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Documenting the Global Medieval Warm Period[W:196]

Deuce said:
Right, but I mean any detail about it other than that. What it was, what dataset it represents, etc.

Anyone who thinks that image needed to be "disappeared" is clearly not very familiar with its details.
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Please tell me.
 
Jack Hays said:
Please tell me.
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It was never a global reconstruction, it was a small proof of concept for tree-rings as a temperature proxy. The data was entirely from Northern Europe, and almost all of it was from the UK. Look at it. There's no label for the Y-axis. It looks like it was drawn by hand. This is not a comprehensive temperature reconstruction.

It's also not obvious by looking at it, but the dataset ends in 1950.

There's no "threat" to AGW here. It doesn't matter how warm the MWP is. Nobody is trying to make it disappear. Its scope "disappeared" because that's what the data says when you gather more of it.
 
Deuce said:
It was never a global reconstruction, it was a small proof of concept for tree-rings as a temperature proxy. The data was entirely from Northern Europe, and almost all of it was from the UK. Look at it. There's no label for the Y-axis. It looks like it was drawn by hand. This is not a comprehensive temperature reconstruction.

It's also not obvious by looking at it, but the dataset ends in 1950.

There's no "threat" to AGW here. It doesn't matter how warm the MWP is. Nobody is trying to make it disappear. Its scope "disappeared" because that's what the data says when you gather more of it.
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[h=1]When the IPCC ‘disappeared’ the Medieval Warm Period[/h]IPCC changed viewpoint on the MWP in 2001 – did this have effect on scientific results? Guest post by Frank Lansner Latest News (hidethedecline) A brief check indicates a “warm MWP-consensus” before IPCC published the Mann hockey stick graph in 2001. But after 2001, results on MWP seems to approach the IPCC viewpoint. In April 2009…

March 10, 2010 in IPCC, Paleoclimatology, Politics.
 
Jack Hays said:
[h=1]When the IPCC ‘disappeared’ the Medieval Warm Period[/h]IPCC changed viewpoint on the MWP in 2001 – did this have effect on scientific results? Guest post by Frank Lansner Latest News (hidethedecline) A brief check indicates a “warm MWP-consensus” before IPCC published the Mann hockey stick graph in 2001. But after 2001, results on MWP seems to approach the IPCC viewpoint. In April 2009…

March 10, 2010 in IPCC, Paleoclimatology, Politics.
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Yes, that's what I said. They expanded the concept and the global average changed. Turns out, Northern Europe isn't the only part of the world.
 
Deuce said:
There's no "threat" to AGW here. It doesn't matter how warm the MWP is. Nobody is trying to make it disappear. Its scope "disappeared" because that's what the data says when you gather more of it.
Click to expand...

Except that the MWP's scope grows as more data are included.

[h=1]The truth about ‘We have to get rid of the medieval warm period’[/h]In the thread Intelligence and the hockey stick commenter “Robert” challenged a well known quote about the MWP from 2006 by Dr. David Deming in his statement before the Senate EPW committee which is the title of this post. I thought it was worth spending some time setting the record straight on what the original quote…

December 8, 2013 in MedievalWarmPeriod.[h=1]New paper shows Medieval Warm Period was global in scope[/h]Andrew Revkin writes: Michael Mann can’t be happy about this work. Here’s a chat with two authors of an important new Science paper examining 10,000 years of layered fossil plankton in the western Pacific Ocean. The paper finds that several significant past climate ups and downs — including the medieval warm period and little ice…

October 31, 2013 in Ocean Heat Content, Oceans, Paleoclimatology.
 
Jack Hays said:
[h=1]When the IPCC ‘disappeared’ the Medieval Warm Period[/h]IPCC changed viewpoint on the MWP in 2001 – did this have effect on scientific results? Guest post by Frank Lansner Latest News (hidethedecline) A brief check indicates a “warm MWP-consensus” before IPCC published the Mann hockey stick graph in 2001. But after 2001, results on MWP seems to approach the IPCC viewpoint. In April 2009…


//wattsupwiththat.com/2010/03/10/when-the-ipcc-disappeared-the-medieval-warm-period/"]March 10, 2010[/URL] in IPCC, Paleoclimatology, Politics.
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Greetings, Jack. :2wave:

I found the article "Documenting the Global Extent of the MWP" very interesting, since it seems to verify handwritten observations from people who lived during that time period! Thanks for the links! :thumbs:
 
Jack Hays said:
Turns out the MWP was everywhere.
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Just not as pronounced, and the peaks not at the same time. Hence the reason for the lower global temperature peak shown by newer graphs.
 
Jack Hays said:
Those whose basic claim has been that the MWP was only a regional phenomenon are in a weak position to protest when its timing varies region by region.
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So now your saying the MWP timing was different depending on the region.

Non-deniers call that 'regional variability'.
 
polgara said:
Greetings, Jack. :2wave:

I found the article "Documenting the Global Extent of the MWP" very interesting, since it seems to verify handwritten observations from people who lived during that time period! Thanks for the links! :thumbs:
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Odd, given that an entire hemisphere of people didn't have handwriting at the time.

Critical thinking. It's not just for breakfast anymore.
 
Threegoofs said:
You mean the MWP that started in year 0 and continued to year 1000, or the one that was from 900AD-1400AD?

Or is it just whatever period fits in with your preconceived notions?
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LOL at Jack posting a WUWT blog piece from Tim Ball. In a previous WUWT blog piece, Jack was totally convinced that a fake graph from Tim Ball was factual. The fake graph showed that the current global average temperature was MINUS 32C. :)

WUWT has even less credibility than the supermarket tabloid, the National Enquirer.
 
Quaestio said:
LOL at Jack posting a WUWT blog piece from Tim Ball. In a previous WUWT blog piece, Jack was totally convinced that a fake graph from Tim Ball was factual. The fake graph showed that the current global average temperature was MINUS 32C. :)

WUWT has even less credibility than the supermarket tabloid, the National Enquirer.
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As Black Knight reminds us, he is but a servant to the data...
 
Threegoofs said:
Oh, look.

Deniers clinging to their idea that the world was warmer once, so it cant be warmer now. Thus their obsession with making the MWP a real thing - regardless of the data.

They are so invested in this, they are starting a BLOG PROJECT! :allhail

Of course, in the scientific literature, it looks like the fabled MWP was neither global nor particularly warm.

Heres the last thing I saw on it. Glacier maxima in Baffin Bay during the Medieval Warm Period coeval with Norse settlement | Science Advances



I think the general scientific consensus is last stated in the last IPCC report, which states:



Of course, the 2012-2016 data has only moved the average of the last 30 years higher, which would probably give more confidence that the NH is warmer now than in the past.
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But the world got warmer and colder without data. How do you explain that?
 
Threegoofs said:
So now your saying the MWP timing was different depending on the region.

Non-deniers call that 'regional variability'.
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No. Actually I'm not making any claim about timing. I'm just noting that argument is out of bounds for you.
 
polgara said:
Greetings, Jack. :2wave:

I found the article "Documenting the Global Extent of the MWP" very interesting, since it seems to verify handwritten observations from people who lived during that time period! Thanks for the links! :thumbs:
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Greetings, Polgara.:2wave:

Happy Sunday. The solo exhibition of Mrs. Hays's paintings opens today.
 
Quaestio said:
LOL at Jack posting a WUWT blog piece from Tim Ball. In a previous WUWT blog piece, Jack was totally convinced that a fake graph from Tim Ball was factual. The fake graph showed that the current global average temperature was MINUS 32C. :)

WUWT has even less credibility than the supermarket tabloid, the National Enquirer.
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Zealous but inaccurate.
 
Jack Hays said:
That seems like an evasion.
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Uhh, it's not.

A proof of concept was done, but with a small dataset. When expanded to more complete data, you get a different graph.

If everywhere on earth peaked at the same time, you'd see a global chart with a much sharper/higher peak temperature. But since they didn't, the peak in Europe was dampened out by the lack of peak in other areas. When those areas peaked, Europe wasn't as hot.

Get it? It's not evasion, it's math.
 
Deuce said:
Uhh, it's not.

A proof of concept was done, but with a small dataset. When expanded to more complete data, you get a different graph.

If everywhere on earth peaked at the same time, you'd see a global chart with a much sharper/higher peak temperature. But since they didn't, the peak in Europe was dampened out by the lack of peak in other areas. When those areas peaked, Europe wasn't as hot.

Get it?
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Which is why the Luening-Vahrenholt research is important.


 
Jack Hays said:
Which is why the Luening-Vahrenholt research is important.
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Great, so you agree then that the newer temperature reconstructions weren't "hiding" anything. It's just how the math works out when you expand the tree ring data from England to the whole world.
 
Deuce said:
Great, so you agree then that the newer temperature reconstructions weren't "hiding" anything. It's just how the math works out when you expand the tree ring data from England to the whole world.
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To know about "hiding" I would need to understand the motives of those involved. Even "hide the decline" is merely suggestive, not conclusive.
 
Jack Hays said:
To know about "hiding" I would need to understand the motives of those involved. Even "hide the decline" is merely suggestive, not conclusive.
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Oh, so you're also not aware of the exact nature of the "decline" in question either?
 
Deuce said:
Oh, so you're also not aware of the exact nature of the "decline" in question either?
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I'll get back to you on that. Other business calls me away right now. Short version: Steve McIntyre has this right.
 
Jack Hays said:
I'll get back to you on that. Other business calls me away right now. Short version: Steve McIntyre has this right.
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Well, when you have something specific I'll have a response.
 
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