Talk:Medieval Warm Period

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Archive of talk through May 2005

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[edit] Rm graph: why

SEW added the hand-drawn graph. I removed it. As a useful graph for MWP studies, its very poor, indeed quite misleading. It hasonly historical interest.If it belongs anywhere it belongs...on MWP and LIA in IPCC reports. Oh look, its there already. William M. Connolley 09:55:05, 2005-09-03 (UTC).

http://www.atmos.washington.edu/2001Q2/211/groupE/maya_files/image003.jpg

What have you got against the image? Care to explain how exactly Greenland was green in the Medieval period when, according to your lot, it was colder than now?

You are the one 'misleading' by essentially deleting an important period from history. Never let facts get in the way of the Global Warming Religion. Mixino1 13:22, 26 January 2007 (UTC)

What I've got against the image is explained in MWP and LIA in IPCC reports, with refs. The graph is a sourceless schematic that has been obsolete for years and shouldn't be used. Its also not a freely usable image. As to greenland, etc, thats quite another matter William M. Connolley 13:36, 26 January 2007 (UTC)
Your only interest is in keeping the facts from the public. Like many pages on Wikipedia, this one has a load of interferers making sure the facts are diluted and emaciated. I seriously fear for the environmental lobby's lasting effect on science being taken seriously. Obviously, for those that have sidelined climate change into a religion, the interests of science are no longer of any merit. I notice you refuse to answer the pertinent question - which is no more than I would have expected. Mixino1 02:21, 28 January 2007 (UTC)

[edit] End of the MWP

Folks, I've changed mentions of the end of the MWP to be vague on dates, being no more specific than "14th century". This is because what year the MWP ended depends on what criteria you use to define it and where you're measuring; certainly it was still warm most places in 1270 and Northern Europe was in cold winters and short summers by 1350, but points anywhere in between are matters of scholarly opinion ... and the scholars don't agree. More discussion on the LIA discussion page. Jberkus 05:11, 11 September 2005 (UTC)

[edit] anon skepicism

An anon (school board of calgary, it seems) added:

Some investigators believe that the medieval warming effect was global, and that average global temperatures between the 10th and 14th century were higher than at present, calling into question both the uniqueness of the present global warming trend and the origin of the present trend from human-generated greenhouse gases. That perspective was belittled in the 2001 IPCC report...

and other misc stuff. This is the standard misinterpretation, as is the vitiated bit. The refs added don't seem to useful and the syntax is poor, so if anyone wants them in, its up to you. William M. Connolley 19:22, 4 October 2005 (UTC).

A review of more than 200 climate studies led by researchers at the Harvard-Smithsonian Center for Astrophysics has determined that the 20th century is neither the warmest century nor the century with the most extreme weather of the past 1000 years. The review also confirmed that the Medieval Warm Period of 800 to 1300 A.D. and the Little Ice Age of 1300 to 1900 A.D. were worldwide phenomena not limited to the European and North American continents. http://cfa-www.harvard.edu/press/pr0310.html Mixino1 22:44, 29 January 2007 (UTC)
This is Soon & Baliunas, and was dodgy. See http://www.realclimate.org/index.php?p=11 #2, if interested. Which of course you aren't :-( William M. Connolley 22:52, 29 January 2007 (UTC)
Anything that quotes anything by Mann is now of no interest to me. He made a mistake. Fair enough. Everyone has made a calculation blunder at one point or another. However, he continues to treat science with contempt by claiming his mistake never happened. The whole basis of his EOS article is to defend his now disproven hockey stick. Anything that quotes him, therefore, is not worth screen space. This is one reason I find climate activists contemptible. They love ad hominem attacks by saying Dr. X or Prof. Y was once paid to investigate something by the oil industry - yet they don't see that Mann's failure to acknowledge his own error is many times worse.
I regard Mann as an untrustworthy witness for the above reason. Mixino1 02:09, 30 January 2007 (UTC)
"Dodgy" is charitable — the managing director of the journal's parent company ended up apologizing for having published the article. Raymond Arritt 22:57, 29 January 2007 (UTC)
Source? Mixino1 02:09, 30 January 2007 (UTC)
Right here. Raymond Arritt 02:43, 30 January 2007 (UTC)
So Mann, someone who has been thoroughly discredited for writing an article based on nonsense statistics and failing to admit it, writes a piece denouncing a paper that overstates its conclusions and this requires a mass of apologies? All this shows is the power of the green religion rather than the science. I have seen this kind of goading all too often. The BMJ published a perfectly valid article about passive smoking, only for the editor to have several thousands of pressure group emails and letters. Luckily the BMJ editor had bigger cahones and stuck to his guns. Consensus science, or to give it the correct title 'Mob' science, does not convince me. It is not of any scientific value .
Meet the sibling of Mob Science: Publication bias. Mixino1 03:17, 30 January 2007 (UTC)
Just to be sure - you are aware that Von Storch, who was one of the editors who quit - is one of the critiques of the Hockey-stick - right? --Kim D. Petersen 02:22, 31 January 2007 (UTC)
Quit or was pushed? You know exactly what I mean. Mixino1 20:27, 2 February 2007 (UTC)
You must not know the man. Nobody pushes von Storch around. Raymond Arritt 22:45, 2 February 2007 (UTC)

[edit] I'm confused

From the article:

"A radiocarbon-dated box core in the Sargasso Sea shows that sea surface temperature was approximately 1°C cooler than today approximately 400 years ago (the Little Ice Age) and 1700 years ago, and approximately 1°C warmer than today 1000 years ago (the Medieval Warm Period).[11] However, all the reconstructions, as shown above, appear to indicate that it was not."

What is this actually saying, in the context of the rest of the text? Doesn't the last sentence there just cancel everything else out?

Inspector Baynes 22:06, 16 October 2006 (UTC)

The last sentence is because global warming believers claim that old warming or cooling must have been local events, and there couldn't have been global warming events. (SEWilco 05:08, 17 October 2006 (UTC))
Its an odd sentence, I hope I didn't write it. To make sense, it would have to say "...it was not global" or somesuch. The easiest thing to do seems to be to remove it William M. Connolley 08:31, 17 October 2006 (UTC)

[edit] making wine vs. growing grapes in Alaska

Hi! In the 'Climate events/North Atlantic region' section of the article, there is this first sentence:

" During the MWP wine grapes were grown in Europe as far north as southern Britain[4][5][6] although less extensively than they are today[7] (however, factors other than climate strongly influence the commercial success of vineyards, for example wine is made in Alaska today; and the time of greatest extent of medieval vineyards falls outside the MWP). "

I would dispute the phrase, "..for example, wine is made in Alaska today.." since there are no grape vineyards in Alaska. Wine made in Alaska is made from many locally grown things including wild berries or dandelions, but any grape juice would have to be imported. The fact that wine is made in Alaska today doesn't have any bearing on the commercial success of vineyards, since there aren't any up here. Marty gla 23:11, 9 January 2007 (UTC)

[edit] Scientists told to keep quiet about the Medieval Warm Period

Next, the UN abolished the medieval warm period (the global warming at the end of the First Millennium AD). In 1995, David Deming, a geoscientist at the University of Oklahoma, had written an article reconstructing 150 years of North American temperatures from borehole data. He later wrote: "With the publication of the article in Science, I gained significant credibility in the community of scientists working on climate change. They thought I was one of them, someone who would pervert science in the service of social and political causes. One of them let his guard down. A major person working in the area of climate change and global warming sent me an astonishing email that said: 'We have to get rid of the Medieval Warm Period.' "

http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2006/11/05/nosplit/nwarm05.xml

Mixino1 13:33, 26 January 2007 (UTC)

You should know better than to trust stuff in the telegraph. But you may want to read MWP and LIA in IPCC reports William M. Connolley 11:36, 28 January 2007 (UTC)
You mean the same IPCC that 'got rid' of the Medieval Warm Period? As Professor Edward Wegman puts it "the work has been sufficiently politicized that this community can hardly reassess their public positions without losing credibility." Mixino1 16:40, 29 January 2007 (UTC)
Sorry - I've corrected the redlink. You might try reading it, if you're interested in the subject. There is no quesstion of "trusting" the IPCC in this respect - just finding out what happened. And as for Wegman - why do you think he is unbiased? William M. Connolley 17:54, 29 January 2007 (UTC)
I do not believe Wegman to be biased. Why should he be? Everything he stated was verifiably correct and sound statistical commentary. I can tell that in a professional capacity.
I actually fully believed the anthropogenic global warming claims until I looked at the evidence myself. I was honestly shocked to the core when I began to look at the evidence. Mann et al is a lowpoint in science. Even if you take Mann's work out of the equation now, it is clear that all graphs and models are designed to replicate the hockey stick. The damage is done.
Look at the history of Greenland. People lived and farmed there in the Medieval Warm Period. They could not have done that if it was colder than it is now. Despite this, climate scientists continue to only believe the graphs that show that it was colder than now. That belief goes against common sense.
To be honest, I am not sure if you actually believe what you are saying. Mixino1 19:01, 29 January 2007 (UTC)
I don't know if you believe what you're saying. Why should Wegman be biased? Because he was selected by Inhofe, perhaps? You won't attempt to assert that Inhofe is unbiased, will you? If your problems are with the statistics of MBH, then feel free to trow that study away and only use the other ones which show... pretty well exactly the same during the MWP (though they differ during the LIA). As fr Greenland... you are aware that these records are not just for Greenland, but for the whole hemisphere. A warm Gr and cool elsewhere is perfectly possible. —The preceding unsigned comment was added by William M. Connolley (talk • contribs) 19:29, 29 January 2007 (UTC).
Sorry, forgetting to sign. Anyway, we started with the Torygraph piece. Which contains The UN's second assessment report, in 1996, showed a 1,000-year graph demonstrating that temperature in the Middle Ages was warmer than today. This is false, and is why I referred you to MWP and LIA in IPCC reports which demonstrates that falsehood. Are you, I wonder, prepared to admit that the Telegraph is wrong in this? William M. Connolley 19:32, 29 January 2007 (UTC)
Here is what he said: "The graph from the 1996 UN report is not available online. I found it in a document from Professor McKitrick, one of the two Canadian scientists who first exposed the falsity of the graph." http://www.telegraph.co.uk/news/graphics/2006/11/12/warm-response3.pdf Mixino1 22:43, 29 January 2007 (UTC)

Sigh. I buess you're not going to read that page, no matter how much it explains your confusion. Hey ho William M. Connolley 22:48, 29 January 2007 (UTC)

You say Wegman is biased but you have produced no evidence that he is other than he was selected by some politician that might be. Has it never crossed your mind that McKitrick and McIntyre had actually discredited the piece anyway - and that any statistician would have said the same as Wegman unless he/she was extremely biased? By the time Wegman was involved, the errors were known and the (mis)calculations had been verified over and over. It seems more bizarre to me that Wegman even had to be involved given the wealth of information supplied by McKitrick and McIntyre that confirmed that the methodology was flawed. Mixino1 02:45, 30 January 2007 (UTC)

[edit] Hockey Stick Graph

What's with the Hockey Stick graph? That graph is at least 50 years out of date.

http://www.geo.arizona.edu/Antevs/nats104/nhem_reconsml.gif

This one's more accurate. It shows the little ice age in all its glory but doesn't quite show how warm the medivel warm period is. —The preceding unsigned comment was added by 72.72.202.222 (talk) 21:47, 31 January 2007 (UTC).

Your picture is of the original hockey-stick (notice the caption: Mann et al. (1999)) - while the picture on the page contains several reconstructions, most of them newer. --Kim D. Petersen 01:00, 1 February 2007 (UTC)

[edit] The current global warming period

did not begin in the 19th century. From 1945-75 global temperature fell. So much so that scientists of that time were predicting a new Ice Age. I deleted a line to that effect. SmokeyTheCat 22:04, 13 March 2007 (UTC)

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