at 14:15 PM on 23 February 2011Hockey Stick Own Goal
Albatross, "Why do some people insist on being stuck in circa 2000? " Surely you know the answer to that: It's when warming stopped. -
scaddenp at 14:12 PM on 23 February 2011Hockey Stick Own Goal
"Mann 1998 is junk science" - Mann 1998 was first attempt - it would be better to describe it as superceded science. I would refer to "junk" as papers with serious logical flaws or methodologies that would be inappropriate for the time of publication. -
HumanityRules at 14:12 PM on 23 February 2011Hockey Stick Own Goal
22 muoncounter No science, no comment. -
Marcus at 14:09 PM on 23 February 2011Hockey Stick Own Goal
"Great Mann 1998 is junk science, that's good to know. Mann 2003 also" No-so typical of a denialist to misrepresent the facts. Mann 98 was just plain science. You seem to not understand that paleo-climatology was still in its relative infancy when Mann started this work. Science is rarely letter perfect first time round (if ever), it usually needs an iteration or two (or even 3) to get it completely right. In this case, Mann relied too heavily on a single proxy to obtain his reconstructions-getting a *slightly* flatter temperature graph than what's been obtained in subsequent reconstructions. Given that Mann 2003 is much closer to the more than half a dozen reconstructions that currently exist suggests that he took the criticisms on board & extended his range of proxies the next time around. The point is that no matter what reconstruction you look at, the extent & rate of warming is *nothing* like what we've seen in the last 50 years-no matter what you & your denialist mates say. Yet instead of dealing with this uncomfortable fact, you'd rather create straw-men arguments that reveal a great deal more about your own ignorance of scientific processes than about the science itself. -
muoncounter at 14:09 PM on 23 February 2011Meet The Denominator
PT, My reply was in reaction to Alex's comment here. You are free to read either Alex's statement or my reply in whatever manner you choose; subject, of course to the conventions of normal English usage. -
Albatross at 14:08 PM on 23 February 2011Hockey Stick Own Goal
Are the "skeptics" trying to see how many own goals they can score on this thread? Truly unbelievable. HR, continues to miss the point and argue strawmen. It seems that he has not read the main post which has this quote from the Ljungqvist (2010): "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.” And "skeptics" love the Ljungqvist reconstruction. How very inconvenient for them that it agrees well with Moberg and Mann, and shows that current N. Hemisphere land temps are warmer than those observe during the MWP. Come on, Marcus never said that MBH98 was "junk science", neither did the NAS panel--now HR is grossly distorting and misrepresenting the facts. And Hegerl and Knutti (2008) is the most recent meta analysis of estimates of climate sensitivity. Why do some people insist on being stuck in circa 2000? -
scaddenp at 14:04 PM on 23 February 2011Hockey Stick Own Goal
Excellent points muoncounter. I've learnt that no point in debating within anyone where their position is such that they can imagine no data that would change their mind. Do philc and chemist1 fit this? Perhaps we should ask. -
Tom Curtis at 14:01 PM on 23 February 2011Hockey Stick Own Goal
HR @18, the real question here is why are you ignoring the push by deniers to retain an obsolete reconstruction based on a single temperature series in central England, plus (for the early periods) the estimates of one researcher? The preference for this obsolete graph is clearly stated by McKitrick, for example in "What is the 'Hockey Stick'debate about?" (April 2005), in which he reproduces that obsolete graph as Figure 3. If you missed that date, McKitrick was still pushing that obsolete graph two months after the publication of Moberg 2005. In view of that, it is disingenuous for deniers to now claim Moberg as confirmation of MacIntyre and McKitrick's views, rather than of Mann's. To make this plain, consider this graph of Mann, Bradley and Hughes 99 (blue), Moberg et al 2005 (black), and IPCC 1990 (McKitrick's preferred obsolete graph, in red).
It is very clear that Moberg 2005 matches much better with MBH 99 than with IPCC 1990, particularly during the MWP. MBH 99 clearly understates the LIA, although the extent to which they do may be exaggerated in this graph in that Moberg 2005 shows a much cooler LIA than most modern reconstructions.
So, it is clear that MBH 99 (and 98) are a major advance over IPCC 1990. Since then statistical techniques in reconstructions have improved so that there are several reconstructions that give better results than MBH 99, and are consequently preferred. Stuck in a time warp, deniers are still using IPCC 1990 and attacking MBH 98 as if that somehow undermines modern reconstructions.
As to M&M's particular criticisms of MBH 98, many of them are simply wrong, and the rest much over exaggerated in their effect on the reconstruction. I do not think it is good science to be merely political attack dogs trying to pick up any flaws on papers whose conclusions you dislike while giving a free pass to papers whose conclusions you do like. The complete hypocrisy of M&M is shown by the complete pass they give to IPCC 1990 compared to the fine tooth comb they run through MBH 98.
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HumanityRules at 13:58 PM on 23 February 2011Hockey Stick Own Goal
21 Andy S Thanks Andy for that graph. I guess the big problem is 0.4oC or so extra variability seen in the blue curve than the red curve from 1000-1500. If as you suggest this level of difference in temp is not worth arguing over than why are we getting so excited by what's happening present day? 19 Marcus Great Mann 1998 is junk science, that's good to know. Mann 2003 also? And why is this important? Well from a glance at Hegerl 2000 (which should be Hegerl et al 2006 I think Dana) it looks like his results are being influenced by these early incorrect reconstructions. -
muoncounter at 13:58 PM on 23 February 2011Meet The Denominator
Alex, Nicely put, sir. You have a way with words that serves as an excellent example. Unfortunately, a conversation requires two to meaningfully engage -- and often sinks to the lowest common denominator. -
muoncounter at 13:50 PM on 23 February 2011Hockey Stick Own Goal
Let's take a step back here for a minute. We have philc rejecting Moberg, Ljungqvist and GISSTemp here, with Chemist doing the same here. HR, of course, misses the point entirely, choosing to focus on the old hockey stick (an outdated MWP graph) rather than the business end of the hockey stick (most goals are scored when the puck leaves the blade, not the shaft). Are these folks actually saying that not only is there no way to form any reconstruction of past temperatures, but even current temperature measurements are suspect? Does anyone really believe that we do not even know enough to measure temperature? Or how temperature variation impacts things like tree ring growth and other proxies? That there is no valid science behind any of these reconstructions? If so, all such measures are invalid -- and how can they now insist that 'it warmed before' or 'it's not warming rapidly now'? This is denial plain and simple: Denialism is choosing to deny reality as a way to avoid an uncomfortable truth: "[it] is the refusal to accept an empirically verifiable reality. It is an essentially irrational action that withholds validation of a historical experience or event". It is thus entirely useless to debate theoretical models and details of radiative physics (in a separate thread, Chemist injects the old it-violates-thermodynamics-canard and seeks to resurrect the discarded 'iris effect'). To validate theory, we must have some shared sense of reality. -
Andy Skuce at 13:42 PM on 23 February 2011Hockey Stick Own Goal
For the benefit of Humanity, I roughly digitized both the Mann 98 curve that he provided in comment #18 and the green curve in Dana's Figure 1 and replotted them at the same scale.
The two curves differ for the period 1600-1700 and at the very beginning of Mann's curve. Was that the big problem highlighted by ClimateAudit?
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Bibliovermis at 13:31 PM on 23 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
chemist1 (#51), Laws of ThermodynamicsThe third law of thermodynamics states that if all the thermal motion of molecules (kinetic energy) could be removed, a state called absolute zero would occur.
What relevance does a entropy-less state known as absolute zero have to temperature reconstructions, much less radiative forcing by aerosols?
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