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Wednesday, January 22, 2014

Resurrecting Fred Singer and the MWP at WUWT

Sou | 10:11 PM Go to the first of 173 comments. Add a comment

As if anyone needed more proof that WUWT is just another outlet for anti-science disinformation propaganda.  Today Anthony's put up a pack of lies by Fred Singer (archived here), who's made it his business to invent disinformation.  The article is another "hockey stick is a fraud" article.  Wouldn't it be nice if Fred Singer and Anthony Watts were added to one of the cases currently being heard in the US courts.


Fred Singer Manufactures Lies and Dispenses them at WUWT


Here is some of what Fred wrote in today's WUWT article:
...the Hockeystick is a manufactured item and does not correspond to well-established historic reality. It does not show the generally beneficial Medieval Warm Period (MWP) at around 1000AD, or the calamitous Little Ice Age (LIA) between about 1400 and 1800. In the absence of any thermometers during most of this period, the Hockeystick is based on an analysis of so-called proxy data, mostly tree rings, from before 1000AD to 1980, at which point the proxy temperature suddenly stops and a rapidly rising thermometer record is joined on.
Talk about "manufactured items".  Here are a few "hockey sticks" from the IPCC AR5 report.  I've indicated the times that are usually referred to as the MWP.  There's no fixed period.  I've also indicated the Little Ice Age - and you can see that in the case of the Little Ice Age there was cooling overall.  In the Medieval period most reconstructions in the Northern Hemisphere show a slight warming particularly starting around 950, but not so much in the southern hemisphere.  Globally there's a slight bump around 950.  So Fred's wrong on that score.  Nothing been "disappeared".  It's just that with more and more data the record is becoming more refined, but there are still differences in the different reconstructions - that aren't being hidden by anyone.  Click for larger image as always.

Figure 5.7 IPCC AR5 WG1 Reconstructed (a) Northern Hemisphere and (b) Southern Hemisphere, and (c) global annual temperatures during the last 2000 years. Individual reconstructions (see Appendix 5.A.1 for further information about each one) are shown as indicated in the legends, grouped by colour according to their spatial representation (red: land-only all latitudes; orange: land-only extra-tropical latitudes; light blue: land and sea extra-tropical latitudes; dark blue: land and sea all latitudes) and instrumental temperatures shown in black (HadCRUT4 land and sea, and CRUTEM4 land-only; Morice et al., 2012). All series represent anomalies (°C) from the 1881–1980 mean (horizontal dashed line) and have been smoothed with a filter that reduces variations on timescales less than ~50 years.

Fred bemoans the "good old days" when knowledge was scarce


Fred puts up a couple of drawings in a single image.  At the top of the drawing below is one of the images Fred included and at the bottom I've included a diagram from the first IPCC assessment report, published 24 years ago in 1990. This was before there were any global temperature reconstructions of the type we have today.  Fred is still living in the dim distant past.  He's getting on a bit (he's 89 years old) and can't hack this modern society or cope with new knowledge.


I don't know why Fred shifted the timescale to the left in his diagram above.  He could have left it as it was in the FAR report.  Anyway, about the Medieval Warm Anomaly, this is from FAR:
The late tenth to early thirteenth centuries (about AD 950-1250) appear to have been exceptionally warm in western Europe, Iceland and Greenland (Alexandre 1987, Lamb, 1988) This period is known as the Medieval Climatic Optimum China was, however, cold at this time (mainly in winter) but South Japan was warm (Yoshino, 1978) This period of widespread warmth is notable in that there is no evidence that it was accompanied by an increase of greenhouse gases.

In FAR (WG1), the word "medieval" appears only four times, once in the above diagram and three times in the text - and not once in the title of any reference.  In the AR5 report the word "medieval" appears 45 times including in the title of numerous references.

If you look at the top chart above and then the one below, you can see the difference between what was known in 1990 with what is known from scientific research conducted since that time. You can also tell from the text.  Compare the extract from FAR above with the following from the IPCC AR5 report (my bold italics):
For average annual Northern Hemisphere temperatures, the period 1983–2012 was very likely the warmest 30-year period of the last 800 years (high confidence) and likely the warmest 30-year period of the last 1400 years (medium confidence). This is supported by comparison of instrumental temperatures with multiple reconstructions from a variety of proxy data and statistical methods, and is consistent with AR4. Continental-scale surface temperature reconstructions show, with high confidence, multidecadal intervals during the Medieval Climate Anomaly (950 to 1250) that were in some regions as warm as in the mid-20th century and in others as warm as in the late 20th century. With high confidence, these intervals were not as synchronous across seasons and regions as the warming since the mid-20th century

You may have noticed Fred's references above were to work done in 1978, 1987 and 1988.  Fred did manage to move into the 21st century further on in his article, bypassing all the other temperature reconstructions and singling out  two authors whose work he seems to have approved from a science denying perspective.  After maligning Michael Mann and misrepresenting his early work while ignoring his later work, Fred wrote:
In actuality, we now have adequate proxy data from other sources, most particularly from Fredrick (sic) Ljungqvist and David Anderson. Their separate publications agree that there has been little if any temperature rise since about 1940! However, there was a real temperature increase between 1920 and 1940, which can be seen also in all the various proxy as well as thermometer data.

I guess Fred's not too familiar with the work of  Fredrik Ljungqvist because he misspelt his name.  Thing is, he also is not too familiar with the work of Fredrik Ljungqvist because he misrepresented it.  The following is from Ljungqvist et al (2012):
Our results show, in a comparative manner, the degree to which the various proxy types can be used to assess regional temperature variability on centennial time-scales. We conclude that during the 9th to 11th centuries there was widespread NH warmth comparable in both geographic extent and level to that of the 20th century mean. Our study also reveals that the 17th century was dominated by widespread and coherently cold anomalies representing the culmination of the LIA. Understandably, the centennial resolution of this study precludes direct comparison of past warmth to that of the last few decades. However, our results show the rate of warming from the 19th to the 20th century is clearly the largest between any two consecutive centuries in the past 1200 yr.

And does Fredrik Ljungqvist dispute the global surface temperature record in the instrumental era as Fred claimed?  I'd say not.  Here's another section of that same paper:
Analyses of instrumental data (Brohan et al., 2006) shows that the last decade of the 20th century was much warmer than the 20th century mean nearly everywhere over NH land areas with sufficient data (Fig. C1). Moreover, the first decade of the 21st century was even warmer in most locations, thus, providing evidence that the long-term, largescale, NH warming that began in the 17th century and accelerated in the 20th century has continued unabated (see Appendix C for more details).

What about David Anderson? I couldn't find any global temperature reconstructions (or hemispherical ones either) by any David Anderson - but I probably missed it.  Anyway, if it's this David Anderson he's talking about, then Fred's barking up the wrong tree.  This from a 2002 paper:
Climate reconstructions reveal unprecedented warming in the past century; however, little is known about trends in aspects such as the monsoon. 
 Incidentally, the work of Fredrik Ljungqvist is cited several times in the AR5 report.


Below is a reference to a Ljungqvist paper plus just a sample of all the published work of Michael Mann and his various co-authors, to give you some idea of just how selective is Fred Singer.  Notice his paper on the Little Ice Age and the Medieval Warm Anomaly.  I'd say he knows a lot more about this than does professional denier Fred Singer.

Notice too all the different authors and how Fred Singer singles out Michael Mann?  That's the Serengeti Strategy in action.

(Copies of Michael Mann's papers are usually available at his website.)

Ljungqvist, F. C., Paul J. Krusic, Gudrun Brattström, and Hanna S. Sundqvist. "Northern Hemisphere temperature patterns in the last 12 centuries." Climate of the Past 8, no. 1 (2012): 227-249.. doi:10.5194/cp-8-227-2012 (open access).
Mann, Michael E., and Jeffrey Park. "Global‐scale modes of surface temperature variability on interannual to century timescales." Journal of Geophysical Research: Atmospheres (1984–2012) 99, no. D12 (1994): 25819-25833.

Mann, Michael E., Raymond S. Bradley, and Malcolm K. Hughes. "Global-scale temperature patterns and climate forcing over the past six centuries." Nature 392, no. 6678 (1998): 779-787.

Mann, Michael E., and Philip D. Jones. "Global surface temperatures over the past two millennia." Geophysical Research Letters 30, no. 15 (2003).

Jones, Philip D., and Michael E. Mann. "Climate over past millennia." Reviews of Geophysics 42, no. 2 (2004): RG2002.

Mann, Michael E., Zhihua Zhang, Malcolm K. Hughes, Raymond S. Bradley, Sonya K. Miller, Scott Rutherford, and Fenbiao Ni. "Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia." Proceedings of the National Academy of Sciences 105, no. 36 (2008): 13252-13257.

Mann, Michael E., Zhihua Zhang, Scott Rutherford, Raymond S. Bradley, Malcolm K. Hughes, Drew Shindell, Caspar Ammann, Greg Faluvegi, and Fenbiao Ni. "Global signatures and dynamical origins of the Little Ice Age and Medieval Climate Anomaly." Science 326, no. 5957 (2009): 1256-1260.


From the WUWT comments


It's mostly a lot of people raging at Michael Mann, not suitable for HotWhopper. The Serengeti Strategy works for WUWT dismissives but it no longer works with the general public, from what I can see.  There are a couple of choice comments that I can print though.



Steve from Rockwood says the recent warming "doesn't look natural".  Well, duh!
January 21, 2014 at 3:25 pm
Just looking at Mann’s reconstruction – it doesn’t look natural. The Earth has been cooling for 1,000 years and suddenly warms out of control? It can’t be real. If he had left in the LIA and MWP maybe I would have believed him.

Perennially Puzzled Bob Tisdale must have a soft spot for Fred, because he accepts Fred's lies - though he couldn't swallow some of Don Easterbrook's lies yesterday. He says:
January 21, 2014 at 3:30 pm
Thanks, Fred. Nicely done.

173 comments:

  1. One should also remember that the IPCC FAR temperature reconstruction (based on the work of Hubert Lamb in the 1980's) was for Central England. It was not really global.

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    1. I've read that elsewhere, Lars. However the chart is clearly labeled "global" and the text I copied discusses different parts of the world.

      Whatever, it was not based on anything like the proxies that have been collected by researchers over the past 24 years - in the variety nor the geographic spread.

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    2. Briffa et al 2009 explores the origin of the figure in Appendix A.

      "In summary, we show that the curve used by IPCC (1990) was
      locally representative (nominally of Central England) and not
      global, and was referred to at the time with the word ‘schematic’."

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    3. Thanks very much, Lars. Something more I've learnt today. I'll bookmark that for future reference.

      Maybe the fake sceptics weren't as diligent back then as they are now or they would surely have shouted from the rooftops that the IPCC made an error :D

      (Not that I'm aware of a fake sceptic ever picking up an error in an IPCC report. The only errors I'm aware of were picked up by scientists.)

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  2. The MWP was real, and it was global in nature. Your "slight bump" is significant in the Pacific Ocean near the equator. Rosenthal et al. Proxy data does not have the accuracy or precision as that of the satellite data, so one can't expect perfect synchronization from one form of proxy data to another. Mr. Mann discovered this to his great detriment.

    Anyone that believes that the MWP was "regional" or "slight" is biased and has an agenda. The thing is that being scientifically honest about the MWP doesn't really affect the case for or against CAGW. But being dishonest about it proves bias.

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    1. Rosenthal13 was an interesting paper. Thanks for reminding me about it. I wonder why Fred didn't mention it. Surely he could have twisted it somehow to suit his fake message.

      I see you are very certain about what you think. Being firm in one's convictions can be good. Being firmer than the evidence warrants - not so good.

      I agree the evidence shows surface warming in different places between around 950 and 1250. However from all the studies I've looked at, including Rosenthal13, it's not warming everywhere at the same time.

      There were some things that were puzzling about Rosenthal, one being their chart of IWT from the Makassar Straits (Figure 3), which doesn't seem consistent with MWP warming. It shows not much change in temp from 2000 years to 1000 years ago and then a decline. I'm probably missing something there because the authors are obviously convinced.

      Michael Mann raised some interesting points about the paper, too.

      Then there's PAGES 2k, which while not fully global in coverage is making quite a bit of headway. Results so far show that not everywhere warmed at the same time.

      Rosenthal13 was just one region. They argued that it reflected temperatures in a much wider area because of the ocean currents. But it's probably best to wait to see if other studies can confirm their conclusions. Like they say at one point:

      With no additional IWT records, it is difficult to assess the global extent of the trends we have reconstructed.

      Still, I'm glad to see you've found one scientific paper that you think fits your preconceptions, even though it's patently obvious you reject the 97% of papers relating to climate because they don't fit your preconceptions.

      (Anonymous' use of the acronym CAGW gave her or him away, in case a reader was wondering. It's only used by science deniers.)

      Here's a link to Rosenthal 13 (paywalled)

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    2. This comment has been removed by a blog administrator.

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    3. Ah the MWP. Nothing stirs the hornets nest of deniers like it. It's like a bugle call or whistle call to signal the army to start a full frontal assault.

      Oh, and the Rosenthal paper. I've seen deniers use that in defence of the MWP, but they never seem to get to this bit.

      "This seemingly small increase occurred an order of magnitude faster than suggested by the gradual change during the last 10,000 years thereby providing another indication for global warming."
      http://www.carbonbrief.org/blog/2013/10/10,000-year-record-shows-pacific-depths-warming-fast/

      Funny that.

      It has only further reinforced that deniers are never the sharpest tool in the shed. Also yes, the use of the term CAGW is a signature tell of deniers. It tries to paint those who accept the science as a bunch of 'the end is nigh', 'we're all gonna burn', 'It's all doom and gloom' preppers preparing like some cult for the end of the world. Quite disingenuous straw man really.

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    4. The mediæval warm period was at least Eurasian in extent if the Japanese cherry blossom festival is an indication. Those data however show that it was only 'mildly' warm in east Asia compared to today, and that the current warming trajectory is much steeper. To that end "slight" is not inappropriate, and as Sou points out there is evidence that the warmth was not synchronously global.

      If the last century's warming continues on the same path for another century, we will most certainly be in "catastrophic" territory, with respect to local/regional climate events and to biodiversity impacts. If the warming continues beyond that there will be grave consequences for the whole of humanity, and for much of the biosphere.

      Just because you won't be here to see 2-3+ ºC of warming doesn't mean that it won't be catastrophic. It will be, and I for one am completely unperturbed at framing it as such. What I am concerned about is the legacy that we are leaving for the future.

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    5. On the matter of the anonymous claim that "[t]he hockey stick was a fraud upon the public", that's an outright lie or at the very least a complete ignorance of scientific evidence.

      Boreholes, speleothems, glacier structure, ice cores, coral, and lake sediment - in addition to the cherry blossom burst - all describe a hockey stick. And not a tree ring in sight.

      Is anonymous claiming that all of these hockey sticks are also fraudulent? No wonder he's too scared to put a name to his post.

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    6. Oh, and a postscript - a warmer MWP directly implies a greater climate sensitivity to carbon dioxide, with more serious implications for the contemporary warming...

      Just sayin'.

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    7. This comment has been removed by a blog administrator.

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    8. HotWhopper does not allow libellous and false accusations. This is your first warning, Anonymous.

      http://blog.hotwhopper.com/p/comment-policy.html

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    9. Aw Sou, you're too quick - I wanted to see what anonymous said on January 23, 2014 at 1:58 AM!

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    10. Bernard, as well as the unprintable bit, Anonymous' comment did include a question to you:

      Bernard, Did someone mention tree rings? Or just the proxy data?

      I guess Anonymous didn't bother reading either my article or the archived WUWT article, because if so, he or she would have read in the very first quote from Fred up top:

      the Hockeystick is based on an analysis of so-called proxy data, mostly tree rings

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    11. Ah, so he's one of those deniers, where the Stupid is congenital and demonstrating it to the world comes naturally...

      Explains why he couldn't write his name.

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    12. Bernard was talking to me, and I made no mention of "tree ring" data when I was discussing the "proxy data." What was the libel/false accusation?

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    13. Folks [sic] really are dumb [sic] where he comes from.

      Anonymous, you said in the context of Mann's original tree-ring hockey stick that "[t]he hockey stick was a fraud upon the public". In reply I pointed you to half a dozen different and completely independent proxies that had nothing to do with tree rings and that describe hockey sticks of the same trajectory as Mann's.

      I mentioned tree rings for two reasons - first, as Sou explained, they were raised in the original post, and second, because they were the proxie used to obtain the hockey stick that you claimed was a fraud. So my point remains: the same hockey is obtained using completely independent proxies, so are these proxies also "fraudulent"? And if they are not, why then is Mann's hockey stick "fraudulent"?

      And yes, accusing Michael Mann of fraud is a false accusation and libelous.

      Now, think carefully about your answer because if you persist in making patently false and libellous statements Sou's just going to kick your arse and remove your bilge yet again.

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    14. Sou. Any chance of disallowing the Anonymous comment. I know, I know all deniers sound the same but here they really do - very confusing.

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    15. Mike I've looked into the matter and it's not possible without requiring all commenters to register with open id or wordpress or google or similar. It would mean an extra hurdle people have to jump and I don't want that.

      The best I can do is ask nicely, which I have :) I'm not going to delete comments posted as "Anonymous". Most people are being pretty good about this. Over time I expect more and more people will use a name of their own choosing.

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    16. This comment has been removed by a blog administrator.

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    17. Given that Singer has been involved in denying that smoking causes cancer, denying that secondary smoke causes cancer, denying that CFCs cause ozone degradation, and essentially any other cause someone will pay him to promote, there's very little doubt that he's lying for all he's worth.

      Bernard isn't going on a tangent. Mann's various paleoclimate reconstructions are based on tree-ring proxies. If they are fraudulent, like you claim, then why do other proxies using totally different mechanisms, by different authors, match up? Are all paleoclimate reconstructions fraudulent, in your view?

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    18. The tangent was not the tree ring post, it was the insult post. Proxy data if collected, assembled and analyzed without bias is certainly not fraudulent. It is the best that we can do. But we must look at it knowing its inherent flaws. It is not the same as the instrumental record. And, it is funny that many read Rosenthal thinking that it is.

      I am still interested to know what, if any, science training Bernard has.

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    19. This comment has been removed by the author.

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    20. Why are you interested in Bernard's "training"? (sounds a bit like what one does with a circus animal). Perhaps you are thinking of getting some "training" yourself?

      (I generally find the experience and knowledge of scientists more interesting than their education history. The scientific expertise of different people who comment here spans quite a wide range of subject matter relevant to climate and enriches HW a great deal, but isn't usually the subject of my articles.)

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    21. Just wondering based on his posting this:

      "Ah, so he's one of those deniers, where the Stupid is congenital and demonstrating it to the world comes naturally...

      Explains why he couldn't write his name."

      Apparently it is a perfectly allowable post on your blog despite your stated rules. I supposed my even talking about his worthless post also violates your rules and will cause this to be deleted?

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    22. "I am still interested to know what, if any, science training Bernard has.

      "Still"? You haven't previously raised this straw man, so why the compounding straw man?

      FYI, undergraduate Bachelor (science), postgraduate Diploma (education), postgraduate Bachelor (psychology, philosophy/logic, computing, education), Masters (science), PhD (science).

      Oh, and I've worked in scientific (biomedical then ecological) research and tertiary education for three decades, if that makes a difference.

      Now, what "training" have your had?

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    23. Anonymous, I fail to see what that has to do with Bernard's scientific expertise (which far exceeds yours). I allowed that comment because, although the bit you quoted from it is borderline, it followed your (now deleted) comment which included a false allegation about a scientist, which was way beyond the pale.

      I can tell from your comments that you have a great deal of difficulty with understanding what most HW readers would regard as obvious. I suggest you lurk for a while (ie read more before contributing) so you can get a better feel for the norms of behaviour expected and tolerated on HW, as well as, hopefully, getting a better appreciation of science.

      See Rule 3

      Also, Bernard's post was far from worthless. In that comment Bernard highlighted the silliness of people who dispute one "hockey stick" while ignoring all the others.

      As for tone trolling - yes, it does violate the rules, but I'll not delete your comment because you are clearly having trouble understanding the rules. Any other comments from you in a similar vein will be deleted, however.

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    24. Anonymous with the glass jaw.

      You libellously accused Michael Mann of fraud - a scientist of integrity and renown no matter the campaign against him by the denialist establishment. You offer no testable evidence to support your claims of fraud, and indeed you are even unable to deal with the very basic questions put to you above regarding the science and the reputation that you presume to denigrate.

      You, on the other hand, have demonstrably participated in besmirching the name of a well-know researcher and also shown yourself to be unable to handle basic facts of the climatological science. If you as a completely anonymous non-entity find it distressing and unacceptable to be called on your poor behaviour, how do you think your own behaviour toward Mann shapes by comparison?

      Hypocrisy, much?


      [Apparently Recaptcha is taking a stab at your name - "rsolsowa matthew". Perhaps we should call you 'Matthew' in order to expedite further communication...]

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    25. Bernard J. said:

      "You libellously accused Michael Mann of fraud - a scientist of integrity and renown no matter the campaign against him by the denialist establishment."

      Which turns out to be very topical. Breaking:

      http://rabett.blogspot.ie/2014/01/mann-vs-steyn-lurches-forward.html

      Steyn and the NRO took it for granted that the new judge on the case would be more sympathetic to their efforts for dismissal than the previous judge. They were very wrong on that score. And so, class, the word for today is: Schadenfreude.

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    26. As Rick Steyn said:

      The defendants and their support subculture have been throwing around this sort of casually malicious and intellectually sloppy defamation of climate scientists so much, for so long, that perhaps they're surprised to learn they can be busted for it.

      Busted in court, not just have their comment deleted from HW!

      http://www.climatesciencewatch.org/2014/01/23/dc-judge-denies-motion-to-dismiss-mann-defamation-complaint/

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    27. Oops, getting my names mixed up. Meant to say Rick Piltz. Mark Steyn is being sued - and his lawyers have deserted him. He's now representing himself according to the Washington Post. (Sorry for the link, but it's interesting to read the conservative opinion, too.)

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    28. Bernard, very cool on your science background. Where did you go to school, and in what areas of science were your majors?

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  3. I don't see any conflict between what Singer wrote and your quote from the Ljungqvist paper.

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    1. Fredrik Ljungqvist acknowledges the instrumental record that shows the sudden and rapid rise in surface temperatures from the 1970s. Fred Singer claims the contrary. He claimed the Fredrik Ljungqvist thought has been little if any temperature rise since about 1940!

      Fred Singer can put one over deniers - that's easy, because they "don't see any conflict" if they shut their eyes tight and refuse to read published papers.

      Now whether or not Fredrik Ljungqvist is happy to be misrepresented by Fred Singer is something I'm not able to answer. I'd have thought not.

      Fred isn't the only one to try to play these sort of tricks with Fredrik Ljungqvist's work.

      http://tamino.wordpress.com/2010/09/28/vindication/

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    2. About that MWP having global impacts, besides the warning implying a higher climate sensitivity as Bernard pointed out. During that same period the folks living in Southwester USA were having a heck of a tough time due to extended drought.

      "A 1,200-year perspective of 21st century drought in southwestern North America"
      Woodhouse, Mekob, MacDonald, Stahled, Cook
      http://www.pnas.org/content/107/50/21283.full
      ~ ~ ~ ~ ~ ~ ~

      So, besides no climatologist ever 'ignoring' the MWP to begin with - and considering the evidence of droughts in SW America, parts of South America and China - I'm not sure what the denialist's point is.

      Well yes I am, it's another exquisitely crafted non sequitur - jewels of disinformation - intent on distracting attention away from understanding the real world.
      ~ ~ ~

      Climate has always fluctuated, driven by a variety "forcings" - the bottom line remains - today, the forcing that is driving the current trend in warming is greenhouse gases, specifically a 33% increase in our planet's atmospheric insulating medium, and getting growing very rapidly.
      ~ ~ ~ ~ ~ ~ ~

      >>> Does any one have thoughts on what it is that denialists find reassuring about the MWP ?

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  4. Of course, Fred lied to the IRS, claiming a Chairman dead for 2 years, so why not to everybody else?

    Fred is still a Flat-Earther, along with anonymous.
    http://scienceblogs.com/stoat/2012/10/10/adoration-of-the-lamb/
    http://scienceblogs.com/stoat/2012/10/08/more-use-and-abuse-of-ipcc-1990-fig-7-1c/
    http://www.shapingtomorrowsworld.org/news.php?p=4&t=390&&n=167#2069

    FIg7.1(c) is one of the most abused graphs in history, especially because people claim a graph came from the FAR, but show one that came from somewhere else, probing they didn're read (or have) the FAR and read the caveats around it. In academe, this is called *false citation*. Fred (and AVery) had an especially ludicrous version of it in their 2007 book, where they claimed it was a specific figure from the SAR, not the FAR. Such include Joihn Daly, McIntyre, McKitrick, the Wall Street Jounral, and many others, including Inhofe(2012).

    Fred helped manufacture the whole hockey-stick attack, among other tiings by pre-publishing David Deming's dog astrology journal essay on Crichton, that had the "we have to great rid of the MWP" pseudo-quote.

    McIntyre picked that up and used it, as well as a false-citation version of the IPCC Fig 7.1(c). That was identical to John Daly's, but Tom Curtis later asked McdI where he got it, and McI had forgotten ... but it was not the FAR, although the curve is correct ...


    As for McIntyre & McKitrick(2005), that paper at its core used *fraudulent* statistics, the easiest of which to understand is the 100:1 cherry-pick.
    See Deep Climate and <a href="http://moyhu.blogspot.com/2011/06/effect-of-selection-in-wegman-report.html.</a>, as that shows people can't b bothe4red even to stick a pseudonym in.l.



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    1. Sorry, got grabbed to go out. That last was supposed tp say:
      Moyhu

      People might do as I do, never ever read Anonymous(es), since they can't be bothered even to enter a pseudonym, even when the posting directions ask nicely. Using anonymous just adds noise to a discussion, especially if reviewed later ... but that may be the goal.

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  5. And by happy coincidence, here's another hockey stick, this time from Tibetan tree ring proxies (Zhang et al. 2014). H/T to Richard Telford, who also points out that this is yet another paleoclimate study that fails to substantiate a claimed solar fingerprint in paleoclimate variability.

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  6. I'm curious if any of you folks have thoughts on what it is that denialists find reassuring about the MWP ? How are they rationalizing the thing?
    ~ ~ ~ ~ ~ ~ ~

    ... exquisitely crafted non sequiturs - jewels of disinformation - intent on distracting attention away from understanding the real world.


    Maybe more than the science,
    it's time to spend more time focusing on
    the process that makes these "talking points" such successful tools.


    . . . and perhaps even beginning to call the audience itself to task for accepting transparently fraudulent arguments.

    Because that's the unspoken monster in the room -
    Most people WANT to hear these false messages of reassurance.
    They rather get all lathered up and hateful, then reexamine their own assumptions.

    God forbid self-skepticism.

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    1. "I'm curious if any of you folks have thoughts on what it is that denialists find reassuring about the MWP ? How are they rationalizing the thing?"

      I think there's a legitimate point there. If the MWP is real, it implies that natural variability could be high enough to produce the current warming, falsifying the idea that current warming was caused by humans and lowering the CO2 equilibrium sensitivity.

      This pretty much relies on there being unknown mechanisms for large variability, and plays well into the meme of the "uncertainty monster": "We don't understand climate well enough to say what causes climate change or what the effects of CO2 are".

      OTOH, if the MWP as interpreted by Watts et al is not real, and natural (internal) variability is low, one of the best objections to AGW theory is taken away. It'd mean that we are already causing global warming, and it's substantial.

      Delete
    2. I'm not sure about that, Windchasers. Doesn't it depend on what would have caused global warming. If it was just a bit extra solar energy, for example, and it really did cause a bigger hike in global temperatures than appears to be the case, then wouldn't that be an argument for higher climate sensitivity?

      Anyway, just because in the past global temperatures had ups and downs (eg the Holocene Optimum, glacials and interglacials) doesn't negate the greenhouse effect in any way. (Glacials and interglacials are the greenhouse effect in action.) Prior cases of global warming say nothing about what is causing the current rapid warming - which is GHGs. One has to go to causes of prior ups and downs of temperature, and GHGs generally play a part in one form or another depending on the duration of the episode (as a forcing or feedback).

      Delete
    3. Windchasers

      I think there's a legitimate point there. If the MWP is real, it implies that natural variability could be high enough to produce the current warming, falsifying the idea that current warming was caused by humans and lowering the CO2 equilibrium sensitivity.

      No. What Sou said. You cannot artificially separate natural variability and forced climate response. *Both* are an indication of the climate system sensitivity to radiative perturbation. If the climate system were insensitive, then we'd get a low S to CO2 and no millennial-scale variability to speak of.

      Whereas in fact what we actually get is a fair bit of regional and somewhat antiphased hemispheric variability but no global and synchronous MCA or LIA. Forcing changes seem to be mostly volcanic aerosols and solar. This sits quite happily with an ECS/2xCO2 of ~3C.

      Delete
    4. One more time:
      1) Neither the MWP (such as it was, as the peaks weren't synchronous or worldwide) nor the LIA were entirely natural.

      2) Law Dome CO2, 2000 years.

      3) The big drop into 1600AD was almost certainly caused mostly by the 50Mperson die-off in Americas from disease, followed by the Maunder Minimum half a century later, during a period when volcanoes happened to be more active ... Put all that together: LIA = part human, multi-decadal GHG drop, plus natural volcanoes + solar.

      4) But CO2 was *higher* during the MWP (and somewhat during the earlier Roman era) because of CO2 from human agriculture/tree cutting ~8000BP, with CH4 higher via rice paddies from ~5000BP or so. Over last 2000 years, at least some of the CO2 jiggles correlate well with plagues, and CH4 jiggles with wars, too, as when Mongol invaders purposefully wrecked numerous Chinese rice paddies.

      Ruddiman, etal (2011)
      FIg 2.B, p 3. (top scale) and Fig 6, p.7: if our interglacial were "typical", our CO2 "should" have been down around 250-255ppm by 1000AD, instead of being over 280ppm. CH4 was higher than natural as well.

      Sapart, et al(2012)

      For a coherent, well-written explanation, see Earth Transformed, a beautiful book with many illustrations, well worth buying or getting your library to have, or for $28 you can use e-book version.

      Really, over the last 10 years, much research has been done on the Holocene:
      a) Of course there is natural variation, solar jiggles, volcanoes, etc.

      b) Some millennial-scale trends are natural, such as Milankovitch orbital changes to solar iinsolation patterns.

      c) Some millennial trends were human, from deforestration/agriculture, rice paddies, cows .. which happened because early farmers had much bigger acreage footprints than current ones, per person fed.

      d) Some multi-decadal or century-scale jiggles in CH4 and CO2 are human, from wars or plagues, but only after there got to be enough humans for these effects..

      Delete
  7. I note that the Anonymous has gone quiet after his initial rapid burst of factoid assertion. Could it be that he recognises that his spray was ill-advised and indicative of an unpracticed mind? That following on from some of the evidence that has been posted here, he regrets his error and wishes for the intellectual equivalent of dapoxetine?

    Nah...

    He simply wanted to quickly spill his canard-of-the-day enough times that it appeared to be credible simply because it was asserted in multiplicity. Job done, responses irrelevant, even though they humiliatingly deconstruct his nonsense.

    He probably has a smaller-than-average IQ too...

    And yes, Anonymous, I am mocking you. Yourmodus operandi indicates that you weren't interested in discussing fact, or in supporting your argument with evidence, so you deserve nothing but a contemputous pointer to your failure to perform.


    [I'm sure that Recaptcha is sentient... "masculine sohemer"]

    ReplyDelete
    Replies
    1. Bernard,

      I made the point that the MWP was real and global in nature. You posted nothing of consequence to refute that point. Did you want to discuss the global nature of the MWP? If so, take a position and post some evidence.

      The rest of your comments were just too boring to warrant a reply.

      By the way, you are losing the argument. CO2 is good for the planet. Humans will continue to increase the amount of CO2 emitted, and there is absolutely nothing you can do about it. Just watch. Year after year after year, more CO2 will be emitted. Nothing bad will happen beyond weather events that have always been happening. There will be no "climate refugees," and world agricultural output will continue to rise year after year. And, the planet will continue to green year after year after year. Your grandchildren will mock you for your attempts to stifle the greatest civilization in human history.

      Delete
    2. Dear Anon.

      By the way, you are losing the argument.

      No, he isn't, because you argue from ignorance and by assertion - logical fallacies both - so you have lost before you even begin.

      There is no evidence whatsoever supporting the claims that:

      - The MCA was global and synchronous and as warm as or warmer than the present. There is lots of evidence that it wasn't.

      - There is no evidence that "nothing bad will happen" and lots of evidence that the rapid rate of warming will push a huge swathe of the biosphere faster than it can adapt, resulting in mass extinctions - and a sharp fall in global agricultural productivity when there will be ~2 billion more people on the planet to feed.

      Delete
    3. I made the point that the MWP was real and global in nature. You posted nothing of consequence to refute that point. Did you want to discuss the global nature of the MWP? If so, take a position and post some evidence.

      Please read Sou's replies to your comments properly. You will find, amongst other things, a link to the PAGES 2k results, which found that there was no synchronous and global MCA or indeed LIA.

      PAGES 2k Consortium (2013) Continental-scale temperature variability during the past two millennia

      Past global climate changes had strong regional expression. To elucidate their spatio-temporal pattern, we reconstructed past temperatures for seven continental-scale regions during the past one to two millennia. The most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century. At multi-decadal to centennial scales, temperature variability shows distinctly different regional patterns, with more similarity within each hemisphere than between them. There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century. The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions. Recent warming reversed the long-term cooling; during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years.


      Delete
    4. "Just watch."

      Anonymous I have to say that this seems to be a bit of a "you have been warned" statement, judging from the substance of your post.

      To the extent that I understand any thing about 'Climate Science' - which is very little - It is also an assertion without any supporting evidence in "highly contested space"; it also runs in the face of what is widely accepted by the experts (for want of a better term). (You should remember that for us non-experts, an expert is somebody professionally engaged in a particular field. It may not make them right - but if you wish to attack them, then some coherent evidence is required).

      Now it is indeed possible that you are correct, but I do have to point out that it is not only an assertion - and without supporting evidence or citations. But, confusingly, you manage to do this in a post where the first paragraph asks another poster to "take a position and post some evidence".

      You have managed "to take a position", but seem to wish to rely on a "just watch" without any supporting evidence.

      But that means nothing. Because time will indeed resolve this dispute. For everyone.

      Do you not see how it might be reasonably expected of you to provide at least a bit of evidence for your (exceedingly positive and optimistic) assertions?

      Anon123

      Delete
    5. BBD,

      Yes, he is, and you are. The funny thing is that it is you that is arguing by assertion. I have cited evidence, not the least of which is Rosenthal. Go check out the video that they made explaining how the MWP was global and warmer than now. Hey, but if you change the name of the MWP to the MCA, maybe it will go away.

      There is also no reason to think that we couldn't easily feed 2 billion more people. Each year, agricultural output goes up, and the amount of needed farmland goes down.

      Either way, you will be proven wrong. Massive growth in CO2 emissions will happen, and it can't be stopped.

      Delete
    6. Dear Anon.

      The funny thing is that it is you that is arguing by assertion.

      No, I referenced PAGES 2k and went to the trouble of quoting from it. You have gone to the trouble of ignoring what was written and making a false claim about lack of evidence, which is really rather blatant of you.

      * * *
      Rosenthal et al. estimated Pacific Ocean heat content from sediment cores taken in the tropical Indo-Pacific. Extrapolating from this to the entire basin is problematic; extrapolating to global scale much more so, not least because the claim that the MCA was synchronous, global and warmer than the present is contradicted by the land surface temperature reconstructions.

      Bear in mind that "the Pacific" is subject to spatial variability in OHC. The tropical Indo-Pacific especially so, as this area becomes anomalously warm during La Nina conditions. Trouet et al. (2009) and Mann et al. (2009) present evidence that anomalously persistent La Nina conditions occurred during the MCA. So the tropical Indo-Pacific was anomalously warm. This *does not* constitute robust evidence that the entire climate system was anomalously warm.

      So I think this needs to be treated with caution. That said, Rosenthal et al. is an interesting study and I look forward to further developments with interest.


      Delete
    7. Anon.

      I should have included this in my previous comment. If you are actually interested in learning about the MCA, then I recommend Diaz et al.'s 2011 review paper Spatial and temporal characteristics of climate in medieval times revisited .

      * * *

      Massive growth in CO2 emissions will happen, and it can't be stopped.

      This has nothing to do with the science, obviously. It is a policy discussion which introduces the debate over emissions reductions in developed economies vs emissions increases in developing economies.

      Arguing by assertion that "nothing can be done" is, of course, a logical fallacy. Better to suggest that the task of reducing global emissions will be extremely difficult, partially unsuccessful but absolutely necessary all the same.

      Delete
    8. For the record, you posted your "evidence" after I began replying to your first post which contained none. As far as the massive growth in CO2 emissions, it does not have anything to do with the science except that it will supply the proof. I was going to read your Diaz paper until I saw it was co-authored by Michael Mann. I don't trust him.

      Delete
    9. For the record, you posted your "evidence" after I began replying to your first post which contained none.

      So what about the evidence?

      As far as the massive growth in CO2 emissions, it does not have anything to do with the science except that it will supply the proof.

      Argument from assertion is a logical fallacy.

      I was going to read your Diaz paper until I saw it was co-authored by Michael Mann. I don't trust him.

      So according to you, Henry F. Diaz, Ricardo Trigo, Malcolm K. Hughes, Michael E. Mann, Elena Xoplaki and David Barriopedro are guilty of scientific misconduct, along with every author of every paper referenced in Diaz et al.

      This is a conspiracy theory and it is as risible as they always are. It is also evidence denial. You asked for referenced support, and when it is provided you either ignore it or claim that it is the product of collaborative scientific misconduct.

      Yet here you are, expecting to be taken seriously.


      Delete
    10. To Anonymous:
      I was going to read your Diaz paper until I saw...etc

      Since you are not familiar enough with science to be able to judge a paper on its merits, you have no business commenting on science at all.

      Any more comments from you where you make assertions about "what the science says" will be removed - maybe not immediately because I'm tied up elsewhere at the moment.

      Other commenters note that this may affect your replies because of blogger idiosyncrasies.

      That's all.

      Delete
    11. "CO2 is good for the planet."

      A generic statement that is untrue.

      Ask the marine species vulnerable to ocean acidification. Ask the species and ecosystems where C4 photosynthesis in competition with C3 photosynthesis plays a key role, and ask human populations whose commerce/diet what they think about future threats to the C4 crop viability in the face of C3 weeds.

      Ask plants whose mycorrhizæ and/or other soil symbionts will be directly and/or indirectly adversely affected whether increased CO2 is "good" for them.

      Ask species, ecosystems and human populations whether the increase in heat extremes, and in storm, flooding and drought extremes resulting from CO2-caused warming is "good" for them.

      Aske the humans and the flora and fauna who are naïve to exotic diseases whether infections introduced on the back of warming is "good" for them.

      "Year after year after year, more CO2 will be emitted. Nothing bad will happen beyond weather events that have always been happening."

      Assertion in direct contradiction to whole disciplines of scientific literature. Where is your evidence?

      "Your grandchildren will mock you for your attempts to stifle the greatest civilization in human history."

      My grandchildren will know that I did my best to stop the fouling of their planet with a 'greenhouse' gas that has the potential to completely destroy Western civilisation, and that will certainly do so in concert with other sequelæ of this civilisation - including but not restricted to resource depletion, and species and ecosystem destruction through over-extraction, exotic species translocation and non-CO2 forms of pollution - unless humans give over their incredible selfishness and steer away from the most profound tragedy of the commons ever.

      Delete
    12. What's up, Anonymous? Are these "good" things sticking in your craw?

      Delete
  8. Ok BBD, I read your evidence. Did you think that it contradicted my assertion that the MWP was real and global? It doesn't.

    ReplyDelete
    Replies
    1. Let's not play silly buggers, Anon.

      I'm puzzled by this claim.

      Where does Diaz11 say that the MCA was globally synchronous and produced a global average temperature equal to or higher than the present GAT?

      Please provide quotations in your response so we can clarify this.

      Delete
    2. BBD, Where does it say it was not real or global in nature?

      Please provide quotations in your response, so we can clarify this.

      Delete
    3. nyah nyah nyah.

      No - you are

      But she did it first

      Your mum

      ...and other childish comebacks.

      Delete
    4. For Pete's sake, even Wikipedia (shudder) says that the Mediæval Warm Peroid wasn't global. And with more than a little irony it also indicates that it was Michael Mann who published on the fact that in some regions the MWP manifested higher temperatures than the last century has globally...

      It's no surprise that Anonymous to too afraid to append even a pseudonym to his errant nonsense.

      Delete
    5. Yeah, yeah, I know - arrant.

      Although "errant" works just as well...

      Delete
    6. Oh, well then, if Wikipedia says it wasn't global, then case closed. I guess Rosenthal and Linsley don't know what he is talking about.

      https://www.youtube.com/watch?v=ta-0mo7UjUE&feature=share&list=UUdeDjsgVdGBoqEuT2d70YbQ

      You will also note that they are comparing the proxy data to the instrumental record when they talk about recent warming being "faster." They come right out and state that with the resolution of the proxy data being about a century, it would be very possible that the sediments just didn't record similar warmings in the past.

      Delete
    7. In the interview, Linsley points out that the MWP shows up in the surface ocean and the deep core data 1000 meters down. And temps in the deep ocean were .65 C warmer than now.

      "It is clearly showing that these events are global." Linsley.

      Delete
    8. Anon.

      You claimed that Diaz et al. supports your contentions about the MCA:

      Ok BBD, I read your evidence [Diaz 11]. Did you think that it contradicted my assertion that the MWP was real and global? It doesn't.

      Yes, it does.

      Either concede the point (and thereby admit that you were lying) or illustrate with relevant quotes from Diaz et al. where it supports your claim that the MCA was global and synchronous.

      * * *

      I pointed out a serious issue with Rosenthal et al. above and you have utterly blanked it. Why?

      Please address my point directly. Your behaviour on this thread is becoming problematic.

      Delete
    9. Since you are dishonest, I will have to be more precise in what I write. So, an edit:

      "Either concede the point (and thereby admit that you were lying) or illustrate with relevant quotes from Diaz et al. how it supports your claim that the MCA was a period of global and synchronous warmth that matched or exceeded that of the present."

      Delete
    10. BBD, you are making a third grade error in logic. I said that Diaz does not contradict my assertion that the MWP was real and global. That does not mean it supports it. The theory of gravity does not contradict my assertion, but it doesn't support it either. The truth of the matter is that Diaz is irrelevant. See how logic works?

      Delete
    11. No. I see an evasive and dishonest troll who made a false claim about Diaz et al. and now refuses to admit that the claim was false.

      Delete
    12. The truth of the matter is that Diaz is irrelevant.

      No, Diaz falsifies you claim that the MCA was global, synchronous and as warm as or warmer than the present.

      Admit this, please.

      Delete
    13. Not only does Diaz not falsify the claim that the MWP was real and global, it doesn't even purport to. The closest it comes to such is to say "Paleodata from the Southern Hemisphere are generally too sparse to draw reliable conclusions about overall temperatures in medieval time (Jones et al. 2009)."

      Delete
    14. Sou writes "Since you are not familiar enough with science to be able to judge a paper on its merits, you have no business commenting on science at all."

      With respect, how does my unwillingness to read every paper cited by the comments of this blog have anything to do with my ability to judge a scientific paper? If you honestly review the comments, you will see that I am one of the few here that can, in fact, judge a scientific paper on its merits.

      My premise from the beginning has been that the MWP was real and global. Then I added that there is evidence that it was warmer than today. I even qualified those statements by stating that neither of them prove that we aren't harming the planet.

      In support of my assertions, I have cited relevant, peer reviewed, respected evidence that has not been refuted by anyone here.

      So ban me from your little blog if you like. I will find some way to go on with my life. But such banning says much more about your ability to discuss science than it does mine.

      Delete
    15. "Oh, well then, if Wikipedia says it wasn't global, then case closed."

      You misrepresent my point by taking advantage of Wikipedia's dubious reputation. My point was not that it must be true because it's on Wikipedia but rather that for all of the caveats that go along with referencing the easily-accessible Wikipedia, the entry for the mediæval warm period summarises the scientific literature fairly effectively, and directs the interested reader to a decent starting point of primary references that support the conclusion that the MWP was not synchronously global.

      Check it out. There's a good starting point of such references, covering many regions of the globe. A seriously genuine person would read some of these before making patently inaccurate statements but then, accuracy is not the aim of your narrative, is it?

      Delete
    16. 5) Parts of the tropics such as the equatorial eastern Pacific may have been cooler than recent decades, indicating a La Niña–like state during some periods of the MCA (Cobb et al. 2003; see also Graham et al. 2007; Mann et al. 2009).

      You missed this bit. The MCA was spatially heterogeneous. Not globally, synchronously as warm or warmer than the present. I also referenced PAGES2k which *post-dates* Diaz et al. Go back, and read the quoted section again. It is unequivocal. There was no global, synchronous medieval "warm period".

      Let's go back to Diaz et al:

      While there is evidence of medieval warmth, its spatial extent does not appear to be as geographically uniform as the warming seen during recent decades (Figs. 1 and 2). Based on the most recent MCA reconstruction (Fig. 2 in Mann et al. 2009), relative to a modern reference period (1961–90), the MCA was found to be warmer than the late twentieth century over ~1/3 of the equivalent global area in the reconstruction, but colder than the late twentieth century (post-1950s) over ~2/3 of the globe. Relative to an early twentieth-century 50-yr baseline (1900–49), the MCA was reconstructed to be warmer than that baseline for ~2/3 of the globe and colder than ~1/3. Therefore, the balance of evidence does not point to a high medieval period (A.D. ~1000–1300) in the Northern Hemisphere or the globe as a whole that was as warm as or warmer than the post-1970 period.

      Delete
    17. If you honestly review the comments, you will see that I am one of the few here that can, in fact, judge a scientific paper on its merits.

      Not true. You missed the problems with Rosenthal et al. and you don't appear to have understood Diaz et al. at all. I also notice that you refuse to even acknowledge the issue with Rosenthal that I pointed out to you above. That's intellectual dishonesty.

      Delete
    18. And Anonymous, you have not responded to the fact that any insistence that the MWP was warmer than the science indicates means that the equlibrium climate sensitivity to increasing carbon dioxide is greater than is otherwise indicated.

      Oh, and during your (apparently) wide reading did you conclude that Moberg et al (2005) demonstrate that the MWP was warmer than the current heating event?

      Also, are you going to offer your bona fides after having demanded them of others?

      You need to tidy your house.

      Delete
    19. "With respect, how does my unwillingness to read every paper cited by the comments of this blog have anything to do with my ability to judge a scientific paper? If you honestly review the comments, you will see that I am one of the few here that can, in fact, judge a scientific paper on its merits."

      Don't read all of them then. Just stick with those that BBD has raised, and quote data and analyses from them that support your position and refute the converse.

      Looking over your posts here you lack of reference to actual data to support your claim is quite conspicuous. It leads one to wonder just what it is that you're relying upon to arrive at your conclusions...

      Delete
    20. "may have been cooler?" "it does not appear to be as geographically uniform..." You take those comments to disprove that the MWP was real and global in nature?

      Very weak BBD. Very weak indeed.

      Delete
    21. Bernard writes "And Anonymous, you have not responded to the fact that any insistence that the MWP was warmer than the science indicates means that the equlibrium climate sensitivity to increasing carbon dioxide is greater than is otherwise indicated."

      Why must I respond to that? What does it have to do with the issue of whether the MWP was real and global? I already stated that a real, global MWP does not disprove man made global warming.

      How about this quote from the editor of Science:

      "Deep Heating

      Global warming is popularly viewed only as an atmospheric process, when, as shown by marine temperature records covering the last several decades, most heat uptake occurs in the ocean. How did subsurface ocean temperatures vary during past warm and cold intervals? Rosenthal et al. (p. 617) present a temperature record of western equatorial Pacific subsurface and intermediate water masses over the past 10,000 years that shows that heat content varied in step with both northern and southern high-latitude oceans. The findings support the view that the Holocene Thermal Maximum, the Medieval Warm Period, and the Little Ice Age were global events, and they provide a long-term perspective for evaluating the role of ocean heat content in various warming scenarios for the future."

      Delete
    22. No, Anon. Not weak at all. Let's consider the facts.

      A review of the evidence demonstrates that your claim that the MCA was globally, synchronously as warm or warmer than the present is false.



      Delete
    23. Anon.

      You are still refusing to acknowledge the issue I raised with Rosethal et al. which is damning.

      Let me develop this further for you. When you have a single study that is at odds with literally everything else known about some event like the MCA, the objective response is to treat that study with great caution.

      What you are doing is elevating that single study above everything else known. This is blatantly partisan and actually *undermines* your argument. I'm surprised that you cannot see this.

      Delete
    24. Since Anon. persists in dishonesty, let's repeat a few relevant quotes from the scientific evidence:

      Diaz et al. (2011):

      Therefore, the balance of evidence does not point to a high medieval period (A.D. ~1000–1300) in the Northern Hemisphere or the globe as a whole that was as warm as or warmer than the post-1970 period.

      PAGES 2K Consortium (2013):

      Past global climate changes had strong regional expression. To elucidate their spatio-temporal pattern, we reconstructed past temperatures for seven continental-scale regions during the past one to two millennia. The most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century. At multi-decadal to centennial scales, temperature variability shows distinctly different regional patterns, with more similarity within each hemisphere than between them. There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century. The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions. Recent warming reversed the long-term cooling; during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years.

      Delete
    25. Here is more evidence of a global MWP including a different paper by Rosenthal:
      Evidence for a ‘Medieval Warm Period’ in a 1,100 year tree-ring reconstruction of past austral summer temperatures in New Zealand. E.R. Cook et al, Geophys. Res. Lett., 29(14), 1667 (2002). ("clear evidence for persistent above-average temperatures within the interval commonly assigned to the MWP"; "the New Zealand temperature reconstruction supports the global occurrence of the MWP").
      Climate, Environment and Society in the Pacific during the Last Millennium. P.D. Nunn (2007). Most of this 300-page book can be found on Google books here. See also Nunn's press release here. Nunn, who is a Professor of Geography and IPCC author, finds clear evidence for the MWP and a rapid cooling event around 1300 AD. At the end of a 28-page chapter on the MWP, Nunn writes: "Key points:
      1. The climate of the MWP in the pacific basin was marked by warm dry conditions exhibiting a low degree of interannual variability.
      2. Available data suggest that sea level rose in many parts of the Pacific Basin during the MWP, reaching a maximum at its end that exceeded present sea level.
      3. Most Pacific Basin societies enjoyed times of plenty during the MWP to which the comparatively constant climate contributed. Many societies also show adaptation to increasing warm and dry conditions. Food crises arising from droughts affected parts of the eastern Pacific Rim."
      Climate and hydrographic variability in the Indo-Pacific Warm Pool during the last millennium
      Climate and hydrographic variability in the Indo-Pacific Warm Pool during the last millennium. A. Newton, R. Thunell, L. Stott, Geophys. Res. Lett., 33, L19710 (2006). ("The warmest temperatures and highest salinities occurred during the Medieval Warm Period (MWP), while the coolest temperatures and lowest salinities occurred during the Little Ice Age (LIA)").
      1400 yr multiproxy record of climate variability from the northern Gulf of Mexico. JN Richey, RZ Poore, BP Flower, TM Quinn, Geology,35; 423-426 (2007) ("Two multidecadal intervals of sustained high Mg/Ca indicate that Gulf of Mexico sea surface temperatures (SSTs) were as warm or warmer than near modern conditions between 1000 and 1400 yr B.P.")
      2,000-year-long temperature and hydrology reconstructions from the Indo-Pacific warm pool. DW Oppo, Y Rosenthal and BK Linsley, Nature, 460, 1113-1116 (2009). ("Reconstructed SST was, however, within error of modern values from about AD 1000 to AD 1250, towards the end of the Medieval Warm Period.")
      The little ice age and medieval warm period in the Sargasso Sea. LD Keigwin, Science 274, 1504-1508 (1996). ("Results from a radiocarbondated box core show that SST was ~1°C cooler than today ~400 years ago (the Little Ice Age) and 1700 years ago, and ~1°C warmer than today 1000 years ago (the Medieval Warm Period).")
      Glacial geological evidence for the medieval warm period. JM Grove and R Switsur, Climatic Change, 26, 143-169 (1994). ("The results suggest that it was a global event occurring between about 900 and 1250 A.D")
      Evidence for the existence of the medieval warm period in China. D Zhang, Climatic Change, 26, 289-297 (1994). ("It can be estimated that the annual mean temperature in south Henan Province in the thirteenth century was 0.9–1.0°C higher than at present.")

      Delete
    26. I see Anon. is a fan of CO2 "Science". You should do a background check on the Idsos, Anon. You may be surprised to find where their funding is coming from.

      And you need to read this.

      Remember: global *AND* synchronous... You need to be alert to the relative timings of regional events. All you are doing here is extrapolating from a wide temporal scatter of regional events to make claims about global average temperature which are wrong. Go back and read Diaz again. Try to understand the words this time.

      Delete
    27. Wow, what a scholar you are, Anon. You cutnpasted from a whole page!

      You are bluffing, Anon. You have read nothing and you haven't got a clue.

      Delete
    28. Do you mean that I got my information from somewhere else? Of course I did. This is an internet discussion, not a PHD thesis.

      Diaz doesn't say what you claim it to. You are the one not being honest about the meaning of Diaz.

      Delete
    29. Diaz doesn't say what you claim it to.

      Yes it does. You are lying again:

      While there is evidence of medieval warmth, its spatial extent does not appear to be as geographically uniform as the warming seen during recent decades (Figs. 1 and 2). Based on the most recent MCA reconstruction (Fig. 2 in Mann et al. 2009), relative to a modern reference period (1961–90), the MCA was found to be warmer than the late twentieth century over ~1/3 of the equivalent global area in the reconstruction, but colder than the late twentieth century (post-1950s) over ~2/3 of the globe. Relative to an early twentieth-century 50-yr baseline (1900–49), the MCA was reconstructed to be warmer than that baseline for ~2/3 of the globe and colder than ~1/3. Therefore, the balance of evidence does not point to a high medieval period (A.D. ~1000–1300) in the Northern Hemisphere or the globe as a whole that was as warm as or warmer than the post-1970 period.

      Delete
    30. And yet Linsley and Rosenthal agree with me. I guess they must be lying. Maybe you should tell them your concerns about their work.

      "It is clearly showing that these events are global."

      Notice the lack of words like "suggested" and "may have been" in favor of the word "clearly."

      The thing about proxy data is that it is pretty silly to expect it to line up perfectly from one proxy type to the next. It just doesn't have that kind of resolution. That there are so many different sources of proxy data that show a MWP and a LIA that are as close as they are is pretty conclusive of those two global events even if time scale resolution is not perfect.

      On the other hand, using proxy data from the locations that Rosenthal takes it is a pretty good indication of a global nature of these events because of the far reaching currents in the areas where Rosenthal took their samples.

      Delete
    31. "Therefore, the balance of evidence does not point to a high medieval period (A.D. ~1000–1300) in the Northern Hemisphere or the globe as a whole that was as warm as or warmer than the post-1970 period."

      What does that have to do with whether or not the MWP was real or global? That was my assertion. I later mentioned that the MWP was even warmer than it is now. The pacific Ocean was .6 C warmer at depth. Add that to Diaz's "balance."

      Delete
    32. I've pointed out that there are issues with Rosenthal and you are blanking me. I've linked to the reference review paper and the most spatially complete and up-to-date reconstruction (PAGES 2K). You have nothing of any substance and yet you still expect to be taken seriously - even after I caught you out cutting and pasting from some denier website. I repeat: you don't know what you are talking about and you are bluffing.

      Do us all a favour and accept the obvious. Time to wind this up.

      Delete
    33. What does that have to do with whether or not the MWP was real or global? That was my assertion. I later mentioned that the MWP was even warmer than it is now.

      So your claim is that the MCA was global and synchronously warmer than the present. Which it wasn't.

      Stop playing silly buggers. It's tedious.

      I've told you that Rosenthal is problematic and contradicts everything else known about the MCA and I've pointed out that only a fool would claim that an outlier overturns a substantial existing body of work. But you are still doing it. Please try to understand that I reject your argument because it is ill-founded.

      Delete
    34. BBD, this thing is quite clear. Revisionist with all the attributes, nothing more to it.
      Nice catch on CO2 "Science". Gonna check on copypasting first in future snipes.
      Anom's last post is unadulterated trolling.

      That ocean might heat up a half degree. Takes some heat but it seems to come available.



      Delete
    35. "I've told you that Rosenthal is problematic and contradicts everything else known about the MCA and I've pointed out that only a fool would claim that an outlier overturns a substantial existing body of work."

      Rosenthal didn't overturn anything. It just added to the huge pile of research that shows a MWP. Just because the proxy temperature graphs of different areas of the planet don't all line up perfectly does not negate this concept. One simply doesn't get that level of accuracy or precision from the proxy data.

      My first premise was that the MWP was real and global. Then I added that it was warmer than today. Surely you can read the exchange here, no?

      Delete
    36. My first premise was that the MWP was real and global. Then I added that it was warmer than today. Surely you can read the exchange here, no?

      Of course. While nobody disputes that the MCA was real and had a global expression, the evidence suggests that there was no global and synchronous period of warmth that matched or exceeded present global average temperatures.

      So your complete claim becomes problematic and that is what I am striving to point out.

      You suggest that my reading comprehension is faulty. I suggest that the problem lies with you.

      Delete
    37. What you are saying is just not true. Rosenthal adds to the evidence. The OHC was much higher and the Ocean temperature was a little higher. Rosenthal and Linsley explain this in the interview. They most certainly are not "deniers." The idea is that the Ocean really does show the temperature of wide areas of the globe because of Ocean currents and how much heat can be absorbed by the Ocean. It has a great dampening effect. Watch the interview.

      Delete
    38. No, what I am saying is based on the majority of the evidence. What you are saying is that Rosenthal overturns the evidence but that is not the case. R13 *does not* argue that the MCA was globally and synchronously as warm, or warmer than the present. Or at least if it does, I have missed it.

      Can you provide a supporting quotation? Or are you going further than the authors actually did in the study?

      Delete
    39. All kidding aside here BBD, watch the interview. It is very good, and it is most certainly not a "denier" interview. They discuss these issues. Are you sincerely interested in whether the MWP was real, or do you just want to "make it go away?" Rosenthal does not overturn anything. It is just more evidence of a global MWP. In the interview they refer to their own previous studies showing corresponding increases in surface ocean temps as well. Read the Science editor comment on the paper as well.

      "Deep Heating

      Global warming is popularly viewed only as an atmospheric process, when, as shown by marine temperature records covering the last several decades, most heat uptake occurs in the ocean. How did subsurface ocean temperatures vary during past warm and cold intervals? Rosenthal et al. (p. 617) present a temperature record of western equatorial Pacific subsurface and intermediate water masses over the past 10,000 years that shows that heat content varied in step with both northern and southern high-latitude oceans. The findings support the view that the Holocene Thermal Maximum, the Medieval Warm Period, and the Little Ice Age were global events, and they provide a long-term perspective for evaluating the role of ocean heat content in various warming scenarios for the future."

      Delete
    40. We are not arguing about whether the MCA and LIA were global events.

      We are arguing about your full claim, which is that the MCA was globally as warm or warmer than the present.

      You have not presented any evidence that supports your claim and there is plenty to contradict it. So why do you not concede the point?

      Delete
    41. BBD,

      2 Questions for you. 1) Did you read Rosenthal? Be honest. 2) Did you watch the interview?

      If so, how can you possibly say that I have not presented any evidence that supports my claim?

      Delete
    42. Yes, I read Rosenthal, and I'm still waiting for you to quote where it says that the MCA was globally as warm or warmer than the present.

      No, I haven't watched the interview. Please point to the bit you want to discuss; just give me the video time to the nearest minute and I will watch it now.

      Delete
    43. https://www.youtube.com/watch?v=ta-0mo7UjUE

      9:16. But watch the whole thing. Seriously.

      Delete
    44. Oh this is painful to watch. There needs to be moderation. Anonymous claimed early on that the MWP or MCA was warmer than today yet can't provide the proof. He keeps trying to switch the subject to a semantic issue of what constitutes global, yet hasn't conceded that he has no proof that it was globally warmer in the MWP or MCA than today. Concede the point already Anonymous because I don't know how low your credibility can go.

      BTW, BBD, the video was pretty interesting and is worth a watch. Also, when you watch the whole thing, well...it does not say what Anonymous wants it to say :) First, they make a clear distinction between sea temperatures and surface temperatures, which is what all the reconstructions by Mann and others are about as well as this discussion. Second, they clearly say that this is just for one region of the ocean, which is exactly what you said above.

      Their key points that are different and new are: 1. That since there is evidence of the MWP or MCA in their ocean data, then these events weren't completely European events and could be more global than originally thought. 2. That the ocean can absorb more heat than they claim was expected by previous research. However, even on point 2, they state that the current modern increase in heat is so fast that they're not sure if the ocean capacity be able to absorb at the current rate for more than decades. To quote Rosenthal, "I hope so" when referring to the idea that the ocean can maybe absorb more than thought. Again, though, he's talking about temperature. Obviously, this "great experiment," as they call it, of CO2 increase and AGW has other effects which they don't focus on such as sea level rise, CO2 acidification, arctic ice decline,...

      At the end, they sound a like like ATTP, who says it's more about global heating than global temperature warming. Global heating is undeniable. They hope their data helps tune the models with respect to global ocean capacitance to absorb heat.

      Delete
    45. Where do they say that the MCA was as warm or warmer than the present?

      I cannot find this quote.

      Delete
    46. Haha! I'm not surprised you can't find it. Read my comment above that crossed with yours.

      Delete
    47. BBD,

      1. Do you agree that the MWP was global?

      2. Do you agree that the Pacific Ocean was warmer during the MWP in the Makassar Strait and Flores Sea in Indonesia at a depth of 1000 meters?

      3. Do you believe the Pacific Ocean surface temperature was warmer during the MWP than now?

      4. Do you believe the heat content of the Pacific Ocean was greater during the MWP than now?

      Delete
    48. 1/ I never disputed it and your attempt to suggest that I did is irritating. Bad start.

      2/ It's not robustly demonstrated by R13. If you read it you would know why I say this - too many assumptions were made in the calibration of the cores to the core tops. R13's pattern of variability across the Holocene is completely plausible. It's relative magnitude to the present is not convincingly supported.

      3/ Moot, see above - and why if this hypothesis were true, were global land surface average temperatures LOWER during the MCA than the present? You simply *have*to deal with this as it is supported by all the available evidence and you are blanking it. Again.

      4/ No, nor does R13 make that argument. It deals only with a layer of the intermediate ocean. Read the paper FFS.

      Start with the abstract, where the authors acknowledge that the variability in OHC that they claim to demonstrate is at odds with the rest of the evidence - specifically surface temperature reconstructions. *Read* for once, will you.

      Observed increases in ocean heat content (OHC) and temperature are robust indicators of global warming during the past several decades. We used high-resolution proxy records from sediment cores to extend these observations in the Pacific 10,000 years beyond the instrumental record. We show that water masses linked to North Pacific and Antarctic intermediate waters were warmer by 2.1C +/- 0.4°C and 1.5C +/- 0.4°C, respectively, during the middle Holocene Thermal Maximum
      than over the past century. Both water masses were ~0.9°C warmer during the Medieval Warm period than during the Little Ice Age and ~0.65° warmer than in recent decades. Although documented changes in global surface temperatures during the Holocene and Common era are
      relatively small, the concomitant changes in OHC are large


      *Read* the last sentence again:

      Although documented changes in global surface temperatures during the Holocene and Common era are relatively small, the concomitant changes in OHC are large

      R13 *does not* support your claim that the MCA was as warm or warmer than the present. The authors never make this claim. That's why I asked you to provide a quote from R13 supporting your contention that they *did* make such a claim. You were unable to provide that quote yet here you are again, pushing the same false claim about R13, which is evidence of yet more intellectual dishonesty on your part.

      This conversation is effectively over.

      Delete
    49. What Joe said:

      Oh this is painful to watch. There needs to be moderation.

      Delete
    50. BBD,

      I asked you a series of questions just to clarify where we were.

      With regard to question 4 and the claims made by Rosenthal. You say they are not making an argument about the OHC of the Pacific? They are, in fact, doing that very thing:

      "We use a suite of sediment cores along bathymetric
      transects in the Makassar Strait and Flores
      Sea in Indonesia (figs. S1 and S2) to document
      changes in the temperature of western equatorial
      Pacific subsurface and intermediate water masses
      throughout the Holocene [0 to 10 thousand years
      before the present (ky B.P.)] (Table 1). This region
      is well suited to reconstruct Pacific OHC, as
      thermocline and intermediate watermasses found
      here form in the mid- and high-latitudes of both
      the northern and southern Pacific Ocean and can
      be traced by their distinctive salinity and density
      as they flow toward the equator (7) (fig. S3). The
      Makassar Strait between Borneo and Sulawesi,
      the Lifamatola Passage east of Sulawesi on the
      northern side of the Indonesian archipelago, and
      the Ombai and Timor Passages to the south serve
      as major conduits for exchange of water between
      the Pacific and Indian Oceans;water flow through
      these passages is collectively referred to as the
      Indonesian Throughflow (ITF)"

      Delete
    51. Also check out the graph labled: "Fig. 4. Holocene changes in Pacific Ocean heat content," and then tell me "It deals only with a layer of the intermediate ocean."

      Delete
    52. You say they are not making an argument about the OHC of the Pacific?

      Do we have to do this denier nit-pick thing? It is unbelievably tiresome.

      I said that R13 does not provide robust evidence for basin-scale Pacific OHC because it doesn't. It is replete with extrapolations. How do I support my suggestion that it is not robust? By considering the implications. Let's explore this together.

      Now you must answer a question: how do you reconcile R13 with the fact that all the land surface temperature reconstructions cooler on average than the present?

      Delete
    53. When you have given the implications of that little conundrum some thought, you can answer a further question:

      Where does R13 make any claim that the MCA was as warm as or warmer than the present?

      You lied about Diaz et al. and I nailed you for it. History is about to repeat itself unless you admit that R13 does not support *your* claim about the MCA being as warm or warmer than the present and you have been misrepresenting the study and the authors' views on this question.

      Delete
    54. Nit pick?

      I asked: "4. Do you believe the heat content of the Pacific Ocean was greater during the MWP than now?"

      You stated:

      "No, nor does R13 make that argument. It deals only with a layer of the intermediate ocean. Read the paper FFS."

      It doesn't make that argument? That is an outright LIE. The whole paper is about making that argument. The title is "Pacific Ocean HEAT CONTENT During the Past 10,000 Years."

      You sir, are just not honest. You said you read Rosenthal, but then said it didn't make that argument. That is too big a mistake to make for someone of your supposed intellectual caliber. Did you even read the title?

      But now you claim it is not "robust" enough for your standards. But that is not what you said. You said it didn't make that argument. Do you retract your lie?

      As far as "robustness," we didn't have ARGO back then, so we do what we can. They explained why they believe it was ROBUST. Take it or leave it.

      Now, look at that graph entitled "Holocene changes in Pacific Ocean heat content" and tell me whether the Pacific Ocean had more heat during the MWP or now? Was Rosenthal's findings of temperature of the Pacific Ocean warmer during the MWP, or now?

      And you are still wrong about Diaz as well.

      Delete
    55. It doesn't make that argument? That is an outright LIE.

      Yet you still haven't been able to come up with a single quote from the paper stating that the MWP was globally warmer than it is today. Which is not surprising because there is none.

      If that is what they concluded, they would be shouting it loudly for all the world to hear. But they didn't and they haven't. That should be enough for you but instead you avoid the central issue that you yourself raised in the first place and accuse everyone else of "lying".

      As for you claiming "the whole paper is about making that argument", that's wishful thinking on your part. The paper is about the last 10,000 years not just the MWP. And since you cannot produce any passage where they state that the MPW was globally warmer than today, you don't have a leg to stand on.

      Enough prevaricating accusing people of lying.

      The chart you refer to at the end would have been the one they'd use to justify such a claim if they were going to make it. But they didn't make the claim. They stopped short of doing so. As others have pointed out there are too many other hurdles to cross, not the least of which is sea level, but also all the other temperature reconstructions of other locations all around the world. (Indonesia is not the entire world.)

      Why do science deniers latch onto a single paper and ignore all the other thousands of climate science papers? And even when they latch onto a paper they think they like, they have to misrepresent it and waffle on trying to distract readers by peppering their comments with a lot of rubbish.

      Your claims about "robustness" are also more than the authors themselves claim. They've done their best and reported what they found, but they themselves wrote:

      With no additional IWT records, it is difficult to assess the global extent of the trends we have reconstructed. Instead, we evaluate the possible implications for Pacific OHC at four discrete periods during the Holocene.

      Also, the authors are well aware of anthropogenic global warming. Which makes me wonder why Anonymous, who has shown themselves here and elsewhere to be a science denier, wants to use this paper to support his/her denial of science.

      Delete
    56. Sou,

      Look carefully at the exchange. I quoted it. The lie is that the paper doesn't make an argument about Pacific Ocean Heat content. It most certainly does. Now I notice that when I catch BBD making a very clear misstatement about Rosenthal, here you are swooping in to moderate. But when BBD accuses me of lying, you are nowhere to be found. What did I lie about?

      You can see what the OHC was during the MWP in the graph. The paper shows that there was more heat in the Ocean during the MWP than there is now. The paper shows that the Pacific Ocean was warmer than it is now. That is EVIDENCE that the Earth was warmer. It alone does not prove it, but it is evidence. Evidence that can be added to the wealth of other evidence out there.

      Now we can certainly discuss the probative value of this paper. Given that we are emitting unprecedented amounts of CO2 into the atmosphere which is going to heat the planet to dangerous levels, but the temperature of the planet hasn't done a whole lot in the last 16 years because......

      The heat has all gone into the Ocean! Yet, there was more heat in the Ocean during the MWP. But the Earth was cooler then? Or does the fact that the Ocean was warmer tend to show it might have been warmer than now?

      The point all along was that the MWP was real and global. I specifically stated that it had nothing to do with whether humans are hurting the planet now. Nothing at all.

      Delete
    57. "You can see what the OHC was during the MWP in the graph. The paper shows that there was more heat in the Ocean during the MWP than there is now."

      What is shows is more heat in the upper 700m of the PACIFIC OCEAN than now, and declining over the entire timespan, then what looks like what i'd call a trend reversal towards present. Hmm.

      " That is EVIDENCE that the Earth was warmer."

      It's evidence that the upper 700m of the PACIFIC OCEAN was warmer.

      "but the temperature of the planet hasn't done a whole lot in the last 16 years because......

      The heat has all gone into the Ocean! "

      Some heat has indeed gone into the ocean. "ALL" of it? Sounds like you're lying.

      "Yet, there was more heat in the Ocean during the MWP."

      DECREASING ocean heat content thousands of years ago disproves INCREASING ocean heat content presently?

      "The point all along was that the MWP was real and global."

      But you're talking about a paper of PACIFIC OCEAN heat content. How does the "global" part make its way in there?

      For that I reference http://www.nature.com/ngeo/journal/v6/n5/full/ngeo1797.html
      in which the authors state:

      "There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century. The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions. Recent warming reversed the long-term cooling; during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years."

      cabc

      Delete
    58. @Anonymous

      You wrote
      " The paper shows that the Pacific Ocean was warmer than it is now. That is EVIDENCE that the Earth was warmer"

      It is not evidence that the Earth was warmer. If you read the paper, it states that the peak heat of the Pacific Ocean was during the HTM and has been in a cooling trend since then.

      "changes in Pacific OHC are largely determined by climate changes in the high latitudes that possibly respond to changes in the tilt of Earth’s axis since the early Holocene"

      The peak heat also coincides with the peak of the Earth's tilt.
      http://en.wikipedia.org/wiki/File:Obliquity_of_the_ecliptic_laskar.PNG

      This change in the Earth's tilt, also has slowly been reducing the amount of insolation, so the Earth for the last 8,000 years has been in a cooling trend. The Rosenthal paper clearly shows that the Pacific ocean also cooled during that time, with the lowest temperature during the end of the LIA Yes, there is the suggestion using extrapolation that the OHC of the Pacific was higher than today, but that is the heat that is left over from the HTM because it takes thousands of years for the ocean to cool. It in fact shows that the MWP was cooler than today, as the flux of heat was from the ocean into the atmosphere as represented in Fig 4 part B. Now the flux has suddenly changed direction, yet the changes in the Earth's tilt hasn't changed direction. This is evidence that the changes in the earth's climate is not natural.

      If you have a look at Fig 2 part A and B, you will see that the surface temperature of the ocean was cooler during the MWP, and then over the last 100 years kicks up suddenly, showing the heat from increasing CO2 now entering the ocean. If you look at Fig 4 part B, you will also see that the heat from anthropogenic CO2 is orders of magnitude higher than during the previous 10,000 years.

      So the Rosenthal paper, far from showing that the MWP was warmer, actually shows the opposite, but also shows that the recent climate is heating the ocean at rates not seen before. This is actually more evidence that shows that anthropogenic CO2 is having rapid influences on OHC.

      Delete
    59. cabc,

      Yet it is still evidence of a warmer planet. Now combine that with Rosenthal's previous work on surface temperatures.

      That has been my point all along. Thank you for helping close the door on this discussion. The MWP was real and global (as confirmed by Rosenthal), and there is evidence that it was warmer than today.

      "DECREASING ocean heat content thousands of years ago disproves INCREASING ocean heat content presently?"

      While that might be mildly interesting, what does it have to do with the discussion at hand?

      Delete
    60. Dave,

      Your analysis is one plausible explanation except that "2,000-year-long temperature and hydrology reconstructions from the Indo-Pacific warm pool," Delia W. Oppo1 , Yair Rosenthal2 & Braddock K. Linsley3

      shows that SSTs were peaking during the MWP. They were lower prior to the MWP, but something made them rise. What might that be?

      Delete
    61. @Anonymous
      You wrote
      "and there is evidence that it was warmer than today."

      What evidence. You haven't provided any. Rosenthal's paper does not say the MWP was globally warmer, which is why you haven't yet been able to find a quote in it. All you have is your own misinterpretation.

      Most of the proxies that have been examined DO NOT show a warmer MWP.

      Here is some more evidence, this time from ice data.

      http://www.see.ed.ac.uk/%7Eshs/Climate%20change/Data%20sources/Kaufman%20Schneider%20recent%20warming.pdf

      Have a look at Fig 3

      Also this quote.
      "Our synthesis, together with the instrumental record, suggests that the most recent 10-year interval (1999–2008) was the warmest of the past 200 decades. "

      Or this paper
      http://www.nature.com/nature/journal/v479/n7374/full/nature10581.html

      and this quote.

      "both the duration and magnitude of the current decline in sea ice seem to be unprecedented for the past 1,450 years. "

      Or this
      http://web.science.unsw.edu.au/~sjphipps/publications/pages_2k_consortium2013.pdf
      and the quote.

      "Our regional temperature reconstructions (Fig. 2) also show little evidence for globally synchronized multi-decadal shifts that would mark well-defined worldwide MWP and LIA intervals. Instead, the specific timing of peak warm and cold intervals varies regionally, with multi-decadal variability resulting in regionally specific temperature departures from an underlying global cooling trend."


      So how about this. Even if the Rosenthal paper did have a quote that said the MWP was globally warmer, a single paper is not very convincing. So, provide at least another paper, and this time a quote that says that the MWP was GLOBALLY warmer. Not your own misguided misinterpretation.

      But I doubt that will ever happen. Expert handwaving and foot stamping will be likely!!

      Delete
    62. Anonymous writes

      "except that "2,000-year-long temperature and hydrology reconstructions from the Indo-Pacific warm pool"

      says this.
      "Northern Hemisphere surface temperature reconstructions suggest that the late twentieth century was warmer than any other time during the past 500 years and possibly any time during the past 1,300 years"

      So even the reference that you provided counters your assertion that the MWP was globally warmer than today's climate.

      Talk about an own goal!!!

      Delete
    63. Anonymous wrote: The MWP was real and global (as confirmed by Rosenthal), and there is evidence that it was warmer than today.

      Except that, as everyone has been pointing out, Rosenthal13 didn't confirm any such thing.

      As for the MWP being real, yes - there were parts of the world that warmed in medieval times, but not all at the same time. Other parts were cool. Was the world as a whole warmer globally than it is now? Almost certainly not. Anyone can check the myriad scientific papers in the latest IPCC report - such as those used in the IPCC figure in the article above.

      Even Fred's simplistic FAR schematic shows the Medieval period was cooler than today:

      http://blog.hotwhopper.com/2014/01/anthony-watts-forgot-to-satire-tag.html


      Give it a rest Anonymous. The reason I swoop in on you is because you are a typical science denier. HotWhopper is for demolishing disinformation not promoting it.

      Delete
    64. "So even the reference that you provided counters your assertion that the MWP was globally warmer than today's climate"

      Not quite Dave, did you read it? Why do you suppose they said "possibly" as it relates to the MWP? It is because of the error range. It is equally true that, according to their data, the MWP was as warm as today within the range of error. For you to say that the paper "counters" my assertion is just not an honest interpretation of their work.

      Delete
    65. Sou, look carefully at what you wrote. Look carefully at my words that you quoted. I said they confirmed the MWP was real and GLOBAL. Did you see the interview of Rosenthal and Linsey? They said that one of the most surprising findings of their work is that the MWP was a global event. The paper even says "...thereby supporting the idea that the HTM, MWP, and LIA were global events."

      Rosenthal and Linsey think that they did confirm that the MWP was global. Go back and look.

      Sou, please admit that Rosenthal and Linsey said that MWP was a global event.

      Delete
    66. That should be "Linsley."

      Delete
    67. Anonymous January 26, 2014 at 6:55 AM
      wrote

      "I have cited evidence, not the least of which is Rosenthal. Go check out the video that they made explaining how the MWP was global and warmer than now."

      You see, I've looked at the video, and I've looked at the paper, and in neither did they EVER say that the MWP was global AND warmer than now.

      Yes they said the MWP was Global.
      Yes they said that the MWP Pacific ocean was warmer.

      It is YOU who has then misinterpreted this to be a MWP that was global AND warmer.

      You have then spent countless posts trying to squirm yourself out of the hole you've dug, unable to concede that you were wrong. This is a very common tactic, and should maybe be called Greiging, after the little gish gallop session of Greig.

      It is clear that you are unable to understand the papers that have been presented, and you will obsessively persist in your crusade. Maybe Sou could create another thread dedicated to your obfuscation.

      Delete
    68. Seeing I quoted you word for word I know what you wrote and Rosenthal13 said nothing of the sort. Nowhere in the paper did it state that, and again I quote you directly: "The MWP was real and global (as confirmed by Rosenthal), and there is evidence that it was warmer than today."

      You enjoy playing with words but your meaning has come through loud and clear. You seem to have invested a lot in the notion that it's still colder globally now than it was around a thousand years ago. Almost all evidence that has been emerging in the past several years suggests that is not the case. Not just proxy temperatures but sea level as well.

      I get my science from published papers, you get yours from videos. That's fine as far as it goes. I don't have time to look at the video but regardless, the authors might think, based on the observations they made around Indonesia, that there was a period when the earth as a whole got markedly warmer a thousand years ago. The only statement made of relevance is this:

      IPWP SSTs are within error of modern (~1950 CE) values between 900 and 1200 CE during the Medieval Warm Period (MWP) .

      Which is not inconsistent with other work.

      On a personal level, Rosenthal13 authors might even think it was warmer than it is today (rather than around 1950) but if so, they didn't publish their personal thoughts in Rosenthal13.

      Scientists will keep collecting more evidence to demonstrate the extent of any temperature rise around 1000 CE (the paleo charts suggest the global temperature rose about 0.1 degree between 900 and 1150 CE, on par with that of around 600 CE), how widespread it was (the paleo records to date demonstrate clearly that it wasn't warm everywhere and where it did warm, it wasn't synchronous) and what caused this. It will need to be consistent with sea levels, the cryosphere and other related aspects of the earth system too.

      While it is all very interesting to look back over the Holocene, it's all about to change. It's not just scientifically interesting. That period was also the time when civilisations grew and flourished. The relatively benign climate, with little change for 10,000 years, is arguably what allowed civilisations to flourish. We will face many challenges in future decades and centuries given the amount of climate change that will take place, with all its repercussions.

      (For myself, I'm interested in how regional climates changed over the past 10,000 years or so.)

      Delete
    69. What did I lie about?

      Diaz supporting your claim that the MCA was as warm or warmer than the present. Over and over again, despite being given exact quotation demonstrating that you were wrong (that's why you were *lying* - you knew your claim was false and kept on repeating it, as you do again here.

      And you are still wrong about Diaz as well.

      That's a lie.

      * * *

      You have been lying about Rosenthal for dozens of comments as well. Nowhere does that paper make the claim that the MCA was as warm as or warmer than the present. You have been challenged to provide quotes supporting your claim and failed, so you know your claim is false yet you keep on repeating it.

      You can see what the OHC was during the MWP in the graph. The paper shows that there was more heat in the Ocean during the MWP than there is now. The paper shows that the Pacific Ocean was warmer than it is now. That is EVIDENCE that the Earth was warmer. It alone does not prove it, but it is evidence. Evidence that can be added to the wealth of other evidence out there.


      That's a lie. In fact it is two lies - the claim that there is a "wealth of evidence out there" is false too. And you know it, because you have been shown that the "wealth of evidence" shows that global average temperatures were *cooler* during the MCA than the present. Lie after lie.

      * * *

      Now to the nit-pick over my (4):

      "4/ No, nor does R13 make that argument. It deals only with a layer of the intermediate ocean. Read the paper FFS."

      Okay, there is a problem - I wrote sloppily. I should have said:

      "4/ No, nor does R13 demonstrate this directly. It deals only with a layer of the intermediate ocean. Read the paper FFS."

      At this point you are in no position to accuse me of not having read R13 and/or of lying about what it says.

      But now you claim it is not "robust" enough for your standards. But that is not what you said. You said it didn't make that argument. Do you retract your lie?

      Now I refer you back to everything else I have said following on from this point - all of which you have ignored as you always do because it contradicts your nonsense. Start here:

      I said that R13 does not provide robust evidence for basin-scale Pacific OHC because it doesn't. It is replete with extrapolations. How do I support my suggestion that it is not robust? By considering the implications. Let's explore this together.

      And this time, answer the bloody question instead of blanking it yet again.

      How do you reconcile your interpretation of R13 with the fact that all the surface temperature reconstructions of the MCA show that on average, it was cooler than the present?

      Answer that. Don't dodge it again. We don't *need* any more evidence of your intellectual dishonesty.

      * * *

      In summary, you have lied your way through this thread in the face of constant, referenced correction. This is solid evidence of bad faith and this has gone on long enough.

      You have been corrected by Sou herself, Dave, cabc and others. Enough is enough.

      I hope Sou will now act, as I am very, very tired of pushing back against this endless spewing of misrepresentations and *lies*.

      Delete
    70. Sou,

      Look at the sentence again:

      "The MWP was real and global (as confirmed by Rosenthal), and there is evidence that it was warmer than today."

      The "as confirmed by Rosenthal" only applies to the "real and global" part. Now I cited Rosenthal's paper as saying such, and Linsley says it in the video. What more do you want? Will you agree that the "as confirmed by Rosenthal" applies to the global statement just from pure sentence structure alone?

      Rosenthal's surface temperatures show a warmer Pacific during the MWP, but within the margin of error, so we must keep that in mind.

      Sou, seriously watch the video. For all sorts of reasons beyond the points that I am making here. It is a great interview with a couple of scientists that explain their work. Others here have referred to the video as "fascinating."

      BBD, I never said Diaz supports my claims. It just didn't support yours. There is a difference, and I already explained that in detail.

      The bad faith is yours. And the lie about what Rosenthal was saying was yours.

      From the beginning I kept the MWP in context. Just because the evidence points to it being global and as warm or warmer than today doesn't prove anything about man made global warming.

      Now you ask "How do you reconcile your interpretation of R13 with the fact that all the surface temperature reconstructions of the MCA show that on average, it was cooler than the present?"

      What evidence do you have to support that assumption? Diaz doesn't quite say that. Even if we take Diaz as the definitive collection and analysis of all the data (which it isn't), if 1/3 of the planet was warmer and 2/3 was cooler does that prove that it was cooler? Or does it depend on how much warmer and how much cooler those places were? Perhaps you can point me to an honest tabulation of all of the data?

      One thing that is shining through here is how the alarmists view the science with extreme bias.

      We have Dave's statement that the Rosenthal SST paper claims that it SSTs were cooler in the MWP than now, when the opposite is true. It merely said it was possible that they weren't as warm as now because it was within the margin of error. And we have BBT's claims about Diaz.

      That is why we shouldn't trust alarmists with agendas to do proxy temperature reconstructions nor should we trust them to compile the data of objective scientists that did the same.

      Here is Michael Mann himself showing bias. He makes this statement about the Rosenthal paper:

      The study finds, specifically, that (to quote Columbia University's press release) the "middle depths [of the Pacific Ocean] have warmed 15 times faster in the last 60 years than they did during apparent natural warming cycles in the previous 10,000".

      Could someone here please point to where Rosenthal "specifically" makes that finding? Anyone? If Mann is going to make a statement about a "finding" of a scientific paper, why not quote the paper? Why quote someone else's press release about it? Is that "honest?"

      The statements that I have made here were objective and qualified. I bet that even Rosenthal and Linsley would agree. The real issue that they found "surprising" from their work is the global nature of the MWP. Whether or not it was warmer than today is really almost irrelevant. But, as I indicated, there is evidence to show such.

      And one thing about bias is that it is not necessarily fraud. People are biased, and they just can't help it. It is human nature.

      Michael Mann is the one that has invested years of his life trying to prove that the MWP wasn't global. I just happen to remember the science as it existed before his agenda.

      Delete
    71. All this talk about the relative warmth of the Mediæval warm period compared with today misses a basic point - the MWP peaked and then declined in response to known forcing mechanisms, and the modern temperature trajectory is going to keep skyrocketting for the next few centuries and then hang about the plateau for a few more centuries to millenia afterward.

      And as has been noted several times now on this thread, the warmer the MWP was, the more poo the Earth is in as a result of the trajectory that humans have initiated with the Industrial Revolution.

      What Anonymous is trying to tell us is that the world is toast. I don't disagree with him on that.

      Delete
    72. Anonymous wrote.

      "Here is Michael Mann himself showing bias. He makes this statement about the Rosenthal paper:

      The study finds, specifically, that (to quote Columbia University's press release) the "middle depths [of the Pacific Ocean] have warmed 15 times faster in the last 60 years than they did during apparent natural warming cycles in the previous 10,000".

      Could someone here please point to where Rosenthal "specifically" makes that finding? Anyone? If Mann is going to make a statement about a "finding" of a scientific paper, why not quote the paper? Why quote someone else's press release about it? Is that "honest?"

      It was the co-author Linsley, you know, the one that you couldn't even spell.

      "That might seem small in the scheme of things, but it’s a rate of warming 15 times faster than at any period in the last 10,000 years, said Linsley."
      http://www.earth.columbia.edu/articles/view/3130

      You have now proven beyond any doubt to be totally bigoted and dishonest and a proven illiterate ignorant idiot. Not only that you seem to be totally colour blind, and are unable to interpret a graph. You have shown yourself to be beholden to the professional deniers at co2science, and are now resorting to the denouncement of Mann, and ad hominem attacks of everyone else. You are claiming that everyone is biased but cannot see the extreme bias in yourself and your statements. You are running to a script, written by co2science, and as such, you are unable to think for yourself. You have an ideological view of the past climate, and are trying to find the data to fit your preconceived ideas. That is not how science works, in fact it is the opposite.

      It is clear that when talking about climate science, there needs to be a new addition to Godwin's law, that is whenever there is an ad hominem of Michael Mann, the thread needs to be closed immediately.

      Delete
    73. BBD, I never said Diaz supports my claims. It just didn't support yours. There is a difference, and I already explained that in detail.

      No, you did not and I have been through this with you again and again. You are a liar.

      From the beginning I kept the MWP in context. Just because the evidence points to it being global and as warm or warmer than today doesn't prove anything about man made global warming.

      More lies. You have been shown that the evidence DOES NOT point to an MCA as warm as or warmer than the present.

      Now you ask "How do you reconcile your interpretation of R13 with the fact that all the surface temperature reconstructions of the MCA show that on average, it was cooler than the present?"

      What evidence do you have to support that assumption?


      All of it, including Rosenthal 13. You, on the other hand have nothing except your incessant lies.

      Moderation please, Sou.

      Delete
    74. Dave,

      Do you have trouble reading? Mann said that the Rosenthal paper had a specific finding that "middle depths [of the Pacific Ocean] have warmed 15 times faster in the last 60 years than they did during apparent natural warming cycles in the previous 10,000."

      Can you please show me where the paper makes that specific finding?

      Delete
    75. Dave

      It is clear that when talking about climate science, there needs to be a new addition to Godwin's law, that is whenever there is an ad hominem of Michael Mann, the thread needs to be closed immediately.

      Or the offending ad hom snipped, at the very least. The whole personalise-and-demonise denier tactic needs to be stamped out. It is a vicious and underhand attempt to deceive the public by trashing the professional integrity of scientists.

      Delete
    76. From R13 p 621:

      The modern rate of Pacific OHC change is, however, the highest in
      the past 10,000 years (Fig. 4 and table S3).


      Delete
    77. BBD writes: "The modern rate of Pacific OHC change is, however, the highest in the past 10,000 years (Fig. 4 and table S3)."

      Yes. Exactly. Now that is not what Mann wrote now is it? Here is a hint for you. Even if they did include the "15 times" statement in the paper, it would probably not have made it past peer review because such a statement is comparing proxy data to the instrumental record which has different resolution. They can't possibly know that it was 15 times greater based on the data they collected. 15 times greater is far different than saying "greater."

      Delete
    78. The statement is from the press release, which is subtitled:

      The intermediate waters of the Pacific Ocean are absorbing heat 15 times faster over the past 60 years than in the past 10,000

      From the main text:

      Climate scientists say it went into the ocean, which over the past 60 years has acted as a buffer against global warming. However, a new study led by Rutgers’ Yair Rosenthal shows that the ocean is now absorbing heat 15 times faster than it has over the previous 10,000 years.

      If the authors disagreed with their own press release, don't you think they would have said something?

      Or perhaps you are simply thrashing around desperately trying to distract attention from the fact that you have been exposed as a serial liar?

      Delete
    79. BBD,

      No one said that the author's don't believe that warming is 15 times faster or whatever. Had Mann said that the author's believe such, it sounds like he would have been accurate.

      But he made a statement about a paper's finding which was untrue.

      Delete
    80. No he did not. You are lying again.

      Dave has already linked the Colombia press releasefor you above (I linked the Rutgers press release), but since you clearly did not bother to read it, here it is again, with an expanded quote:

      From about 7,000 years ago until the start of the Medieval Warm Period in northern Europe, at about 1100, the water cooled gradually, by almost 1 degree C, or almost 2 degrees F. The rate of cooling then picked up during the so-called Little Ice Age that followed, dropping another 1 degree C, or 2 degrees F, until about 1600. The authors attribute the cooling from 7,000 years ago until the Medieval Warm Period to changes in Earth’s orientation toward the sun, which affected how much sunlight fell on both poles. In 1600 or so, temperatures started gradually going back up. Then, over the last 60 years, water column temperatures, averaged from the surface to 2,200 feet, increased 0.18 degrees C, or .32 degrees F. That might seem small in the scheme of things, but it’s a rate of warming 15 times faster than at any period in the last 10,000 years, said Linsley.

      So that's Rosenthal approving the 15x figure in the Rutgers release (his institution) and Linsley (sp!) approving the 15x figure in the Colombia release (his institution).

      It is self-evident that the paper's finding support this claim or both press releases would have been rejected by both authors.

      The relevant numbers seem to be in Table S3 in the SI.

      You are trying to distract from the fact that you have been exposed as a serial liar. It's not working.

      Delete
    81. BBD,

      It is not a finding of the paper. It is a sensational headline of a press release, and, perhaps, an opinion of the authors. The paper is subject to peer review, and the outside opinions and sensational headlines are not.

      Do you see the difference? Do you understand the significance of the difference? One can even argue that the paper supports this conclusion, but it is not a finding of the paper as represented at least erroneously by Mann.

      If you do not understand the difference, then there is really not much more I can do for you. You don't even seem to know what a lie is. Arguing with you is like the Connecticut Yankee in King Arthur's court arguing with the peasants.

      Delete
    82. One can even argue that the paper supports this conclusion, but it is not a finding of the paper as represented at least erroneously by Mann.

      Another lie.

      It IS a finding of the paper - look at the SI - and it is explicitly endorsed by the authors and Mann made no error referring to it. Read the press releases issued by their respective institutions.

      Do you seriously argue that Rosenthal and Linsely would sign off on two separate press releases that materially misrepresented their findings? Don't be fucking ridiculous.

      I know exactly what a lie is and what a liar is - and you are a liar. This thread stands as incontrovertible evidence of that. The depth of your mendacity is evidenced by the fact that you are still here and still lying.

      Something needs to be done about this.

      Delete
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    84. This comment has been removed by a blog administrator.

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    86. I keep posting examples of you lying. All you have to do is read them, Anon.

      And you are lying about the 15x figure not being a finding of R13. If it was not a finding of that study, then the authors would not have allowed this specific figure to feature in the *two* press releases describing the study.

      The figures are in the supplementary information, Table S3, link above.

      Stop lying.

      Delete
    87. This comment has been removed by a blog administrator.

      Delete
    88. Do you really think that the headline in a press release about a scientific paper qualifies as a finding of that paper?

      Yes. And only a desperate liar like you would try to pretend otherwise.

      Parts of Pacific Warming 15 Times Faster Than in Past 10,000 Years

      [...]

      But rather than letting humans off the hook, a new study in the leading journal Science adds support to the idea that the oceans are taking up some of the excess heat, at least for the moment. In a reconstruction of Pacific Ocean temperatures in the last 10,000 years, researchers have found that its middle depths have warmed 15 times faster in the last 60 years than they did during apparent natural warming cycles in the previous 10,000.


      It's a finding of the paper.

      I suppose when you've been nailed for so many other lies, belabouring a new one is about the only way to distract attention you have left.

      It isn't working.

      Delete
    89. Oh dear, what a sorry and sordid web anon has weaved.

      Here is the biased and alarmist Linsley stating the sensationalist major finding of his latest research.
      http://www.youtube.com/watch?v=gHpwQTI_Bn4

      Ouch, that's gotta hurt!!

      If you were able to comprehend graphs, instead of focussing on the 'MWP is warmer than today' folly, you would see that IT IS a major finding of the paper.

      What's going to be the next crazy excuse, 'Oh, it's actually Mann's voice being dubbed over the top', 'The biased greenies gave him a cheque to make him say it', 'Ahhh, it's not peer reviewed'

      Anon, you are the quintessential intentionally deceptive troll, on a compulsive obsessive crusade from the cesspool of WUWT. This blog makes fun of the stupid, brainless and whimsical antics of the intellectual bereft and ignorant Wattie cult. You have come onto this blog, intent to show off your reverence to your dogma, but instead it horrendously backfired and blew up in your face, and your sole achievement has been making a complete fool of yourself. You have been pinged so many times, and have petulantly hand waved and foot stamped, and twisted and turned, you are now beyond any redemption.

      But I will leave the final word to the NOAA, you know, the experts in climate and weather.

      "In summary, it appears that the late 20th and early 21st centuries are likely the warmest period the Earth has seen in at least 1200 years"
      http://www.ncdc.noaa.gov/paleo/globalwarming/medieval.html

      Delete
  9. This comment has been removed by the author.

    ReplyDelete
  10. BBD, Where does it say it was not real or global in nature?

    Please provide quotations in your response, so we can clarify this.


    IMO, you are "Greig". Sou, if you see this, it might be worth checking IPs.

    ReplyDelete
    Replies
    1. IMO, you are "Greig". Sou, if you see this, it might be worth checking IPs

      Not that that it is relevant to anything important, but you are wrong. Sou will no doubt confirm , Anonymous.ne.Greig

      Frankly, I don't see any relevance to the arguing that the MWP was warmer or cooler than today, the point is the MWP and LIA are global events (albeit perhaps not perfectly synchronous as suggested by Diaz et al), but importantly not driven by greenhouse. i.e. there are substantial and as yet not fully quantified processes which drive global temperature. (Note: this does not invalidate AGW, and I am not saying that it does)

      The Rosenthal et al paper is an interesting addition to climate science. And the interview with Rosenthal and Linley was fascinating. I am a bit surprised by BBD arguing against the veracity of the paper's conclusions, since it adds weight to BBD's suggestion that the current warming hiatus is explained by ocean heat uptake being more rapid than previously thought.

      On the other hand, Rosenthal was very clear in stating that the conclusion is that ocean heat uptake may have a buffering effect, substantially lowering the short to mid-term (decade/century scale) rate of GHG forced atmospheric temperature increase. And this would of course thereby lower environmental impact. Clearly, and as Rosenthal confirms, this has implications with regard to policy.

      Delete
    2. I think you need to quantify the difference in the rate of change in forcing during the MCA and the present. Then quantify the difference in magnitude of forcing change (already much larger in the present, and open-ended)

      If you are trying to argue that ocean heat uptake will take care of our present little problem you are effectively arguing for a low fast feedback sensitivity. If the oceans were able to buffer forcing changes to a significant extent, we should be stuck in the last glacial. The ocean should have eaten our global warming. But it didn't.

      Delete
    3. BBD, read my comment above. Greig/Anonymous/whatever [I will believe an IP address check when done by Sou] is overstating things. Also, as stated above, they are just talking about energy absorption by the ocean without talking about other issues such as sea level rise, CO2 absorption in the ocean, etc.

      Delete
    4. I'll only respond on this matter because it keeps coming up. I realise that it's easy to confuse one denier with another (they all look the same sometimes), however Greig is not the same person as Anonymous in this thread. They are from different parts of the world. (Also, to my eyes their writing style is different, so I'd never have taken them for the same person.)

      I hesitate to write the above because of privacy considerations. However I don't think this comment can be construed as a breach of privacy and in any case there are veracity issues at stake.

      Delete
    5. Sorry Greig, Anon. and Sou.

      My mistake.

      Delete
    6. If you are trying to argue that ocean heat uptake will take care of our present little problem

      I am doing no such thing. However Rosenthal and Linley consider it worthy of further research because it clearly has policy implications. I am going with the stated view of the climate scientists.

      Delete
    7. Thanks Sou and sorry to Greig, Anon and Sou.

      As to the video, they are only talking about ocean heat as I said above. They also said, "I hope so," when asked if ocean heat absorption will have a significant effect. My impression was that they wanted their findings to direct climate models more than anything because they backed off of policy implications later in the discussion. Rosenthal said, "it may not help us in terms of the current change in the atmosphere." Finally, they do not talk about other issues such as sea level rise, etc.

      Delete
    8. "On the other hand, Rosenthal was very clear in stating that the conclusion is that ocean heat uptake may have a buffering effect, substantially lowering the short to mid-term (decade/century scale) rate of GHG forced atmospheric temperature increase. And this would of course thereby lower environmental impact. Clearly, and as Rosenthal confirms, this has implications with regard to policy."

      1) It is dangerous to compare mediæval ocean temperature buffering to contemporary ocean temperature buffering because, as so many have indicated to you, the causes and the regional distributions of the heat accumulation are different. Different mechanisms of ocean warming will have different sequelæ. Your speculation of enhanced ocean heat sinking, even if it has some basis in fact, does not extrapolate to modern conditions.

      2) On the matter of the mechanisms of warming, the mediæval warming was more of a pulse event where the human-caused warming is a press event. As such the ecophysiological responses will be very different, especially at the ecosystem level. And it is incorrect to claim that there would be a "lower environmental impact" today for the reasons below.

      3) Avoiding the implication of trying to exaggerate the magnitude of the MWP does not change the fact that the warmer it is compared to a millennial baseline, the greater is the climate sensitivity to atmospheric carbon dioxide. And you still haven't proffered any significant evidence to counter the work that shows that current temperatures are warmer than those of the MWP.

      4) Sherwood et al 2014 show that equilibrium climate sensitivity is likely greater than 3 ºC. From their discussion:

      "Taking the available observations at face value implies a most likely climate sensitivity of about 4 °C, with a lower limit of about 3 °C. Indeed, all 15 of the GCMs with ECS below 3.0 °C have an LTMI [lower-tropospheric mixing index] below the bottom of the observational range."

      5) Claiming enhanced ocean temperature buffering in the short term now implies a higher-end equilbrium climate sensitivity in the longer term, as thermodynamics always has its way. It just does - it's the Law. And in conjunction with Sherwood et al this only underscores the folly of claiming lower environmental impact.

      6) There is much scientific literature indicating that an increase in temperature above 2-3 °C will have profound and adverse impacts on the biosphere, and the agricultural, horticultural, fishing and forestry industries on which humans inextricably rely.

      7) Business-as-usual combustion of fossil fuels for the span of a human life-time from today will result in approximately a trebling of atmospheric carbon dioxide over the pre-Industrial Revolution level, to around 800 ppm (and this is ignoring methane release...) which is likely to increase the mean global temperature above 4-5 °C at equilibrium... at the very least.

      8) These temperature rises at equilibrium have already factored into their values the heat capacity of the planet's oceans - any variation that you imagine will have no effect on the medium to long term equilibrium.

      9) "Policy" set by us today should consider non-First World people, future generations, and non-human species. Hypocrisy, selfishness and nihilism are not valid policy bases.

      10) The laws of nature trump ideology, mythology, ignorance and perversity. As noted in point 5 there is no hiding in space-time from the universe's truths - and superstitions about sky fairies are not universal truth.

      Delete
    9. Bernard J,
      Iam certain that Rosenthal's comments about ocean buffering impacting policy was concerning the RATE of future warming , and your response did not address his claim.

      Delete
    10. Also I strongly agree with your points (9) and (10).

      Delete
    11. "Iam certain that Rosenthal's comments about ocean buffering impacting policy was concerning the RATE of future warming , and your response did not address his claim."

      What part of "equilibrium climate sensitivity" was unclear?

      Delete
    12. Which part of rate of warming was unclear:

      For a full coupled atmosphere/ocean GCM, however, the heat exchange with the deep ocean delays equilibration and several millennia, rather than several decades, are required to attain it.

      If you are suggesting that rate of warming has no relevance to ecological impact (and policy), I think you should make your case. I am certain that Rosenthal is assuming the difference between decades and millennia in warming rate is relevant.

      Delete
    13. The rate of future warming will be substantially determined by the rate of change (increase) in GHG forcing. The argument that ocean heat uptake will be so rapid and so sustained that surface temperature warming will be slowed to a crawl and policy intervention rendered unnecessary is unfounded. No solid body of work demonstrates that TCR is likely so low that we can all stop worrying and go to the pub. We are in fantasy land again.

      Rosenthal and co-authors explicitly caution against this distortion of their extremely tentative findings wrt OHU. Let's not get carried away here.

      Delete
    14. "If you are suggesting that rate of warming has no relevance to ecological impact..."

      You know full-well that that I am claiming no such thing: cease and desist with the verballing. I'm on the record more than once noting that the contemporary rate of warming is a severe danger to species and to ecosystems.

      And my point was, if you care to reread my comments, that the medium to long term (which an informed person would usually take to mean centuries to millennia) warming resulting from another century of business-as-usual would be catastrophic for many species.

      It will certainly be so even if the future rate of warming is only 1 °C/century, which is beyond parsimoniously low given the projected total output of carbon dioxide. If the rate of warming is higher - say, several degrees Celsius per century - then the ecological effects will be even more dramatic as fewer species have the opportunty to migrate successfully with shifting climate zones.

      For effectively stationary species subject to altering bioclimatic envelopes the end result is largely the same no matter the rate, and it's only a matter of the time interval to crisis. A potential confounder would be the interaction with novel, migratory species, which could have a positive or a negative interaction with climate.

      Even the value of equilibrium climate sensitivity is somewhat irrelevant, as the odds are ever-diminishing that ECS is less than 2.5 °C, and that it's quite possibly up to 4 °C or higher. Given the lack of global effort to date to move from fossil fuels it seems more and more certain that a doubling at least of atmospheric carbon dioxide will occur, and quite likely overshoot past this point. 2.5 °C would be bad enough in a world where fossil fuels are exhausted on top of the biosphere being wrecked and where non-biological resources* are depleted; 4.5 °C ECS doesn't bear thinking about, especially if BAU continues to 2100 and an atmospheric level of carbon dioxide around 800 ppm is reached.

      This whole "short-term rate", besides being a distraction from the ultimate consequences of human-caused global warming, is also limited by attempts to state with any confidence the real short-term rate as opposed to that indicated by the data - when the units of time are reduced the noise becomes significant compared with the signal, and this has an increasing effect on the shape of the trajectory. And as anyone familiar with rates/tangents/first derivatives would know, it doesn't take much of a change in the noise on small scales to greatly affect the slope of a curve at a given point.

      Take home message:

      1 °C/century -> 2+ °C/century = bad -> worse**

      2.5 °C ECS -> 4+ °C ECS = bad -> worse**.

      Long-term warming rate inferences from < 2-3 decades of data is crossing into a loss of effective resolution, and hence comments based on such have poor utility. Of course, low rates of warming obtained by such 'analyses' are manna for inactivist policy, which in the end is what a lot of this babbling is about.


      [*water, top soil, phosporus, habitable space - even, eventually, some fissionable elements and certain other rare materials]

      [**where 'worse' = worse -> worst]

      Delete
    15. You know full-well that that I am claiming no such thing: cease and desist with the verballing.

      1. I was asking an honest question.
      2. Is this the same Bernard J who name-calls and verbally abuses me in every second post? if so you have a real hide to ask me to "cease and desist" anything
      3. the rest of your post seems to be arguing that rate of warming has no relevance to policy (ie you have contradicted yourself).

      Again, I remind you that a senior climate scientist disagrees with your view. Argue with him. And when it comes to "inactivist policy", I suggest you take the matter up with the developing world as they seem intent on building 100s of coal plants regardless of the rate of future warming.

      even, eventually, some fissionable elements

      Huh?

      Delete
    16. "1. I was asking an honest question."

      Wrong.

      You said "If you are suggesting that rate of warming has no relevance to ecological impact (and policy), I think you should make your case", which is not a question but a leading statement.

      "2. Is this the same Bernard J who name-calls and verbally abuses me in every second post?"

      I said that you were "verballing" me, not verbally abusing me. If it's not clear, I was using the definition where a person puts words into another's mouth.

      As to being called names, if you are inclined to make ignorant statements about science don't be surprised when someone uses an appropriate descriptor to label your claims.

      "3. the rest of your post seems to be arguing that rate of warming has no relevance to policy (ie you have contradicted yourself)."

      Wrong again.

      I was addressing your comment "I am certain that Rosenthal is assuming the difference between decades and millennia in warming rate is relevant" in the context that differences in short-term and long-term rates of warming will have little (but not absent) effect on the outcomes at equilibrium. Parse my comment carefully and you will (perchance) grok my meaning.

      And in case it's not clear, I distinguished the effect that differences in rates of warming over different time-scales can have on policy by pointing out that inactivists are trying to use the current "low" rates of warming, resulting from 'noise' in the signal, to camouflage the underlying trajectory. I also pointed out that even if the low rate of warming were maintained beyond what is noise in an inappropriately-taken short time-span, this only delays the inevitable rather than 'disappearing' the inevitable.

      It's only in the minds of denialists and their ignorant/unaware audiences that the tricksy misrepresentation of the underlying significances of the numbers seems plausible.

      Delete
  11. Picked up Diaz. Found him et al to have collected a scattering of climate-changed phenomena over the world in terms of both temp and precipitation during the MWP.
    Taking temp it is clear from Diaz et al that:

    1) Though the climate-changed patterns appear to have been global, the direction of change was not (e.g. suggested cooling of the tropics during 'our' MWP) which contrasts the modern, truly global climate change;

    2) Like the LIA the process was NOT synchronous i.e. different regions experienced max warmth (or re LIA, max cold) in different decennia or even centuries; this also contrasts with recent decennia;

    3) During the decennia of maximum MWP warmth temps on 1/3 of the globe may have reached or slightly surpassed those of the modern epoch (mentioned as 1950 onwards); but temps on 2/3 of the globe have not done so at all.

    The claim "the MCA was a period of global and synchronous warmth that matched or exceeded that of the present." is therefore false re both adjectives and this is according to Diaz et al. Whose research was course bloody relevant.

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  12. It might be worthwhile for some, the Rosenthal paper is here for free
    http://www.seas.harvard.edu/climate/seminars/pdfs/Rosenthal_Science_2013.pdf

    Why are deniers so obsessed with a warmer than today MWP? It's basically an extension of the 'it was warmer in the past when there was low CO2, therefore CO2 is not the cause of global warming' flawed logic. For that logic to apply in the first place, you have to first ignore the fact that CO2 is thermally resistant and is a proven greenhouse gas. Deniers are always quick to try and disprove the greenhouse gas warming model, but never try and replace it with a 'better' model. In their mind, all they have to do is show that the MWP was warmer and then therefore the greenhouse gas warming model is wrong and it's all 'natural', but that is totally flawed logic. Even if the MWP was warmer, what it would in fact show is that the earth's climate is more sensitive to solar forcing and has a higher internal variability, and therefore would be also more sensitive to CO2 forcing and would be MORE prone to extreme events. The fact that the MWP is cooler than today's climate is a good thing.

    Also, I think there is little doubt that the MWP and LIA were global events, but there is little evidence that it was globally warmer. Yes, there were some regions that were warmer than today, but on average, the globe was much cooler than todays climate.

    One of the best proxy's to determine that is the rate of sea level rise. If the MWP was globally warmer, the prediction would be that the sea level rise rate would also be the same as today. In fact you would predict that it would be higher than today since the MWP was around for much longer.

    Here is a paper looking at sea level rises over the last 2,000 years.
    http://www.pnas.org/content/early/2011/06/13/1015619108.full.pdf

    "Sea level was stable from at least BC 100 until AD 950. Sea level then increased for 400 y at a rate of 0.6 mm/y, followed by a further period of stable, or slightly falling, sea level that persisted until the late 19th century. Since then, sea level has risen at an average rate of 2.1 mm/y, representing the steepest century-scale increase of the past two millennia."

    Sea level rise is now at about 3 mm/y, a rate that is 5x more than during the MWP. With that evidence it is very hard to argue that the MWP was globally warmer than today.

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  13. I don't have time to moderate all the comments right now or several of the above would have been deleted already. In the meantime I've switched to comment moderation so be patient. Your comment will appear eventually provided it complies with the comment policy.

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  14. I'm wrapping this up now.

    To summarise the Rosenthal13 discussion - the authors found that the MWP and LIA were global events. Many other papers (see main article) suggest that the MWP at least was not synchronously global (as a peak warming). Global temperatures dropped after the medieval period to the low of the Little Ice age. At both periods global surface temperatures were likely less than half a degree from the 1881-1980 mean.

    It is very unlikely that global temperatures in the MWP were warmer than those of today, which are 0.7-0.8 higher than the 1881-1980 mean (GISTemp), or 0.2 to 0.3 degrees warmer than the peak of global surface temperatures in medieval times.

    Rosenthal13 found that the rate of change of ocean heat content between 1955 and 2010 was 15 times greater than previous - as shown in Figure 4b of their paper and as described by them in the press releases.

    All the repetition here is very tiring. The references have been provided in the comments, so readers can check for themselves the various notions put forward by everyone above.

    This article was not about Rosenthal13. I'd normally not let things to off the rails so much but, like I've said elsewhere, I'm not able to spend as much time here as usual - so apologies to everyone.

    I'm not bothering with publishing the comments in the moderation queue that added nothing new to the discussion.

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  15. Sou,

    Are you really not going to publish my comments about the "findings" of the Rosenthal paper? I was called a liar and a troll for my statements that the paper did not "find" current warming to be 15 times faster. But, it didn't. Even using their original data, and assuming it is a useful comparison, the math is that it was 10 times faster. But now they corrected the data, and it is only 7.22 times.

    The interesting part is that they acknowledge that the error has "no bearing on the main conclusions of the paper." This is because the 15 times statement was never a "finding" of the paper.

    I seem to remember you saying that I don't know how to read a paper. Now who is it that doesn't know how to read a paper? And, why won't you acknowledge the true state of the science as I have been accurately describing it? Your other commenters are posting in error. Your summary wrap up is in error. Do you care?

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    Replies
    1. Give it a rest, Anonymous. You've been granted more than 80 comments to this article so far not counting the ones that I deleted, which is overly generous of me. Especially considering the appalling way you started out.

      If you can't express your opinion on Fred Singer's idiocy in 80 plus comments then you are very poor at communicating.

      As for your "accuracy" - your comments that remain here tell the tale. The first deleted comments of yours were far from accurate and many of your other comments were not better from what I've seen. I doubt too many other people could be bothered reading the mess it's all turned into. I've much better things to do.

      As for warming - using the corrected data from Rosenthal13, they estimated that between 1965 and 2010 the Pacific Ocean warmed at more than seven times faster than between 1600 and 1950, which is only 350 of the 10,000 plus years of the Holocene. For the previous centuries there was a loss of ocean heat. So once again you are being highly selective.

      Here are some numbers:

      2 - 7.5 Ka -5.5E+21 ∆Ho J/century -0.02 ∆T °C/ century
      1700-1100 CE -3.4E+22 ∆Ho J/century -0.15 ∆T °C/ century
      1950-1600 CE 1.8E+22 ∆Ho J/century 0.08 ∆T °C/ century
      2010-1965 CE* 1.3E+23 ∆Ho J/century 0.24 ∆T °C/ century

      No matter which way you look at it, by their estimates, in the past 40 years the warming is dramatic.

      http://www.sciencemag.org/content/342/6158/617/suppl/DC1

      Delete
  16. I seem to remember you saying that I don't know how to read a paper.

    No, that's not what I said. I referred to your comment that you wouldn't consider the paper and wrote:
    -----------------------------
    To Anonymous:
    I was going to read your Diaz paper until I saw...etc

    Since you are not familiar enough with science to be able to judge a paper on its merits, you have no business commenting on science at all.

    ---------------------------

    Which is yet another demonstration of what other people here have been complaining about.

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