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Comments 67401 to 67450:

67401. dawsonjg at 00:00 AM on 3 January 2012
       Tree-rings diverge from temperature after 1960
       Michel I have read thoroughly convincing analyses that the hockey stick is 'problematic' (to put it in terms that I hope won't get snipped). But knowledgable people on sites such as this ridicule such analysis as il-motivated nonsense (Mann has been doing this very noisily for nearly a decade, before tacitly backing down very quietly on issue after issue). So who am I to believe? All I can do is read the pro and con arguments and pose a few questions to see if I get credible answers. But accusations that my questions amount to 'frantic handwaving' or 'crafted disinformation' for an industry funded defamation campaign are not very informative. I can't give you evidence re the 2001 graph because that's deemed dead horse territory, I've given some evidence re the 2008 graph above.
67402. banana at 23:39 PM on 2 January 2012
       Tree-rings diverge from temperature after 1960
       This page contains the supplementary material for Mann 2009 (direct link to pdf). The figure provided in post 32 above has been altered from the original (Figure S8, p31). Specifically, the green line before 1500AD is dashed in the original. This is because it does not pass the validation tests. These tests are described in the section titles "Validation Exercises" on p4. To pass the test the reconstruction must rule out a 'red noise' null hypothesis at the 5% significance level. Care should therefore be taken when interpreting the green line. To quote from the "Sensitivity Tests" section, p9: "This additional test reveals that with the resulting extremely sparse proxy network in earlier centuries, a skillful reconstruction is no longer possible prior to AD 1500. Nonetheless, even in this case, the resulting (unskillful) early reconstruction remains almost entirely within the estimated error bounds of the original reconstruction." I think it would have been nice to show uncertainty bands for the green line alone. However, presumably that would require significant CPU time and not add much information.
67403. Nick Palmer at 23:31 PM on 2 January 2012
       Tree-rings diverge from temperature after 1960
       dawsonjg... "Why can't you just admit that Mann and the IPCC got it wrong?" and "Thanks Rob - I know what science is suposed to do" Do you really know - or are you just using the words for rhetorical effect? Why do you fall into the common trap laid by incorrigible denialists of pretending that new science can ever be about presenting 100% perfect papers? That is an impossible standard which has never been achieved or has never been presented (by scientists) as achievable. It is absolutely not how science works. Only the ignorant, or those wishing to twist ordinary people's minds with propaganda, would ever claim that. What you are doing is this. You are misrepresenting the situation by trying to suggest that Mann, by presenting 13 years ago a "first of a kind" paper that was not 100.00% "perfect", was "wrong". Clearly, you do NOT know what science is supposed to do. You, along with all the others like you, are clearly trying a well worn propaganda technique by creating a blizzard of misdirection that because the paper was not 100.00% perfect it must, in the weird, difficult, nit-picky, obstructive way that too many think, be wholly worthless and evidence of incompetence at best and fraud at worst. Deny you are doing that that, dawsonjg. I dare you. The all too familiar use of such innuendo was the reason for my "mole-on-the-face-of-the-supermodel analogy. She remains incredibly beautiful and any minute nit-picky perceived flaws (most of which are misperceived camera artefacts anyway) doesn't in any way take away from that. Similarly, small perceived flaws, even if a few of them are real, in otherwise sound science are only "evidence" that climate science is "wrong" in tinfoil hat land, not in the real world.
67404. Tom Curtis at 23:24 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       OPatrick @30, what ever the merits of your view, it still remains the case that the video has been released to the general public. That being the case, the best way to ensure viewers take away the main points and not some of the denier fluff included is to discuss those main points. Continuous discussion of the merits of the video only distract further from the key points that: 1) There is a scientific consensus on key aspects of climate science; 2) That consensus shows that very optimistic views and very pessimistic views both have low probability (ie, that life itself is threatened); 3) That special interests try to distract from that key consensus with "blather"; 4) That a proper response involves realistic risk assessment; 5) That a realistic risk assessment recognizes that the center of the probability estimates suggests significant damage to the planetary life support system; and 6) There are tipping points which make a controlled response much more difficult if it is a delayed response.
67405. OPatrick at 23:12 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       ...churn...
67406. OPatrick at 23:11 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       Tom Curtis, to be fair Rob Honeycutt wrote "If you have friends who are just starting to become interested in the climate change issue, this would be an excellent place to point them for an introduction." It seems fair to question whether this is an effective piece of communication. I would show this video selectively. There are some people I would trust to be reflective enough to see and remember the genuine message in the video, but if the Debunking Handbook is correct then I suspect this would not be an effective communicator for everyone. What I think the introspection here illustrates is the fundamental difference between selling doubt and communicating confidence. Those selling doubt can afford to chirn out anything they like, it only takes one of those messages to hit the mark for them to succeed.
67407. Tom Curtis at 22:57 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       John Russell @28, you don't communicate a message by talking about the best way to communicate a message. This site is about communicating science, not about communicating the best way to communicate science.
67408. Tom Curtis at 22:53 PM on 2 January 2012
       Tree-rings diverge from temperature after 1960
       Dawsonjg is referring to this chart reproduced from a chart which I believe to be from the supplementary material of Mann 2009: The original Mann 2008 EIV reconstruction is in red, the no tree ring reconstruction is in blue, the reconstruction with seven series with higher uncertainties (including tiljander) removed is in brown, and the reconstruction with neither tree rings nor the seven series with higher uncertainties is in green. Some things are immediately obvious: 1) The green reconstruction is still a Hockey Stick; 2) The highest temperatures in the MWP in the green reconstruction is still less than current temperatures; 3) The highest temperature in the green reconstruction still lies withing the error bars of the original reconstruction (shaded yellow); and 4) The green reconstruction is still closer to Mann 2008 than to Lamb 1966. These four facts show clearly, according to the deniers, that Mann committed fraud; that Mann's reconstructions of MWP temperatures are entirely in error regardless of how many independent confirmations show the same thing; and that Lamb's 1966 guesstimate was much more accurate than Mann's 2008 reconstruction. More reasonable people might consider these facts to show that Mann's reconstructions are essentially confirmed by this sparse network. They might also conclude that the increased variability is more likely to be due to the restricted number of the remaining data sets rather than because Mann 2008 got anything wrong.
67409. John Russell at 22:52 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       @Tom #27 writes: "I will point out that endlessly discussing whether or not the video is effective at communicating its message does not aid in communicating that message." I only respond to what other commenters have written and they seem to want to talk about how effective the message is, Tom; and the moderators have not offered any steer away from that. Also is this website not about communicating climate science? I find your sentence above very strange, in that one learns how to communicate by analysing and learning from what others have done before. Is there a better way?
67410. michael sweet at 22:06 PM on 2 January 2012
       Tree-rings diverge from temperature after 1960
       Dawsonjg, Where is your evidence that "When you eliminate all the 'problematic' Tiljander and bristlecone data together rather than one at a time, you eliminate Mann 2008's claim to fame"? here you claim to ask if Mann performed these analysis. here you claim that you have not seen the analysis done. You now claim that the analysis shows Mann was wrong. You are not arguing in good faith.You have been given the information that Mann has done that analysis and it makes no difference in the result, except lowering the statistics. You are now claiming, without any evidence, that Mann is wrong. Please produce some evidence to support your frantic handwaving.
67411. Tom Curtis at 21:32 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       John Russell @26, the filmmaker's target audience SFAIK was the audience of the presentation of the inaugural Stephen Schneider Climate Communication Award to Richard Alley. The video was intended as a tribute to Stephen Schneider at that presentation. I will point out that endlessly discussing whether or not the video is effective at communicating its message does not aid in communicating that message. Perhaps we could return comments to the message rather than the technical value of the video.
67412. John Russell at 21:06 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       Well made point, Chris G. #24 As a film maker (but excluding those just making 'art') the first and most important thing is to be aware of the audience you're creating your film for. Everything Steven Schneider says is spot on, but I don't think he was aiming at the lowest common denominator. The film maker has made this film following Schneider's death and when watching it, it's clear that he has aimed for a different audience to that which Schneider was addressing. So, to be clear, the producer has taken disparate sound bites of what Schneider said over the years and woven them together to tell a story that Schneider never told -- or at least not in those words. He's also laid over Schneider's words images which both support and possibly, to some degree, modify what Schneider says. So we're all arguing about two different things: what Schneider was saying and what the film maker is saying. It is my contention that the film will work with a sophisticated audience who understand and sympathise with the message. I question whether it will be understandable to an unsophisticated, uninformed or cynical audience (i.e., think a typical GOP politician or someone who might vote for them). As a tribute to Schneider it works with people who remember and agree with him. To the uninformed it's not a persuasive piece of work that will bring them on side. What's frustrating to me is that if I had rights to use the right footage, I could do this. Unfortunately as a professional working in this area I could not just use footage without the necessary permissions. This film, for instance, contains scenes shot for the feature film 'The Road' and I'm pretty certain they didn't receive any permission to use it. If this film was as high-quality and effective as we'd like it to be, the copyright owners of the material would take the producers to court and take a lot of money off them -- or, more likely, have the film destroyed.
67413. dawsonjg at 19:56 PM on 2 January 2012
       Tree-rings diverge from temperature after 1960
       Thanks Rob - I know what science is suposed to do. What Mann does is not it at its best. Thanks DB, I've read Tamino's review. I guess comments would be deemed 'beating a dead horse' Thanks jmsuly, I've read some of what you suggested. Might I suggest further reading at http://climateaudit.org/2011/07/06/dirty-laundry-ii-contaminated-sediments/ ? When you eliminate all the 'problematic' Tiljander and bristlecone data together rather than one at a time, you eliminate Mann 2008's claim to fame. But why their persistent inclusion when it has been acknowledged that they are 'problematic'?
67414. Brian Purdue at 18:50 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       barry @23 - that’s pretty well the way I saw it too and a lot of people I know, as well. And a bit of advocacy helps motivate people and Stephen Schneider excelled at it.
67415. radnagpe at 17:17 PM on 2 January 2012
       2011 Year in Review (part 1)
       The debate on weather disturbances being usual, unusual, part of a pattern & what the possible pattern might be influenced by, will be best understood by our insurance companies. From what I know, their rising premiums and recent tendency to exclude high-risk regions tells the story convincingly enough.
67416. Chris G at 17:10 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       Muon, I think the information is straightforward, particularly for those already familiar with the topic. It is like taking a seldom used path in a familiar garden. I think the overview of the point the creator is trying to make is not as clear as it could/should be if the target audience is not already familiar with the topic. The transitions are a bit abrupt, and the audience could get lost at a crossing. Human memory is faulty; a naive audience is just as likely to remember Geraldo's forceful assertion that the science is not settled as they are to remember Stephen's least-probable-outcomes dichotomy. Example: My wife and I when we were putting things on our wedding present registry needed dishes and were adding some to the list, there was a particular pattern at the local store that we did not like, and everything else would be great. So, we put on the list "no ducks". Twenty years later, half of our dishes still have ducks on them. It was like the average person who saw the list remembered "ducks" and forgot the negation. Honestly, we would have been better off having said nothing and taken our chances. So, no, I have little confidence that the average person will get the intended primary meaning on the first pass though that video. I don't think you can wait until 4 minutes into a video to tell the audience the main point you are trying to make. The video works if you are preaching to the choir; otherwise, it is open to incorrect interpretation. DB, Thanks, but that tip is actually what I'm complaining about. Compare the tip for links where "http://url" clearly means a URL and "Description of page you're linking to" is whatever text you use to describe the contents of the link, with the next tip where, I've learned, the text "Description of page you're linking to" actually has two meanings, "URL of the linked page" and "URL of the image within that page". In the first, it is a description, and in the second it is two different URLs. It would be a more helpful tip if the it indicated that the contents between the quotes were URLs.
67417. barry1487 at 16:49 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       Other than some unfortunately unqualified language ("...we keep adding unprecedented levels of warming to the system..." 9:38) and that there is more advocacy here than I'm used to for SkS, I enjoyed the presentation. Schneider outlines the issues that matter very clearly and concisely. After the science comes the policy. Schneider's lecture is the bridge between.
67418. Rob Honeycutt at 16:05 PM on 2 January 2012
       Tree-rings diverge from temperature after 1960
       dawsonjg... Peter Hadfield (Potholer54) has a youtube video I've always enjoyed titled "The Scientific Method Made Easy." I'm not trying to be patronizing here but there is an element that he brings up in the video that I always find interesting. He says (paraphrasing), "Whether other researchers think John (the "evil" scientist in his example) cheated or just got things wrong doesn't matter because his work won't be consistent with other research and will eventually be discarded." Ultimately what all scientists want is to get things right because that will mean their work will stand the test of time. Even if Mann was (as deniers suggest) trying to push fraudulent work it doesn't matter because if he was it wouldn't fit the broader body of research. What has happened though is Mann's work has fit quite well. Other researchers have been able to reproduce his results with other methods. In fact, there are now almost a dozen multi-proxies that are pretty well consistent with Mann's earlier work. That work has improved on what he did and even Mann's own work has improved on his earlier work. All a case of science doing what it's supposed to do.
67419. jyyh at 15:51 PM on 2 January 2012
       UAH Misrepresentation Anniversary, Part 2 - Of Cherries and Volcanoes
       Isaac Held talks of MSU: http://www.gfdl.noaa.gov/blog/isaac-held/2012/01/01/21-temperature-trends-msu-vs-an-atmospheric-model/
67420. Rob Honeycutt at 15:38 PM on 2 January 2012
       Tree-rings diverge from temperature after 1960
       dawsonjg... "Why can't you just admit that Mann and the IPCC got it wrong? " You're describing science at it's best. Mann's work in 1998-99 was new and different. Why would you expect it to be correct by today's standards? Do we expect Darwin's work to be correct by today's standards? No. But what I would say about Mann's work (as with Darwin) is that it has stood up to intensive, hostile scrutiny and has lead to a better understanding of the subject matter today. What more could you want from science?
67421. jmsully at 14:37 PM on 2 January 2012
       Tree-rings diverge from temperature after 1960
       dawsonjg, You obviously have not actually bothered to *read* the Mann 2008 paper or the associated SI (and the online update at Mann's personal website). Mann did a reconstruction, reported in the main paper, which excluded all of the dendro proxies. He got essentially the same answer although it was not statistically significant as far back in time as the full recon. In the SI, he tested the results of leaving out the problematic proxies (Tiljander and a couple of others) to test the sensitivity of the main recon to these proxies. No big differences. As a result of complaints in the blogosphere Mann reported in the updated SI the result of tests which left out the Tiljander data and the dendro data. The result of this was reduced significance in the earliest part of the no dendro/no Tiljander part of the reconstruction, mostly due to the fact that Tiljander represented a significant part of the earliest data. So did Mann 2008 get it wrong? I would say no. He showed that dendro evidence is a valid proxy, in spite of the attacks mounted on it by the denialists. There are almost certainly not enough non dendro proxies with sufficient resolution to do a long recon with nothing but non dendro evidence. The fact that Mann 2008 agrees broadly with other reconstructions despite differences in proxy selection and analytical methodology would seem to indicate that he is in the ballpark. We'll never know with any certainty what the exact history of global temperature is over the last couple of millennia but I think that it is possible to get a pretty good idea of what happened by using the multiproxy methods which Mann pioneered.
       Response:

       [DB] In addition to your sage advice, and also the reading of the OP and the other comments above, this post at RC by Tamino is relevant:

       http://www.realclimate.org/index.php/archives/2010/07/the-montford-delusion/

67422. muoncounter at 14:04 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       ChrisG#17: "the take-away is muddled." No, its straight-forward. The section around 4 minutes in deals with a multiple range of possible outcomes: what science does is try to winnow out the relative probabilities of possible outcomes, if you try to cover it as a yes or no you are distorting and yes, we get a little mad about that. There's the key message. One who gets distracted by '5 ft of sea level rise' or 'catastrophic change' or 'end of the world' is missing the point. And isn't that the ultimate goal of propaganda? To manipulate your thought process so that you miss the point? Propaganda is a form of communication that is aimed at influencing the attitude of a community toward some cause or position so as to benefit oneself or one's group. So we hear about 'balance,' we hear an endless succession of false equivalences and a blizzard of 'it can't be true' spin stories. Schneider is very clear on this point: Feeding people the yes/no message when there are a range of alternatives is still propaganda. Hyping the supposed 'uncertainty' when there are factors that are well-understood is still propaganda.
67423. Paul Magnus at 13:40 PM on 2 January 2012
       Science and Distortion - Stephen Schneider
       Tom @15. Thanks for cheering me up a bit....
67424. dawsonjg at 13:35 PM on 2 January 2012
       Tree-rings diverge from temperature after 1960
       Thanks michael Mann responds by deleting problematic sets from his 2008 paper one at a time, not by deleting them all at once. I'd like to know where he deletes both bristlecone and Tiljander sets at the same time. You have a very malleable definition of a hockey stick. No one anymore defends a millenium graph with a straight handle and 20th century blade such as appeared in the IPCC's 2001 report to (-Snip-). Why can't you just admit that Mann and the IPCC got it wrong?
       Response:

       [DB] perhaps you missed this warning about needed compliance with the Comments Policy.  This site is about the science of climate change, not about scoring rhetorical points.

       Inflammatory rhetoric snipped.

67425. michael sweet at 12:59 PM on 2 January 2012
       Michael Mann, hounded researcher
       Dawsonjg: Please see my response on the tree ring thread linked above.
67426. michael sweet at 12:57 PM on 2 January 2012
       Tree-rings diverge from temperature after 1960
       Dawsonjg, Who says including those data sets was in error? Mann uses specific criteria to exclude problematic data sets. Deniers then add data sets they like and claim Mann is in error for including ones that they do not like. Mann responds by showing that deleting the supposed problematic sets does not affect the result. You are confusing unsupported blog criticism with actual peer reviewed criticism. Keep in mind that the Mann hockey stick has been reproduced by numerous other peer reviewed studies. Can you provide a reference to a peer reviewed study that does not show a hockey stick? If everyone gets a hockey stick, how can you claim that Mann is in error?
67427. dawsonjg at 12:45 PM on 2 January 2012
       Michael Mann, hounded researcher
       (-Pointlessly off-topic snipped-)
       Response:

       [DB] Please note that posting comments here at SkS is a privilege, not a right.  This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

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67428. dawsonjg at 12:33 PM on 2 January 2012
       Michael Mann, hounded researcher
       Thanks caerbannog. I confess that running those scenarios is beyond my capacities. But I would be interested if you can point me to where anyone has done that exercise. I believe that Mann and co have excluded Tiljander and bristlecone proxies one at a time to claim that they don't matter, but has anyone eliminated both at once and checked that result?
       Response:

       [DB] Anyone responding to this please do so on the Tree-rings diverge from temperature after 1960 thread or other, more appropriate, thread; follow that up with a placeholder with a redirect link from here. Thanks!

67429. Nick Palmer at 12:24 PM on 2 January 2012
       Michael Mann, hounded researcher
       If I adopted the same mind set as those who crafted your twisted disinformation - that means they wrote it to deceive, not to enlighten, I would describe the supermodel Cindy Crawford as having a foul pestilential precancerous eruption on her face and highlight it microscopically to try to convince gullible people that not only was she ugly, but that all her family and relatives were ugly too. Other more rational people might see just a facial mole. Some might even call it a "beauty spot".
67430. dawsonjg at 12:11 PM on 2 January 2012
       Michael Mann, hounded researcher
       Thanks Nick, I'll take that as a no he didn't make those errors. Thanks Philippe, glade to amuse. But I made no accusation that Mann made those errors purposely to deceive - I agree that its unlikely he's that stupid. That, however, doesn't answer my questions. I'll take your answer to mean: he might have made those errors but they dont matter.
       Response:

       [DB] This fixation you have on Mann is useful only as an affirmation of the title of the OP.  You were earlier directed to place such specific questions on more specific threads on Mann, his research and the "hockey stick" (many exist; use the Search function to locate).

       Comments continuing here in this vein will be deleted.

67431. caerbannog at 12:07 PM on 2 January 2012
       Michael Mann, hounded researcher
       dawsonjg, What effect does excluding the supposedly problematic bristlecone pines from Mann 2008 have on the results? What affect does excluding the supposedly problematic Tiljander proxies from Mann 2008 have on the results? You can download all of Mann's data/code and run those scenarios yourself. Get back to us when you have some results to show (but not before then).
67432. Philippe Chantreau at 11:52 AM on 2 January 2012
       Michael Mann, hounded researcher
       Dawsonjg, you really are funny. So Mann did all these terrible things, with obviously the intent to commit fraud, and yet came so close to the result one gets when not commiting these abominable errors that they make no significant difference, even when all accumulated together. Why go through all the trouble then? Let me get this straight, this would be the theory of the fruitcakes accusing Mann of all evils in creation: he accumulated all these errors with the intention of accomplishing a deceitful goal and did not accomplish that goal, yet went ahead with the publication and all that. That makes perfect sense. Every time I see that kind of idiotic nonsense it becomes easier for me to remember why I was so quick to make up my mind about the so-called climate change skeptics years ago. Keep-up the good work.
67433. Nick Palmer at 11:29 AM on 2 January 2012
       Michael Mann, hounded researcher
       No dawsonjg, you are not "just asking". You are in full fledged "quoting crafted disinformation mode".
67434. dawsonjg at 11:24 AM on 2 January 2012
       Michael Mann, hounded researcher
       Didn’t Mann 2008 include bristlecone pines in its dataset that had been discredited as reliable proxies? Didn’t Mann 2008 ignore the effects of ditch digging on Tiljander’s lake sediment proxies? Didn’t Mann 2008 reverse the meaning of the x-ray scores recorded by Tiljander, thus recording the temperatures upside down? Didn’t Mann include a proxy line as temperatures in Africa that turned out to be rainfall in Spain? Or not? Just asking.
67435. Tom Curtis at 10:59 AM on 2 January 2012
       Science and Distortion - Stephen Schneider
       Chris G @18, you are absolutely correct that it is the rate of change of temperature rather than the absolute temperature (within limits) that determines extinction rates and the relative harm to human society. The reason is that life, and human's adapt. Life adapts on a million year timescale, with restoration of the full range of biodiversity and productivity of ecosystems taking up to 10 million years after a major extinction event. In human terms, that means any loss of biodiversity is effectively for ever. Humans also adapt, and much faster so that a thousand years from now even in the worst case of the reasonably probable scenarios global warming will have little impact on the standard of living. But our response now makes a large difference to the effect over the next 100 to 200 years.
67436. paulhtremblay at 10:58 AM on 2 January 2012
       Science and Distortion - Stephen Schneider
       >>I don't like the use of fantastical, graphically-enhanced 'scare' composites showing -- for example -- barefooted children standing on parched, cracked mud with smoke rolling over them in an orange landscape. Thanks for your comments, John. I think the graphic showing the girl was meant to show the extremes that Schneider doesn't agree with: look at how ridiculous that extreme is! Though, the confusion underscores your point that the clip isn't always as clear as you think it should be. Interestingly, I thought this clip was excellent compared to many others I have seen. It seemed less polemical and more likely to convince those not already convinced.
67437. Chris G at 10:45 AM on 2 January 2012
       Science and Distortion - Stephen Schneider
       Re: Tom C's post (#15), Several years ago I overlaid the geologic record of cooler/warmer temps with the mass extinction record. Just eye-balling it, the mass extinctions seemed not to be associated with cooler or warmer per se, but with changes in slope of the temperature graph. Which is basically another way of looking at the "warmer is fine" versus "it's the rate of change that matters" debates that frequently pop up. It involved a flip and a stretch; sorry, looks like I lost the work, but the link is where I started from. P.S. I'm having some trouble with the tips on posting images. href and src are both "Description of page you're linking to" and that seems not correct.
       Moderator Response:

       [DB] Chris, Wiki pages can be a little tricky to use a source for hosted graphics. In the following html string:

       

       The first url would be the location of the hosting Wiki page. The second URL would be the location of the graphic on the Wiki page. The way to find that second location would be to right-click on the desired graphic/image on the Wiki page and select either "View Image" or "Copy Image Location" to find out the URL you need.

       If you need additional posting tips, follow this link.

67438. Chris G at 10:23 AM on 2 January 2012
       Science and Distortion - Stephen Schneider
       My two cents: Since Dr, Schneider gave that talk, we've learned that we have already passed the tipping point for a big chunk of the WAIS. Pine Island Glacier has retreated passed the choke point, and loss is accelerating. I'd side with Rob P and John Russel on this one. Dr. Schneider's speech is excellent, but the take-away is muddled.
67439. lloyd at 10:01 AM on 2 January 2012
       Science and Distortion - Stephen Schneider
       John at (12) I agree with you. Keeping the conversation simple is best. Trying to share my knowledge over time has taught me to relate the effects of climate change to something they understand. They get effects such as dirtier air making it harder to breathe, power and water rationing, or an explosion of bugs devouring their gardens and trees. Trying to convey the concept of AGW, which most are unaware of or ignore, is counterproductive. People want to know how their choices are going to impact them but not what it is called. They want us to keep it simple!
67440. Tom Curtis at 09:43 AM on 2 January 2012
       Science and Distortion - Stephen Schneider
       Paul Magnus @13, I believe there is some confusion about Stephen Schneider's comment about "end of the world" is a low probability outcome. A decade ago it was considered a real possibility by at least some commentators that global warming could result in a runaway greenhouse effect. Such an eventuality would result in the oceans boiling away and the Earth becoming a second Venus, and consequently the death of all life on Earth. Since at least 2002 it has been known that that sort of runaway greenhouse effect is impossible on Earth. (There remains a slight epistemic possibility that it could happen in the sense that the science that shows it is impossible could be wrong.) That is the end of the world scenario that Schneider considered one of the two lowest probability outcomes. At 6:45 in the video, Schneider says,

       "... here we talk about 50% risks and the planetary life support system..."

       Clearly the high probability scenario Schneider is considering is very grim. It involves mass extinctions. Given other concurrent human pressures on the environment, it is likely to at least equal the end Eocene extinction and has a low but significant probability of exceeding the End Permian Extinction (at 250 million years before present on the chart below): In the more extreme scenarios with significant probability the ocean will become anoxic (without oxygen), a possibility that is distinctly more probable than "it is good for you". So, what we are talking about in the middle of the range is something in the range of great depression plus Spanish Flu simultaneously for a century or so to Great Depression plus black death plus mongol invasion for a century or so. That is on business as usual. If we do nothing it will not be the end of the world. It will not result in the extinction of the human species (with high probability) but it will be grim, and may be the end of our civilization (which would winnow the human population down to between half and a billion people). That is your 33 to 66% range. Having said that, I believe Paul Magnus is being overly pessimistic. Two degrees C represents a significant (around 50%) possibility of the loss of major reef systems around the world including the Great Barrier Reef, but not of the loss of coral reefs altogether. That level of impact will place a large strain on our civilization, but we will cope. We have coped with far larger strains (including, but not limited to the Black Death and WWII).
67441. Paul D at 09:34 AM on 2 January 2012
       2011 Year in Review (part 1)
       Well here in the UK we have had the second hottest year on record in 2011. The spring in the South was dry as has been the autumn, two trees I got planted in the winter were struggling a bit in the spring. Rivers and reservoirs are low this winter and there have been hose pipe bans in some places in the autumn, which is practically unheard of. Unless we get substantial amounts of rain (which may produce flooding, if the vast amounts needed come in a short time) then we will be seeing a drought in 2012.
67442. Daniel Bailey at 08:55 AM on 2 January 2012
       Science and Distortion - Stephen Schneider
       @ Paul Magnus

       "I dont think that there is sufficient evidence for anyone to say that the 'end of the world' probability outcome is low."

       Having the probability of such an outcome being a non-zero sum should be terrifying enough for any sane person.
67443. Paul Magnus at 08:01 AM on 2 January 2012
       Science and Distortion - Stephen Schneider
       "The end of the world and what’s good for you are the two lowest probability outcomes" I dont think that there is sufficient evidence for anyone to say that the 'end of the world' probability outcome is low. We just dont know. And it actually at least to me looks high and getting more probable. And as commented above the risk factors need to be taken into account. It seems to me it is more and more likely that we are going to get >3C which is basically the end of the world for humans. I subscribe to the belief that a 2C warming means the end, more of less of, modern society. Currently we havent even reached 1C and basically if the current rate of extreme weather events continue at the level of 2010/11 we will have a collapse. But hey, guess what, they are going to get worse - more intense, more frequent, larger areas. So I think a collapse is inevitable. Not good. All the best for 2012 and good luck.
67444. Phila at 07:50 AM on 2 January 2012
       2011 Year in Review (part 1)
       Pirate: The first few paragraphs were plainly written to garner an emotional response. So if an article on AGW is disturbing or depressing, it can be discounted. And if it expresses basic human sympathy for victims of tragic events, it can be mocked as "emotional" (subtext: feminine and foolish). A nice way to win every argument before it begins! Do you apply the same stringently rational litmus test to articles positing a "Great Global Warming Swindle"? Or the "dangers" of reducing CO2 emissions? Aren't inactivist arguments about some grave existential threat to "liberty" equally emotional? And isn't there an intense emotional gratification in believing oneself to be smarter and better informed than expert climatologists? Or for that matter, in believing on principle that nothing really bad will come of AGW? Are you equally wary of these pitfalls? Do you look as consistently and carefully for these appeals to emotion and wishful thinking in your own rhetoric as you do in other peoples'? Be honest, now.
67445. John Russell at 06:14 AM on 2 January 2012
       North American mammal evolution tracks with climate change
       At this point it seems apposite to post a link to this website. So, I wonder; will we be the first species to actually commit suicide -- or will we in fact join some form of green slime in achieving that remarkable distinction? Happy New Year everyone!
67446. MarkR at 04:52 AM on 2 January 2012
       2011 Year in Review (part 1)
       #14 noelfuller : thanks, fixed! #17 apiratelooksat50 : I have to admit, I reacted emotionally to the disasters. A lot of other people do too, and 'did climate change cause x disaster?' is a common question. As a science communication site, we should answer these questions & I don't think we should be afraid of reporting the science and the context it's in because some people feel an emotional reaction to it. As long as the scientific content is clear and correct (which I believe it is), that's what's important. The recent series of record-breaking natural disasters that are now beginning to be detected as most probably human caused is one of the biggest science stories of 2011 IMO. It would have been ridiculous to leave them out as an appeasement policy, and the science on them needs to be communicated. I obviously agree with "An active extreme event year in weather related disaster no more indicates AGW than a year with few weather related disasters indicates the opposite", but the attribution studies work around this, and that was what I reported.
67447. MarkR at 04:41 AM on 2 January 2012
       2011 Year in Review (part 1)
       #13 fydijkstra : Have these results been published? In the context of that paragraph, we can see rigorously that the full satellite record shows faster sea level rise than we measured last century. I'm not aware of any study showing a significant 'slowdown', especially not in the global warming 'signal'. We had a strong La Nina which depresses sea levels. So there might very well be a statistically significant negative trend over that very short time period, but it doesn't say anything about the background trend. Which is what Foster & Rahmstorf worked on with atmospheric temperatures in their paper. You can get statistical results you like by picking certain periods, but considering the physical reality also helps. Given that over the past 20-odd years there's been a slight downwards trend in the MEI index, if anything, I felt confident that using the FULL satellite record would better represent the real signal.
67448. MarkR at 04:37 AM on 2 January 2012
       2011 Year in Review (part 1)
       #11 mace: The UK is only one small region, and experiences a lot of interannual variability so the temperature series has a lot of noise. It takes about ~17 years (Santer et al, 2009) to get statistical confidence in (less noisy) global changes, so you'd expect even more time for just the UK before you can be confident about saying anything... If you look at what you linked to, and switch to average temperatures, you see the smooth points downwards in some months, but upwards in others. Annually, it's flat at the end, but it's sensitive to the final datapoint which was cool thanks to the massive blocking event last winter that gave us a very cold January and December. Once this year (2nd warmest) is added, it won't look the same. And as I said, I'm not sure you can take anything from this curve fitting exercise. All you can say is that the last decade was the warmest.
67449. EOttawa at 02:23 AM on 2 January 2012
       Tree-rings diverge from temperature after 1960
       I noticed that in early December, McIntyre was again/still attempting to sow doubt about reconstructions. In this case, it was the Briffa et al 2001 line in Figure 1 of Mann et al (2003). In short, that line of the plot appears to end around 1940. Someone asked about this over at RealClimate and I think it might be useful to provide a link to the question and Gavin's response Dr. Schmidt's key points are -

       It's interesting to add that in Briffa et al, 1998, they state: "Over the hemisphere, the divergence between tree growth and mean summer temperatures began perhaps as early as the 1930s;".

       and

       The divergence issue as a recognised problem predates this paper by years (Briffa et al, 1998), and was discussed in the almost contemporaneous Jones and Mann (2004) paper. That paper was a little clearer about what was done and why (i.e. fig 5): The various other (smoothed) NH reconstructions shown in the enlargement to Figure 5a have been scaled by linear regression against the smoothed instrumental NH series over the common interval 1856–1980, with the exception of the ‘‘Briffa et al.’’ series, which has been scaled over the shorter 1856–1940 interval owing to a decline in temperature response in the underlying data discussed elsewhere [Briffa et al., 1998a].

67450. ta7king at 02:17 AM on 2 January 2012
       Positive feedback means runaway warming
       Nealjking, Thanks for your explanation, and especially thanks for the maths! I know you have stated that your mathematical analyses is overly simplified, but considering an increase in temperature can allow a rapid rise in absolute humidity, inducing an increase in radiative forcing which is not restricted to a logarithmic limiter, shouldn’t your advanced explanation at least take this into account. I still can’t see that earth could be subject to a Venus type runaway, but the argument doesn’t seem to be as obvious as you make out. To me the main danger is that the upper troposphere warms enough to allow a parcel of air to rise through it without dew point being reached. Is that so improbable at low temperatures and pressures?

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