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Comments 51 to 59 out of 59:

51. Riccardo at 20:10 PM on 25 November, 2011
    Arkadiusz at #48 is a good example of how the reading of scientific papers by people untrained in that specific topic may be tricky. In the conclusions of Kobashi et al. quoted by Arkadiusz, the authors highlight the possible reasons of the discrepancies between Central Greenland and the Arctic as a whole. This should sound as a ringing alarm bell to those who'd like to use their reconstructions as indications of a more general trend. Indeed, the authors are clearly trying to put central Greenland temperatures in the context of the Arctic as a whole to improve the understanding of the former. As already noted by Tom @50, Arkadiusz himself highlights the reason why his quote is irrelevant to the topic at hand, which makes me wonder why he extensively quoted it.
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52. pauls at 22:33 PM on 25 November, 2011
    Rob Painting, Skept.fr: As discussed in an earlier SkS post, the MWP seems to have been a re-organization of the global climate. Despite the localized warming aroung Greenland, the global mean background state was much cooler than today. Also consider that the map is relative to 1961-90 and that the Greenland area was relatively cold during this period, even compared to earlier in the 20th Century. That said, I'm with Skept.fr on being skeptical of these findings. The MWP doesn't just show smaller change than today, but change in the opposite direction to what we would expect. And the previous lowest minimum occurring during the Little Ice Age? It's counter-intuitive at least. Could it be that cooling in Europe was due to some prolonged blocking pattern caused by, or resulting in, a warmer Arctic? I guess I'll have to check out the paper.. hope my Nature subscription hasn't expired yet.
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53. barry1487 at 01:49 AM on 26 November, 2011
    Rob,

    Many climate change "skeptics" obsess over the 'hockey stick', and their discussion inevitably leads back to 1998, when climate scientist Michael Mann first published his paper indicating that current global warming was anomalous in the last 1000 years or so

    In 1998, Mann, Bradley and Hughes published a reconstruction going back 600, not 1000 years. The millennial reconstruction was done in 1999. These two papers often get confused, but usually by skeptics.
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54. Pete Dunkelberg at 03:04 AM on 26 November, 2011
    Moderator (DB) way back at 11, thanks for the link to Kobashi et al. 2011. When I first heard of that paper I didn't find a pdf. It follows Kobashi et al. 2009: Persistent multi-decadal Greenland temperature fluctuation through the last millennium. Here is a free pdf link to Flanner et al. 2011 mentioned by Tom Curtis. One more hockey stick: Tingley and Huybers' bayesian approach The spatial mean and dispersion of surface temperatures over the last 1200 years: warm intervals are also variable intervals for which I still find only a manuscript, no publication.
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    Moderator Response: [DB] Tingley has an identical copy here, but it is to be found nowhere else. Presumably still in review.
55. skept.fr at 05:10 AM on 26 November, 2011
    #52 : Pauls : I'm with Skept.fr on being skeptical of these findings Oh, hem, I'm not particularly skeptic of the paper we're discussing, I just quoted its findings. For the MWP or MCA in general, I think our level of understanding will progress, the paleoclimate community is very active. All studies conclude that the 1970-present period is unusually hot in the past thousand years on a hemispheric or global scale, it seems unlikely this result will substantially change. But the precise signature and mechanisms of past variability at centennial scales are still unclear and reconstructions may diverge for the amplitude of pre-industrial temperature changes (eg the 'spaghetti' schema in AR4). Mike Mann himself continuously refines his work (Mann 2009 differs in many details from Mann 1999) and so do the other teams working on past climates. Jan Esper 2010 made an interesting synthesis of the progress accomplished since the IPCC AR1 and the current research priorities of paleoclimate community.
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56. Glenn Tamblyn at 18:13 PM on 27 November, 2011
    In references to Lars earlier comments about Nordic swimming exploits (Although Beowulf probably beat him) and water temperatures. Although Lamb's comments are anecdotal, they may well be right. Surely that is the whole gist of the map from Mann 2009. If the North Atlantic basin, particularly around Greenland was an area that showed so much warming, one would expect the water to be warmer. In fact our Nordic Hero/Shepherd couldn't have done what it is claimed he did if it wasn't. And it is most likely that an incursion of warm water into those regions was the likely cause of the hot spot on Mann's map. Nothing exceptional about any of this. But it has no relevance whatsoever to the question of whether the whole Earth was warmer at this point in time. Which is surely the point of why skeptics love to cite Greenland, grapevines in England etc ad infinitum but don't mention the North-East Pacific, Australia, etc during the same period. That is surely the point. It is what the global picture looks like that counts.
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57. dvaytw at 01:02 AM on 10 September, 2013

    Hey fellas - in the Nature  article, the abstract says:
    
    "Here we use a network of high-resolution terrestrial proxies from the circum-Arctic region to reconstruct past extents of summer sea ice..."

    Can anyone explain to me in simple language what that basically entails?  
    
    Also, I've asked before and so far still haven't heard an answer: is there a way to set the thread so I'll be emailed a notification if there's a response?  
    
    (Mod - please feel free to answer and delete this part of the post!)

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    Moderator Response:

    [DB] "is there a way to set the thread so I'll be emailed a notification if there's a response?"

    Not at the present time, sorry.

58. KR at 03:51 AM on 10 September, 2013

    dvaytw - Kinnard et al 2011 (paper here) used ice cores, lake and ocean sediment cores, tree rings, and documentary evidence from the last 200 years.

    The various proxies describing temperature, water vapor, ion and methane-sulphonate concentrations (tied to sea ice openness/windiness). etc., were calibrated against historic documented ice cover, and from that used to infer ice cover over the last 1450 years. 

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59. dvaytw at 18:22 PM on 10 September, 2013

    Thanks as usual, KR!  

    And Mod, I hate to look a gift-horse in the mouth as it were (this site has already been a God-send to me!), but I think you guys might want to get that changed.  I think it would very positively facilitate continued discussion.  I've made posts to threads that died down several years ago, but if you had that function, people who participated (and are thus interested) would know the thread is active again.  I don't know much about programming, but given it's such a common function of Internet forums, it can't be too difficult.  Just my two cents...

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    Moderator Response:

    [DB] The majority of regular users follow the Recent Comments thread, so they will always see any new comments regardless of whatever thread (of the many thousand) they are placed on.  Thus, no thread at SkS is by definition "dead", but many are just temporarily inactive.

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