Loehle: Vindication

Guest Post by Craig Loehle (cloehle -at- ncasi.org)

When I published my 2000 year reconstruction (Loehle, C. 2007. A 2000 Year Global Temperature Reconstruction based on Non-Treering Proxy Data. Energy & Environment 18:1049-1058) and the subsequent correction with better confidence intervals (Loehle, C. and Hu McCulloch. 2008. Correction to: A 2000 Year Global Temperature Reconstruction based on Non-Treering Proxy Data. Energy & Environment 19:93-100) it was an immediate hit in the blogosphere.

At the same time, I have been repeatedly insulted about it on the web. It is claimed that it has been debunked, is junk, that E&E is not a “real” journal, that I’m a hack, that I “only” used 18 series (though 2 were composites covering China & North America), etc. In the ClimateGate emails, Mann called it “awful” (which I’ll take as a compliment!). Lot’s of fun. In this post I demonstrate perhaps a little vindication.

A new reconstruction is now out (Ljungqvist, F.C. 2010. A new reconstruction of temperature variability in the extra-tropical northern hemisphere during the last two millenia. Geografiska Annaler 92A(3):339-351). Many past reconstructions have used bristlecones and similar trees with strange growth forms, and then weighted these heavily. Ljungqvist drops these data from the US Southwest and from Mongolia. He uses more data for the older periods and only uses long records (though not all 2000 yrs, as in my reconstruction). Some of his data overlap with mine, but not too much. He uses the CPS (Composite Plus Scale) method favored by dendro paleo Team members. Here is the abstract.

ABSTRACT. A new temperature reconstruction with decadal resolution, covering the last two millennia, is presented for the extratropical Northern Hemisphere (90–30°N), utilizing many palaeotemperature proxy records never previously included in any largescale temperature reconstruction. The amplitude of the reconstructed temperature variability on centennial time-scales exceeds 0.6°C. This reconstruction is the first to show a distinct Roman Warm Period c. AD 1–300, reaching up to the 1961–1990 mean temperature level, followed by the Dark Age Cold Period c. AD 300–800. The Medieval Warm Period is seen c. AD 800–1300 and the Little Ice Age is clearly visible c. AD 1300–1900, followed by a rapid temperature increase in the twentieth century. The highest average temperatures in the reconstruction are encountered in the mid to late tenth century and the lowest in the late seventeenth century. Decadal mean temperatures seem to have reached or exceeded the 1961–1990 mean temperature level during substantial parts of the Roman Warm Period and the Medieval Warm Period. The temperature of the last two decades, however, is possibly higher than during any previous time in the past two millennia, although this is only seen in the instrumental temperature data and not in the multi-proxy reconstruction itself. Our temperature reconstruction agrees well with the reconstructions by Moberg et al. (2005) and Mann et al. (2008) with regard to the amplitude of the variability as well as the timing of warm and cold periods, except for the period c. AD 300–800, despite significant differences in both data coverage and methodology. reprint available from author: fredrik.c.l@historia.su.se


Fig. 3. Estimations of extra-tropical Northern Hemisphere (90–30°N) decadal mean temperature variations (dark grey line) AD 1–1999 relative to the 1961–1990 mean instrumental temperature from the variance adjusted CRUTEM3+HadSST2 90–30°N record (black dotted line showing decadal mean values AD 1850–1999) with 2 standard deviation error bars (light grey shading). data available at ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ljungqvist2010/ljungqvist2010.txt

Gee, this looks kind of familiar. Let’s see how this looks overlaid with my graph. I centered both on their respective long-term mean values (I did NOT rescale) and got the following.


x-axis is Calendar date AD and y-axis is anomaly temperature deg C.

There is excellent agreement over the past 1100 years (r = 0.86) with less agreement prior to that (r = 0.6 for entire record). My peak temperature occurs about 100 years earlier, but I agree with the new reconstruction which has a peak closer to what Craig Idso has identified from his MWP project. The two graphs agree on the warming trend from AD 250 to AD 900, though differ in the rate.

The new recon shows the Roman Warm Period, which I agree is probably more correct than in my graph. So, a new paper with much more data, using the “approved” CPS method gets essentially the same result as I got.

I would also note that Moberg et al. 2005 in Nature (the low-frequency signal component) looks very similar (but he is an approved person, so no one gives him grief about it). No unprecedented warming in recent decades, just a repeat of what looks to me like a periodic pattern of warming and cooling.

The MWP looks real.

About these ads
This entry was posted in Paleoclimatology. Bookmark the permalink.

270 Responses to Loehle: Vindication

  1. D. Patterson says:

    Well Done! A toast of sparkling apple cider to you, carbon dioxide and all….

  2. Espen says:

    Excellent! This makes so much more sense than the hockey sticks. I must say it’s worrying to note that there might be some 1000 year cycle there. What if we are soon slide into a multi-centennial cooling trend again? Will it dip deeper than the LIA – possibly starting a new glacial? Or will we be saved by co2?

  3. Mike Haseler says:

    As I’m doing an archaeology course, I find this fascinating because it finally starts to show the kind of temperature variation that archaeologists have known about and talked about whilst the climate “scientists” told the world that there was no historic temperature variation.

    The thing that I could never understand, is that if “warming” is bad, and if the current warming is “unprecedented”, how come archaeologists always refer to cooling as being bad and the social and political impacts of past temperature change were always massive, whilst the present “catastrophe” seems to have had negligible affect on the rising human population (irony!)

  4. R.S.Brown says:

    So, when various persons and institutions call the recent warm
    temperatures “unprecedented in the last 1,000 years”, they might
    be telling sort-of the truth based on selective data analysis…

    But if they’d say “unpecedented in the last 1,100 years” that
    would be generally refuted by Ljungqvist 2010.

    If they say “unprecedented in the last 1,300 years” they’re treading
    into out right lie territory.

    Obviously those who support Mike Mann’s interpretation of the
    past and present temperature reconstructions, and the
    accompanying future model projections will stick with “1,000
    years” for a while longer.

    future

  5. Adam Gallon says:

    It’d be interesting to stick in a graph of one of “The Team’s” reconstructions.
    In terms of roughly comparing yours & Ljungqvist’s results, the shapes are similar over the past 1500 years, but before that, not really.
    Ultimately, it depends upon how reliable the proxies are, do yours exhibit “divergence” compared to the thermometer record?

  6. Peter H says:

    Is it appropriate to compare a global reconstuction with a Northern Hemisphere one? Are the two hemispheres the same?

  7. Cassandra King says:

    The truth will always come out in the end, there is nothing special or alarming the slight warming that ended a few years ago and we know that the so called anthropogenic CO2 effect cannot have the effect claimed for it.
    Natural cyclic cooling is on the horizon and although we do not yet know the possible extent of the coming cooling should we not be using the precautionary principle to prepare ourselves for the negative impacts of a cooling planet?

  8. Alan the Brit says:

    Excellent post. There are indeed similarities in both graphs shown, with areas of divergance in both too. I would be very surprised to see an exact match, if fact I would be positively worried if they did match, rather like the Hockey Stick & the Jesus Papar!

    Cassandra hits the nail with the issue of cooling. With alleged claims that warming causes cooling & vice-versa all we hear about is catastrophic warming from the warmistas. If warming does cause cooling – yeah right! – then why is there no effort to address cooling, rather than just warming?

  9. Dodgy Geezer says:

    “…I would also note that Moberg et al. 2005 in Nature (the low-frequency signal component) looks very similar (but he is an approved person, so no one gives him grief about it). ..”

    Aha, but he says the magic words!

    “..The temperature of the last two decades, however, is possibly higher than during any previous time in the past two millennia, although this is only seen in the instrumental temperature data and not in the multi-proxy reconstruction itself…”

    So long as your paper contains SOMETHING which can be used to justify the political and financial shenanigans which are now deeply embedded into the world’s establishment it will be acceptable. All you needed to do was to end your last paper by saying something like: “Of course, this finding does not completely disprove the Global Warming hypothesis on its own..” and you too would be allowed to attend conferences with slap-up meals and lots of CO2 emissions….

  10. Bruce of Newcastle says:

    Dr Loehle, can you comment on the 1950-present period? I expect certain people will point to the late upswing and say “doom, doom”. The effect of pCO2 on tree growth however seems pretty big, and if not corrected could be biassing the swing “upwards”.

  11. John Marshall says:

    Good work. We know, from archeological evidence, that past warm periods actually happened. The Roman, for instance, must have been warmer than today because they grew red grape varieties north of York, in UK., and these same varieties grow from Dijon south in France some 300 nautical miles south. (5 degrees of lat.). During the Little Ice Age the river Thames froze enough to hold ice fairs and roast beef for the masses. It does not freeze today. Climate changes but the only thing that does not change in sync is CO2.

  12. tokyoboy says:

    In his 2010 book “Climategate” Brian Sussman cites several researches which suggest that the MWP was warmer by 1.0 to 1.2 degC than the present, and those researches cover a wide geographic range not limited to northern hemisphere. As long as Europe is concerned, some reserches appear to strongly indicate that the MWP was some 1.2-degC warmer, based on wine production in England or the old treeline in German highlands. Can these be reconciled with the only 0.4 degC warmer MWP as presented by Dr. Loehle and others above??

  13. Ern Matthews says:

    I don’t think it matters one way or the other, Social Fascism will find a way to power. I don’t like the thought of all that shoveling this winter. :/

  14. Kiminori Itoh says:

    Congratulations! An important part of “the fog from the IPCC” is now disappearing.

  15. Stephen Wilde says:

    I fear they are still holding to the hockey stick scenario by suggesting that the thermometer record of recent warmth is to be preferred over the earlier proxy methods.

    This is simply a continuation of the ‘Nature Trick’ by other means.

    Nevertheless it does fully vindicate Craig’s work whilst attempting to remove it’s significance.

    I think Anthony’s work on the appalling quality of temperature measuring sites and the work of others on all those spurious (mostly upward) adjustments should deal with the thermometer issue if any common sense is aplied.

    Unfortunately the climate propaganda of the last 20 years is so heavily embedded in the minds of policy makers ( the UK’s William Hague for one) that it is going to be like turning around an oil tanker in a bathtub to correct the damage already in the political system and so called ‘scientific’ establishment.

  16. Mike Haseler says:

    Cassandra King says: September 28, 2010 at 12:55 am

    The truth will always come out in the end, … Natural cyclic cooling is on the horizon“.

    Cassandra, the presence of an apparent “cycle” in global climate is no more evidence of cycles in the climate than the presence of an apparent “warming” trend. Both these stem from a fundamental misunderstanding of the noise component in global climate. Unlike the “friendly” white noise (which seems to be all climatologists understand) which is dominated by high frequencies and so rapidly averages to the “real” signal, global climate is characterised by 1/f type noise which is dominated by low frequency noise (i.e. by long term random drifts, turns and other behaviour characteristic of a drunken walk).

    Unlike the Mickey Mouse noise dealt with in basic science degrees, 1/f noise doesn’t yield the “true” signal by simple averaging, instead you can get just a very clean looking bit of noise!!! Noise that appears to be a signal, appears to be a trend or a cycle but which is just random fluctuations.

    This is because high level of the long term noise is almost indistinguishable from any long term signal and simply removing the relatively smaller component of short term noise from the temperature signal does very little to enhance the “real” temperature signal relative to the high level of random (long-term) variation.

    This is where all of climate “science” has gone wrong. They have made the very basic mistake of believing that if they average the temperature signal over, e.g., a decade, then the noise disappears and what they are left must be the meaningful signal.

    In reality, all they may have done is cleaned the noise: made the long-term random fluctuations that dominate global temperature appear to be “something”. That is why we must not start talking about “cycles” in the climate unless we have very strong rigorous statistical proof for such concepts, proof based on mathematical analysis not on climate “science” type hunches and jumps to ill-conceived conclusions.

  17. Laws of Nature says:

    Dear Craig,

    interesting reconstruction . .
    Do you get the same result with your methog and this data?
    What would be the result of a McShane and Wyner-type of analysis for your and this reconstruction?

    All the best,
    LoN

  18. rbateman says:

    Cassandra King says:
    September 28, 2010 at 12:55 am

    We should be applying the precautionary principle here: The first 1000 years was warmer than the 2nd 1000 years. That would be the slow grind down from the Interglacial, of which there are 8 ?? in the last million years.

    The Loehle study looks very similar to a 2000 yr tree ring study taken from the Yolla Bolly Middle Eel Wilderness, though the tree ring only shows wet/dry periods. A monster El Nino shows up in the middle of the MWP.

  19. John Finn says:

    John Marshall says:
    September 28, 2010 at 1:27 am
    Good work. We know, from archeological evidence, that past warm periods actually happened. The Roman, for instance, must have been warmer than today because they grew red grape varieties north of York, in UK., and these same varieties grow from Dijon south in France some 300 nautical miles south. (5 degrees of lat.).

    The romans *attempted* to grow grapes – rather than transport them, I guess. They may have been partly successful but the grapes were, reportedly, of not good quality.

    During the Little Ice Age the river Thames froze enough to hold ice fairs and roast beef for the masses. It does not freeze today. Climate changes but the only thing that does not change in sync is CO2.

    The Thames has frozen numerous times throughout history – including on a number of occasions during the MWP and roman ‘warm’ period. The reason it hasn’t froze as much since the mid-19th century is due to the embankment and the demolition of the old London bridge. The river now flows quicker than it did in the pre-19th century era so there is less opportunity for it to freeze.

    That said, the Ljungqvist reconstruction looks about right for the NH (30N-90N). Certainly the post-1650 period seems to agree quite well with the CET record which shows the same sharp dip in the 1690s and the maunder period, in general, about a deg or so cooler than modern day temperatures. Also note there is nothing particularly remarkable about the Dalton period (1800-1830) – a point I have repeatedly made but for which I have been much criticised.

  20. Tenuc says:

    Good to see your work ‘replicated’, Craig. The truth will always out.

    Also good to see that the Middle-age/Roman climate optimum and the Little Ice Age showing up again nice and strong! Shows how the truth was distorted by the IPCC cabal of cargo cult climate scientists to support their ridiculous conjecture of CAGW. The coming cold over the next few years will vindicate CO2 and show the world that ‘it is the I think the sun, stupid’ which instigates weather regime/climate change.

    Nothing new or alarming happened to climate during the 20th century, just the normal up and down oscillations of quasi-cycles caused by the deterministic chaos which drives our complex climate.

  21. Juraj V. says:

    Without the hockey stick, the AGW is a house of cards.

    http://i55.tinypic.com/28k1yft.jpg

    which warming? which unprecedented rate of climate change? which never-heard before temperatures?

  22. rbateman says:

    John Finn says:
    September 28, 2010 at 2:58 am

    Actually, John, the Dalton is remarkable for what did not happen: Warming. There is no rising edge in the period. It is also much lower in variance, which makes it a truly cool period, as evidenced by widespread historical records of the time.
    You should also note that it came on the heels of a sudden Arctic Warming, which got the Brits all excited and cost many adventurers thier lives. We just found the wreck of the Investigator this year. Poor lads never had a chance.

  23. Christopher Hanley says:

    Following Mike Haseler’s post (12:48 am), climate oscillations have probably been a powerful factor in population movements.

    Famously, around 10,000 BC, hunters from Siberia were able to reach the rich ‘gamelands’ of America via a land bridge and Canadian ice corridor.

    The MWP coincides with the Norse settlement of the southern tip of Greenland.

    The half degree slide c. 200 – c. 600 coincides with the great invasions and migrations which threw the civilized world into disarray.
    AD 400 – 600, the teutonic speaking tribes (Goths, Vandals etc.) pressed down from the north into Italy, Spain and Balkans, the nomadic Siberian tribes (Huns, Avars, Magyars and Turks) into central Europe, the White Huns into Persia and northern India.
    The Eastern Empire (Byzantium) probably survived until mid-fifteenth century probably because of natural barriers (Caucasus and deserts).

  24. Steve says:

    What about the slope of the last 300 years? It is by far the steepest section of the graph. That seems to fit in well with industrialization being the cause for warming. For my part, I wish everyone would believe in CO2 warming and help to get America off of foreign oil. The global warming socialism can’t be any worse than the Military Industrial bankruptcy/facism that has been going on.

  25. Scarlet Pumpernickel says:

    This is the biggest scam in history because people’s lifetimes are too short. It’s like volcanic eruptions, people would see a mountain that has not erupted for 400 years and say, hey that didn’t erupt and plant their crops all around it. The same with the warmers denying the medieval warming, we should call them the deniers, as they are ignoring all scientific and historical evidence and they have no explanation on why the climate changed in the roman warming, medieval warming, and little ice age. All connected to significant changes around the world, civilizations rose and fell because of these periods and the El Nino cycle.

    The main objective in this exercise is power, the power to see who can live and die, since who controls the price (overinflated) of energy, controls food and freedom and the power to make people live and die in poor countries.

  26. richard verney says:

    Whilst the position with respect to the SH may be less certain due to a lack of proxy records and historical record, as far as the NH is concerned, we know as fact that this was warmer than today around the time of the Viking settlement of Greenland. As the Greenland glacier retreats, we are beginning to see Viking settlements and, of course, they were actually farming where they settled. Someone should calculate how much warmer northern latitudes would have to be so as to permit farming around the Viking settlements in Greenland. This would then give a reference point for temperature anomolies around 1000AD in comparison to those seen today.
    It is clear that Ljungqvist has underestimated the temperature anomoly around 1000AD. If Ljungqvist is correct that in 2000AD the temperature anomoly stood at 0.3 degC then in 1000AD it must have stood considerably higher than that figure

  27. Pleione says:

    “Unfortunately the climate propaganda of the last 20 years is so heavily embedded in the minds of policy makers …”

    They don’t really care about climate or science.

    They just love the idea of being able to tax and control us.

    It’s all about the money.

    AGW will die that same day that politicians will realize that they can’t make additional money on it.

    Regards.

  28. Jimmy Haigh says:

    25.Steve says:
    September 28, 2010 at 3:51 am
    “What about the slope of the last 300 years? It is by far the steepest section of the graph. That seems to fit in well with industrialization being the cause for warming.”

    How about looking at this the other way? How about warming being the cause of industrialisation? Just a thought…

  29. Ljungqvist says about his reconstruction: ” Our temperature reconstruction agrees
    well with the reconstructions by Moberg et al. (2005) and Mann et al.
    (2008) “, thus vindicating Mann et al….

  30. tonyb says:

    Steve said

    “September 28, 2010 at 3:51 am
    What about the slope of the last 300 years? It is by far the steepest section of the graph. That seems to fit in well with industrialization being the cause for warming. For my part, I wish everyone would believe in CO2 warming and help to get America off of foreign oil. The global warming socialism can’t be any worse than the Military Industrial bankruptcy/facism that has been going on.”

    The period 1698-1730 is the steepest part according to actual instrumental records. Temperatures have generally been rising ever since that earlier date. If you believe the graph from that date is an indication of the effect of trivial industrialisation at that time it is effectively saying we can no longer colonise this planet as surely we can never again emit those extremely low levels of Co2?

    Agree with you about the need to get off foreign oil but that is a different argument which we could much better address if we werent spending bilions mitigating something that doesnt really need to be mitigated.

    tonyb

  31. Dixon says:

    Interesting work. I wish more could be done using ‘weight of evidence’. Combining archaeological information with historical records and proxy data would reap dividends.

    Mike Haseler – you are spot on with why climate science has gone so wrong!

  32. Bill Yarber says:

    Stephen Wilde

    How can you possibly believe the “thermometer” record over the past 30 years with all the “manipulations” being done under the guise of “adjustments”?

    1 Anthony and his volunteer team have demonstrated a greater than 1 deg F error in the US record due to poor siting or stations.

    2 Hansen’s graph from ’97 is strikingly different from his 2007 version – with the 1930’s cooler and the 1990’s warmer.

    3 More than half of the data sites no longer report and the majority of the missing sites are from rural areas – vastly skewing today’s mean temperature value.

    4 The UHI adjustment has become positive when it should be negative. See point 2 for proof.

    5 History and geology book, written prior to the AGW madness, all confirm:
    Roman Warm Period
    Midieval Warm Period
    Little Ice Age

    All of which Dr Mann ignores and wants us to forget so the “unprecedented” BS becomes believable! Dr Mann’s “hockey stick” graphs are a [/snip], as is AGW.

    Your statement in favor of the hockey stick has seriously degraded your credibility!

    Bill Yarber

    [REPLY: How about we stick to adjectives like..... balderdash? .... ~bl57mod]

  33. thefordprefect says:

    the mwp in historical documentation:
    http://booty.org.uk/booty.weather/climate/751_999.htm

    the LIA in historical documentation
    http://booty.org.uk/booty.weather/climate/1650_1699.htm

    Unfortunately people4 only record oddities and extremes so not a full record.

  34. thefordprefect says:

    What is interesting in the graph is that the MWP and LIA is only+- 0.5 from the nominal. These temperatures are seen as significant. We currently have +0.6C with a possibility of more than +1C and this is seen as insignificant

  35. simpleseekeraftertruth says:

    Steve says:
    September 28, 2010 at 3:51 am

    Have you not been paying attention Steve?

  36. Craig Loehle says:

    Re: amplitudes. Please remember that my paper uses a 29 yr smooth and the new one is decadal means, so short term variation is not shown. Also, many records used have dating error and averages of those will damp out peaks.
    Mike Haseler on 1/f noise. It is certainly true that 1/f noise can trick one into thinking you found a signal, but that does not prove that cycles do not exist. My new paper on cycles is in press in a Canadian journal.
    Laws of Nature: you ask if I tried my method with the new data. My method requires that all proxies be calibrated to local temperature, but not all of these were.

  37. tallbloke says:

    Congrats to you Craig. I got a copy of your book, which I’ll find time to read soon once winter is in.

    The latest reconstruction from Ljungqvist is thought provoking. The ~1000 year cycle period got skewed in the last millenium by the Maunder minimum. To me, this says that there is a natural cycle of ~500 years warm – ~500 years cold, which operates regardless of additional accentuation or diminution from extra deep Solar grand minima.

  38. Ric Werme says:

    Leif Svalgaard says:
    September 28, 2010 at 4:25 am

    Ljungqvist says about his reconstruction: ” Our temperature reconstruction agrees
    well with the reconstructions by Moberg et al. (2005) and Mann et al.
    (2008) “, thus vindicating Mann et al….

    I was going to comment on that from a different direction, Criag, did Ljungqvist reference your work?

    Cynically, perhaps “vindicating Mann et al…” was done as part of dance to get the paper past the editors.

    If Dr. Roger Pielke Sr. had just casually mentioned “vindicating Mann et al…” somewhere in his letter to Nature instead of http://www.surfacestations.org, his letter would have been published.

  39. Craig Loehle says:

    “Warm” posts an overlay of the new recon with Mann 08 EIV. The most recent alarming rise in the two graphs is only possible with the new recon if you splice the instrumental record on, which I did not do in my overlay.
    Steve at 3:51 attributes the 300 yr run up to industrialization. My dear boy, CO2 did not become elevated until the 1940s. Causation has a time direction. For much of the early industrial revolution the power was wood and water in any case.

  40. hunter says:

    Stick to your guns. Good work.
    Thank you for posting this where we can see it.

  41. “Our temperature reconstruction agrees well with the reconstructions by Moberg et al. (2005) and Mann et al. (2008) with regard to the amplitude of the variability as well as the timing of warm and cold periods, except for the period c. AD 300–800, despite significant differences in both data coverage and methodology. reprint available from author”

    Perhaps my eyes deceive me, but I don’t see much of a warming trend from AD 300-800 in their reconstruction. The main difference between this reconstruction and that of Mann et al, oddly enough, seems to be that this one is -cooler- during that period.

    Also, I’m not sure what the dashed line is supposed to represent on your graph. If you are grafting the temperature record, it looks a bit odd, given that NH land temps have increased ~1 C in the last 130 years.

  42. Craig Loehle says:

    The question was posed did I compare to Mann 08? I never did because he used some invalid proxies, because I’m never sure what he did, and because I don’t trust the EIV method.

  43. Craig Loehle says:
    September 28, 2010 at 5:37 am
    For much of the early industrial revolution the power was wood and water in any case.
    Wood is CO2 emission-free?

  44. mikef2 says:

    John Finn – cheap shot at the Thames freezing over statement.
    I know certain people are desperate to try and show that the well documented frost fairs were not part of any cooler climate, but down to particular flow rates on the river, but really, you go too far. The other surrounding rivers also froze, other major rivers froze, in other european countries too. Its not just the Thames, so you can’t try to say “oh the Thames only froze over because its flow rate was sluggish” as if thats a way to dispute the general coolness of the era.
    For sure the Thames flow rate is affected, but I don’t think that affected the Avon did it?
    How desperate are you guys ..?

  45. mikef2 says:

    for peeps not following the logic…
    Its vital for warmists to dowplay the LIA, because a vindication of the existence of the LIA = natural variability bigger than CO2 response.
    Hence the Thames does not freeze over now ‘because we changed the flow rate’ or in other words “the Thames would still be freezing over until about 1970 when we affected the climate with our CO2 and made it much warmer, as up to then the temp has been the same for 1000s of years’…..
    You gotta larf…

  46. jorgekafkazar says:

    Steve says: “…The global warming socialism can’t be any worse than the Military Industrial bankruptcy/facism that has been going on.”

    Wrong. Global warming socialism includes a high religious factor, one that permits no dissent. Can you say, “Inquisition?” I knew you could. Well, actually, I didn’t. Nothing even close to Green Fascism has resulted from your putative “Military Industrial fascism,” bankrupt or not. The problems with our society today are largely due to liberal meddling, forcing lenders to float loans to people who couldn’t afford them, etc.

  47. steve says:

    Craig Loehle says:
    “Steve at 3:51 attributes the 300 yr run up to industrialization. My dear boy, CO2 did not become elevated until the 1940s. Causation has a time direction. For much of the early industrial revolution the power was wood and water in any case.”

    I have no idea what the point is regarding my post and CO2. I mentioned something that strikes me as obvious: industrialization and the largest and steepest temperature rise coincide. Coincidence? Maybe. The observation still stands.

    By the way, Craig, do have any idea how much of a creep you sound like when you use the patronizing phrase “My dear boy…”. It would be distasteful in person. In a blog, it makes you sound like ..well i don’t know but it makes me want to wash my hands or something.

  48. Slioch says:

    Before people here get too excited, and crack open too many bottles of champagne, I suggest they take a look at this:

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

  49. mikef2 says:

    Leif…..wood CO2 free?
    Yes I always wonder that. I guess its down to timeframes, the arguement being I suppose that by burning coal & oil we are reintroducing long ago sequestered CO2, whilst wood being reletively short term would have been part of a natural cycle anyway. Not sure how that argument stands up myself, anyone fancy doing the math?

  50. Craig Loehle says:

    Leif asks if wood is CO2 emission free–no on short timescales, but it grows back and soaks up CO2.
    To elaborate on an earlier point: Mann 08 get a huge blade (rapid and unprecedented warming in recent decades) by using bristlecone and similar trees with funky growth and also using upside down Tiljander sediment proxies. I do not use these and neither does the Ljungqvist paper, and thus neither of us gets a huge recent warming jump.

  51. Vince Causey says:

    Excellent work, but obviously uncompleted. Where are the adjustments to flatten out historical warmings?

  52. mikef2 says:

    Slioch…………..heh, oh look, Tamino shows a pretty deep LIA…has he told Michael Mann?

  53. simpleseekeraftertruth says:

    Leif Svalgaard says:
    September 28, 2010 at 5:59 am

    “Wood is CO2 emission-free?”

    As I understand it, wood is part of the short-term carbon cycle and one of its main drivers. Personaly, I hope it stays exempt from a ban on ignition of carbon fuels as I have found it impossible to light cigarettes from windmills reliably or from solar after dark.

  54. Phil. says:

    Craig Loehle says:
    September 28, 2010 at 5:37 am
    “Warm” posts an overlay of the new recon with Mann 08 EIV. The most recent alarming rise in the two graphs is only possible with the new recon if you splice the instrumental record on, which I did not do in my overlay.

    Actually you tried to do that verbally: “While instrumental data are not strictly comparable, the rise in 29 year-smoothed global data from NASA GISS (http://data.giss.nasa.gov/gistemp) from 1935 to 1992 (with data from 1978 to 2006) is 0.34 Deg C. Even adding this rise to the 1935 reconstructed value, the MWP peak remains 0.07 Deg C above the end of the 20th Century values, though the difference is not significant.”

  55. anna v says:

    Leif Svalgaard says:
    September 28, 2010 at 5:59 am

    Craig Loehle says:
    September 28, 2010 at 5:37 am
    “For much of the early industrial revolution the power was wood and water in any case.”
    Wood is CO2 emission-free?

    The cycle/CO2/wood/decay-or -burning/CO2/wood seems to me to be carbon neutral within the lifetime of trees:50 to 100 years?

  56. Craig Loehle says:
    September 28, 2010 at 6:39 am
    Leif asks if wood is CO2 emission free–no on short timescales, but it grows back and soaks up CO2.
    Yes, but with a delay of decades [up to century] and many of the forests back then are now gone. Europe is now not so wooded as it were, so not all CO2 is soaked up.

  57. Larus says:

    Dear Mr. Loehle,

    tamino seems unimpressed with your vindication, suggesting that you achieved the overlap in the two reconstructions (yours and Ljungqvist’s) by a dishonest sleight of hand: http://tamino.wordpress.com/2010/09/28/vindication/

    Would you care to comment?

  58. Leonard Weinstein says:

    Leif Svalgaard says:
    September 28, 2010 at 5:59 am
    “Wood is CO2 emission-free?”
    Yes! You cut down trees, burn the wood, and new trees or plants grow to replace the old trees. It is called renewable energy. The new growth take up as much energy as the amount released.

  59. Leonard Weinstein says:

    Takes up as much CO2 as released (not energy).

  60. Slioch says:

    The above post by Loehle is not a vindication of his earlier work. See:

    http://tamino.wordpress.com/2010/09/28/vindication/#comment-44572

  61. mikef2 says:

    As i understand it trees are not quite so dependable on the old CO2 soak up thing as we think, or perhaps I should say trees in temperate regions. At mature ages the growth becomes slow and CO2 take up slows. So its good to have lots of young plantation forests where the trees get cut down often, and replaced.
    But its a very moot point that a europe, that was quite a big place and decidely woody, now has very little woodyness at all.
    Thats why we should not be advocating recycled paper, its bad for tree growing, as it cuts demand to grow trees for paper.
    Sorry…going OT on a pet hobbyhorse…

  62. Larus says:
    September 28, 2010 at 6:54 am
    tamino seems unimpressed with your vindication
    A ‘better’ comparison might be to adjust both to agree on their overlapping part with the instrumental record.

  63. anna v says:

    Leif Svalgaard says:
    September 28, 2010 at 6:53 am

    Yes, but with a delay of decades [up to century] and many of the forests back then are now gone. Europe is now not so wooded as it were, so not all CO2 is soaked up.

    A problem worthy of climatologists. The woods were replaced by at worst grass at best wheat etc. What eats up more CO2? the fractal cover of dense grass “wall to wall” or the shaded woods ? Does hay carry more CO2/per year than equivalent woodland per year?

  64. Fredrik Charpentier Ljungqvist says:

    A comment from the author:

    Some remarks have been made suggesting that the amplitude of past temperature variability are deflated. It is indeed true and discuss in length in the article. The common regression methods do deflate the amplitude of changes in the reconstructed temperatures. This reconstruction shares this problem with all others.

    For the last 1100 years the errors bars between my new reconstruction, Moberg et al. (2005), Mann et al. (2008) and Loehle (2007) more or less always overlaps. They are clearly in major agreement despite differences in method and data and show a consistent other picture than pioneering “hockey stick” shaped reconstructions (e.g., Jones et al. 1998; Mann et al. 1999, Mann and Jones 2003).

    Concerning the remark on Greenland: Yes, it was more likely warmer on (southern) Greenland than it is now when the Norse settles there (around AD 985). However, the medieval warming was more prominent in this region (Iceland and Greenland) than in most other parts of the world. This will be discussed by me in two hopefully soon upcoming articles.

  65. Craig Loehle says:

    Steve: sorry if my attempt at humor sounded creepy. feel free to wash your hands. concerning industrialization causing global warming starting 300 years ago: industrialization per se can’t cause global warming, only by outputs of greenhouse gases and by changes in land cover. According to the IPCC and multiple attribution studies, greenhouse gases were not sufficiently elevated to cause any climate effect prior to world war 2. Land use change might have had some effect, though much of it began long before 300 years ago, so why the sudden jump then is not clear. If a 300 year run up was caused by land use change, then the models have it wrong because they blame most of the warming on greenhouse gases.
    Laurus asks about Tamino’s comment that I used a sleight of hand to compare the graphs. In order to compare the graphs, I shifted them each to a zero mean over the period. In this way one can compare different time trends. These are anomaly graphs, not absolute temperature graphs. Otherwise, I am not interested in what Tamino has to say.

  66. John Whitman says:

    Craig Loehle,

    Nice post. Appreciate the background and the update on paleo-reconstructions. Please do periodic updates and commentary on them. Those would be invaluable for all of us who are not experts in the paleo area. Thanks.

    I have read your book “Becoming a Successful Scientist”. I enjoyed it. I especially liked the section on bias. Also, I appreciated the occasional references to the history of science and to the related general problems in the history of philosophy. Those gave a valuable long term context to your treatment of science.

    Look forward to your new paper on cycles.

    If you are nearby, drinks are in order for the basic verification of your papers. I am in Northern NY State . . . . about 180 miles to the Canadian border.

    John

  67. latitude says:

    You have to figure, if a 1/2 degree was so insignificant in the past that it could be erased – giving us the hokey schick – then a 1/2 degree is no more important today….

  68. Smokey says:

    Phil. says:

    “…the MWP peak remains 0.07 Deg C above the end of the 20th Century values, though the difference is not significant.”

    Thank you for once again confirming the fact that natural climate variability caused the planet to become warmer more a thousand years ago than it is today.

    You can ring your alarm bells when you believe you’e falsified the null hypothesis, which you obviously have not; rather, you have confirmed it. Natural variability fully explains the current climate, as you inadvertently acknowledge by comparing the MWP with today’s temperature. There is no cause to invoke an insignificant and harmless trace gas to try and show that anything unusual is going on. It is not, and frantic arm-waving alarmism is simply a false cry of “Wolf!”

    There is no wolf. What we are observing is normal and natural climate change. It has all happened repeatedly in the past, and often to a much greater degree.

    Unfortunately, logic, open debate, and the scientific method are all anathema to the CAGW crowd.

  69. anna v says:
    September 28, 2010 at 7:11 am
    “not all CO2 is soaked up.”
    A problem worthy of climatologists….

    Biomass per square meter might be a clue. I don’t know the answer, though.

  70. Luboš Motl says:

    Tamino says that Dr Loehle shouldn’t have centered the temperature reconstructions around their long-term mean, before he compared them.

    Well, it depends what they claim to be their “anomalies”. They’re deviations from some “average” measured over a long run, and it matters whether it’s the whole millennium+ or just shorter part of the recent instrumental period.

    If it is the former, Loehle’s step is necessary. If it is the latter, it shouldn’t be there.

    But even if Loehle adds this step, his procedure is still the right one to compare the temperature changes of the two reconstructions at any moment in the past. And they agree very well – their agreement is visually clear. It would be interesting to compare many more reconstructions in this way – and in other ways. I am confident that MBH would fail miserably in the comparison with these newest reconstructions.

  71. Question for both Fredrik and Craig:
    When you plot ‘error band’, it has the same width independent of time. It would seem that the variance should depend somewhat on time.

  72. Phil. says:

    Craig Loehle says:
    September 28, 2010 at 6:39 am
    To elaborate on an earlier point: Mann 08 get a huge blade (rapid and unprecedented warming in recent decades) by using bristlecone and similar trees with funky growth and also using upside down Tiljander sediment proxies. I do not use these and neither does the Ljungqvist paper, and thus neither of us gets a huge recent warming jump.

    The reason you don’t get a recent warming is because your reconstruction ends in 1935!
    The Tiljander proxies do not cause a ‘huge blade’ in Mann 08 either.
    Ljungqvist refers to ” a rapid temperature increase in the twentieth century.” and does ‘splice’ the measured temperature to the end of his graph (dotted line).

  73. Fredrik Charpentier Ljungqvist says:

    As stated in the article (p. 341), the ”error bars” are calculated in the following way:

    “The standard deviation is somewhat larger in the first millennium of the reconstruction, probably primarily because of the decreasing number of proxies covering this period, but even so this deviation is not much higher than in the calibration period. To account for changes in the standard deviation between the records in the error bars, we have increased the width of the confidence interval with the same percentage as the standard deviation between the records in a given decade exceeds the mean standard deviation during the calibration period AD 1850–1989.”

  74. CRS, Dr.P.H. says:

    ” In the ClimateGate emails, Mann called it “awful” (which I’ll take as a compliment!).”

    Indeed it was! Hat’s off to you, Dr. Loehle, and well done!

  75. Phil. says:

    Leif Svalgaard says:
    September 28, 2010 at 7:32 am
    Question for both Fredrik and Craig:
    When you plot ‘error band’, it has the same width independent of time. It would seem that the variance should depend somewhat on time.

    Especially when the number of proxies used varies with time as in Craig’s case.

  76. TomRude says:

    To Warm: We all know the coming out of the LIA will result in a rise in temperature… if that is supposed to vindicate Mann…

  77. Enneagram says:

    Great work. There is a “trick” I was thinking about, after reading several years what it has been presented here in WUWT.
    It seems to me that:
    Maximum temperature records are Weather, while
    Minimum temperature records are Climate

    Real changes are detected “on the floor” -the minimum- reached temperatures: There it is the “symptom” of a changing climate.

  78. Craig Loehle says:

    The error bars in my 2008 paper vary with time based on the number of proxies available. I don’t plot them here.
    When one does a simple correlation between two sets of data, as I did above, it does not matter if one is offset by a constant x, the correlation is unaffected (try it Tamino). If one matches (sets a zero base) two series by a particular decade but the reconstructions have significant random error, then one may be up in that decade and the other down and you will introduce a spurious offset. It is erronious to think that any of these reconstructions are reliable at the scale of decades.

  79. rbateman says:

    Jimmy Haigh says:
    September 28, 2010 at 4:17 am

    How about looking at this the other way? How about warming being the cause of industrialisation? Just a thought…

    And and excellent thought it is. Bravo!
    Free time afforded by a warmer climate with less pressure from the forces of nature. Survival rates increase along with longevity as citizens become more productive and technological advancements arrive to keep the ball rolling.
    Many civilizations flourished in warmer times, and likewise floundered when the good times were over.

  80. dp says:

    Year 1000 to year 1700 shows a precipitous decline with no end in sight. They were all doomed – surely those in 1300 who commented on it and claimed it’s worse than they thought are exonerated. It’s probably a good thing they all rode it out as opposed to imposing global climate disruption taxes on future generations.

    It is interesting that the active range of variation (average) is less than 1.3º over the sample period. The range of activity is less than .5º in recent times. Yet this is enough to cause overturning of global economies, condemning third world people to living without benefit of modern energy, and to force them to convert carbon credits to flora as a means of livelihood. And the EU has ensured I’ll never visit there, again. And for what?

  81. Phil. says:

    Luboš Motl says:
    September 28, 2010 at 7:31 am
    But even if Loehle adds this step, his procedure is still the right one to compare the temperature changes of the two reconstructions at any moment in the past. And they agree very well – their agreement is visually clear. It would be interesting to compare many more reconstructions in this way – and in other ways. I am confident that MBH would fail miserably in the comparison with these newest reconstructions.

    Well Mann-08 agrees rather better with Ljungqvist-10 than Craig’s. Just a word to the wise apparently it is regarded as rude on this blog to refer to posters by their surnames!

    http://img534.imageshack.us/i/manncomp.jpg/

  82. Phil. says:

    CRS, Dr.P.H. says:
    September 28, 2010 at 7:47 am
    ” In the ClimateGate emails, Mann called it “awful” (which I’ll take as a compliment!).”

    Was that the re first version which contained numerous mistakes and had to be rewritten?

  83. robert says:

    It seems to me tamino did raise a valid criticism. Your centering technique makes the previous periods seem warmer than they would have been. You compare it to the 1961-1990 average but which gives the impression that the majority of the reconstruction is above that average. However as tamino points out, very little of it is above the 1961-1990 average. What is your justification for making previous periods seem warmer than they actually were on a skeptic website. I have a lot of trouble not accusing this post of being dishonest when you could have easily shown the actual reconstruction and how it compared to the 1961-1990 average. This deserves to be corrected and is pretty flagrant. I don’t even have much of a problem with your original paper, but this post here clearly makes the past look warmer than it was. I don’t care if you say you had to “center” it. It should be stated directly that your centering made it appear much warmer than it was rather than have it as a sidenote. If the science can’t speak for itself without your centering technique then clearly the science doesn’t support your conclusions.

  84. BillyBob says:

    “The temperature of the last two decades, however, is possibly higher than during any previous time in the past two millennia, although this is only seen in the instrumental temperature data and not in the multi-proxy reconstruction itself.”

    Translation: Only by splicing the instrumental record onto the end of the reconstruction can we claim todayis warmer than the MWP. The proxies suggest otherwise. Therefore we must conclude that our proxies are too low by 1-2C and the MWP is by far the warmest period int he last 1000 years.

  85. Fredrik Charpentier Ljungqvist says:

    I have noted in the post that there are a lot of (indirect) references to Mann et al. (1999) – the so-called “Hockey Stick Graph”. It is science history now.

    Any references to temperature reconstructions by Michael E. Mann should be to his 2008 and 2009 temperature reconstructions. They actually show an even warmer Medieval Warm Period than I do. I don’t think it is fair to refer to an outdated work (from 1999) when we have newer and better.

    As was shown in an earlier post today, my new reconstruction is practically identical with Mann et al. (2008) after c. AD 900. The same is true with Moberg et al. (2005). My reconstruction is also very similar to Loehle (2007) in shape although his reconstructed amplitude is larger.

  86. Craig Loehle says:

    Robert: My data end in 1935 due to too few proxies after that. How could I zero on 1961-1990? To repeat–these are NOT absolute temperatures but anomalies. Is one period warmer than another? This is what you can ask, not what was the temperature in the year 890 AD. Also, read my post just above about the validity of any particular decade. Since my alignment leads to broad agreement over 1100 years in both anomaly and trends and a correlation 0f 0.86, I stand by my approach.

  87. Slioch says:

    Smokey:

    said, “confirming the fact that natural climate variability caused the planet to become warmer more a thousand years ago than it is today.”

    Not according to Loehle 2008 it didn’t.

    According to Loehle 2008, the 29 year average global temperature centred on 1992 was marginally below the MWP peak by 0.07C.
    However, 1992 is not ‘Today’. If we wish to see how ‘Today’s’ temperatures compare with the peak of the MWP, (according to Loehle and his use of non-tree-ring proxies), then we can get an indication by taking five year averages to smooth values to see how temperatures have changed since 1992. We find that 2007 (the latest year for which a five year average can be taken) is 0.31C above 1992 (five year GISS anomaly 1992=+0.24C, 2007=+0.55C). Therefore, ‘Today’ (or as close to today as we can reasonably get) is 0.24C ABOVE the highest peak of the MWP, based on the data in Loehle 2008. [Of course, in order to make that point conclusively, we would need the 29 year global average centred on 2007, but we won't get that until after 2021.]

  88. E.M.Smith says:

    Espen says: What if we are soon slide into a multi-centennial cooling trend again? Will it dip deeper than the LIA – possibly starting a new glacial? Or will we be saved by co2?

    We will fall into a new glacial, just a question of when (and on geologic time scales, it’s “soon”… hundreds to a few thousands of years). We might even be started down “now”; but it would take a few thousand years to know for sure. While it can become cold quickly, the ice builds up slowly over 100,000 years. So it’s about 800 feet of ‘advance’ from the ice sheet toward NYC per year. You can walk further in one lunch hour per year… so if it were happening now you would have a hard time detecting that 800 feet inside the annual variation. We’ve had ice ages with high CO2 before. CO2 will not “save us”. Then again, we’ll have been dead several thousand years before it’s a problem for “them”…

    Mike Haseler says: As I’m doing an archaeology course, I find this fascinating because it finally starts to show the kind of temperature variation that archaeologists have known about and talked about whilst the climate “scientists” told the world that there was no historic temperature variation.

    The thing that I could never understand, is that if “warming” is bad, and if the current warming is “unprecedented”, how come archaeologists always refer to cooling as being bad and the social and political impacts of past temperature change were always massive, whilst the present “catastrophe” seems to have had negligible affect on the rising human population (irony!)

    That’s because archaeologists are classically trained careful scientists with a profound sense of history while “climate scientists” are the guys who liked video games and computer fantasy roll playing games but weren’t good enough to write Halo or design the X-Box. ;-0

  89. Douglas DC says:

    Here is a more modern documentaion of cold winters in Oregon-western in particular.
    http://www.oregonphotos.com/Portland%20Cold.html
    We will see this again. Ya think a PDO shift is the culprit?
    ’49-50′ winters were nasty. My Pop had to go back to horses and Bobsled to get the milk to town….

  90. DCC says:

    Steve said: What about the slope of the last 300 years? It is by far the steepest section of the graph. That seems to fit in well with industrialization being the cause for warming. For my part, I wish everyone would believe in CO2 warming and help to get America off of foreign oil. The global warming socialism can’t be any worse than the Military Industrial bankruptcy/fascism that has been going on.

    OK, what about it? The industrial revolution didn’t get started until the late 1700s. It was 1900 before fossil fuels came into common use in the USA.
    http://www.wou.edu/las/physci/GS361/graphics/US_consumption_1635-2000.jpg
    Why would a temperature increase anticipate CO2 increase? And there are a lot better ways to reduce oil consumption, but the “greenies” (and the Democrats) have worked against experimental breeder reactors in the US time and time again. Don’t let political attitude overpower your common sense. You have to have a replacement power source before throwing out the foundation of the world’s economy. Wind and solar simply cannot do the job.

  91. TomRude says:

    So Dr. Ljungqvist, we all agree we have a Medieval Warm Period and a Little Ice Age. And that the XX century is showing we are coming out of the LIA. Since those are proxies with there inherent calibration problem, this is mainly a qualitative understanding.
    You wish to refer to Mann et al. 2008 and forget Mann 1999. Fine. But this is forgetting the main and only reason the Hockey stick Graph has received the attention it did was because of its shape and flattening of the MWP making the XX century unprecedented.
    The fact that even Mann is now moving away from that extreme is no vindication, just his own survival strategy.
    The AGW un precedented claim is dead, pure and simple.

  92. CRS, Dr.P.H. says:

    Dr. Loehle, here’s the Climategate email you referenced:
    ====
    http://www.eastangliaemails.com/emails.php?eid=820&filename=1196872660.txt

    Mike,
Yes the 1990 graphic is in an Appendix. The last few are being regularly hassled
by Thorsten. The guy from EPRI (Larry) really wants something submitted soon.
So working here to get something in by end of Jan. Keith is going to get
it fast-tracked through the Holocene – well that’s the plan.


    The Loehle paper is awful as you know. So is another article on the IPCC process
in E&E. I did look at Climate Audit a week or two back – I got the impression
that McIntyre is trying to distance himself from some of these E&E articles by
saying we have to be equally skeptical about them as well.

    Cheers
Phil
    =====
    Cheers, Charles the DrPH

  93. E.M.Smith says:

    OMG! OMGOMG!!

    I get to provide some information to Leif! Like in National Treasure when the dodgy side kick gets to say “You mean there is something I know that you don’t know? Is this how you feel all the time?” ;-)

    Leif Svalgaard says:
    anna v says:
    “not all CO2 is soaked up.”
    A problem worthy of climatologists….
    Biomass per square meter might be a clue. I don’t know the answer, though.

    Hay runs about 2 to 10 tons / acre / year

    http://hayandforage.com/mag/farming_pursit_tons_per/

    while trees run about 10 to 50 tons / acre / year depending on species and after the first year of establishment:

    http://www.treepower.org/yields/main.html

    So a hay field will temporarily ‘sequester’ about 5 ton (on average) for a year, while a forest will ‘sequester’ about 20 ton (on average with wide error bands) per year for about 25 years as the stand matures.

  94. Stephen Wilde says:

    Bill Yarber says:
    September 28, 2010 at 4:48 am

    “Your statement in favor of the hockey stick has seriously degraded your credibility!”

    Eh ?

    I think you misread something !!

  95. Espen says:

    E.M.Smith: ice sheets accumulate slowly, but devastatingly cold climate comes quick. And glaciers may do real harm after just a few years of growth in the Alps and elsewhere.

    (glaciers are pretty from a distance, but in reality they’re looming disasters)

  96. mcates says:

    Ljungqvist says:

    I don’t think it is fair to refer to an outdated work (from 1999) when we have newer and better.

    As was shown in an earlier post today, my new reconstruction is practically identical with Mann et al. (2008) after c. AD 900. The same is true with Moberg et al. (2005). My reconstruction is also very similar to Loehle (2007) in shape although his reconstructed amplitude is larger.

    This is a fair statement from a scientific perspective, but when we look at the charts used to shape public perception this point loses its relevance.

    Unless one is going to aruge that the revised work will be used just as much as the old to reshape public perception. If that is your point then I would support that.

  97. Phillip Bratby says:

    A lot of the energy in the early days of the industrial revolution was from charcoal, produced from short-rotation coppicing. Hence the CO2 recycle time was just a few years.

  98. dp says:

    Glaciers are not a problem because they advance 800′ per year. They’re a problem because they grow in place. We don’t have to wait for a glacier to creep in from Canada to be concerned – ice will already be a problem in all the northern tier states.

  99. Tilo Reber says:

    Ljungqvist:

    “I don’t think it is fair to refer to an outdated work (from 1999) when we have newer and better.”

    Do you think it is fair to ask why Mann got it so wrong in 99? Do you think that it is fair to ask why such a bad original reconstruction got so much publicity when it first came out? Do you think that it is fair to ask why Mann choose to weigh in a way that produced radical results that contradicted known history. Is it fair to ask, if proxy reconstructions can undergo so much change in only 11 years, then could climate models still undergo huge changes in the next 20?

    It doesn’t make much sense to look at the mistakes made by climate science such a short time ago and then accept that climate science has found and corrected all their mistakes and that their conclusions should be accepted as “the science” today.

    I agree that Mann-08 agrees well with your reconstruction. But Mann was pulled kicking and screaming to produce a better reconstruction by the endless parade of people and research pointing out his errors. To assume that he simply improved his work and forget the obvious evidence that he was shooting for a specific result in his earlier work is more than I am willing to do.

    Lastly, I think that adding the instrument record to the end of a proxy reconstruction is clearly a travesty. We have no idea what those instruments would have shown back in the MWP. And if we can’t trust proxies to tell us about the current climate, how can we trust them for the past.

  100. DeNihilist says:

    “Phil. says…..
    Well Mann-08 agrees rather better with Ljungqvist-10 than Craig’s.”

    But Phil, isn’t that the way science works? As the techniques are refined, and the data becomes better, then the outcomes change? From Dr. Mann’s ’98 to todays from Dr Ljungqvist, we see that the reconstructions are evolving. Is this not what all of us want? The best science possible to make these grand decisions?

  101. Jim G says:

    Stephen Wilde says:
    “Unfortunately the climate propaganda of the last 20 years is so heavily embedded in the minds of policy makers ( the UK’s William Hague for one) that it is going to be like turning around an oil tanker in a bathtub to correct the damage already in the political system and so called ‘scientific’ establishment.”

    Stephen,
    Unfortunately, in the US, the educational system has also indoctrinated our children for the last 20 years with the same pseudo-science to the extent that my youngest son upon leaving high school was a “greenie”. However, subsequent to obtaining his Mech Engineering degree and some real education he had finally seen the light. The downside for young people who figure out what is going on is that they end up with a great deal of skepticism regarding all published science and politics. But perhaps that is actually an upside. The real downside is that many kids never see the light and join the great unwashed masses who believe the BS and vote in sync with the propaganda thereby assisting the phenomina you address.

    Jim

  102. Vuk etc. says:

    Thank you to both Dr. Leohle and Dr. Ljungqvist. Fascinating discussion from both authors and the other participants too. Have seen Tamino’s as well.
    However as usual I am not swayed by any to start with, it all depends on the ‘geomagnetic’ test. Initial appraisal suggests that both sets pass, however it appears that one has somewhat higher correlation than the other.

  103. Steve Allen says:

    Leif, it also says: “The highest average temperatures in the reconstruction are encountered in the mid to late tenth century and the lowest in the late seventeenth century. Decadal mean temperatures seem to have reached or exceeded the 1961–1990 mean temperature level during substantial parts of the Roman Warm Period and the Medieval Warm Period. ”

    So does this study completely vindicate Mann et al… as you suggest?

  104. Tilo Reber says:

    Slioch:
    “We find that 2007 (the latest year for which a five year average can be taken) is 0.31C above 1992 (five year GISS anomaly 1992=+0.24C, 2007=+0.55C). ”

    Can’t use GISS. It uses an anomolous shore ice effect to extrapolate temperatures all the way to the poles. The results are way off.

    http://reallyrealclimate.blogspot.com/2010/01/giss-temperature-record-divergence.html

  105. Layman Lurker says:

    robert says:
    September 28, 2010 at 8:11 am

    You compare it to the 1961-1990 average but which gives the impression that the majority of the reconstruction is above that average. However as tamino points out, very little of it is above the 1961-1990 average. What is your justification for making previous periods seem warmer than they actually were on a skeptic website. I have a lot of trouble not accusing this post of being dishonest when you could have easily shown the actual reconstruction and how it compared to the 1961-1990 average.

    It appears that you have confused Craig Loehle’s work with Ljungqvist, 2010. From the L10 abstract:

    This reconstruction is the first to show
    a distinct Roman Warm Period c. AD 1-300, reaching up to the 1961-1990
    mean temperature level, followed by the Dark Age Cold Period c. AD 300-
    800. The Medieval Warm Period is seen c. AD 800–1300 and the Little Ice
    Age is clearly visible c. AD 1300-1900, followed by a rapid temperature
    increase in the twentieth century. The highest average temperatures
    in the reconstruction are encountered in the mid to late tenth century
    and the lowest in the late seventeenth century. Decadal mean temperatures
    seem to have reached or exceeded the 1961-1990 mean temperature level
    during substantial parts of the Roman Warm Period and the Medieval Warm
    Period.

  106. Ric Werme says:

    #
    #
    Leif Svalgaard says:
    September 28, 2010 at 6:53 am

    Craig Loehle says:
    September 28, 2010 at 6:39 am
    > Leif asks if wood is CO2 emission free–no on short timescales, but it grows back and soaks up CO2.

    Yes, but with a delay of decades [up to century] and many of the forests back then are now gone. Europe is now not so wooded as it were, so not all CO2 is soaked up.

    Some places recovered better than others. The Year without a Summer in 1816 convinced many farmers to abandon the rocky soil of New England for the easier to work soil in the midwest. (Solving the “Indian problem” and the coming Erie canal helped to.) Also, New Hampshire was in the midst of an energy crisis due clearing the wood from most of the state. We’ve recovered fine and now we’re the second most forested state (Maine is #1).

    I don’t have good data like E.M. Smith does, but it only takes a few years before saplings start crowding out neighbors and losers reenter the CO2 phase. Total wood content must keep growing as wood’s role is to get a plant’s leaves above the competition.

    The Hubbard Brook Experimental Forest folks here must have data about that, perhaps I should see what I can find. One experiment of theirs was to clear cut a large patch of woods and study runoff and regrowth afterward. The clear cut was 30 years or so ago, so they might have interesting data.

  107. Slioch says:

    Tilo Reber

    “Can’t use GISS.”

    It was GISS that Loehle used! It would have been ridiculous for me to use any other.

    As for being ” way off”, that is nonsense. Here are the linear best fits of NASA GISS, HADCRUT3, RSS and UAH from 1992 to the present:

    http://www.woodfortrees.org/plot/hadcrut3gl/from:1992/trend/plot/uah/from:1992/trend/plot/rss/from:1992/trend/plot/gistemp/from:1992/trend

    The values are:

    NASA GISS 0.235C/decade
    HADCRUT3 0.190C/decade
    RSS 0.225C/decade
    UAH 0.230C/decade

  108. Steve M. from TN says:

    Leif Svalgaard says:
    September 28, 2010 at 6:53 am

    Yes, but with a delay of decades [up to century] and many of the forests back then are now gone. Europe is now not so wooded as it were, so not all CO2 is soaked up.

    By the same reasoning that North America isn’t the world’s thermometer, (24 m sq km), so Europe (9m sq km) cannot be the world’s CO2 sink.

  109. Jean Parisot says:

    Does the “steepness” of the change in climatic conditions lead to mechanisms that involve a lot more energy; say solar or oceanic currents, then a diffuse change in the atmospheric blanket would represent?

  110. Paddy says:

    Dr Svalgaard: Your comments about forest growth, re- and de-forestation are dubious. The continental US ended net deforestation in the early 1930s and total forest area has increased since then. In several parts of the country, e.g. New England and the SE former agricultural lands have been naturally reclaimed or planted and cultivated into commercial forests. Rotation terms (time between successive harvests) is 40 to 65 years on private commercial forest lands.

    European and Scandinavian forest areas remain constant. Russian data is not available. China is doing its best to recreate forests. Tropical rain forests replenish themselves rapidly. It is quite difficult to keep trees from overrunning land converted to farming in tropical rain forested areas.

    There is ample evidence to support Dr Leohle’s assumptions regarding carbon neutrality are correct.

  111. robert says:

    layman,

    you don’t even understand the problem. In the graph directly from the study, you see only two peaks where temps were at or above the 1961-1990 baseline. But when loehle re-centers it for “comparison” with his own, you clearly see much more above what is shown in the actual study.

    Either way, skeptical science has done a piece on this and it is clear that this study matched mann better than loehle.

    http://www.skepticalscience.com/new-remperature-reconstruction-vindicates.html

    And that all the evidence shows the same thing. Unprecedented late 20th century warmth.

  112. Drs. Ljungqvist and Loehle,

    I took a stab at comparing your reconstructions to eachother and those of Mann ’08 and Moburg with uncertainty bands over here: http://rankexploits.com/musings/2010/comparing-proxy-reconstructions/

  113. Paddy says:
    September 28, 2010 at 11:19 am
    The continental US ended net deforestation in the early 1930s and total forest area has increased since then.
    The question is what happened to industrial Europe’s forests from 1780 to, say, 1850.

  114. paulw says:

    Craig Loehle: Could you please post your reply regarding the post at
    http://tamino.wordpress.com/2010/09/28/vindication/

    This would help to push this subject further. Otherwise, we repeat the same old things.

  115. Craig Loehle says:

    Zeke: although hidden by the instrumental data, Mann 08 is the only one showing a huge temp spike in recent decades, which goes away if you drop the upside-down tiljander sediment proxies and the stripbark trees. So I am happy to be “out” vs Mann 08. I have discussed above the issue of shifting the axis to compare the reconstructions, as has Lubos on his blog.

  116. TomRude says:

    Robert, looking at Ljundqvist’s reconstruction:
    http://tamino.files.wordpress.com/2010/09/compare.jpg
    So beyond who gets vindicated or not, this is all about the “unprecedented” and its cause “C02″ in the end:

    Tell us what C02 in 0 created the warming period?
    Tell us what C02 in 800 created the sudden warming period?
    Tell us what C02 in 1700 created the sudden warming period?

    Of course Tamino had to include the “instrumental record”, the very same constructions we all know have been demonstrated to be biased toward warming. If you compare what is comparable here i.e. proxy based reconstructions, the Ljundqvist graph is not showing anything unprecedented in the 20th century, it is not showing it warmer than the MWP and worse, it stops at 1999, after the 1998 warm El Nino year while we all know that temps have not risen since 2010 being another El Nino year!

    So in fact it shows a rise during the 20th century that plateaued, just as it did after the rise in 1700, same amplitude.

    Anyone believing this new reconstruction validates AGW needs a pair of glasses!

  117. Andrew W says:

    So climate sensitivity to forcings – natural or anthropogenic – is higher than feared.

  118. Hu McCulloch says:

    A color version of Craig’s 2008 corrected reconstruction, with my 95% CI’s, is at http://econ.ohio-state.edu/jhm/AGW/Loehle/ , along with an ASCII table of the numbers, link to the papers, and an extended description by me of how the CI’s were computed.

    Leif Svalgaard says:
    September 28, 2010 at 7:32 am
    Question for both Fredrik and Craig:
    When you plot ‘error band’, it has the same width independent of time. It would seem that the variance should depend somewhat on time.

    See my SI on the site linked above for discussion of this point.

    Computing the SE’s pointwise would have given a different SE for each point in time, but would be invalid given that the proxies don’t have equal variances about the global mean — see my spaghettigram on above site. Instead I used a panel approach that assumes each proxy has its own constant variance about the time-varying global mean. Then if the set of proxies is constant, the SE’s are constant. In fact, a few of them drop out towards the ends of the period we report, so the SE’s increase a little, but not noticeably in the time period we report.

    We decided to quit the tridecadal (29 year) average in 1935, since several proxies dropped out at once after 1950. This greatly increased the SE’s after 1950, and led to increasingly big extraneous gyrations whenever further proxies dropped out. See my SI for graphs.

    If you want to link Craig’s index to your favorite global instrumental index, a reasonable approach would be to tie his 29-yr centered 1935 value (+.1142 dC) to the 1921-1949 average of your index. Or, if you want to go back two tridecades (of 29 years each), tie the average of his 1906 and 1935 values (-.1162 and +.1142, or -.0010) to the 1892-1949 average value of your index. CRU goes back to 1850, but they admit it is less reliable back there, so there is not much point going back for a third tricade.

    But this would raise questions of whether the airports favored by GHCN and CRU are a good place to measure global temperature change, etc, questions that are irrelevant to Craig’s index. So you’re on your own here.

  119. Tim Clark says:

    anna v says:September 28, 2010 at 7:11 am
    “not all CO2 is soaked up.”
    A problem worthy of climatologists….

    Leif Svalgaard says: September 28, 2010 at 7:29 am
    Biomass per square meter might be a clue. I don’t know the answer, though.

    E.M.Smith says: September 28, 2010 at 8:56 am
    So a hay field will temporarily ‘sequester’ about 5 ton (on average) for a year, while a forest will ‘sequester’ about 20 ton (on average with wide error bands) per year for about 25 years as the stand matures.

    OMG, I get to correct E.M.. The studies you cite measured aboveground tonnage only. Crop species roots die off yearly and the decayed roots build up organic matter in the soil, while tree roots not so much. Doesn’t change the trend much.

    Soils that have developed under forest vegetation usually have comparably low organic-matter levels. There are at least two reasons for these levels: (1) trees produce a much smaller root mass per acre than grass plants, and (2) trees do not die back and decompose every year. Instead, much of the organic material in a forest is tied up in the tree instead of being returned to the soil.

    http://www.noble.org/Ag/Soils/OrganicMatter/Index.htm

  120. Jeff Id says:

    Nice job, Dr. Loehle. I’m sure Mann hates this new work though too.

  121. NucEngineer says:

    Why this is essential:
    Proof that the current warming is within the range of normal climate variation invalidates all, all of the general circulation models used to predict catastrophic global warming. If there is no man-caused warming now, there will be none in the future.

  122. Earle Williams says:

    Phil.,

    I suggest your words to the wise merit an edit: it is considered rude to address people by their surnames only.

    In referring to individuals not present (ie, not engaged in the discussion) it should not be considered rude to refer to them by their surname only. If they are engaged in the discussion it is indeed rude to address or refer to them by surname absent a given name or honorific.

    I would expect these rules to apply to any conversation or blog discussion. Feel free to correct me if you know of a forum where the rules of ettiquette differ.

    Cheers,
    Earle

    REPLY:
    I believe that Phil, an academic at a major university, tends to think of us here much as he does his students, as secondary citizens. He’s been called on this issue before. Unfortunately he’s very set in his ways. – Anthony

  123. Craig Loehle says:

    paulw: when I attempted to reply to Tamino at his site before about my work, my comments were ignored or deleted. I won’t post there.

    REPLY: Ditto that, it’s a waste of time to try any discussion there. If you want to issue a reply, I’ll offer a second guest post opportunity here – Anthony

  124. Niels A Nielsen says:

    Slioch says:
    September 28, 2010 at 10:51 am

    “The values are:

    NASA GISS 0.235C/decade
    HADCRUT3 0.190C/decade
    RSS 0.225C/decade
    UAH 0.230C/decade”

    Should surface and lower troposphere warm at the same rate? No, the troposphere (RSS, UAH) should warm about 1.2 times faster than the surface.

  125. Jordan says:

    From the above abstract: ” presented for the extratropical Northern Hemisphere (90–30°N)”

    And not an assessment of true “global” temperature trend. I don’t suppose this will have any relevance in the search for “true global warming”.

    From the abstract: “The temperature of the last two decades, however, is possibly higher than during any previous time in the past two millennia, although this is only seen in the instrumental temperature data and not in the multi-proxy reconstruction itself.”

    Divergence reigns supreme. Immediately infecting any analysis that dares to venture into the muddy waters of multiproxy reconstruction.

    Nice calibration period – and the analysis isn’t biased by proxy selection?

  126. stephen richards says:

    Slioch says: Use of GISS immediately discredits your point. Sorry that’s a fail.

  127. Fredrik Charpentier Ljungqvist says:

    Zeke Hausfather:
    Nice graphs you produced to compare the different temperature reconstructions.

  128. Don B says:

    Russia is “mining” mammoths for their ivory, to take the place of banned elephant ivory. Some estimate there are 150 million mammoths buried in the permafrost.

    http://www.telegraph.co.uk/news/worldnews/europe/russia/8026187/Russia-digs-up-woolly-mammoth-remains-for-guilt-free-ivory.html

    It was warmer there before they were buried than it is today.

  129. Don B says:

    A mammoth proxy would be ground breaking, so to speak.

    Are there growth rings in mammoth tusks? :)

  130. Layman Lurker says:

    Robert, I understand exactly what Craig Loehle did to compare the two reconstructions by zeroing L10 on the reconstruction mean rather than 1961-90. He makes it clear in the post what he is doing and is not misrepresenting L10 by doing this. This does not change how the relative peaks of the RWP, the MWP, and CWP compare within the L10 reconstruction. Also, Ned appears to do the same thing in figure #2 at your link. Or did you not catch that? BTW, I have no problem with the obvious coherence between L10 and M08.

  131. Rob R says:

    I can’t quite get my head around Leif’s problem with CO2 in the industrial era. Did burning wood (or any other carbon rich fuel) cause significant greenhouse gas warming prior to about 1945? Surely the answer is no. Prior to about 1945 anthropogenically sourced CO2 that was added to the atmosphere was largely scrubbed from the system by a variety of processes including absorption into the global ocean. The actual atmospheric CO2 concentration was rising, but only very slowly. The change in CO2 concentration was not large enough to cause the pre- 1940’s warming that is suggested by the various highly trustworthy global temperature indices (e.g. GISTemp, CRUTemp). The IPCC discussion of the issue seems to agree with this position. So why should we beat ourselves up over wood burning? The real reason to be dissapointed over this use of forested land is the loss of forest and biodiversity, not the CO2 we produced. All of that CO2 has by now been reabsorbed via the global carbon cycle in any case, even if there is still a trivial perturbation (from those days) in the total amount of CO2 in the atmosphere.

  132. Z says:

    Steve says:
    September 28, 2010 at 3:51 am

    What about the slope of the last 300 years? It is by far the steepest section of the graph. That seems to fit in well with industrialization being the cause for warming.

    In every graph that is uneven there will be a “steepest section” and a “flattest section”. People will always attribute some special significance to them, despite the fact that mathematically, they both must exist – even (or especially) in a random number sequence.

    For my part, I wish everyone would believe in CO2 warming and help to get America off of foreign oil.

    Why conflate the two? Why not just get people believing in America getting off foreign oil? That way, you’re not a hostage to fortune to someone holing the CO2 conjecture below the waterline, and it taking the foreign oil cause with it.

    The global warming socialism can’t be any worse than the Military Industrial bankruptcy/facism that has been going on.

    Of course it can. Easily. But why go for extremes? Why not direct yourself to the reasonable line rather than going for a different flavor of totalitarianism simply because you don’t like the flavor of totalitarianism you have already?

  133. Eli Rabett says:

    Leif, I rather suspect that Europe’s forests disappeared earlier than that

    http://www.wsl.ch/staff/niklaus.zimmermann/papers/QuatSciRev_Kaplan_2009.pdf

  134. Adam R. says:

    stephen richards says:
    September 28, 2010 at 12:42 pm
    Slioch says:
    Use of GISS immediately discredits your point. Sorry that’s a fail.

    So, therefore, Loehle is a fail? Got it.

  135. Tilo Reber says:

    Slioch:
    “As for being ” way off”, that is nonsense.”

    Like I said, it’s a problem with shore ice and how it effects shore stations and it has manifested the most since 97.

    http://reallyrealclimate.blogspot.com/2008/10/updated-11-year-global-temp-anomoly.html

    “It was GISS that Loehle used!”

    How does that fix the GISS problems?

  136. John Finn says:

    mikef2 says:
    September 28, 2010 at 6:09 am
    John Finn – cheap shot at the Thames freezing over statement.
    I know certain people are desperate to try and show that the well documented frost fairs were not part of any cooler climate, but down to particular flow rates on the river, but really, you go too far. The other surrounding rivers also froze, other major rivers froze, in other european countries too. Its not just the Thames, so you can’t try to say “oh the Thames only froze over because its flow rate was sluggish” as if thats a way to dispute the general coolness of the era.
    For sure the Thames flow rate is affected, but I don’t think that affected the Avon did it?

    No – but the Avon has frozen over many times since. It was completely frozen in 1963 – as were many other UK rivers and lakes. The point about the Thames is that it also froze many times during the supposedly warmer periods.

    In fact, the Thames also froze in 1963 but not completely. This link includes a photograph which shows people walking on the Thames at Windsor. Scroll down about ¾ of the page (though he 2nd photo is a smaller version)

    http://www.thamesweb.co.uk/windsor/windsorhistory/freeze63.html

    Here’s a few links that refer to the Avon freezing

    http://www.robertdarlaston.co.uk/Railways4.htm

    “The River Avon at Stratford was then completely frozen over and people walked on the ice in front of the Memorial Theatre.”

    http://www.bbc.co.uk/gloucestershire/content/articles/2008/11/26/1962_winter_feature.shtml

    “Michael Hill, of Pamington Court Farm, Ashchurch, remembers snow so high it covered the hedges on surrounding fields and skating with friends and family on the 14-inch thick ice that covered the River Avon at Tewkesbury.“

    The Avon also froze in 1961 as can be seen in this link

    http://www.bidfordonavon-pc.gov.uk/yourphotos.htm

    Scroll about 2/3 down the page and see the series of 4 photographs by Frank Spiers.

    Actually this is a pointless exercise. There are countless examples of UK and European rivers freezing over throughout the 20th century.

    How desperate are you guys ..?

    Meaning what exactly?

  137. Slioch says:

    Niels A Nielsen

    So, what are you trying to say? That temperatures have not risen since 1992?
    Just how many desperate straws are you prepared to grasp at?

  138. EW says:

    Concerning Moberg as a member of the Team – even he got into a problem when not toeing the line exactly – see the email
    http://eastangliaemails.com/emails.php?eid=492
    The Moberg et al paper is at least real science. But there are some real problems with it (you’ll want to followup w/ people like Phil Jones for a 2nd opinion).
    While the paper actually reinforces the main conclusion of previous studies (it also
    finds the late 20th century to be the warmest period of the past two millennia), it challenges various reconstructions using tree-ring information (which includes us, but several others such as Jones et al, Crowley, etc) . I’m pretty sure, by the way, that a very similar version of the paper was rejected previously by Science. A number of us are therefore very surprised that Nature is publishing it, given a number of serious problems…

  139. Tilo Reber says:

    Leif Svalgaard:
    “thus vindicating Mann et al….”

    LOL. After how many tries and a dogged determination to deny the MWP – and with a Tiljander series that is still upside down so as to give more contemporary warming?

    Come on Leif, why did Mann ignore Ababneh and continue to use Graybill when Ababneh made clear what Graybill’s problems were. Are you going to try to rehabilitate a crook when his changes were all forced on him. Now that Mann’s reconstructions no longer look like a hockey stick are you going to act like he was right all along. If we are going to do a rehabilitation here, how about an admission from Mann that his earlier work was garbage and a detailed explanation of how he got it so wrong. You can’t have two reconstructions that look completely different and still claim that both were done with “skill”.

  140. Z says:

    Don B says:
    September 28, 2010 at 12:57 pm

    A mammoth proxy would be ground breaking, so to speak.

    Are there growth rings in mammoth tusks? :)

    Yes, there are, as there are in all teeth.

    Perhaps they have “teleconnection” too… ;)

  141. Tilo Reber says:

    Slioch:
    “So, what are you trying to say? That temperatures have not risen since 1992?”

    I don’t know what he is saying, but I’m saying that if you want to make comparisons to proxies, then you have to use proxies, not instrument data.

    The other issue is the desperate attempt at retaining the term “unprecedented”. This was a term that fit Mann’s original hockey stick very well. But now the best and most modern proxies do not show current proxy temperatures that are warmer than the MWP. Even in cases like Mann 08, where current temperatures are higher than in any other reconstructions (due to Mann’s errors), the difference between contemporary data and proxy data of the MWP is not that great. So the term “unprecedented” is simply hyperbole. What the warmers are trying to do now is claim technical correctness when the original intention behind using that word has been lost.

  142. Craig Loehle says:

    Tamino complains that I adjusted the offsets to compare the two series, but when comparing the temperature histories produced by GCMs, modelers insist on ignoring the offsets (of up to 4 deg C) and just comparing the warming trends they produce. Anything goes to fit an agenda.

  143. John says:

    Craig, I wonder if part of the difference between these new results and yours — mostly before 1000 AD — might be because they use records only from the extra-tropical N Hemisphere, and you had some S African results. (I don’t have your study at hand.) Did your S Hemisphere results to some extent cause you to find warmer years between 500 and 900 AD?

  144. Slioch says:

    Tilo Reber

    “I’m saying that if you want to make comparisons to proxies, then you have to use proxies, not instrument data.”

    Well, I don’t agree with you, but if you really want to take that up then do so with Loehle: it was he that used instrumental data from NASA GISS to extend the proxy data from 1935 to 1992 in his 2008 paper. I then merely extended it to 2007, again using NASA GISS.

    As for “the best and most modern proxies do not show current proxy temperatures that are warmer than the MWP”. (I suppose by best you mean the ones that tell you want you want to know?)

    If the proxy temperatures do not extend to present times then obviously they are not going to tell you how modern times compare with the MWP: that is why the record is extended using the instrumental data, and quite rightly so. When Loehle 2008 did that the result is that the MWP was cooler than today, even though Loehle 2008 gave the MWP as warmer than most constructions, see (usefully displayed by Zeke Hausfather):

    http://rankexploits.com/musings/wp-content/uploads/2010/09/Proxy-Reconstruction-Comparison1.png

  145. Craig Loehle says:

    Slioch: sorry, not quite right. Many of the proxies are at timescales of decades, not years, and my proxy was further smoothed with a 29 yr smooth. They also have error. I compared the result of extending the record with instrumental data in a deliberately coarse way, not by tacking it on. Proxy and instrumental data are not exactly directly comparable.
    John: it is possible that the use of tropical data shifted my results up some.

  146. Tim Folkerts says:

    Craig Loehle says:
    September 28, 2010 at 2:56 pm

    Tamino complains that I adjusted the offsets to compare the two series, but when comparing the temperature histories produced by GCMs, modelers insist on ignoring the offsets (of up to 4 deg C) and just comparing the warming trends they produce. Anything goes to fit an agenda.

    I’m kinda of new to these debates, but isn’t “GCM” a “Global Climate Model”? These are not models you are comparing, but temperature data (OK — proxies for temperature based on various measurements). Do scientists ALSO adjust temperature data like this?

  147. Tilo Reber says:
    September 28, 2010 at 2:26 pm
    Are you going to try to rehabilitate a crook when his changes were all forced on him.
    Ljungqvist, not I, says that the two reconstructions are close.

  148. I posted this at Tamino:
    “Leif Svalgaard | September 28, 2010 at 1:46 pm | Reply
    Your comment is awaiting moderation.
    An ‘honest’ comparison might be to adjust both to agree on their overlapping part with the instrumental record. Try that and report back.”
    Needless to say, it was deleted.

  149. evanmjones says:

    What about the slope of the last 300 years? It is by far the steepest section of the graph. That seems to fit in well with industrialization being the cause for warming.

    Nearly all the CO2 added is in the last 80 or so years. So I doubt it. The relative steadiness of that slope does far more to disprove the CO2 theory than to support it.

    For my part, I wish everyone would believe in CO2 warming and help to get America off of foreign oil. The global warming socialism can’t be any worse than the Military Industrial bankruptcy/facism that has been going on.

    Well . . . in that case I’ll take the latter — since you don’t seem really to care which! (Do women make passes at men who wear fasces?)

  150. phlogiston says:

    @Slioch

    Quite wrongly so.

    You can only compare proxy with proxy, like with like, apples with apples.

    Stitching satellite data to sediment proxies breaks the basic rules of controlled experimental research. It’s otherwise known as “hiding the decline” or “Mike’s Nature Trick”.

    Doesn’t matter who does it, it’s WRONG!

  151. Craig Loehle says:

    Tim Folkerts: my point was that the output of climate models for the past century differs a lot between models, but supporters of the models want us to ignore the differences (the offsets) and just say “look, they produce similar rates of warming”. I was comparing the SHAPES of my curve and the new one, which you do by overlaying them.

  152. D. Patterson says:

    Leif Svalgaard says:
    September 28, 2010 at 6:53 am
    Craig Loehle says:
    September 28, 2010 at 6:39 am
    Leif asks if wood is CO2 emission free–no on short timescales, but it grows back and soaks up CO2.
    Yes, but with a delay of decades [up to century] and many of the forests back then are now gone. Europe is now not so wooded as it were, so not all CO2 is soaked up.

    The biosphere has an enormously underused capacity to consume atmospheric carbon dioxide which makes the deforestation a relatively moot issue with respect to carbon dioxide sinks. When you experiment with domesticated and wild plants in a closed greenhouse environment, an increase to 1,200ppm of carbon dioxide concentrations is very quickly reduced to only 200ppm by the plant life. Present atmospheric concentrations of carbon dioxide at 360ppm to 390ppm are seriously deficient with respect to the 1,200ppm and greater levels of carbon dioxide that is much more optimal for photosynthetic plant life. Maintaining atmospheric carbon dioxide levels at present levels or decreasing carbon dioxide below current levels is harmful to plant life, biodiversity, and the ecology. Plants can and do very rapidly consume carbon dioxide at much higher rates than is possible with the currently very low levels at only 360ppm to 390ppm. Despite the deforestation occurring in some areas of the world, the reforestation of North America and the huge untapped capacity of the plant kingdom to consume carbon dioxide ensures any actual or theoretical anthropogenic emissions have no serious opportunity to accumulate in the atmosphere to any significant amounts. The biosphere simply eats anything that can be thrown at it.

  153. rbateman says:

    Enneagram says:
    September 28, 2010 at 7:57 am
    Great work. There is a “trick” I was thinking about, after reading several years what it has been presented here in WUWT.
    It seems to me that:
    Maximum temperature records are Weather, while
    Minimum temperature records are Climate

    No, you got that misallocated:
    Widespread Minimum temperature extremes are disregarded by the MSM, but not in here.
    Isolated Maximum temperature extremes are regarded by the MSM as proof of AGW, but not in here.
    The MSM only cares about new Maximum records (and some are quite dubious at that), while it looks the other way when 10x as many new Minimum records are set. They must be reporting to themselves, or they haven’t gotten the memo yet.
    The EPA’s latest gig on boiler standards may have something to do with it.

  154. John Norris says:

    Just eyeballing but (Loehle, C. and Hu McCulloch. 2008) and (Ljungqvist, F.C. 2010) look like DNA matches up against any MBH result I have seen. All three are proxy data. Obviously MBH is the outlier.

  155. DeNihilist says:

    Anthony, I must congratulate you for your wiilingness to let any and everyone participate on your blog! My God, you even let rabbits in, even after they have chewed your leg to the bone.

    You are a most honourable person!

  156. barry says:

    The author replied directly to comments made here

    http://wattsupwiththat.com/2010/09/28/loehle-vindication/#comment-493590

    and was treated to a political history of Mann 99. Craig Loehle is able to address the actual points made if no one else will. The author indicates that his reconstructions agree with Mann o8 and Moberg, and that Mann’s o8 reconstruction has a warmer MWP, which corroborates the finding that the last few decades were likely warmer than any comparable period in the last 1200 years. Zeke Hausfather does some comparisons.

    http://rankexploits.com/musings/2010/comparing-proxy-reconstructions/

    Loehle’s alternate findings don’t appear to be vindicated by this new paper.

  157. evanmjones says:

    I like Dr. Loehle’s reconstruction better. (It better accounts for the Roman Warm period.)

  158. barry says:

    According to what?

    REPLY: As you say later, you should probably read the article before commenting – Anthony

  159. barry says:

    evanmjones,

    you should probably read the whole article before commenting.

    Loehle: “The new recon shows the Roman Warm Period, which I agree is probably more correct than in my graph.”

  160. Fredrik Charpentier Ljungqvist says: September 28, 2010 at 8:17 am

    I have noted in the post that there are a lot of (indirect) references to Mann et al. (1999) – the so-called “Hockey Stick Graph”. It is science history now.

    Any references to temperature reconstructions by Michael E. Mann should be to his 2008 and 2009 temperature reconstructions. They actually show an even warmer Medieval Warm Period than I do. I don’t think it is fair to refer to an outdated work (from 1999) when we have newer and better.

    I agree, but one of the problems is that Michael Mann himself still uses Mann 99 for his propaganda messages, such as in this 2010 interview for the National Science Foundation:

    http://www.nsf.gov/news/special_reports/degree/how_do_we_know.jsp

    (click on the video on the right called “what is unusual about the earth’s warming during the past century or so?”)

  161. Phil. says:

    Earle Williams says:
    September 28, 2010 at 12:28 pm
    Phil.,

    I suggest your words to the wise merit an edit: it is considered rude to address people by their surnames only.

    In referring to individuals not present (ie, not engaged in the discussion) it should not be considered rude to refer to them by their surname only. If they are engaged in the discussion it is indeed rude to address or refer to them by surname absent a given name or honorific.

    Which is exactly the situation here, Craig Loehle initiated and has participated in this thread, so why is it only rude if I do it?

    I would expect these rules to apply to any conversation or blog discussion. Feel free to correct me if you know of a forum where the rules of ettiquette differ.

    Where I come from it is considered rude to address someone you don’t know personally by their christian name only. US usage may differ but this is an international forum, others, such as Lubos might not be aware of the convention on here, hence my warning.

    REPLY: I believe that Phil, an academic at a major university, tends to think of us here much as he does his students, as secondary citizens. He’s been called on this issue before. Unfortunately he’s very set in his ways. – Anthony

    Actually Anthony you have no idea about the relationship between me and my students and I suggest you stop making such unfounded speculation. Perhaps your professors treated you thus, I certainly do not treat my students as ‘secondary citizens’, quite the contrary! I was called on this issue once before regarding stevegoddard as a result of a number of posters feeling I was being rude by using his surname (well the apparent surname of his pseudonym). When I was told of this site policy I followed that policy, why is it being ‘set in my ways’ to expect that this policy be applied universally?

  162. barry says:

    REPLY: As you say later, you should probably read the article before commenting – Anthony

    I did. That’s how I know Loehle doesn’t think his Roman Warm period reconstruction is superior to Ljungqvist’s. He says it himself.

    REPLY: well then say that in the first place, don’t post cryptic one-liners -A

  163. Max_OK says:

    John Marshall says:
    September 28, 2010 at 1:27 am
    Good work. We know, from archeological evidence, that past warm periods actually happened. The Roman, for instance, must have been warmer than today because they grew red grape varieties north of York, in UK., and these same varieties grow from Dijon south in France some 300 nautical miles south. (5 degrees of lat.). During the Little Ice Age the river Thames froze enough to hold ice fairs and roast beef for the masses. It does not freeze today. Climate changes but the only thing that does not change in sync is CO2.
    ————————-
    I am skeptical of claims that grape cultivation in England in Roman times is evidence of a warm period. Grapes are grown commercially in Upstate New York, an area that I suspect has a colder climate than the UK had back then.

    http://www.newyorkwines.org/Home/index.ashx

  164. Phil. says:

    DeNihilist says:
    September 28, 2010 at 10:12 am
    “Phil. says…..
    Well Mann-08 agrees rather better with Ljungqvist-10 than Craig’s.”

    But Phil, isn’t that the way science works? As the techniques are refined, and the data becomes better, then the outcomes change? From Dr. Mann’s ’98 to todays from Dr Ljungqvist, we see that the reconstructions are evolving. Is this not what all of us want? The best science possible to make these grand decisions?

    No problem with that, it’s not me who is harping back to the 98 paper whenever this subject arises.

  165. evanmjones says:

    I got the two graphs confused!

  166. Oliver Ramsay says:

    @ Max_OK

    I am skeptical of claims that grape cultivation in England in Roman times is evidence of a warm period. Grapes are grown commercially in Upstate New York, an area that I suspect has a colder climate than the UK had back then.

    —————-
    You might have fallen into the “Just give me the average” trap.
    Grapes need summer heat and sun and can tolerate quite a bit of winter frost.

  167. evanmjones says:

    I am skeptical of claims that grape cultivation in England in Roman times is evidence of a warm period. Grapes are grown commercially in Upstate New York, an area that I suspect has a colder climate than the UK had back then.

    Er, Upper NYS is fully 10 degrees latitude south of Hadrian’s Wall. Upper NYS is considerably south of Paris!

  168. Phil. says:

    Oliver Ramsay says:
    September 28, 2010 at 9:35 pm
    @ Max_OK

    I am skeptical of claims that grape cultivation in England in Roman times is evidence of a warm period. Grapes are grown commercially in Upstate New York, an area that I suspect has a colder climate than the UK had back then.

    There’s no evidence of wine being grown north of south Lincolnshire in Roman times, the claims to the contrary are unsupported fantasies from Plimer.

  169. Richard Sharpe says:

    evanmjones says on September 28, 2010 at 9:45 pm

    Max_OK said:

    I am skeptical of claims that grape cultivation in England in Roman times is evidence of a warm period. Grapes are grown commercially in Upstate New York, an area that I suspect has a colder climate than the UK had back then.

    Er, Upper NYS is fully 10 degrees latitude south of Hadrian’s Wall. Upper NYS is considerably south of Paris!

    Seems to be easy to be sceptical when you are ignorant.

    52 or so degrees North vs 42 degrees North. Guess which is which.

  170. Max_OK says:

    Oliver Ramsay says:
    September 28, 2010 at 9:35 pm
    @ Max_OK

    I am skeptical of claims that grape cultivation in England in Roman times is evidence of a warm period. Grapes are grown commercially in Upstate New York, an area that I suspect has a colder climate than the UK had back then.

    —————-
    You might have fallen into the “Just give me the average” trap.
    Grapes need summer heat and sun and can tolerate quite a bit of winter frost.
    —-
    Grapes grew in England in Roman times and grapes grow in Enland now.

    http://en.wikipedia.org/wiki/Wine_from_the_United_Kingdom

    I’m not aware of any evidence there was a time between when grapes would not grow in England.

    Oliver Ramsay says:
    September 28, 2010 at 9:35 pm
    @ Max_OK

    I am skeptical of claims that grape cultivation in England in Roman times is evidence of a warm period. Grapes are grown commercially in Upstate New York, an area that I suspect has a colder climate than the UK had back then.

    —————-
    You might have fallen into the “Just give me the average” trap.
    Grapes need summer heat and sun and can tolerate quite a bit of winter frost.

    http://en.wikipedia.org/wiki/Wine_from_the_United_Kingdom

  171. Max_OK says:

    evanmjones says:
    September 28, 2010 at 9:45 pm
    I am skeptical of claims that grape cultivation in England in Roman times is evidence of a warm period. Grapes are grown commercially in Upstate New York, an area that I suspect has a colder climate than the UK had back then.

    Er, Upper NYS is fully 10 degrees latitude south of Hadrian’s Wall. Upper NYS is considerably south of Paris!
    —–
    I’ll take your word for it. But the Gulf Stream steers clear of Upper NYS.

  172. anna v says:

    evanmjones says:
    September 28, 2010 at 9:45 pm

    It is the Gulf Stream that keeps Europe more temperate than equivalent latitudes on the New World.

    Grapes can grow on mountainsides that get quite cold in the winters, as long as there is good sunshine in spring and summer. Ι suspect it is the cloudy cool summers that have defeated the vines in the British Isles.

  173. Max_OK says:

    @ Oliver Ramsay
    There’s no evidence of wine being grown north of south Lincolnshire in Roman times, the claims to the contrary are unsupported fantasies from Plimer.
    ——
    I don’t know if we can be sure about Roman times, but we can be sure about now.
    Most of the wineries in the UK are in the South of England. But wine grapes are now grown in Scotland too, which of course has a colder climate than England.

    http://www.telegraph.co.uk/foodanddrink/wine/7182584/First-Scottish-wine-to-be-produced.html

  174. Luboš Motl says:

    Dear Phil., well, Mann 08 is not a hockey stick, either, after all. However, between 3 paper papers, there are 3 correlation coefficients. Generally, between N papers, there are N(N-1)/2 correlation coefficients, so you didn’t cover all the information about the relative proximities of the reconstructions by mentioning that 1 paper is closer to 2nd than to 3rd.

    It may be unpleasant to use surnames – and I am not thrilled if people talk to me as about Motl either – but it is the only consistent and professional way to call authors of papers if Mann is called Mann. If Mann is Mann, then Loehle is Loehle, sorry. That doesn’t mean that I don’t enthusiastically like the latter but it is an impartial terminology that helps impartial reasoning.

  175. Oliver Ramsay says:

    @ Phil,

    I would doubt that you are any more of an authority than I am on vineyards in Roman England, which is to say, not at all. Funnily enough, I grew up in Lincolnshire and saw a lot of sugar-beets and nary a grape-vine, but then, most of the Romans had left by then, leaving behind some fine limestone arches and walls.
    The minor point I sought to make was just that an average annual temperature won’t tell you a lot about the viability of viticulture.
    Grantham, Lincs. home of Isaac Newton and Maggie Thatcher is latitude 53 N.

  176. Max_OK says:

    anna v says:
    September 28, 2010 at 10:40 pm
    evanmjones says:
    September 28, 2010 at 9:45 pm

    It is the Gulf Stream that keeps Europe more temperate than equivalent latitudes on the New World.

    Grapes can grow on mountainsides that get quite cold in the winters, as long as there is good sunshine in spring and summer. Ι suspect it is the cloudy cool summers that have defeated the vines in the British Isles.
    ====
    That’s probably why grapes don’t do as well in the UK as in France and Italy. But grapes can be and are grown in the UK, even as far North as Scotland.

  177. evanmjones says:

    Hadrian’s Wall is 54.9 North.
    Paris is 48.8 North.
    Marseilles is 43.2 North

    Albany, NY, is 42.6 North.

    Upper New York state is the equivalent latitude of southernmost France. It gets very hot during the summer.

    (Also, the Frankengrapes of today are not the same as grapes in Roman times.)

  178. Slioch says:

    Craig Loehle 3:51pm

    “I compared the result of extending the record with instrumental data in a deliberately coarse way, not by tacking it on.”

    Yes. I know you used a 29 year smoothing. That is why I said, (Sept. 28 8:22am)

    “Of course, in order to make that point conclusively, we would need the 29 year global average centred on 2007, but we won’t get that until after 2021.”

    Though I’m not sure what the difference between “extending the record” and “tacking it on” is. Irrespective of whether or not the instrumental record is smoothed it does “extend” the temperature anomaly/time series by “tacking on” the instrumental record – and quite rightly so as far as I can see. It is trying to make the best of a difficult and incomplete picture: in my view it is only those who don’t want to see what the picture tells them that make an objection to the extension process per se.

    As you know, many people, eg Jo Nova, have used your work (2007, 2008) to make the claim, “Temperatures were higher 1000 years ago” than “Today”, for example from WUWT last December:

    http://joannenova.com.au/globalwarming/skeptics-handbook-ii/web-pics/loehle_e-e_2007-5-fig-2-web.gif

    in

    http://wattsupwiththat.com/2009/12/04/jo-nova-finds-the-medieval-warm-period/

    Ie they claim that your work shows that the peak of the MWP was warmer than today.

    That claim (as I am sure you will acknowledge) is false: your proxy results don’t extend into the last few decades of global warming, let alone to “today” (ie very recent average global temperatures) so therefore cannot say anything directly about a comparison between today’s temperature and the MWP.

    So in order to address that claim one can either say i) nonsense, Loehle 2008 proxy results ended at a 29 year smoothed period centred on 1935 and therefore tells us nothing at all about the comparison between “today’s” temperature and the MWP – and leave it at that, or ii) one can take a more pragmatic approach (as you, I think rightly, did) and extend your series using the instrumental record. That latter approach shows that the claim, “Loehle 2008 shows today’s temperatures are lower than the MWP” is NOT supported by such evidence that we have, indeed quite the reverse.

  179. evanmjones says:

    Either the MWP was almost as warm, as warm, or slightly warmer than today.

    In any case, there would appear insufficient evidence at this time to justify abrupt policy change that would reduce world economic growth by a third to half.

  180. John Finn says:

    Tilo Reber says:
    September 28, 2010 at 10:35 am

    Slioch:
    “We find that 2007 (the latest year for which a five year average can be taken) is 0.31C above 1992 (five year GISS anomaly 1992=+0.24C, 2007=+0.55C). ”

    Can’t use GISS. It uses an anomolous shore ice effect to extrapolate temperatures all the way to the poles. The results are way off.
    Absolutely – better to use the UAH data where 5 year mean anomalies are: 1992= -0.03; 2007= +0.024 , i.e. a difference of +0.27. I see what you mean – miles off.
    However this is looking at the global anomalies. The Ljungqvist reconstuction is only for the 30N-90N region which, broadly speaking, covers the extratropics. The UAH NoExt anomalies are as follows: 1992= +0.02; 2007= +0.48.
    The most recent 5 year average for the UAH 30N-90N region is 0.46 deg higher than the 1992 5 year average at the end of the reconstruction. That said I’m not sure a 5 year average of measured observations can be compared with a smoothed 29 year average from proxies

  181. Richard S Courtney says:

    I fail to understand the interest in the history of UK grape growing which has nothing to do with the reconstructions of past global temperatures.

    It was much warmer in the UK 1,000 years ago. Much archaelogy proves it.

    Archaelogical evidence is empirical data. It is not “anecdote”.

    For example, 1,000 years ago a type of beetle that is now constrained to the South of France existed in the UK as far North as York. Remains of the beetles are found in exhumed stone coffins from the period.

    So, the climate of the UK was warmer 1,000 years ago than now. But this says nothing about the climate temperature elsewhere. Live with it.

    Richard

  182. mikef2 says:

    John Finn….
    Soooooooooo…what are you actually saying, what is your point? That the LIA did not exist, because rivers in the UK have frozen over since? You imply I think, that we must discount the frost fair history as nothing exceptional, because we have had weather cold enough to freeze rivers since. Is that the point you were trying to make by suggesting the Thames only froze over often due to its flow rate being slower back then?
    If that is your point (& if not then its a bizarre ot thing to bring up) are you therefore implying that temp has not really changed? After all, the Avon froze this winter too, I know as I was there, and was there in ’63…thanks for the pics but we have our own b&w’s from that time! Your arguement seems to contradicting iteself.
    If the Thames only froze because of sluggish flow, and the Avon has frozen this last 3 yrs, which you will have to trust me on, then logic says temps are the same.
    But we know they are not, according to all the temp curves.
    So it must have been colder for longer back during the frost fairs. But you say no, the Thames only froze due to sluggish flow.

    Which is it John, you can’t take both, unless you are Robert Fisk?

    C’mon…..lets be honest here, you know what you were trying to do was dilute peoples opinion of the LIA by suggesting that the frost fairs were not part of a cooler period and were in fact just a few odd extreme weather episodes made worse by sluggish flow. This is the same ‘d’ modus operandi we get from AGWers about the Greenland settlements.

    Your aguement seems counterproductive to an opinion that todays temps are higher than ‘normal’.

    ????

  183. vukcevic says:

    One of the ways of comparing two sets of reconstructions is to reference them to the geomagnetic field strength, the independent variable following the same trend during the last two millennia.
    http://www.vukcevic.talktalk.net/LL.htm

  184. tonyb says:

    Early on in the Roman invasion of Britain grape growing was not thought possible. As the climate warned many vineyards were subsequently planted. These died out in the 5th century when the Romans left and the climate cooled but by the time of the Domesday book vineyards were flourishing again.

    This about Roman times.

    http://www.english-wine.com/history.html
    Botanically there is no reason to doubt that cultivation could also have been extended to Britain at about the same time as it reached Northern Gaul and the Rhineland in the late 2nd or early 3rd century. Various Classical sources have been used to argue the case, though two relating to the 1st century AD pre-date the likely extension of viticulture into such northern latitudes. The statement by Tacitus (about 98AD) (Vita Agricolae, 12) that all food plants except the olive and vine could flourish in Britain provides no evidence that viticulture was not to be practised later in the Roman period. Similarly, we would not expect Domitian’s wine edict of c. AD 90 or 91, which sought to restrict wine production in the provinces (Jones 1992), to make specific reference to Britain. On the other hand, another imperial edict, by the 3rd-century emperor Probus, can only be interpreted as confirmation that viticulture was by the AD 270s considered possible in Britain: ‘Hence he granted permission to all the Gauls and the Spaniards and Britons to cultivate vineyards and make wines’ (Historiae Augustae, Probus, 18.8).”

    tonyb

  185. Slioch says:

    John Finn 10:35am

    I’m afraid my irony filters don’t work very well.

    But, to be sure about what you are saying: yes, the difference between a five year period centred on 1992 and that on 2007 is +0.27C for UAH ( I’ve just checked that calculation – I agree). Which is not much different from +0.31C from NASA GISS, so Tilo Reber’s objection was without substance.

    As for, “I’m not sure a 5 year average of measured observations can be compared with a smoothed 29 year average from proxies”. No, I agree that it is messy, but one either does that or one does nothing, since it is impossible to know what the 29 year instrumental, let alone proxy, value would be for “today”.

    Remember that the motivation for my above calculation was to counter the false claim (made without ANY justification by Jo Nova) that Loehle 2008 showed that “Temperatures were higher 1000 years ago” (ie during the MWP) than “Today”. It would have been better if no-one had tried to use Loehle 2008 to make claims about today’s temperatures – but that is not the world we live in.

  186. Larus says:

    @ Dr. Loehle
    “In order to compare the graphs, I shifted them each to a zero mean over the period. In this way one can compare different time trends.”

    Yes, but, by your own admission, you “did NOT rescale” the graphs, thus concealing the fact that your graph is seriously out of whack with Ljungqvist’s over the medieval period, and therefore can hardly be considered as “vindicated” by the new work, which confirms Mann’s findings instead.

    The tone of many comments on this site suggests that people believe your “vindication” to mean that Mann’s hockey stick has been demolished, and your graph validated, by Ljungqvist’s new publication. In fact, the reverse seems to be the case.

    This is a serious objection, and the fact that tamino has pointed this out is irrelevant. Disliking one’s critics is not a serious answer to criticism.

  187. Craig Loehle says:

    It is a serious disadvantage to be absent minded and packing for a trip at the same time, but I eventually have remembered that my own reconstruction is set to a zero baseline for the entire 2000 yrs, so it is only possible to compare to other series that are centered likewise. Gee Tamino, didn’t you read my paper before calling me dishonest?

  188. anna v says:

    Larus says:
    September 29, 2010 at 3:19 am
    Yes, but, by your own admission, you “did NOT rescale” the graphs,

    I am curious why you think rescaling is necessary when both graphs are anomalies in given in degrees C. A parallel sliding of graphs means that a change is made to the average value of temperature used, that is all.

  189. vukcevic says:
    September 29, 2010 at 2:42 am
    One of the ways of comparing two sets of reconstructions is to reference them to the geomagnetic field strength, the independent variable following the same trend during the last two millennia.
    Economical with the truth again?
    Here is the variation of the geomagnetic field [at your favorite location] for the last two millennia: http://www.leif.org/research/GEO-F-CALS7K.png
    No resemblance to the temperature.

  190. cope says:

    Well, this comment thread is going to be an interesting test for some of the commentators. We have seen direct attacks on Craig Loehle’s integrity by people such as Robert, Laurus and Slioch. These attacks have now proved to be reckless, and flat out wrong. So the rest of us will wait to see if they step forward with an apology. If they do, full credit to them (though I am a little disappointed to have not seen any movement yet). If they don’t, we should all free to ignore anything they say in the future.

  191. Jimmy Haigh says:

    rbateman says:
    September 28, 2010 at 8:01 am

    How about looking at this the other way? How about warming being the cause of industrialisation? Just a thought…

    “And and excellent thought it is. Bravo!
    Free time afforded by a warmer climate with less pressure from the forces of nature. Survival rates increase along with longevity as citizens become more productive and technological advancements arrive to keep the ball rolling.
    Many civilizations flourished in warmer times, and likewise floundered when the good times were over.”

    Thanks – that’s exactly what I was thinking of.

  192. Oliver Ramsay says:

    Richard S Courtney says:
    September 29, 2010 at 2:30 am

    I fail to understand the interest in the history of UK grape growing which has nothing to do with the reconstructions of past global temperatures.

    It was much warmer in the UK 1,000 years ago. Much archaelogy proves it.

    Archaelogical evidence is empirical data. It is not “anecdote”.

    For example, 1,000 years ago a type of beetle that is now constrained to the South of France existed in the UK as far North as York. Remains of the beetles are found in exhumed stone coffins from the period.

    So, the climate of the UK was warmer 1,000 years ago than now. But this says nothing about the climate temperature elsewhere. Live with it.
    —————————————-
    I understand that Bristlecone pines and Siberian Larch are the ne plus ultra of climate indicators, but I’m disappointed that you so thoroughly disdain the noble grape. Even some unspecified scarab is deemed more worthy.
    Also, I was given to understand that one could draw conclusions about the temperature of a place up to 1200 km away. That would be Marseilles, in this case.

  193. vukcevic says:

    Dr. Svalgaard I shall state:
    Geomagnetic field is not cause of the temperature changes.
    Temperature change is not cause of the geomagnetic change.
    Both are consequence of well known a very simple physical process taking place within well known and well understood events, but ignored by scientists wearing thick sunglasses.
    Now to the substance of your complaint.
    – it would be helpful to the readers if you produce a decent graph, now lets compare two
    – svalgaard: http://www.leif.org/research/GEO-F-CALS7K.png
    – vukcevic: http://www.vukcevic.talktalk.net/LL.htm
    – regular readers as well as you (unless your memory has a temporary lapse) are more than well aware that my geomagnetic graph in more detail that has been featured on number of occasions on this blog, but for your attention here it is again:
    http://www.vukcevic.talktalk.net/Ltr-Gmf.htm
    As you can see it absolutely clear what is meant by each part of the composite, while your interpretation, to be generous, is a ‘joke’, but I will let others make proper judgment .
    – I hope you red latest paper (published just few months ago) from Dr. Korte and her team from Potsdam.
    Conclusion is definite: the Middle Ages temperature, before man started interfering, was controlled by the sun (via sundials) and God (via church builders).
    http://www.vukcevic.talktalk.net/sd-ch.htm
    but on the other hand you may fail to understand that.
    Alternatively, I suggest you look into pre-1833 10Be records again with the both eyes open.
    http://www.vukcevic.talktalk.net/MC-NAP.htm
    Hay, isn’t science fun!

  194. Max_OK says:

    @Richard S Courtney says:
    September 29, 2010 at 2:30 am
    I fail to understand the interest in the history of UK grape growing which has nothing to do with the reconstructions of past global temperatures.

    It was much warmer in the UK 1,000 years ago. Much archaelogy proves it.
    Archaelogical evidence is empirical data. It is not “anecdote”.

    For example, 1,000 years ago a type of beetle that is now constrained to the South of France existed in the UK as far North as York. Remains of the beetles are found in exhumed stone coffins from the period.

    So, the climate of the UK was warmer 1,000 years ago than now. But this says nothing about the climate temperature elsewhere. Live with it.
    ——-
    I agree that the history of UK grape growing has nothing to do with the reconstructions of past global temperatures. But viniculture in England in Roman times frequently is cited as evidence it was warmer there than it is today. I don’t know whether the UK was warmer a 1,000 years ago than now, but I doubt vinicultural is supporting evidence. I see no evidence grape cultivation in England appeared in Roman times and then later disappeared because of climate change.

    According to the linked source on the history of viniculture in England, “The period from the end of the First World War to shortly after the end of the Second World War may well be the only time in two millennia that vines to make wine on a substantial scale were not grown in England or Wales.”

    http://www.english-wine.com/history.html

    I also doubt England was as warm 1,000 years ago as the South of France is today.

  195. Tilo Reber says:

    Larus:
    “The tone of many comments on this site suggests that people believe your “vindication” to mean that Mann’s hockey stick has been demolished, and your graph validated, by Ljungqvist’s new publication. In fact, the reverse seems to be the case. ”

    The title “hockey stick” was given to Mann’s 99 reconstruction. That reconstruction has been destroyed by everyone including Mann 08. Take a look, it no longer resembles a hockey stick. And the only remnant of the hockey stick in Mann 08, the sharp blade at the end, is due to using an upside down Tiljander series and the split bark bristlecone, cherry picked Graybill data. Now look at Moberg and Ljungqvist. They do not rise to the same level as Mann 08 for the current period. Both Moberg and Ljungqvist reconstructions look nothing like a hockey stick. Also, unlike Mann 08, Ljungqvist MWP reaches a higher point than any of his contemporary data. The use of instrument data to get to a higher level than the MWP is also absurd. If the proxy data will not follow the instrument data today, why would we believe that it would have followed it in the MWP.

  196. Slioch says:

    Cope

    claimed, “We have seen direct attacks on Craig Loehle’s integrity by … Slioch.”

    No you haven’t. I have made no direct attack upon Loehle’s integrity, nor even impugned it. I notified people of Tamino’s site where Loehle’s claim of vindication for his graph was severely challenged – but that impugns his competence rather than integrity, and besides I am not responsible for other people’s work, whether I agree with them or not. Are you seriously suggesting that Loehle’s claims should not have been challenged? And are you suggesting that people on this site should not have been aware of Tamino’s assessment of Loehle’s claim?

    As for my other contributions on this thread, they are actually more supportive than censorial towards Loehle: I agree with extending his proxy graph using the instrumental data as Loehle did in Loehle 2008 – I’ve just extended it further than he did. Besides, again, none of that has any relevance to issues of integrity.

    Now, Cope, you have wrongly accused me of directly attacking a man’s integrity, which is a serious accusation. I note what you say, and “will wait to see if” YOU “step forward with an apology.”

    REPLY: This is all pointless. People that demand apologies for “serious accusations”, while hiding behind fake names like “Slioch”, “Tamino”, “cope”, or “Amino Acids in Meteorites” or whatever, have an inflated view of self importance. Put your own name to your words like Mr. Loehle does, and THEN you can talk about integrity and demand apologies. Otherwise I’m just going to snip this blustering rubbish. Sheesh. Be as upset as you wish. – Anthony

  197. Tilo Reber says:

    John Finn:
    Absolutely – better to use the UAH data where 5 year mean anomalies are: 1992= -0.03; 2007= +0.024 , i.e. a difference of +0.27. I see what you mean – miles off.

    The point about not using GISS is due to it’s strong divergence from the other sources since 97. This is due to errors that I pointed out in the link that I gave. It is a general observation, not one having to do with the difference between 92 and 07.

    The problem with using instrument records for comparison with MWP proxies is a seperate problem. The contemporary proxies do not follow the instrument data to it’s magnificent heights. There is a significant divergence problem. So if you want to make comparisons to the MWP, where there is only proxy data, then you have to compare against today’s proxy data. Compare apples to apples. And what do you get when you compare apples to apples? You find that the claim that the temperatures of the last century are unprecedented is just simply garbage. Proxy reconstructions used by themselves without instrumental extensions simply do not support such a claim.

  198. cope says:

    Slioch,

    Just informing people about Tamino’s post is copacetic. However, you did not do that. You prefaced the link to Tamino with your supportive opinion: “The above post by Loehle is not a vindication of his earlier work.”

    And Tamino clearly did question Loehle’s integrity (“…When compared honestly…”).

  199. Tilo Reber says:

    Slioch:
    “If the proxy temperatures do not extend to present times then obviously they are not going to tell you how modern times compare with the MWP: that is why the record is extended using the instrumental data, and quite rightly so. ”

    This is incorrect on several levels. First of all, trees are still producing tree rings every year. Ice cores are still changing every year. Silt is still being deposited on the bottom of lakes every year. There is no reason why we cannot get modern proxy data so that we can compare proxy data to proxy data. Second of all, the contemporary proxy data that is available does not follow the contemporary instrument data. Most of it does not show nearly the magnitude of temperature increase that is shown by the instrument record, and some of it has even gone negative. You can see this in most of the reconstructions, including Ljungqvist’s. So if the proxies don’t match the instruments today, why would we think that they would match them in the MWP. How can we know that an instrument record from the MWP would not also have exceeded the height of the proxies then just like they are today?

  200. Richard Sharpe says:

    Max_OK says September 29, 2010 at 7:34 am

    @Richard S Courtney says:
    September 29, 2010 at 2:30 am

    I fail to understand the interest in the history of UK grape growing which has nothing to do with the reconstructions of past global temperatures.

    It was much warmer in the UK 1,000 years ago. Much archaelogy proves it.
    Archaelogical evidence is empirical data. It is not “anecdote”.

    For example, 1,000 years ago a type of beetle that is now constrained to the South of France existed in the UK as far North as York. Remains of the beetles are found in exhumed stone coffins from the period.

    So, the climate of the UK was warmer 1,000 years ago than now. But this says nothing about the climate temperature elsewhere. Live with it.

    I agree that the history of UK grape growing has nothing to do with the reconstructions of past global temperatures. But viniculture in England in Roman times frequently is cited as evidence it was warmer there than it is today. I don’t know whether the UK was warmer a 1,000 years ago than now, but I doubt vinicultural is supporting evidence. I see no evidence grape cultivation in England appeared in Roman times and then later disappeared because of climate change.

    According to the linked source on the history of viniculture in England, “The period from the end of the First World War to shortly after the end of the Second World War may well be the only time in two millennia that vines to make wine on a substantial scale were not grown in England or Wales.”

    http://www.english-wine.com/history.html

    I also doubt England was as warm 1,000 years ago as the South of France is today.

    It is staggering that Richard Courtney provided archaeological evidence (beetles that are restricted to the South of France today yet existed in England 1,000 years ago) that England was as warm 1,000 years ago as the South of France is today and you ignored it.

    However, I see lots of AGW supporters ignoring archaeological evidence …

  201. This may have been mentioned here previously, but an article from 2009 by Ljungquist is a goldmine of information.

    TEMPERATURE PROXY RECORDS COVERING THE LAST
    TWO MILLENNIA: A TABULAR AND VISUAL OVERVIEW

    http://onlinelibrary.wiley.com/doi/10.1111/j.1468-0459.2009.00350.x/pdf

    28 pages with 71 temperature graphs.

  202. Jordan says:

    Tilo Reber says: “How can we know that an instrument record from the MWP would not also have exceeded the height of the proxies then just like they are today?”

    Looks like a research project for somebody … perhaps if they can get the right guy on the case, it will get the grant, publication in an “acceptable” journal and the clique will get the usual hat tips. Oh … and maybe this time they might even go to the bother of citing Loehle (2007) “A mathematical analysis of the divergence problem in dendroclimatology”.

    (I just cannot contain my cynicism.)

    To Craig Loehle – thanks. I have always had a great deal of respect for your work. It has served me well in giving the needle to some of our blogosphere friends in the pro-catastrophe camp. I recall your recon. as groundbrreaking in the sense that it was a front runner in challenging the HS. The way you submitted it for review at CA was novel.

    And when you drew fire from Gavin on RC, it gave me the chance to say that Gavin had peer-reveiwed it so the pro-catastrophe squad could not harp on about “choice of journal” and “peer review”. It was great fun to rub their noses in that one.

  203. phlogiston says:

    Oliver Ramsay says:
    September 28, 2010 at 9:35 pm
    @ Max_OK

    I am skeptical of claims that grape cultivation in England in Roman times is evidence of a warm period. Grapes are grown commercially in Upstate New York, an area that I suspect has a colder climate than the UK had back then.

    —————-
    You might have fallen into the “Just give me the average” trap.
    Grapes need summer heat and sun and can tolerate quite a bit of winter frost.

    I’m a bit late on this but the grape growing in Medieval England is important evidence of warmth 1000 years ago.

    Vine Street in London owes its name to the substantial grape trade in London at the time. It is one of the most advantageous properties in the game “Monopoly” – whoever gets the Vine Street set often goes on to win.

    There are two possible explanations for this Medieval grape growing, (a) grapes were more cool-resistant then but somehow lost this trait (unlikely) or (b) it was warmer in the Medieval warm period.

    For some I guess the grapes are sour.

  204. John Finn says:

    mikef2 says:
    September 29, 2010 at 2:30 am

    John Finn….
    Soooooooooo…what are you actually saying, what is your point? That the LIA did not exist, because rivers in the UK have frozen over since? You imply I think, that we must discount the frost fair history as nothing exceptional, because we have had weather cold enough to freeze rivers since. Is that the point you were trying to make by suggesting the Thames only froze over often due to its flow rate being slower back then?

    You ask a lot of questions which I’ll try to answer. The fact that Frost Fairs were held in the 17th-19th centuries is as irrelevant as the fact that Bear baiting took place in the 17th century or the fact that test match cricket is played in England (and Wales) to-day. Furthermore the fact that rivers froze in earlier centuries is not proof that the LIA was cold.
    If that is your point (& if not then its a bizarre ot thing to bring up) are you therefore implying that temp has not really changed? After all, the Avon froze this winter too, I know as I was there, and was there in ’63…thanks for the pics but we have our own b&w’s from that time! Your arguement seems to contradicting iteself.
    My argument is contradicting itself? You are the one who suggested that other rivers such as the Avon also froze in the LIA. Then you tell me the Avipon froze this year and in 1963. I think you are the one who needs think through their argument.

    If the Thames only froze because of sluggish flow, and the Avon has frozen this last 3 yrs, which you will have to trust me on, then logic says temps are the same.
    But we know they are not, according to all the temp curves.
    So it must have been colder for longer back during the frost fairs. But you say no, the Thames only froze due to sluggish flow.

    I am questioning your so-called proof. There may be evidence that the LIA was colder but frozen rivers isn’t it. I’m not sure what you mean by the “temp curves”. Do you mean actual observations or proxy reconstructions?

  205. vukcevic says:
    September 29, 2010 at 7:27 am
    Conclusion is definite: the Middle Ages temperature, before man started interfering, was controlled by the sun (via sundials) and God (via church builders).
    I think this very well sums up the substance of your ‘science’.

  206. John Finn says:

    phlogiston says:
    September 29, 2010 at 10:55 am

    I’m a bit late on this but the grape growing in Medieval England is important evidence of warmth 1000 years ago.

    Sheesh.

    There was evidence of vineyards in the 8th century. More often than not they were found in the grounds of monastries.
    Folllowing the Norman conquest in 1066 the popularity of vineyards for wine production grew. Native Anglo-Saxons preferred mead and ale but the invading Normans were wine drinkers.

    In the Domesday Book (1086) the location of 45 vineyards is recorded. The most northerly was at Ely in Cambridgeshire. The majority were owned by Norman nobility or the monastries. Despite the local wine production an increasing amount of wine was imported from France.

    During the reign of Henry VIII (1509-1547) there were, reportedly, 139 vineyards in England. There was a decline after that which many speculate was due to a cooler climate, but the most likely cause was the dissolution of the monastries during the protestant reformation.

    In the late 1980s there were 400 vineyards in the UK. The number has since stabilised to around 300.

    Vineyards in England are not unique to the MWP. Their popularity in the post-1066 period was entirely due to the Norman conquest.

    Not sure I’m totally convinced by Richard’s beetle evidence either.

  207. Smokey says:

    Slioch disagrees with my comment confirming the fact that natural climate variability caused the planet’s surface to become warmer more a thousand years ago than it is today. He says:

    “Not according to Loehle 2008 it didn’t.”

    I’m glad Slioch agrees with Dr Loehle — who is right, and I think Slioch knows it even though he won’t admit it except to attempt to score a minor point: disputing that past warming events exceeded today’s, even in the face of mountains of evidence and reams of eye-witness accounts.

    Natural variability has caused the planet to become warmer than it is now many, many times in the past, whether Slioch likes that fact or not.

    Natural climate variability is an established fact [for everyone except Michael Mann and his clique], and absent testable, empirical evidence, it debunks the belief that a minor trace gas must be the primary cause of this warming cycle, in which the current *mild* warming is indistinguishable from numerous past warming cycles. This time it’s different, eh? Argumentum ad ignorantium.

    So who should we believe? Evidence from planet Earth – or the IPCC’s Hokey Stick fabricator?

  208. Tilo Reber says:

    John Finn:
    “There may be evidence that the LIA was colder but frozen rivers isn’t it. ”

    No, it’s one of many pieces of evidence of that type. While a particularly hard freeze may freeze the Thames today, such a freeze would be out of the ordinary. The fact that fairs were scheduled on the river during the LIA would indicate that such freezes were a consistent and dependable event. It would indicate that people could depend on there being enough ice to hold the weight of many, along with wagon loads of merchandise. And would indicate that the ice was consistently thick enough every winter to handle such a demand. I don’t believe that any business organizations would consider scheduling fairs on the Thames today, even if there is the rare freezover.

    In any case, ice fairs, beetles, grapes, and resettling Vikings all tell a consistent story. If you choose to ignore that story, that is up to you.

  209. Slioch says:

    Tilo Reber at 8:51 am

    When I stated “If the proxy temperatures do not extend to present times then obviously they are not going to tell you how modern times compare with the MWP: that is why the record is extended using the instrumental data, and quite rightly so ” I was referring only to the Loehle 2008 paper, as I have clearly been doing all along.

    Your response refers to the general problem of using proxies and has no relevance to what I was saying. As far as I am aware, no-one has tried extending Loehle 2008 using proxies.
    In brief, what I stated about Loehle 2008 was:
    i) if Loehle 2008 is not extended to today’s temperatures by using instrumental data, then it says nothing about today’s temperatures in comparison with the MWP because its proxies only extend to (centred on) 1935.
    ii) if Loehle 2008 is extended to today’s temperatures by using instrumental data, then it shows that the MWP was cooler than today’s temperatures.

  210. Slioch says:

    Smokey at 12:04 pm

    It’s a pity you don’t actually read what people say rather than imagine what has not been said.

    This thread is about Loehle’s temperature reconstructions, and I have restricted my comments herein to that. Thus I have not mentioned earlier warmer periods in the Earth’s history since they are not relevant to what I was saying about Loehle’s papers.

    No knowledgeable person disputes that “natural climate variability is an established fact”.

  211. Smokey says:

    Slioch says:

    “No knowledgeable person disputes that ‘natural climate variability is an established fact’.”

    Good to see the scales are falling from your eyes. Damascus is straight ahead.☺

  212. Guillermo Gefaell says:

    Based in Mr. Ljungqvist temps reconstruction:

    1.- Present decadal temps do not seem to be much higher (if they in fact are at all) than the ones for the MWP (about 0.2ºC at its most)
    2.- Anthropogenic CO2 is only significative (IPCC) since around 1940, but temperatures have been rising since around 1700.
    3.- Decadal temps have rised +/- 0.72ºC from 1690 to 1940, and +/- 0.36ºC for 1940-2000
    3.- Of the three rapid warming periods since then, of about 0.4 – 0.5 ºC each, only the last one coincides with significant anthropogenic CO2

    Why should we consider this last period (+/-1970-2000) as extraordinary at all? How can it be supported anthropogenic CO2 drove the temperature increase in that period?

    See graph at:
    http://www.boatdesign.net/forums/attachments/open-discussion/48075d1285787282-what-do-we-think-about-climate-change-temps-1690-2000.png

  213. Jordan says:

    Slioch ssys: “i) if Loehle 2008 is not extended to today’s temperatures by using instrumental data, then it says nothing about today’s temperatures”

    True. But if anybody thinks the two can be legitimately strung together, then the instrumental record would predict a rise in the proxy reconstruction when we get data to extend the recon.

    Would you be prepared to venture a prediction that the proxy reconstructions will rise if they are extended?

    I doubt it, because you’d be placing a risky bet against whatever lies behind the so-called “divergence problem”.

  214. vukcevic says:

    Leif Svalgaard says: September 29, 2010 at 11:17 am
    ………
    Hi doc
    I did say: ‘but on the other hand you may fail to understand that.’
    I only ploted data
    http://www.vukcevic.talktalk.net/sd-ch.htm
    by highly respectable Dr. M. Korte at al (Helmholtz Zentrum Potsdam, Deutsches GeoForschungsZentrum GFZ) from the recent work:
    A historical declination curve for Munich
    published in Physics of the Earth and Planetary Interiors.
    While your plot of their ‘premier’ data set
    http://www.leif.org/research/GEO-F-CALS7K.png
    is a bit of embarrassment, since earlier today my graphs are viewed people like:
    National Academy Of Sciences (144.171.192.164) Washington
    State Of Alabama, Information Services Division (216.226.180.3) Montgomery
    Duke University (152.3.249.19) North Carolina
    University Of Berne (130.92.53.236) Switzerland
    Lawrence Livermore Laboratory (128.115.27.11) Livermore, California
    Stockholm University (130.237.199.223) Sweden
    Idaho National Laboratory (134.20.54.68) Idaho Falls
    Lockheed Martin Corporation (192.91.173.42) Ashburn, Virginia
    The Boeing Company (130.76.96.18) Chesterfield, Missouri
    Wyeth-ayerst Research (155.94.62.222) Phoenixville, Pennsylvania
    Usda Office Of Operations (199.156.164.36) Portland, Oregon
    National Aeronautics And Space Association (128.159.194.23) Cocoa, Florida
    University College London (128.40.1.34) London, UK
    Open University (137.108.85.101) Milton Keynes, UK
    Staffordshire University (194.66.175.89) Stoke-on-trent, UK
    Sheffield Hallam University (143.52.5.10) Sheffield, UK
    Uk Meteorological Office (151.170.240.10) Exeter, UK
    Danish Network For Research And Education (130.225.73.247) Copenhagen
    (was that you still in Denmark?) and many others.

  215. Steven Mosher says:

    “I’m a bit late on this but the grape growing in Medieval England is important evidence of warmth 1000 years ago.”

    wow, here we go again. folks who question whether a world wide network of thermometers is dense enough to capture the climate signal, but find grapes
    in a couple places and the conclusion is self evident.

  216. Steven Mosher says:

    evanmjones says:
    September 29, 2010 at 1:46 am (Edit)
    Either the MWP was almost as warm, as warm, or slightly warmer than today.

    #########

    That’s about the gist of it. overplaying the hockey stick hand is a huge mistake.. on both sides. it just doesnt matter much to the real debate.. Which, ironically, is why people are so attracted to it as a debating grounds. we always gravitate to the grounds of debate where nothing much is at stake. And on those grounds we fight dirty and nasty. the less important the matter they nastier the fight.

    The Hope is that if you defeat your opponent on the “test battle” that they will just give up on main front. It’s also important to send proxy warriors to these side fights. That’s why mann will never engage McIntyre directly on the issues.

  217. John Finn says:

    Tilo Reber says:
    September 29, 2010 at 12:16 pm

    John Finn:
    “There may be evidence that the LIA was colder but frozen rivers isn’t it. ”

    No, it’s one of many pieces of evidence of that type. While a particularly hard freeze may freeze the Thames today, such a freeze would be out of the ordinary.

    It wasn’t commonplace back in the “Little Ice Age”. Very few winter months in the CET record have a mean temperature below
    Zero deg C.

    The fact that fairs were scheduled on the river during the LIA would indicate that such freezes were a consistent and dependable event.

    Dependable?? This link says it all

    http://www.icons.org.uk/theicons/collection/the-thames/features/frost-fairs

    “Frost fairs could never be predicted, but when they did happen they were amazing spectacles……”

    Of course they couldn’t be predicted. These events were few and far between. The 2 most famous Frost Fairs (i.e. 1683/84 and 1813/1814) were 130 years apart. Frost Fairs could have been held in the MWP if it had been fashionable at the time.

    In any case, ice fairs, beetles, grapes, and resettling Vikings all tell a consistent story. If you choose to ignore that story, that is up to you.

    Well the ice fairs and grape growing don’t tell us anything – so you’re left with vikings and beetles. We know the vikings came to England in 793 AD which is a bit quick off the mark if their “resettling” was triggered by the warmer climate. According to the 2 reconstructions above the period around 800 AD doesn’t seem overly toasty. But then again the MWP, like the LIA, seems to be a pretty flexible period.

    Perhaps I’m just sceptical.

  218. KLA says:

    While I am a skeptic, I don’t think viniculture in England during the Middle Ages is evidence of a warmer climate. There’s much varied and better evidence for that.
    The reason I think so is that I grew up in a wine-region in southern Germany (warm local micro climate). All during the Middle Ages and during the LIA to the beginning of the 20th century grapevines were also grown in colder areas of Germany that don’t grow any grapes today. The resulting wine would be simply of too low of a quality (very sour) to be sellable today, although it could with modern wine-making technology.
    One recorded story was that during the Ottoman wars in the 15th century (LIA) a returning German king was greeted by the townspeople of one of those then vine-growing towns with a glass of local wine.
    After drinking it the king reportedly said that he would rather go again through the siege of Belgrade than drink another glass of that wine.
    According to another anecdote it said that a glass of wine from that same town will rip your stomach open. You have to drink a glass of wine from a neighboring town (same micro-climate), as it is so sour that it will pull that ripped stomach back together.
    Medieval viticulture in areas that don’t grow grapes today could also just show that people had stronger stomachs back then.
    Remember, Europeans since the Middle Ages to the end of the 19th century had much less access to clean potable water (than for example Americans) because of large amounts of untreated farm animal runoff in rivers and wells combined with high population density. The only way to preserve drinkable liquids for them was to ferment fruit or grain “juices”.
    Meaning also that europeans were continually “buzzed” for nearly 1000 years, which also explains much of european history.

  219. vukcevic says:
    September 29, 2010 at 1:33 pm
    I only ploted data http://www.vukcevic.talktalk.net/sd-ch.htm
    That bears no resemblance to you other plots. And does not cover the last 2000 years.

  220. Slioch says:

    Jordon asks

    “Would you be prepared to venture a prediction that the proxy reconstructions will rise if they are extended?”

    Yes.
    The proxies that have “diverged” in recent decades are tree rings. Loehle explicitly excluded tree ring data in his paper. Your question is misconceived.

    Steven Mosher “it just doesnt matter much to the real debate”
    True.

  221. mikef2 says:

    Tilo – thanks for your support, I’m glad I’m not the only one who can see through Johns rather contradicting statements. Unfortunately John is now in a no win situation, so there is no point continueing this debate on this point.
    It seems that no matter what anectdotal historical, archeological, or even temperature proxy evidence is given, if it conflicts with the mainstream view John has bought into – ergo the temp of the last 1000 yrs or so is pretty constant, and only the last 30yrs has seen something new and unprecedented, then John will dismiss all that evidence.
    I find such blind faith rather bizarre myself. But then, the inability to understand his own contradictions (mentioned in a previous reply) is perhaps a mark of faith rather than logic.

    I tend to agree with Steve Mosher and others that indeed too much store is put in proxies, be they sediments, treerings, beetles, wine, viking settlements..whatever. We can, if we are honest and keep an eye on developing social trends (like wine may have stopped being sold because it was just rubbish and imported stuff was much better…) still determine trends though, and those trends suggest that the LIA and the MWP existed, and yes it may be fractions of a degree as an average, but then thats all we are talking about this last few years if we are honest enough to take out El Nino (Bob Tisdales stuff well worth reading).
    We are arguing about angels dancing on the head of a pin.
    Thats why John, I did not like your comment dissing the idea that the LIA was real…it was real, the MWP was real. You and some others need to admit this demonstrably proven fact. Then once that is done, we can look at the last 30yrs to see if it is at all unprecedented.
    Until then, I’m afraid the mainstream of climate science is in a very long river in Africa.

  222. mikef2 says:

    ..ok…just popped over to Lucias for supper, Lucia has dropped a number of reconstructions on top of each other.
    My lying eyes tell me there is a rise until around 1000 yrs ago, then quite a drop, then a steep rise again. So far…nothing to get excited about.
    Then a whopping rise in the last few decades….but then again…this is where thermometers take over, and lets not even mention Yamal (oops too late)……so my BS indicator tells me I need a lot more convincing about the record itself, let alone the role of CO2 in it.

  223. Tilo Reber says:

    Slioch:

    “The proxies that have “diverged” in recent decades are tree rings. ”

    Yes, tree rings have certainly diverged. And this, in spite of tree ring series being selected based upon their matching of the instrument record. But, more importantly, do you have an example of non tree ring data that shows the same magnitude of temperature rise as the instrument record?

  224. John Finn says:

    mikef2 says:
    September 29, 2010 at 3:21 pm
    Tilo – thanks for your support, I’m glad I’m not the only one who can see through Johns rather contradicting statements. Unfortunately John is now in a no win situation,….

    Are you for real? YOU cited the Avon freezing as evidence of the LIA. YOU then told me that the Avon froze recently as well is in 1963. If the Avon freezing in the 19th century is evidence of the LIA – what does it mean that it froze in 1961, 1963 or las year?

    I find such blind faith rather bizarre myself. But then, the inability to understand his own contradictions (mentioned in a previous reply) is perhaps a mark of faith rather than logic.

    Blind faith comes from believing that one or two mythical anecdotes count as evidence for significant shifts in climate.

    KLA says:
    September 29, 2010 at 2:34 pm
    While I am a skeptic, I don’t think viniculture in England during the Middle Ages is evidence of a warmer climate.

    KLA

    Do you not see the irony in your comment. If you are a “skeptic” you should question the evidence for the MWP. Being an AGW “skeptic” (or sceptic) doesn’t mean accepting any old claptrap just because it appears to counter the AGW case.

    Steve Mosher is bang on when he says

    “folks who question whether a world wide network of thermometers is dense enough to capture the climate signal, but find grapes in a couple places and the conclusion is self evident”.

    Grapes have been grown in England for centuries. The Normans (after 1066) popularised grape growing but there were more vineyards during the reign of Henry VIII than during the MWP. There are around 6 times as many vineyards in the uK to-day as there were in the period following the Norman conquest.
    The Thames has been frozen dozens of times throughout history. It froze during the roman occupation of Britain. It froze several times – for months on end – during the MWP. It froze solidly during the reign of Henry VIII – presumably while there were still 130-odd vineyards knocking about.

    The “grape growing” and “Thames freezing” evidence is complete cobblers.

  225. Stilgar says:

    Fredrik Charpentier Ljungqvist says:
    September 28, 2010 at 8:17 am
    I have noted in the post that there are a lot of (indirect) references to Mann et al. (1999) – the so-called “Hockey Stick Graph”. It is science history now.

    Any references to temperature reconstructions by Michael E. Mann should be to his 2008 and 2009 temperature reconstructions. They actually show an even warmer Medieval Warm Period than I do. I don’t think it is fair to refer to an outdated work (from 1999) when we have newer and better.

    Sorry, I missed that part of Mann’s paper that said 99 was all wrong and to ignore it. Where in 08/09 does Mann (or in peer reviewed papers by other Team members) say that his new work completely replaced his older work and the reason for the replacement (ie, it was wrong/flawed) or failing that could you point out where in your own paper you state that 99 was wrong and will be ignored (as well as all the studies that also said 99 was correct)?

    What exactly is not fair? People to this day claim 99 is correct, including Mann. As far as I can tell, Climate Scientists such as yourself are happy to reference 08/09 because you know 99 is absolutly wrong. What is not fair is the attempts by people to sweep 99 under the rug as if 99 and the considerable effort to uncover the problems with 99 never happened. BTW, any paper showing 99 is wrong which was heavily critisized by Team members is not proof the Team agrees that 99 is wrong (in fact it pretty much shows the opposite).

    You have to admit mistakes before you can move on (even those made by others in your field). If someone doesn’t admit they made mistakes, don’t be surprised if no one moves on dispite how unfair you think it may be.

  226. John Finn says:

    Thats why John, I did not like your comment dissing the idea that the LIA was real…it was real, the MWP was real.

    I don’t believe I said that the LIA and MWP weren’t real. I “dissed ” the evidence that was being presented. It’s called scepticism.

    You and some others need to admit this demonstrably proven fact.

    I don’t need to admit anything of the sort – particularly as there is some uncertainty over both the extent and timing of these events. For what it’s worth I do think the middle ages were generally warmer than the 16th-19th centuries in Europe at least, but we can’t rule out the fact that this wasn’t a regional (and seasonal) effect.

  227. phlogiston says:

    Its interesting – continuing the theme of British wine growing – that wine drinking foreigners invade old foggy Albion only at 1000 year intervals. During the Roman Warm period Caesar’s legions introduced us woad-painted savages to the noble grape. A millenium later it was the Varangian-Normans who renewed our acquaintance with wine and vineyards.

    Why are the British Isles attractive enough to invade only every 1000 years or so? Easy – the rest of the time it’s too bloody cold.

    So who are the invading foreigners this time? – O yes [mods - political incorrectness alert] its the Pakistanis; but hang on – they’re muslims and dont drink alcohol. And the Poles too – but they prefer “wodka” which comes from wheat, not grapes. (I think – someone correct me if I’m wrong there.)

  228. thefordprefect says:

    Leif
    http://img412.imageshack.us/img412/9641/ljungqvistloehlecrut3vn.png
    Is a plot of offset Loehle andLjungqvist proxies aligned to CRUT3V Nh where the records overlap

    As can be seen there is visual similarity between the proxies but not good. But the overall plot does seem to resemble a hockey stick!!!!

  229. Carrick says:

    Jeff, regarding rescaling…I think you do want to rescale, because there is a difference in Loehle geographic representation relative to Ljungqvist. I did this for yuks, using the variance adjustment method, but you might be match scales using calibration period data, which is of course a cleaner approach to use.

    Not surprisingly after making an additional adjustment, my results look marginally better than yours, but the description remains qualitatively the same as what you found. The biggest difference is Ljungqvist doesn’t see a Roman Warming Period, which is odd, thought they both agree on the MWP duration, temperature and extent.

  230. Tilo Reber says:

    thefordprefect
    “But the overall plot does seem to resemble a hockey stick!!!!”

    Nah. The shaft isn’t nearly as straight as the Mann 99 shaft. And the only thing that gives you a blade is the instrument record. There is no blade in the proxy data.

  231. Smokey says:

    John Finn says:

    If you are a “skeptic” you should question the evidence for the MWP.

    Why the quote marks around skeptic, John? We don’t put quotation marks around “alarmist”.☺

    Skeptics question everything on occasion, but most don’t give much thought to the law of gravity. But the CO2=CAGW conjecture? Of course we give it much more thought, in this most-to-least questioned order: Conjecture, Hypothesis, Theory, Law.

    The existence of the MWP, having withstood a concerted attack for over a decade, has remained the accepted scientific hypothesis. Only those who still believe in the straight handle of the hockey stick invented by MBH98-99 argue that there was no MWP or LIA. But now even Michael Mann admits the MWP happened. Why won’t you?

    The evidence for the pronounced, world-wide climate change during the LIA and the MWP [ice cores, oxygen isotope ratios, and proxies such as tree rings and higher tree lines] has been peer reviewed and remains un-falsified. When multiple data points based on physical evidence support a hypothesis, skeptics have been given satisfactory evidence. Convincing new questions will only arise challenging the existence of the MWP/LIA if contradictory new evidence is found. But so far, the opposite has been occurring.

  232. mikef2 says:

    John Finn….go back & read my critique of your orig comment again, & the one posted at 2.30am Sept 29, read it in full.

  233. mikef2 says:

    Anyway…
    So, is it fact that the ‘nature trick’ divergence still holds true these past decade or so? Does the general gammut of proxies, based on how we use them, still tell us that temps are going down, whilst our lying eyes tell us the thermometre readings are still up (or at least not down).
    Like S.Mosher my money is on the mercury in the tubes, UHI/spatial averages etc notwithstanding. So the important thing is to really get to grips with the reasons for the divergence yes? Only by understanding why our proxies say ‘down’ (if that is still true of course?) while the facts say ‘same’ can we really have a clue about the past?

    Whats the latest on the Yamal dozen for example? Anyone care to chip in?

  234. anna v says:

    thefordprefect says:
    September 29, 2010 at 5:44 pm

    Leif
    http://img412.imageshack.us/img412/9641/ljungqvistloehlecrut3vn.png
    Is a plot of offset Loehle andLjungqvist proxies aligned to CRUT3V Nh where the records overlap

    As can be seen there is visual similarity between the proxies but not good. But the overall plot does seem to resemble a hockey stick!!!!

    Was not this the way the hockey stick was created?
    By splicing proxies with thermometer records? Except they, and you, forgot that if the the proxies are continued to the present there is great discrepancy , the famous decline that had to be hid.

    The moral of the whole story is that tree rings are bad proxies, and proxies in general have to be take with a lot of salt because they have not been really callibrated. No thermometers in the middle ages.

  235. evanmjones says:

    I have met Dr. Loehle and heard him speak. For what it’s worth, I found him to be honest, cautious, thoughtful, and impeccably polite. Willing to admit errors, willing to readdress, update, and clarify. Not a hint of arrogance or condescension. A foremost exponent of the scientific mind.

  236. John Finn says:

    Smokey says:
    September 29, 2010 at 7:55 pm
    John Finn says:

    If you are a “skeptic” you should question the evidence for the MWP.

    Why the quote marks around skeptic, John? We don’t put quotation marks around “alarmist”.

    Because, in the UK, we spell “skeptic” as “sceptic” and I was quoting the previous poster rather than writing it as I would normally write it.

  237. vukcevic says:

    Leif Svalgaard says:
    September 29, 2010 at 2:39 pm

    You are obviously not on touch with latest from:
    Dr. M. Korte at al (Helmholtz Zentrum Potsdam, GFZ) from the recent work:
    A historical declination curve for Munich, published in Physics of the Earth and Planetary Interiors. (Fig. 8, p.167).
    http://www.vukcevic.talktalk.net/sd-ch.htm

  238. John Finn says:

    mikef2 says:
    September 29, 2010 at 10:20 pm
    Anyway…
    So, is it fact that the ‘nature trick’ divergence still holds true these past decade or so? Does the general gammut of proxies, based on how we use them, still tell us that temps are going down, whilst our lying eyes tell us the thermometre readings are still up (or at least not down).

    The ‘nature trick ‘ has nothing to do with a decline in thermometer readings. It’s due to an apparent temperature decline in the proxy data (tree-rings) in the mid to late 20th century. The timing of the decline appears to be related to the calibration period used in the reconstruction (though Steve McIntyre may correct me on that), i.e. the divergence happens in the post-calibration period. This decline is, of course, inconvenient as it shows observations and reconstructions heading in different directions. The ‘trick’ was to pad the smoothed series beyond the end time with actual themometer data and so ‘hide the decline’.

    I challenged Michael Mann (on realclimate) about the divergence issue nearly 6 years ago – when only a handful of people (Steve & Ross mainly) were seriously examining the hockey-stick. This is from a previous WUWT post, i.e.

    http://wattsupwiththat.com/2009/11/20/mikes-nature-trick/

    Back in December 2004 John Finn asked about “the divergence” in Myth vs. Fact Regarding the “Hockey Stick” -thread of RealClimate.org.

    Check out the RealClimate link. You will notice I was very sceptical about the validity of the Hockey-stick, so when you asked “How desperate are you guys ..?” , as you did in one post, I ‘d like to know which “guys” you are referring to.

    True scepticism cuts both ways. You would do well to remember that.

  239. John Finn says:

    Re: my previous post (i.e. John Finn says: September 30, 2010 at 12:28 am)

    I’ve re-read this post

    mikef2 says:
    September 29, 2010 at 10:20 pm

    I apologise. I misinterpreted it the first time. I thought you were saying the ‘decline’ was a temperature related to the “divergence” in some datasets in the past decade. The rest of the post is still relevant, though.

  240. John Finn says:

    phlogiston says:
    September 29, 2010 at 5:05 pm
    Its interesting – continuing the theme of British wine growing – that wine drinking foreigners invade old foggy Albion only at 1000 year intervals. During the Roman Warm period Caesar’s legions introduced us woad-painted savages to the noble grape. A millenium later it was the Varangian-Normans who renewed our acquaintance with wine and vineyards.

    The Normans and Romans were wine-drinkers. That much is true. The rest is drivel.
    In the works (Agricola) of Cornelius Tacitus he describes Britain in the 1st century AD (see
    http://www.ourcivilisation.com/smartboard/shop/tacitusc/agricola/chap1.htm ). He writes

    The climate is objectionable , with its frequent rains and mists, but there is no extreme cold.

    Hardly a holiday hotspot. Sounds a bit like the 1960s in August.

    Tacitus continues

    Their day is longer than is normal in the Roman world. The night is bright and, in the extreme North, short, with only a brief interval between evening and morning twilight

    The “longer” day suggests he is describing summertime. Further on Tacitus writes

    The soil can bear all produce, except the olive, the vine, and other natives of warmer climes , and it is fertile. Crops are slow to ripen, but quick to grow—both facts due to one and the same cause, the extreme moistness of land and sky. Britain yields gold, silver and other metals, to make it worth conquering.

    The Romans probably attempted to grow grapes but were, by and large, unsuccessful. We also note the motive for the invasion was not the delights of the British weather.

    The Normans did grow grapes, mainly in the South of England, but there were only ~45 vineyards at the time of the Domesday Book (1086) which was considerably less than in the early 16th century in the reign of Henry VIII and only a small fraction of the vineyards in existence to-day.

    Why are the British Isles attractive enough to invade only every 1000 years or so? Easy – the rest of the time it’s too bloody cold.

    Just a guess but I think the alleged promise made by Harold to William, Duke of Normandy, regarding access to the English throne may have had some bearing on reasons for the Norman conquest. Also, I’m not sure Britain was only invaded by the Romans and Normans. Ever hear of the Angles? Saxons? Jutes?

  241. phlogiston says:

    Analogous to the flat earth society, there appears to be an equally anachronistic “flat hockey-stick handle society”, stubbornly denying evidence for the MWP and trying to oppose any evidence of climate variation prior to 1900.

    The web site CO2 science has a database of 300-400 published papers documenting the MWP in all continents, as well as the oeans.

    http://www.co2science.org/index.php

    Would a representative of the flat hockey-stick handle society please provide us with a methodological refutation of every one of these 300-400 papers?

  242. phlogiston says:

    Now that, Steve, is what I would call a “jar of fleas!”

  243. vukcevic says:
    September 30, 2010 at 12:20 am
    You are obviously not on touch with latest
    The Declination changes all the time and has no more to do with temperatures than the US Postal Rate:
    http://joannenova.com.au/2009/05/shock-global-temperatures-driven-by-us-postal-charges/

  244. phlogiston says:

    John Finn says:
    September 30, 2010 at 1:52 am

    The post in question was somewhat tongue-in-cheek, no need for the po-faced rebuttal.

    For invasions of Britain you could have chosen the Spanish Armada (1588) plum in the middle of the LIA.

  245. John Finn says:

    phlogiston says:
    September 30, 2010 at 4:02 am
    John Finn says:
    September 30, 2010 at 1:52 am

    The post in question was somewhat tongue-in-cheek, no need for the po-faced rebuttal.

    For invasions of Britain you could have chosen the Spanish Armada (1588) plum in the middle of the LIA.

    I could have but I would have been wrong. The Spanish never invaded Britain (or England). The Armada refers to to the spanish navy who were defeated at sea by Drake et al.

  246. Wren says:

    @Richard Sharpe says:
    September 29, 2010 at 8:53 am

    It is staggering that Richard Courtney provided archaeological evidence (beetles that are restricted to the South of France today yet existed in England 1,000 years ago) that England was as warm 1,000 years ago as the South of France is today and you ignored it.

    However, I see lots of AGW supporters ignoring archaeological evidence …
    ——–
    If you are referring to an insect called Heterogaster urticae, it’s been recently reported as an invasive species in Norway, which we know has a cooler climate than the South of France.

    http://www.bioforsk.no/ikbViewer/Content/42258/BIOFORSK_RAPPORT_FINAL2.pdf

    If you are referring to another insect, please identify it.

  247. Phil. says:

    John Finn says:
    September 30, 2010 at 5:01 am
    phlogiston says:
    September 30, 2010 at 4:02 am
    John Finn says:
    September 30, 2010 at 1:52 am

    “The post in question was somewhat tongue-in-cheek, no need for the po-faced rebuttal.

    For invasions of Britain you could have chosen the Spanish Armada (1588) plum in the middle of the LIA.”

    I could have but I would have been wrong. The Spanish never invaded Britain (or England). The Armada refers to to the spanish navy who were defeated at sea by Drake et al.

    My high school had a holiday to celebrate the defeat! Given the forum I’m surprised no one mentioned the Vikings.

  248. Tilo Reber says:

    John Finn:
    “The ‘nature trick ‘ has nothing to do with a decline in thermometer readings. It’s due to an apparent temperature decline in the proxy data (tree-rings) in the mid to late 20th century. ”

    Yes, and the question that the divergence brings out is – how do we know that this is only a phenomena of the mid to late 20th century?

    Beyond that, I’m still waiting for someone to point to a proxy of any type that consistently reflects the magnitude of the gain that is shown by the instrument record for the last 50 or so years.

  249. Craig Loehle says:

    I would like to thank most posters for being polite even when disagreeing with how I compared my results. What this issue of shifting the baseline etc points out is the general problem that when dealing with proxies we have no way at present to prove which type of analysis or which type of data is valid. Some think you should rescale proxies to the same variance as the instrumental data and set the same baseline. I disagree on this point. Some use CPS (the subject of this post) which weights all proxies the same and combines before rescaling them to temperature. Some use RegEm or other method that gives each proxy it’s own wt. Which is right? All we have is opinions on these questions. Similarly, the Divergence question is swept under the rug, is a fatal flaw, or can be dealt with by “careful” choice of data etc, depending on your temperment and preferences. Tree ring data are the best data or the worst. Dating error are a problem that damp reconstructed peaks or something to ignore. The outcome and its meaning are all based on the assumptions made. So do not think that I give more than qualitative meaning to even my own results. None of these reconstructions in my opinion is a “temperature” history. At most, they can inform about the gross historical events such as the MWP and LIA and their approximate timing. Not more than this. Not temps to the nearest 0.1 deg. That is ludicrous.

  250. phlogiston says:

    John Finn says:
    September 30, 2010 at 5:01 am
    phlogiston says:
    September 30, 2010 at 4:02 am
    John Finn says:
    September 30, 2010 at 1:52 am

    For invasions of Britain you could have chosen the Spanish Armada (1588) plum in the middle of the LIA.

    I could have but I would have been wrong. The Spanish never invaded Britain (or England). The Armada refers to to the spanish navy who were defeated at sea by Drake et al.

    OK but the “Armada” was phase 1 of the planned invasion of England with the troops and troopships waiting in Holland for a successful clearing of the channel. Very similar scenario to the 1940 Battle of Britain and Hitler’s operation Sealion. Both were real invasion attempts but in both case the prerequisite of gaining sea / air superiority was not attained and the invasions were aborted.

    Spain’s Armada and its subsequent ignominious return home the long way around Scotland, explains the curious phenomenon of people you can find in coastal towns around Britain, with distinctly Spanish features but long British ancestry.

  251. Smokey says:

    Wren says:

    “If you are referring to another insect, please identify it.”

    R. Pachaurii?☺

  252. vukcevic says:

    Leif Svalgaard says: September 30, 2010 at 2:54 am
    The Declination changes all the time and has no more to do with temperatures than the US Postal Rate.

    I did not say they did, not declination, not Z or R, or total field. However it would be short-sighted not to consider a ‘cause commonality’, and I think I know what it is. The correlation is not always direct, as you keep pointing out, it flips from one mode to the other.
    Thanks to the Dr. Korte’s help, the cross over points have been now satisfactorily resolved and dated, by something I decided to call ‘GMF swing’, I am surprised by its accuracy.
    http://www.vukcevic.talktalk.net/GT1.htm
    Timing differences have to be put into context:
    M. Korte –“For individual data points dating uncertainties can reach the order of a few hundred years, and smooth time series for sites can be stretched or compressed in time by dating uncertainties of the individual points of which they are compiled.”
    UK Heritage: “With the present calibration data the practical limit on the maximum resolution of dates is around + – 50 years at the 95% confidence level.”
    Your challenges are always welcome, eventually I get a result.
    A very big THANK YOU !

  253. vukcevic says:
    September 30, 2010 at 2:20 pm
    However it would be short-sighted not to consider a ‘cause commonality’, and I think I know what it is.
    The easiest one to fool is oneself, and you do a nice job at it.

  254. vukcevic says:

    Leif Svalgaard says: September 30, 2010 at 4:59 pm
    The easiest one to fool is oneself, and you do a nice job at it.

    I did not expect you to agree, but it is encouraging to know that you have run out of good, solid objections.
    Fooling oneself is usually a consequence of ones belief, I do not believe in any of it, I just think if one is persistent in digging through data available, kind of a jigsaw puzzle could be put together. Of course not all pieces will be there, but it might give us a glimpse of what actual picture might be. Everything is pointing to a ‘ Y ’-shape should be the center piece, not an outdated ‘ I ’, as you would have it.

  255. vukcevic says:

    Leif Svalgaard says: September 30, 2010 at 4:59 pm
    The easiest one to fool is oneself, and you do a nice job at it.

    I did not expect you to agree, but it is encouraging to know that you have run out of good, solid objections.
    Fooling oneself is usually a consequence of ones belief, I do not believe in any of it, I just think if one is persistent in digging through data available, kind of a jigsaw puzzle could be put together. Of course not all peaces will be there, but it might give us a glimpse of what actual picture might be. Everything is pointing to a ‘ Y ’-shape should be the centre piece, not an outdated ‘ I ’, as you would have it.

  256. vukcevic says:
    October 1, 2010 at 1:29 am
    I did not expect you to agree, but it is encouraging to know that you have run out of good, solid objections.
    We have been over this many times before, and the objections still apply.

    Fooling oneself is usually a consequence of ones belief, I do not believe in any of it
    As you rightfully shouldn’t. To keep digging until something emerges is subject to bias. We once had a student who after trying 100 different time series found a correlation that was significant at the 95% level. You are like that student.

  257. Max_OK (formerly Wren) says:

    Smokey says:
    September 30, 2010 at 10:28 am
    Wren says:

    “If you are referring to another insect, please identify it.”

    R. Pachaurii?☺
    ——————
    I used to post here as Wren. I have recently posted as Max_OK for consistency, since that’s what I use at other sites. Max is my real first name, but there are many Max’s, so adding the OK hopefully gives me a unique handle.

  258. vukcevic says:

    Leif Svalgaard says: October 1, 2010 at 2:10 am

    Did you look at:
    http://www.vukcevic.talktalk.net/GT1.htm
    If dipole was I-shape, than GMF swing line would be = 0 (right hand scale), but it is not, it oscillates between two prongs of Y-shape. When Hudson bay > Siberia swing is negative (reversed correlation) and vice versa.

  259. vukcevic says:
    October 1, 2010 at 5:27 am
    If dipole was I-shape, than GMF swing line would be = 0 (right hand scale), but it is not, it oscillates between two prongs of Y-shape. When Hudson bay > Siberia swing is negative (reversed correlation) and vice versa.
    Numerology and ‘after-rationalization’. The dipole is not Y-shaped and doesn’t swing. The geomagnetic field where it is generated is very disorganized and varies largely randomly, consisting of many ‘multi-poles’. At great distance [3000 km] the low-order poles begin to dominate and a simpler configuration results. It is a pity you waste your time on such drivel, but, then, many people do on other forms of entertainment, so as long as you consider it as such, you have company, but a serious blog is hardly the place [of course, WUWT may not be a serious blog when the 'kooks' come out, as has been remarked by some posters].

  260. vukcevic says:

    Leif Svalgaard says: October 1, 2010 at 5:56 am
    ————-
    Do you mind, I am doing here an important ‘research on behalf of humanity’ and you call it , ‘waste of time and drivel’, how inconsiderate!
    You are so ‘1990’s.
    Quotes:
    5.3.4 Dipole field and the geomagnetic poles
    – Example of the geomagnetic dipole derived a geomagnetic field model from 1990:
    N.B. (1) Although the dipole component accounts for much Earth’s field IS NOT just
    a simple dipole and it makes no physical sense to think of it as such!

    (2) Geomagnetic dipoles ‘poles’ ARE NOT coincident with the magnetic poles
    where D=0, I=90, the position of magnetic polars are affected by non-dipole field.
    5.5.2 Intensity for field to L=13
    – The geomagnetic field is NOT simply a dipole. Departure from dipolarity
    can locally be very important. Dipole model is only a first approximation!
    http://www.epm.geophys.ethz.ch/~cfinlay/teaching/core_l5.pdf
    You should move on into 21st centaury!

  261. vukcevic says:
    October 1, 2010 at 7:17 am
    Do you mind, I am doing here an important ‘research on behalf of humanity’ and you call it , ‘waste of time and drivel’, how inconsiderate!
    I think your opinion of yourself is a bit over the top, considering the nonsense you spout.

  262. vukcevic says:

    I was expecting you to comment on above quotes, but you appear to be suddenly deprived of your scientific proves, i.e. you are unable to demonstrate by argument that ‘the Earth’s field IS NOT just a simple dipole’ is a falsehood.
    http://www.epm.geophys.ethz.ch/~cfinlay/teaching/core_l5.pdf
    My opinion of myself is rather humble, but also it is true Scandinavians will never understand Mediterranean sense of humour:
    Do you mind, I am doing here an important ‘research on behalf of humanity’ and you call it , ‘waste of time and drivel’, how inconsiderate!

  263. vukcevic says:
    October 1, 2010 at 7:59 am
    I was expecting you to comment on above quotes
    Why should I comment on something that already Gauss knew in 1835? Now, if you do wish to receive instruction in Geomagnetism, I’m all for giving you that, but perhaps on another thread, as we should not hijack Loehle’s thread.

    it is true Scandinavians will never understand Mediterranean sense of humour
    Now that you mention it ['I am doing here an important ‘research on behalf of humanity’ '], it does sort of sound a bit ridiculous, so there is perhaps some ‘humor’ there.

  264. vukcevic says:

    I agree, but you can’t be certain that Dr. Leohle may not be interested in these matters particularly in:
    http://www.vukcevic.talktalk.net/GT1.htm
    See you elsewhere.

  265. desmong says:

    Max_OK: Grapes in Scotland? Here are grapes in Sweden! http://www.eventyrvin.no/english

    However, it is not warm enough to have grapevines in Greenland, as it was possible during the MWP.

  266. toby says:

    It seems that the MWP and the LIA happened, at least in the North Atlantic.

    But there is absolutely no evidence that the MWP was “warmer than the present”. Loehle’s series ends in 1982 – nearly 30 years ago, so it has nothing relevant to say aboutr current temperatures.

Comments are closed.