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We know that's the canonical dogma of the CultOfMcIntyre. However, the CultOfMcIntyre has a long history of just making shit up, which is why nobody outside the cult pays any attention to them.
From Nature, Geoscience;
Continental-scale temperature variability during the past two millennia – Ahmed et al. (2013) “Past global climate changes had strong regional expression. To elucidate their spatio-temporal pattern, we reconstructed past temperatures for seven continental-scale regions during the past one to two millennia. The most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century. At multi-decadal to centennial scales, temperature variability shows distinctly different regional patterns, with more similarity within each hemisphere than between them. There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century. The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions. Recent warming reversed the long-term cooling; during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years.”Moinuddin Ahmed, Kevin J. Anchukaitis, Asfawossen Asrat, Hemant P. Borgaonkar, Martina Braida, Brendan M. Buckley, Ulf Büntgen, Brian M. Chase, Duncan A. Christie, Edward R. Cook, Mark A. J. Curran, Henry F. Diaz, Jan Esper, Ze-Xin Fan, Narayan P. Gaire, Quansheng Ge, Joëlle Gergis, J Fidel González-Rouco, Hugues Goosse, Stefan W. Grab, Nicholas Graham, Rochelle Graham, Martin Grosjean, Sami T. Hanhijärvi, Darrell S. Kaufman + et al. Nature Geoscience(2013), doi:10.1038/ngeo1797.
Kaufman's original paper. this thread is about the corrections made to this paper, and the mistakes left unfixed. try to get up to speed Old Rocks.
even the uncorrected paper had many of the areas around the globe with a warmer MWP than at present
Antarctica: This is a composite of 11 isotope series (mostly d18O). It includes some new data (e.g. Steig’s new WAIS series) and some long unavailable data (Ellen Mosley-Thompson’s Plateau Remote). It shows a long-term decline with nothing exceptional in the 20th century. Steig has recently characterized the recent portion of Antarctic isotope as “unusual”, but this is really stretching the facts to the point of disinformation. I’ll post separately on this.
Arctic: This is a somewhat expanded version of the Kaufman data, unsurprising since Kaufman seems to have been the leader of the program. It shows an increase from 1800 to 1950, with leveling off since 1950. Its modern values are higher than medieval values. It is heavy on varvology (22 varve series), but, like Kaufman et al, also has ice cores (16) and tree rings (13, including Briffa’s Yamal) plus a few others. They use Korttajarvi, but Kaufman has issued one correction on this already in 2009 and avoided use of the contaminated portion. We’ve discussed Arctic d18O values from time to time, observing that their 20th century values are rather unexceptional. My surmise is that the varve data, which, as discussed in other CA threads, is highly problematic, is the main contributor to the modern-medieval differential in the PAGES reconstruction.
Asia: This reconstruction is based entirely on tree rings (229 series), all, interestingly, used in a positive orientation. 20th century values are elevated but the reconstruction lacks the distinctive blade of, for example, the Gergis stick. The majority of the tree ring data is unarchived: chronologies have been included in the PAGES2K data, but the underlying measurement remains unarchived.
Australia: this is the Gergis reconstruction. There are only two long series (both tree ring). As is well known, Gergis picked data according to ex post correlation to temperature (contrary to the representation in the disappeared article). The present network is little changed from the network in the disappeared article, with the precise differences remaining to be explained. The network is about half tree ring data and about half is short coral (nearly all O18) data. The blade in the Gergis stick comes almost entirely from coral O18 data – for which corresponding medieval information is lacking. The reconstruction is thus a sort-of splice of low-amplitude tree ring data with high amplitude coral O18. Coral specialist literature nearly always uses Sr data as a measure of temperature. The 20th century increase in coral Sr data is much less than O18 data: however, Gergis screened out the Sr data and almost exclusively used coral O18 data.
Europe: The network is 10 tree ring series and one documentary. I don’t know at present how the series were chosen. Most of the increase in the reconstruction took place prior to 1950. Late 20th century values equal and then exceed mid-century values. It will be interesting to see whether sustained ring widths will be maintained with these particular chronologies during warmer temperatures.
North America. There are two North American reconstructions. A reconstruction using pollen is at 30 year intervals and ends in 1950. It shows elevated temperatures in the late first millennium that exceed the most recent values in the series. The other reconstruction uses tree rings. It includes many series from the MBH98 dataset, including the Graybill bristlecone chronologies. Although the tree ring data is accurately dated, the reconstruction is only reported at 10-year intervals. Although the data set includes new data reaching into the present century, the reconstruction is shown only to 1974.
South America: This network is particularly hard to understand. It shows particularly low medieval values relative to the modern period – a point that is relevant to assertions on medieval-modern differential. The network also uses intrumental data. It has two long ice core series from Quelccaya, which, as previously noted, appear (according to the SI) to have been inverted, a decision which, if correct, would rather detract from conclusions about modern-medieval differential drawn from this reconstruction, given that the medieval portion of the reconstruction only has a few contributors, of which Quelccaya is prominent.
after prodding to the authors and the Journal from McIntyre, the digital corrected version of the Arctic reconstruction was released (but no one had the courtesy of notifying McIntyre, as per usual). here is the comparison between the first and corrected versions (although there are other mistakes still to be fixed)-
this shows both the 5th and 11th centuries as having higher average temps, although I would only call them roughly equivalent. one more kick to the nutsack of the MWP and LIA deniers.
ever notice that when mistakes are corrected, or updated proxies are included, that the results always show less of a hockeystick and more of a MWP? if the other upsidedown proxy is fixed and the much larger and inclusive new dendro proxy was used instead of the problematic Gaspe then there would be another 0.25-0.5C added to the MWP.
[/QUOTE]John Cook
John is the Climate Communication Fellow for the Global Change Institute at the University of Queensland. He originally obtained a Bachelor of Science at the University of Queensland, achieving First Class Honours with a major in physics. He co-authored the 2011 bookClimate Change Denial: Heads in the Sand with Haydn Washington, and the 2013 college textbook Climate Change Science: A Modern Synthesis with Tom Farmer. He also lead-authored the paper Quantifying the Consensus on anthropogenic global warming in the scientific literature, which was tweeted by President Obama and was awarded the best paper published in Environmental Research Letters in 2013.
Global Warming and Climate Change skepticism examined
Whereas YOU, Ian, you.... did what? You post your puerile comments on this website. VERY impressive.
why do you hate science so much? You say you are full into the science, and then you behave 180 degrees opposite from what the field is about. how is that?Humans aren't supposed to make the assumptions about other humans that deniers consistently make about climate scientists. I think it indicates they're stupid and jealous. hahahahahah
Bump for our newest AGW apologist, threegoofs.
I haven't reread the thread. Another upsidedown proxy was corrected last fall but I don't think a new graph was produced.
from the latest CA article on PAGES2K-
"
Discussion
Because of the heavy weighting of Kaufman et al 2009 proxies, the McKay and Kaufman conclusion that the “decadal-scale variability in the revised [PAGES2K] reconstruction is quite similar to that determined by Kaufman et al.” is, as advertised above, more of a tautology rather evidence of robustness of the result in the additional data.
At the end of the day, any proxy reconstruction is either a linear combination of the underlying proxies (or can be closely approximated by such a linear combination.) Over the years, I’ve consistently urged that the effective weights be shown for novel methods. Had this been done, I doubt that the above weights would have been the result, since it’s hard to believe that the Arctic2K authors intentionally adopted the above weights. Jean S has done some experiments and there are definitely alternative weighting schemes that can result from slightly varied implementations of paico.
As CA readers are aware, I remain dubious that material benefits arise from putting relatively simple datasets into increasingly complicated and poorly understood multivariate methods and remain of the opinion that there are better opportunities for improving analysis by first comparing like proxies across regions and comparisons of unlike proxies within a region, prior to venturing into the assimilation of unlike proxies in different regions. But this recommendation has been mostly rejected by specialists in the field, who remain committed to dumping data into black boxes, but who get huffy when resulting defects are criticized.
Finally nearly all the difference between the PAGES2K-2013 and the revised result arises from a single proxy (Hvitarvatn, used upside down in the earlier version.) Some readers have expressed surprise at the idea that specialists could use proxies upside down, observing that their interpretation as temperature proxies must be very tenuous if even specialists didn’t know which way was up. Particularly in a multi-author Nature article, subsequently relied upon by IPCC. I agree with this and have written numerous articles critical of varvology, proxies that have become widely used in post-AR4 multiproxy studies. I think that there may well be usable information in this data, but as long as thick varves are interpreted by some specialists as evidence of cold and by other specialists as evidence of warmth, the first order of business for assessment is to reconcile varve thickness data before dumping the data into a multiproxy composite, rather than after.
" The Kaufman Tautology Climate Audit
yet crick and his ilk believe fully, believe deeply, that reconstructions are not only correct but precise.
After rereading this thread I can guarantee that it holds a trove of information on paleoreconstructions. PAGES2K, Gergis2012 (with correspondence between the Journal and authors), with comments and links to many proxy 'problems'.
from the latest CA article on PAGES2K-
"
Discussion
Because of the heavy weighting of Kaufman et al 2009 proxies, the McKay and Kaufman conclusion that the “decadal-scale variability in the revised [PAGES2K] reconstruction is quite similar to that determined by Kaufman et al.” is, as advertised above, more of a tautology rather evidence of robustness of the result in the additional data.
At the end of the day, any proxy reconstruction is either a linear combination of the underlying proxies (or can be closely approximated by such a linear combination.) Over the years, I’ve consistently urged that the effective weights be shown for novel methods. Had this been done, I doubt that the above weights would have been the result, since it’s hard to believe that the Arctic2K authors intentionally adopted the above weights. Jean S has done some experiments and there are definitely alternative weighting schemes that can result from slightly varied implementations of paico.
As CA readers are aware, I remain dubious that material benefits arise from putting relatively simple datasets into increasingly complicated and poorly understood multivariate methods and remain of the opinion that there are better opportunities for improving analysis by first comparing like proxies across regions and comparisons of unlike proxies within a region, prior to venturing into the assimilation of unlike proxies in different regions. But this recommendation has been mostly rejected by specialists in the field, who remain committed to dumping data into black boxes, but who get huffy when resulting defects are criticized.
Finally nearly all the difference between the PAGES2K-2013 and the revised result arises from a single proxy (Hvitarvatn, used upside down in the earlier version.) Some readers have expressed surprise at the idea that specialists could use proxies upside down, observing that their interpretation as temperature proxies must be very tenuous if even specialists didn’t know which way was up. Particularly in a multi-author Nature article, subsequently relied upon by IPCC. I agree with this and have written numerous articles critical of varvology, proxies that have become widely used in post-AR4 multiproxy studies. I think that there may well be usable information in this data, but as long as thick varves are interpreted by some specialists as evidence of cold and by other specialists as evidence of warmth, the first order of business for assessment is to reconcile varve thickness data before dumping the data into a multiproxy composite, rather than after.
" The Kaufman Tautology Climate Audit
yet crick and his ilk believe fully, believe deeply, that reconstructions are not only correct but precise.
This is an important idea. Leaders in the field of climate science cannot even standardize the orientation of many of the proxies! Yet they pour a bunch into black box blender of a methodology and spit out a graph with error bars of tenths of a degree. Just how useful are proxies that can be used right side up or upsidedown, depending on the particular need at the time?
Why, he isn't with your team? Looking to change company?On what do you base your charge that he is paid to be here?
Again, thanks for noting my professional demeanor and skills. Glad it comes across so well.Don't waste your time Ian. threeturds is a troll and will never be anything but a troll. I have shown him plenty of links that refute his propaganda and he ignores everything.
in other words he's a paid propagandist who is here to talk AT people. Not with people.
