EnviroLink Forum

I disagree that the data doesn't line up with each other.

The MWP is showing up at around 1000 AD on one of your charts, wheras on another it has shown up from 1050 AD-1300 AD. Assuming that there is room for error with these proxies (which there always is) then they don't disagree with each other as much as you claim they do.

http://www.clim-past.net/8/765/2012/cp-8-765-2012.pdf

The corresponding
95% confidence intervals have widths of 0.6 (two millennia
long reconstruction) and 0.4 C (500-yr long reconstruction)
for 50-yr smoothed values, thereby showing
that the residual noise-variance is relatively small compared
to the reconstructed low-frequency signal.
Our main conclusions are as follows.
– Our reconstructions indicate – in agreement with the
results of Moberg et al. (2005); Ljungqvist (2010), and
Loehle and McCulloch (2008) – that the first millennium
AD was generally significantly warmer than the
second millennium AD. The 17th century was the coldest
century during the last two millennia and most of
the LIA seems to have been colder than during the Dark
Age Cold Period ca. 300–800 AD. In general, our LOC
reconstructions show larger low-frequency variability
than previous reconstructions.
– Our two-millennia long reconstruction has a well defined
peak in the period 950–1050AD with a maximum
temperature anomaly of 0.6 C. The timing of
the peak of the MWP in our reconstruction is in agreement
with the reconstructions of Esper et al. (2002a)
and Ljungqvist (2010). The reconstructions of
Mann et al. (2008, 2009) show a longer peak warming
covering the whole period 950–1100 AD, and the reconstruction
of Moberg et al. (2005) shows a somewhat
later as well as longer peak MWP warming than in the
present paper. The level of warmth during the peak
of the MWP in the second half of the 10th century,
equalling or slightly exceeding the mid-20th century
warming, is in agreement with the results from other
more recent large-scale multi-proxy temperature reconstructions
by Moberg et al. (2005), Mann et al. (2008,
2009), Ljungqvist (2010), and Ljungqvist et al. (2012).

Then you cannot read a graph or you do not care to misrepresent what is stated in them.



They are the SAME proxy taken from the SAME location byt the SAME people. If that allows for such a variation how can either be considered to be evidence of anything?



This shows an anomaly of ~1 degree at year 1000 with a higher peak prior. The increase from 0 started at about year 750 and returns at about year 1100 with another series of increases until about year 1600.



This shows a MWP supposedly from year 1000 to year 1300 with the highest peak at 1300. Unlike the previous graph with the highest peak near 1500.

The NH temperature reconstructions speak of the MWP from 950 to 1050 AD (you referenced one yourself) Neither of these seem to agree with that timeframe, however.

Not sure how quoting from a study that I provided to show that the MWP was likely warmer than the present shows that the Hockey Stick Proxy is correct.

The corresponding 95% confidence intervals have widths of 0.6 (two millennia long reconstruction) and 0.4 C (500-yr long reconstruction) for 50-yr smoothed values, thereby showing that the residual noise-variance is relatively small compared to the reconstructed low-frequency signal.

– Our two-millennia long reconstruction has a well defined peak in the period 950–1050AD with a maximum temperature anomaly of 0.6 C.

That's not correct as the Christainsen and Ljungqvist paper came to a very opposite conclusion than the conclusion a researcher would come to if the proxy record looked like a hockey stick. The yellow is obseved temperatures, and they still are not warmer than the MWP.

I'm not willfully misrepresenting anything.

You have a very strange idea that proxy series have very low error margins, and this conviction simply holds no ground with reality.

And by the way, those two charts were not from the same people.

I'm not willfully misrepresenting anything.

You have a very strange idea that proxy series have very low error margins, and this conviction simply holds no ground with reality.

And by the way, those two charts were not from the same people.

First, it indicates the multiple correlations between it and other proxy reconstructions, which show a hockey stick when the modern measurements are added. Second, the paper show how accurate your claim concerning the reconstruction really is.

A maximum anomaly of 0.6 with a confidence interval of 0.6 does not indicate the MWP was warmer than the present.

The hockey stick is created by the sharp increase in temperature after a long term decrease. The MWP does not impact that area at all.

Cold Air Cave, Makapansgat Valley of South Africa


http://www.co2science.org/data/mwp/stud ... ircave.php

Reference
Holmgren, K. , Tyson, P.D. , Moberg, A. and Svanered, O. 2001. A preliminary 3000-year regional temperature reconstruction for South Africa. South African Journal of Science 97: 49-51.

http://www.co2science.org/data/mwp/stud ... ansgat.php

Reference
Tyson, P.D. , Karlen, W., Holmgren, K. and Heiss, G.A. 2000. The Little Ice Age and medieval warming in South Africa. South African Journal of Science 96: 121-126.


K. Holmgren primary in one and third in the other, P.D. Tyson is second in one and first in the other, which means the primary authors are the same for the two papers and they would be the ones with the critical conversion criteria.

I was unaware that authors with different names was the same group of people.

And even with some similar correlations (there is warming in the CWP in both reconstructions) to the Hockey Stick reconstructions, this proxy has the MWP as being warmer than the CWP and has obvious periods of multi-centennial periods of natural variability, with the latest spike in the CWP being well within that variability. This reconstruction looks nothing like the hockey stick reconstruction, even with the added on instrumental temperatures. Therefore, your claim that every single proxy reconstruction with an attached instrumental temperature series for the CWP is simply not correct.

Then why have the authors stated that it was in their paper?

The Hockey Stick reconstruction is characterized by flatlining temperatures before the CWP and a sharp uptick in temperatures during the CWP. The MWP definitely impacts the shape of the temperature reconstruction.

Since you either did not notice the bold names, or your education is so lacking that you were not taught that P.D. Tyson and Tyson, P.D. or Holmgren, K. and K. Holmgren are different ways to write the same name, I will inform you of that fact. So you see the lead authors of the both papers are the same team. Those are the folks who do the actual conclusions while the lesser authors do the "grunt work". Often they are what is commonly called grad student slave labor.

Yes, it is because the addition of the instrumental measurements create the blade of the stick, which is what the whole point of the graph was to indicate. The error bars for your proxy and all of the others overlap significantly so they are within a similar range, as the portion of the paper quoted clearly stated.

That could be due to the fact they did not state it in their paper.

The "bump" in the hockey stick makes it something else? Odd that definition has mutated so significantly since it first came out. Wait, it is not that odd given the situation with that camp.

I was refering to the two authors whom you had not bolded. Even though they may do grunt work it is a different group with different people in that group.

The instrumental temperatures may cause what looks to be the blade of a stick in the Christensen et al. reconstruction, but the actual stick part of hockey sticks do not bend and twist. They are straight with little if any signs of variability.

They state it multiple times in the paper, with this being one example:

Our reconstructions indicate – in agreement with the
results of Moberg et al. (2005); Ljungqvist (2010), and
Loehle and McCulloch (2008) – that the first millennium
AD was generally significantly warmer than the
second millennium AD.

There is little temperature variability before the CWP. There is definitely a lot more variability with the Ljungqvist and Christensen reconstruction than there is with the Mann 1998 reconstruction.