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One of the longstanding Climate Audit challenges to the paleoclimate community, dating back to the earliest CA posts, was to demonstrate out-of-sample validity of proxy reconstructions, by updating inputs subsequent to 1980. Because Graybill’s bristlecone chronologies were so heavily weighted in the Mann reconstruction, demonstrating out-of-sample validity at Sheep Mountain and other key Graybill sites is essential to validating the Mann reconstruction out of sample.
The new information shows dramatic failure of the Sheep Mountain chronology as an out-of-sample temperature proxy, as it has a dramatic divergence from NH temperature since 1980, the end of the Mann et al (and many other) reconstructions. While the issue is very severe for the Mann reconstructions, it affects numerous other reconstructions, including PAGES2K.
Well thanks for that, professor. I wish I had the slightest clue what the hell you're talking about. Level down the pedantry about six notches and see if you can put that in language a poor pretension-disabled old hack like me can understand.
Well thanks for that, professor. I wish I had the slightest clue what the hell you're talking about. Level down the pedantry about six notches and see if you can put that in language a poor pretension-disabled old hack like me can understand.
sure. tree ring proxies were used by Mann and others to produce Hockey Stick graphs that make it look like it is warmer today than say... the Medieval Warm Period. typically they had few modern trees included (Yamal) and/or they were cut off 30-50 years ago. they were also subsets of larger available collections of data. McIntyre and other skeptics said that if more data was used, or updated data was collected, then the hockeystick shape would disappear.
one by one, all the proxy sets that added a hockeystick shape to paleoreconstructions are being found to be seriously flawed. this latest update on stripbark bristlecone pines takes yet another piece of ammunition out of the warmists's armory.
Well thanks for that, professor. I wish I had the slightest clue what the hell you're talking about. Level down the pedantry about six notches and see if you can put that in language a poor pretension-disabled old hack like me can understand.
sure. tree ring proxies were used by Mann and others to produce Hockey Stick graphs that make it look like it is warmer today than say... the Medieval Warm Period. typically they had few modern trees included (Yamal) and/or they were cut off 30-50 years ago. they were also subsets of larger available collections of data. McIntyre and other skeptics said that if more data was used, or updated data was collected, then the hockeystick shape would disappear.
one by one, all the proxy sets that added a hockeystick shape to paleoreconstructions are being found to be seriously flawed. this latest update on stripbark bristlecone pines takes yet another piece of ammunition out of the warmists's armory.
True face of climate s hockey stick graph revealed - environment - 07 March 2013 - New Scientist
Shaun Marcott of Oregon State University in Corvallis and colleagues have compiled 73 such proxies from around the world, all of which reach back to the end of the last glacial period, 11,300 years ago. During this period, known as the Holocene, the climate has been relatively warm – and civilisation has flourished.
"Most global temperature reconstructions have only spanned the past 2000 years," says Marcott.
Marcott's graph shows temperatures rising slowly after the ice age, until they peaked 9500 years ago. The total rise over that period was about 0.6 °C. They then held steady until around 5500 years ago, when they began slowly falling again until around 1850. The drop was 0.7 °C, roughly reversing the previous rise.
Then, in the late 19th century, the graph shows temperatures shooting up, driven by humanity's greenhouse gas emissions.
Hmmmmmmm................ 73 differant proxies.
True face of climate s hockey stick graph revealed - environment - 07 March 2013 - New Scientist
Shaun Marcott of Oregon State University in Corvallis and colleagues have compiled 73 such proxies from around the world, all of which reach back to the end of the last glacial period, 11,300 years ago. During this period, known as the Holocene, the climate has been relatively warm – and civilisation has flourished.
"Most global temperature reconstructions have only spanned the past 2000 years," says Marcott.
Marcott's graph shows temperatures rising slowly after the ice age, until they peaked 9500 years ago. The total rise over that period was about 0.6 °C. They then held steady until around 5500 years ago, when they began slowly falling again until around 1850. The drop was 0.7 °C, roughly reversing the previous rise.
Then, in the late 19th century, the graph shows temperatures shooting up, driven by humanity's greenhouse gas emissions.
Hmmmmmmm................ 73 differant proxies.
which one of the 73 proxies do you consider to be the smoking gun?
True face of climate s hockey stick graph revealed - environment - 07 March 2013 - New Scientist
Shaun Marcott of Oregon State University in Corvallis and colleagues have compiled 73 such proxies from around the world, all of which reach back to the end of the last glacial period, 11,300 years ago. During this period, known as the Holocene, the climate has been relatively warm – and civilisation has flourished.
"Most global temperature reconstructions have only spanned the past 2000 years," says Marcott.
Marcott's graph shows temperatures rising slowly after the ice age, until they peaked 9500 years ago. The total rise over that period was about 0.6 °C. They then held steady until around 5500 years ago, when they began slowly falling again until around 1850. The drop was 0.7 °C, roughly reversing the previous rise.
Then, in the late 19th century, the graph shows temperatures shooting up, driven by humanity's greenhouse gas emissions.
Hmmmmmmm................ 73 differant proxies.
which one of the 73 proxies do you consider to be the smoking gun?
bump to second page so Old Rocks doesnt accidentally 'miss' it
To me, his worst insult is that he keeps bringing Mann's work to the table. Mann used the Tiljander cores upsidedown, and when questioned about it, said it didn't matter! What use is a proxy like that?
It's a tree ring circus!
Marcott, Shakun, Clark and Mix did not use the published dates for ocean cores, instead substituting their own dates. The validity of Marcott-Shakun re-dating will be discussed below, but first, to show that the re-dating “matters” (TM-climate science), here is a graph showing reconstructions using alkenones (31 of 73 proxies) in Marcott style, comparing the results with published dates (red) to results with Marcott-Shakun dates (black). As you see, there is a persistent decline in the alkenone reconstruction in the 20th century using published dates, but a 20th century increase using Marcott-Shakun dates. (It is taking all my will power not to make an obvious comment at this point.)
Interesting that you use the 'wildly differant' shapes as though that were some sort of evidence. Since each proxy is a measure of a differant quantity, that means some would go up, some down, with increasing or decreasing temperature, rainfall, or other factors.
Ian, the scientists are doing careful deliberate work, you skeptics have destroyed any credibility you ever had by careless statements, and by the use of 'evidence' that has been completely destroyed by careful research.
Up to 2000, you were all stating that there was no warming, that it was all fudged data. After everyone could see that there was indeed some pretty strong warming, then you stated that it was natural varition from natural causes, but cannot name those causes. Today, you are stating that there is going to be cooling in the future, yet cannot name why, or how much.
The scientists studying this issue, state there is going to be warming, and by at least 2 C by the end of this century. This year, neutral ENSO, decline in TSI, looks like it will be the warmest on record. Some cooling.
