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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 Misplaced Pages, 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)

I'm confused about the graph in this article. It makes it seem as if the MWP was actually colder then it is now. However, this article clearly states:

Results from a radiocarbon-dated box core show that SST was ~1°C cooler than today ~400 years ago (the Little Ice Age) and 1700 years ago, and ~1°C warmer than today 1000 years ago (the Medieval Warm Period).

This article was published in 1996 and temperature has risen a marginal amount since 1996. Clearly the MWP was warmer then it is now. Therefore, the graph that is show in this article is misleading/completely false. Codingmonkey 02:30, 8 April 2007 (UTC)

As Mr. Connolley pointed out below, the above article refers to the Sargasso Sea. Nevertheless, as I stated below, I would like Mr. Connolley's sources that demonstrate that global temperatures were lower in the MWP then they are today. Codingmonkey 15:44, 9 April 2007 (UTC)

As soon as the coding factors that were used to multiply temperature changes since 1940 by as much as 2.6X in East Anglia's (now missing) raw temperature data are removed, the recent spike disappears entirely. This whole AGW thing is a fraud according to the emails and computer programs from East Anglia. Mr. Connolley may use his absolute power at Misplaced Pages to remove this statement and ban me as he has done to 5000 articles and 2000 editors. But the jig is up. You got that, Mr. Connolley? 19 Dec 2009 —Preceding unsigned comment added by 74.132.27.108 (talk) 16:04, 20 December 2009 (UTC)

No, no, no, no and no. --Stephan Schulz (talk) 04:02, 30 December 2009 (UTC)

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). 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)

The graph is a complete fraud for reasons stated above. 19 Dec 2009 —Preceding unsigned comment added by 74.132.27.108 (talk) 16:15, 20 December 2009 (UTC)

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)

I'm confused as to why the two of you are arguing whether he is biased or not. Perhaps Mr. Connolley, who is refuting the claims made by Wagman, can produce evidence to the contrary. Instead of making personal attacks on the person, produce evidence. Who cares how bias the person is if they have the facts correct. Codingmonkey 02:17, 8 April 2007 (UTC)

http://en.wikipedia.org/Revert_wars, totally excluding a common viewpoint is bannable if carried out to extreme, the viewpoint can be moved to a different section or article if needed, eg controversy. IF a large minority percentage of the population's viewpoint is completely editted out then article is no longer neutral. —Preceding unsigned comment added by 174.3.145.178 (talk) 14:10, 26 November 2009 (UTC)

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)

The hockey stick graph is based on two papers by Mann that have been proven to rely on very poor mathematics and infact being just wrong. There is nothing like a hockey stick graph (at least not in the data sets MBH used). Two scientists (McIntyre and McKitrick) tried to reconstruct the figure and found serious mistakes in the original work by Mann. These mistakes have been published and meanwhile credited among the scientific community especially in the wake of the Wegmann report: http://www.uoguelph.ca/~rmckitri/research/WegmanReport.pdf. For those who want to know about this matter in short, refer to this document: http://www.uoguelph.ca/~rmckitri/research/APEC-hockey.pdf - McKitrick explains in short and reasonably how they came to start digging and what they found. Contact me if you have doubts about my intentions (http://www.nt.tuwien.ac.at/about-us/staff/bastian-knerr/) - As I believed that there's 'evidence' for this graph showing the global warming caused by humanity, it hit me quite hard to find out my beliefs were based on really poor use of the Principal Component Analysis (that's the fundament of this hockey stick graph). Besides I can do some maths.

Original (flawed) work by MBH: Mann, Michael E., Bradley, Raymond E., and Hughes, Malcolm K. (1998) “Global-scale temperature patterns and climate forcing over the past six centuries,” Nature, 392, 779-787. Mann, Michael E., Bradley, Raymond S., and Hughes, Malcolm K. (1999) “Northern hemisphere temperatures during the past millennium: Inferences, uncertainties, and limitations,” Geophysical Research Letters, 26(6), 759-762.

All mistakes of MBH and their effect on the data/hockey stick by MM: McIntyre, Stephen and McKitrick, Ross (2003) “Corrections to the Mann et al. (1998) proxy data base and Northern hemispheric average temperature series,” Energy and Environment, 14, 751-771. McIntyre, Stephen and McKitrick, Ross (2005a) “The M&M critique of MBH98 Northern hemisphere climate index: Update and implications,” Energy and Environment, 16(1), 69-100. McIntyre, Stephen and McKitrick, Ross (2005b) “Hockey sticks, principal components, and spurious significance,” Geophysical Research Letters, 32, L03710, doi: 10.1029/2004GL021750

The Graph was created using software that fraudulently removed data that showed was contrary to the "Researcher's" agenda.

An example of this Agenda can be seen in the Work of Wiki Editor Stephan Schulz protecting falsified data in this article —Preceding unsigned comment added by AardvarkAvacado (talk • contribs) 21:25, 24 November 2009 (UTC)

In the light of the recent revelations of 'scientists' lying about global warming the hocky stick graph makes the entire page look suspect.It need to be removed.

Incidently I've noticed that all wiki pages are biased in favor of man-made global warming, removing key facts and presenting all information as if there were no doubt that global warming is caused by man made carbon emissions. —Preceding unsigned comment added by 91.109.66.153 (talk) 06:25, 14 December 2009 (UTC)

The graph is inaccurate

It shows that the current temperature is hotter than in the MWP. This is wrong. If Greenland was capable of supporting colonisation it must have been much warmer than it is today. I would like to see a better graph. SmokeyTheCat 07:55, 8 April 2007 (UTC)

It was, in fact, warmer. See here. I really think that the graph should be removed, it seems to go against the evidence. Codingmonkey 07:09, 9 April 2007 (UTC)

Being a perceptive chap I'm sure you noticed that you ref says in the Sargasso Sea not globally William M. Connolley 07:31, 9 April 2007 (UTC)

Good catch, I missed that. However, the Sargasso Sea does cover a large part of the North Atlantic Ocean. Nevertheless, since you say that global temperatures were lower in the MWP then present day global temperature, may I have the source? Codingmonkey 15:41, 9 April 2007 (UTC)

I removed the graph as we seem to have agreement that it was not accurate.  SmokeyTheCat  •TALK• 20:12, 19 August 2007 (UTC)

Not so fast, please. These are the best reconstructions we have available. Raymond Arritt 20:21, 19 August 2007 (UTC)

I still think that the graph is inaccurate and that seems to be the consensus here.  SmokeyTheCat  •TALK• 08:12, 23 August 2007 (UTC)

You are wrong William M. Connolley 08:28, 23 August 2007 (UTC)

You are finished. 19 Dec 2009 —Preceding unsigned comment added by 74.132.27.108 (talk) 16:19, 20 December 2009 (UTC)

Or, in more detail: The graph is sourced to a large number of reliable sources. Your personal opinion on Viking colonization is not. You might also want to look at entry in our GW FAQ. --Stephan Schulz 08:32, 23 August 2007 (UTC)

All the graph sources go back to the East Anglia Climategate fraudulent computer code which multiplied temperature changes since 1940 by up to 2.6X and then they disposed of the raw data to cover it up. Global Warming FAQ is no longer worth the cyberspace it is written on. 19 Dec 2009 —Preceding unsigned comment added by 74.132.27.108 (talk) 16:52, 20 December 2009 (UTC)

These "reliable sources" wouldn't happen either to be papers authored by the CRU correspondents complicit in the Climategate fraud or to depend secondarily upon the "research" duplicitiously published by these AGW "hide the decline" thieves and liars? 71.125.130.14 (talk) 16:49, 20 December 2009 (UTC)

Get an up to date graph, this hockey stick stuck in 2004 is ridiculous and an embarrassment to wikipedia. Don't you wiki censors know how ludicrous this graph is ? —Preceding unsigned comment added by 76.67.239.216 (talk) 03:24, 29 October 2009 (UTC)

Agreed. This graph has been thoroughly discredited yet[REDACTED] still uses it as a reference? I don't understand. —Preceding unsigned comment added by 208.178.63.106 (talk) 21:24, 23 December 2009 (UTC)

Medieval warming Graph

The graph is a compilation of a number of datasets around a mean. What mean was used for each of the data sets? Are the means different for each dataset? Since these are comparative, the mean (and offsets of each dataset) is somewhat important for a relative comparison. I didn't see a citation for the methodology of the overlay. --DHeyward (talk) 23:03, 20 November 2007 (UTC)

According to Robert's page, "each reconstruction was adjusted so that its mean matched the mean of the instrumental record during the period of overlap." Raymond Arritt (talk) 23:10, 20 November 2007 (UTC)

Get an up to date graph, this hockey stick stuck in 2004 is ridiculous and an embarrassment to wikipedia. Don't you wiki censors know how ludicrous this graph is ? —Preceding unsigned comment added by 76.67.239.216 (talk) 03:27, 29 October 2009 (UTC)

English wine again, updates proposed

I offer this as a new section, since several sections already have discussed this,but a while ago.

"During the MWP wine grapes were grown in Europe as far north as southern Britain"

seems either too much or too little, and some of its references are a bit out of date and/or dominated by much better ones. I can think of 3 actions:

1) One could just delete that sentence.

2) OR one could at least fix/enhance the references.

I'd suggest that 7. "The History of English Wine..." and "8. Making Wine in a Changing World" are far less extensive sources than Richard Selley's "The Winelands of Britain: Past, Present, & Prospective", 2nd Edition, 2008, using his website: http://www.winelandsofbritain.co.uk/index.htm. That's certainly worth adding.

It isn't perfectly up-to-date, and the overall map is inherently imprecise, but if one really wants to understand the history of wine in Britain from a geological+climate view, that's a 113-page book written by a serious geologist/oenophile. He suggested the creation of the Denbies vineyard, now the largest in the UK. As the grapes march North, they generally skip the Midlands, and Selley explains why (soils, especially). Selley doesn't try to show all the Abbeys and such, in part, I think, because it's hard to compare an Abbey (which would grow grapes if at all possible, regardless of the resulting wine quality) with a serious commercial operation that thinks it can sell wine competitively. Put another way, the mere existence of a vineyards is a very fuzzy proxy, as is a total count of vineyards at any point in time. The modern non-existence of an old vineyard is often due to development or local objections, examples of which Selley mentions. Anyway, it's seems odd to discuss English grapes and climate without mentioning this book at all.

Jancis Robinson's "The Oxford Campanion to Wine", Third Edition, 2006 certainly deserves a reference, especially to pp. 178-181 (Climate) and pp. 252-254 (England), although of course these few pages don't go into the depth that Selley does.

Finally, "10. The Vineyards of England and Wales" is OK, but EnglishWine.com, http://www.englishwine.com/ looks much more comprehensive, although it can take some checking (Google & GoogleEarth) to see how far along they really are. Some are serious operations, some look like hobbies, and some are serious, but newly planted. One finds for example, that Acomb Grange, voracious rabbits devoured their newly-planted vines.

3) OR one could rewrite it into a few sentences, adding Seeley, Robinson, and EnglishWine.com references.

As is well-covered by Robinson, Selley, or Gavin Schmidt references, vineyard location is an imprecise proxy. Hence, if one is going to mention English wine at all, I'd suggest something like:

Viniculture has been practiced in England from Roman times. The location and extent of vineyards support an English temperature pattern of warm (Roman), cool (Dark Ages), warm (Medieval), cool (Little Ice Age), warm (current). Vineyard location alone are not necessarily good proxies of average English temperatures, given the many confounding factors. Vineyards are rapidly moving North, already as far as North Yorkshire (Bolton Castle, for eaxmple). These locations may not prove that current temperature exceeds that of Medieval times, but they support the reverse even less.

In support of the above:

Talking vaguely about medieval vineyards in Yorkshire doesn't really help much.

Yorkshire is split into South Yorkshire, West Yorkshire, and North Yorkshire (the largest piece). As a whole, Yorkshire has a North-South distance of ~90 miles, or about 25% of England's total. In addition, while Abbey wineries were found around York itself (elevation ~50-100 feet), there's at least one new modern vineyard (Bolton Castle) 25 miles further North and 500 feet higher, and at least 4 other vineyards North of York. West Yorkshire is North of South Yorkshire and mostly South of North Yorkshire, and York itself (where there were medieval vineyards) is in the South of North Yorkshire.

There seem to be another 4 elsewhere in Yorkshire as a whole (Acomb Grange, Leventhorpe, Summerhouse, Holmfirth), but I found 5 North of York:

A) Bolton Castle (North Yorkshire): 54deg19'20.18"N

http://www.boltoncastle.co.uk/metadot/index.pl?id=2210 which says: "Although historically there would not have been a vineyard this far north, the one recently established in the lee of the castle is stocked with a modern hybrid, frost hardy and early ripening variety of red grape, Vitis Vinifera x Vitis Amurensis. In time, this small vineyard should produce up to 1000 bottles of wine a year."

And http://www.boltoncastle.co.uk/metadot/index.pl?id=2256 says:

"The grounds were archaeologically surveyed and gardens recreated along medieval lines, including a herb garden, a rose garden, a maze, bowling green and a vineyard - the vineyard being the only feature that would not have existed here in medieval times, although people had grown, or attempted to grow, vines in this country as long ago as the Romans."

Of course, they may or may not be correct about the non-existence of vineyard that far North - many vineyards are claimed to be the Northernmost. Also, the castle was started in 1350, which might have been late, but they do seem to have a solid history of the place.

B) Helmsley Walled Garden (North Yorkshire), 54deg14'40.53N C) Mount Pleasant (Lancashire), 54deg6'33.56"N D) Ryedale (North Yorkshire), 54deg3'44.62"N E) Yorkshire Heart (North Yorkshire), 54deg00'01.87"N

We've driven within a few miles of all of these at one time or another. Since many of these are newly-planted, it looks like a meaningful 2010 or 2011 Yorkshire Wine Tour may be at least possible. It won't be Napa, but the mere existence of such is interesting. JohnMashey (talk) 03:51, 2 February 2009 (UTC)

I think the focus here should be to elucidate to new readers rather than merely debunk the claims of a few partisan hacks. The MWP probably was warmer than now in Europe; you and WMC seem to be trying to imply that no conceivable evidence could suggest it was. But the IPCC's position is only that the MWP was "a local event", not that it didn't exist at all. Okay, so if it was a "local event", there were places on the globe where the temperature was unusually warm at the time. Where were those places? England and Europe in general were among them. You can admit this without denying the consensus. You can even admit we have some evidence it was warmer then than now in that location without denying the consensus. Like this chart from The Oxford Companion to Wine's entry on Climate Change (2nd edition, published 1999, scanned by me):

 http://www.impel.com/pictures/european%20wine%20climate.jpg

--Blogjack (talk) 15:41, 3 February 2009 (UTC)

As I've posted elsewhere, I personally don't care whether it was warmer or not, or where, during the MWP, since that has exactly zero influence on the future. I don't know how you get the "no inconceivable evidence" from me - I think you may be projecting your own strong views onto others. I just want to get an accurate, up-to-date, and unconfusing statement about British vineyards, or get rid of it.

My comments were directed specifically to the one sentence about grapes in Britain, which of course is *not* the European continent .

If you want to open a separate section about grapes & temperatures on the continent, for others to argue about, that might be useful. I did take a quick look at Pfister(1988) from Third Oxford, but it didn't yield any firm conclusions about Britain. It's 20 years' old, and when it says there were vineyards in the MWP, that doesn't help much when there are vineyards today in the same areas.

However, I'd suggest a more serious discussion than posting a low-quality, unattributed chart from the Second Oxford book (1999). I couldn't find that chart in my Third edition (2006). I rather doubt it would make it into Misplaced Pages without the proper reference to the original paper, especially given the many ambiguities. If it has indeed disappeared from the current Edition, one might ask why, and a vague chart with little documentation is unlikely to be viewed as an authoritative reconstruction by anyone serious.

If you look at the chart carefully, it says "relative to the average for the first half of the 20th century." The horizontal line in that chart marked 0 is for the average of ~1900-1950. The "Central England Temperature Series" is the longest instrumental temperature record. I downloaded the Monthly Mean data from http://hadobs.metoffice.com/hadcet/data/download.html, and I found the average yearly CET was 9.41C for 1901-1950, 10.39 for 1999-2008 (not 1998), and 7 of the latter 10 years were above 10.41 (and as a group average 10.52). The CET anomaly of the last decade (which is *not* necessarily the same as the Europe anomaly) is ~1C above the 1901-1950 range, or for the hottest 7 years, 1.1. Assuming June-Sept wine-growing season, it's about .9C. Given that the chart has no error-bars, and no indication of the reconstruction method, these numbers are are hard to distinguish from the 1.2-1.3 there.

"Average temperature" is not the same as "vine growing season temperature", and the latter is not simply-defined as a set of months. Practical vineyard locations are not only determined by summer temperatures, but by avoidance of frost at wrong time, i.e., the entire temperature distribution matters, it has almost certainly changed , and there are arguments (Keenan, 2007) about the reliability of using harvest dates as proxies for summer warmth.

One cannot draw any strong conclusions from all this, especially when comparing with a poorly-understood, error-bar-less chart that may or may not apply to Britain. All this is why I said, "Vineyard location alone...even less."

68.125.68.77 (talk) 04:07, 4 February 2009 (UTC)

I'm only objecting to the "...even less" sentence. I agree that one cannot draw strong conclusions from all this. The balance of the evidence from vineyards is ambiguous. It does suggest it was roughly as warm then as now but does not allow us to conclude which was warmer. So why not just say that? Why pick specific parts that slightly favor your side so you can sneak in a less/more claim, however carefully worded? (Evidence in the other direction includes the sheer number of british vineyards then versus now - over 1300 by the end of the 12th century - and the fact that they managed to be so productive and reach such an extent as they did without the benefit of modern "frost-hardy hybrids".)

My local library doesn't have the OCtW 3rd edition or I would have used that. A major source for the second edition on these subjects seems to have been "John Gladstones" who wrote a book called "Viticulture and Environment" (ISBN 1875130128). One can order it for $66 here, but I haven't: http://www.bizgate.sa.gov.au/shop/pirsa  :--Blogjack (talk) 17:48, 4 February 2009 (UTC)

Grape Varieties

Has no-one considered the concept of grape varieties? New strains of grapes are created all the time. Eg the Bacchus grape that is commonly grown (because it can be grown in colder climates) in the UK has only been available for general cultivation since the 70s. I would propose that viticulture is a bad proxy as the Romans didn't have access to varieties such as the Bacchus grape. The climate changes but so does mankind's ability to cultivate.

Another aspect to consider is the demand for grapes. A change in culture could increase a demand for grapes hence an incentive to breed and plant different strains. Of course I'm being speculative here but wine popularity has generally been on the increase in the UK in the last few decades. More demand means more opportunity and incentive for farmers to experiment with grapes as a crop.

What do you think? TheJoff (talk) 02:36, 2 December 2009 (UTC)

If anything, demand has been much reduced, at least relative to population and supply. In Roman and medieval times, there was a strong cultural (Mediterranean culture revolved around it) and religious (for last supper rites) demand for wine, but wine import was very limited and expensive. Nowadays, you can buy a bottle of Chilean or Romanian wine for a Euro or Pound in Britain . But yes, the whole point of the section is to point out that viticulture is indeed a bad climate proxy. --Stephan Schulz (talk) 08:32, 2 December 2009 (UTC)

A better graph

Would anyone mind if I replaced the misleading temperature graph with have at present with this more accurate one?

File:Whatwarming.jpg (Source IPCC 1990)

 SmokeyTheCat  •TALK• 00:15, 3 March 2009 (UTC)

Question: WhatFile.txt? --Stephan Schulz (talk) 00:18, 3 March 2009 (UTC)

Sorry I was just uploading it.  SmokeyTheCat  •TALK• 00:20, 3 March 2009 (UTC)

Yes, I would mind if you replace a large ensemble of recent climate reconstructions with a 20 year old schematic with unclear copyright status. --Stephan Schulz (talk) 00:26, 3 March 2009 (UTC)

....which represents Central England temperatures - and not global.... --Kim D. Petersen (talk) 02:08, 3 March 2009 (UTC)

Well I won't cause a fuss. England is not in a climate bubble so it seems a fair sample. Anyway, I don't have an axe to grind. If we're all still here in 20 years time all the present global warming hysteria will be long forgotten and laughed at, just as we laugh at the predictions of a new ice age which were all the rage in the 1970s. It's no skin off my nose. Having just endured the coldest Winter in 20 years the whole thesis is looking distinctly pear-shaped now. SmokeyTheCat  •TALK• 11:20, 3 March 2009 (UTC)

Thanks for this opinion. It displays very well just how deep your understanding of the domain is. --Stephan Schulz (talk) 11:55, 3 March 2009 (UTC)

The graph at the beginning of this article should be removed as the black hockey stick line ending with the astrix 2004 clearly represents the totaly discredited Yamal treemometer. As per Steve McIntyre http://www.climateaudit.org/ Sun Spot —Preceding unsigned comment added by 76.67.246.58 (talk) 02:57, 21 October 2009 (UTC)

Cold climate grapes

I'm sorry - but the reference doesn't state that Sweden only produces cold climate grapes, quite the opposite in fact - it states that most (ie. not all) are cold-climate grapes. And the 50° is for cold-climate grapes. The text inserted is complete original research. --Kim D. Petersen (talk) 20:09, 20 May 2009 (UTC)

Add: The new insertion about whether its climate or because of the grapes, jumps to conclusions not supported in the reference. (just an addition here to the above: Riesling is one of the cold-climate grape that the article is talking about, and that is the grape that is recommended up to 50°) --Kim D. Petersen (talk) 20:11, 20 May 2009 (UTC)

The vinyard from which the photo's in the article comes, Wannborg Vingård. Produces amongst other grapes Rondo, Léon Millot, Regent, Solaris, Orion. As well as Merlot, Pinot Noir and Chardonnay, all of which aren't exactly "cold climate grapes". So can we stop this WP:OR now?

--Kim D. Petersen (talk) 20:24, 20 May 2009 (UTC)

I checked your source, you missed some important information. They grow only the hardiest cold climate grapes, but have, in the past, experimented with other cold climate grapes (yes they are - just less hardy varieties) like Merlot, Pinot Noir, Chardonnay, Riesling etc. 89.133.33.102 (talk) 11:21, 21 May 2009 (UTC)

One of very few commercial Wine Yards in this northern region. We are experimenting with nearly 40 different kinds of grapes to find out who are best suited for our cold climate. Our main species are Rondo, Leon Millot, Regent, Solaris, Orion. But we also grew some well known grapes with good result as Merlot, Pinot Noir, Chardonnay, Riesling etc.

For those still sceptical - please check the memberlist of the Svenska Vinodlara (Swedish Viticulture) - for most members the grapes produced, and the area cultivated, is listed. Riesling, Merlot, Chardonney etc. are all amongst them. --Kim D. Petersen (talk) 20:30, 20 May 2009 (UTC)

Sorry, I edited the article before checking here first. But I think the whole section on the Gotland grape should be removed, as it is misleading. Grapes have been grown in Britain also for many years, but Britain, nor Gotland, is a "wine growing region". There were vinyards in Britain in the 18th and 19th century. The problem is that the climate was not suitable for good wine, not that you can't grow grapes there.

The section on Gotland should probably be removed, as it is misleading and doesn't really make a point. The northernmost wine growing region is widely considered to be northern Germany, not Sweden. This might change with the climate, and if you can find an article that states the climate might alter this that fact then great, but it currently doesn't include Gotland. Antistar (talk) 22:16, 20 May 2009 (UTC)

This is not correct. Ireland, United Kingdom, Belgium, Poland, the Netherlands, Denmark and Sweden have been in the EU wine-growing region A (c), at least since in 2000, and thus can (and do) produce commercial wines at least from that time on (Denmark was added in 2000). They btw. all produce good wine. Denmark (my region) has a marginal production - but it still manages to produce international winning wines , as does the UK. --Kim D. Petersen (talk) 23:12, 20 May 2009 (UTC)

I'll btw. be adding some of these references, but will not right now - since i'm at 3RR. Btw. strangely enough you missed the english-wine growing reference in the article - England produces quite a lot of good wine... --Kim D. Petersen (talk) 23:16, 20 May 2009 (UTC)

Maybe you should slow down and read before rushing to "correct" me. How could I "miss" the English wine growing reference, when I write "grapes have been grown in Britain also for many years". If you slow down and try to understand what I am writing, you will realise that I accept that wine grapes are grown in many regions north of Germany, but nowhere north of the 50 is considered a "wine growing region". This is because the vineyards may be able to succeed there, but the produce is not considered good enough quality and/or the risk of a killer winter is too high to make them a reliable region.

Climate change is obviously making some regions more capable of growing good, reliable crops, but so are hardier "cold climate" hybrids, soil technology, etc. Seriously you can't be thinking that climate change alone could have shifted the latitudinal limit as much as 7 degrees north already?

For whatever reasons, be it climate, necessity, whimsy or what have you, Britain was a relatively significant wine producer in the 14th century. Today it is so minor that it isn't even considered to be a wine producing region (yes the EU recognises that it has vineyards, but the EU would recognise any region that produces one bottle because it has to).

The latitudinal limit is considered to be 50, and this is a well known fact (it is even stated as such in the Gotland article). Even if that is changing, or has changed, in recent years, the fact is that for many centuries it has been considered to be 50, yet in the 14th century Britain (which is beyond this limit) was a significant wine producing region. That is evidence, although not conclusive, that the climate in the 14th century was at least warmer than it has been until recently.89.133.33.102 (talk) 11:08, 21 May 2009 (UTC)

but nowhere north of the 50 is considered a "wine growing region" - by you, perhaps. yet in the 14th century Britain (which is beyond this limit) was a significant wine producing region - for the obvious reason: production was marginal, but viable because of transport difficulties. It doesn't provide any meaningful climate information. Comparison of your arbitrary 50 limit with the 14C is meaningless William M. Connolley (talk) 11:12, 21 May 2009 (UTC)

Maybe that is true, do you have a source for your claim? I know that before the 14th century there were contracts made for hundreds of thousands of liters of wine to be delivered to London, so I can't imagine transport was that difficult. Sometimes war with France would cause problems, but there were other regions to import from, and intermediate traders like the Dutch to buy from.

BTW, it's not "my" limit, it is one that is accepted as fact by vitners globally. This fact is not from my head, but even stated in the original linked article. I can find many, many more articles which back this up. Given its wide acceptance, it's hardly "meaningless", as this is a guideline developed over centuries of wine growing.89.133.33.102 (talk) 11:27, 21 May 2009 (UTC)

Well, the reading part is mutual it seems. "nowhere north of the 50 is considered a "wine growing region" is contradicted by the references (see EU wine regions), as well as reality 5 of Germany's 13 wine regions lie above 50° (Ahr (wine region),Mittelrhein (wine region),Rheingau (wine region),Saale-Unstrut,Saxony (wine region)) and you counter that by "but the EU would recognise any region that produces one bottle because it has to" is 100% incorrect, if you had read the references posted here, you would have noticed that (amongst others) Denmark had lobbied for more than 10 years to be allowed to produce commercial wines, if finally got that acceptance in 2000, the EU doesn't have to do anything (thats yet more WP:OR).

Your comments on quality and that it should be based only on hybrids is (again) contradicted by the references. As far as i can see the whole of EU wine growing zone A should not be able to produce wine then.

Finally when you are saying "considered a "wine growing region", "good enough quality" and "reliable", you should establish that England in the MWP adhered to these descriptions - can you do that? Otherwise the argument is moot, since the context here is "During the MWP wine grapes were grown in Europe as far north as southern Britain" not "During the MWP reliable good quality wines where produced as far north, as in the then well known and recognized wine region of Southern Britain". --Kim D. Petersen (talk) 12:14, 21 May 2009 (UTC)

I find it amusing and disturbing that I receive an edit war warning when I simply restored comments that someone removed without reason. The entire section on growing grapes in Gotland is questionable at best in an article on the Medieval Warming Period. The cited reference is poor, it's a news report on people growing grapes in Sweden. It is not a scientific report making any commentary on the relative warmth of the region today vs. the past. Attempts to do original research and suggest that the existence of vineyards in Sweden "proves" something about climate change is against wiki policy. I think most would have no objection to a statement that some grapes are now being grown in Sweden but whether this is because of stronger efforts being made to grow wine in a non-traditional region or because of a warming in the region is unknown. It is NOT known according to the cited reference and to suggest otherwise is against wiki policy on no original research, to remove an edit that says it is not known is vandalism or pov. Either the section should be removed entirely or it should be stated in an npov way. The original reference is a freelance writer's story on growing wine in Sweden and drawing conclusions one way or another from it in an article on the Medieval Warming Period seems unlikely to satisfy policy on quality. BobKawanaka (talk) 13:28, 21 May 2009 (UTC)

Thats rather a lot of strawmen: A) No one here is trying to prove anything. Its a simple comparison. MWP: Wine England Now: Wine: England+other places. B) "Traditional" is irrelevant here - England then wasn't "traditional" either. C) Noone is trying to say anything other than that vinyards now exist as northernly as Sweden. --Kim D. Petersen (talk) 13:35, 21 May 2009 (UTC)

I find it hilarious that you think that "The entire section on growing grapes in Gotland is questionable at best" but that of growing grapes in Britain is not. Obviously grapes are a poor indicator of climate, and the whole section should be thrown out as off-topic OR. Lars T. (talk) 21:04, 21 May 2009 (UTC)

See: google search on "Viticulture as a climate proxy. The reason for the interest in England, the MWP and wine, is (iirc) H.H. Lamb and the temperature reconstruction of Central England. (as well as several sceptics using the argument "England used to grow wine - now it can't" --Kim D. Petersen (talk) 21:52, 21 May 2009 (UTC)

See Werder, Brandenburg#Viticulture — Sorry, but when you can grow wine near Berlin during the "Little Ice Age", growing of grapes (without any information on quality) is a useless climate proxy. Time to tell us about the actual wines. Lars T. (talk) 00:55, 22 May 2009 (UTC)

Not really. The trouble with the comments so far, is that the poster has taken the 50° argument as valid (and more than a guide), the more "real" limit is the 12°C-22°C (±) growing season isotherm (which is more important than the annual average temp.). Viticulture is limited by more than just latitude - soil, mesoclimate and of course grape are all important. What you've noticed here would be a good proxy (if they have good records of harvests) to climate in Werder. --Kim D. Petersen (talk) 01:07, 22 May 2009 (UTC)

London#Climate vs. Berlin#Climate — Southern Britain should be better suited to grow wine than Brandenburg. And why exactly do you want detailed harvest records of Werder when all we know that during the MWP "wine was grown as far north as southern Britain"? Lars T. (talk) 19:19, 23 May 2009 (UTC)

In order for this comparison to be meaningful in this context, we need to have references which show not only A) that grapes are now grown as far north as Gotland and northern Britain but also B) that it was not possible to grow grapes in these places during the MWP. My understanding is that it was historically possible to grow grapes in Sweden, but it was not economic to do so versus importing products from France and elsewhere. Happy to be corrected, but for the moment the grape thing is unverified content and thus doesn't belong here. Gnomatic (talk) 09:10, 10 October 2009 (UTC)

I think you miss the point. The argument was never "its warmer today, look how far north we can grow grapes", it always was "wine is a lousy climate proxy, and growing grapes in Yorkshire does not tell us anything useful about temperatures". I'm fine with the whole paragraph gone. --Stephan Schulz (talk) 10:28, 10 October 2009 (UTC)

Reconstruct Temperature, Graph

The graph at the beginning of this article should be removed as the black hockey stick line ending with the astrix 2004 clearly represents the totaly discredited Yamal treemometer. As per Steve McIntyre http://www.climateaudit.org/ Sun Spot —Preceding unsigned comment added by 76.67.246.58 (talk) 02:46, 21 October 2009 (UTC)

If you perform the distinctly tricky procedure of clicking on the graph and reading the caption - hard, I know - you can discover that the black line is the instrumental data. It seems that you are "lacking in clue" William M. Connolley (talk) 07:19, 21 October 2009 (UTC)

Yes, not the place for a protracted discussion. But something has always bothered me about that graph and that's the statement "The single, unsmoothed annual value for 2004 is also shown for comparison" ... it would be better not to include an unsmoothed point (from 5 years ago) and even it is included "for comparison" it should not be connected by black line to the rest of the series. It should be a single point. I don't believe I've read the caption incorrectly. HarmonicSeries (talk) 14:55, 21 October 2009 (UTC)

Get an up to date graph, this hockey stick stuck in 2004 is ridiculous and an embarrassment to wikipedia. Don't you wiki censors know how ludicrous this graph is ? —Preceding unsigned comment added by 76.67.239.216 (talk) 03:22, 29 October 2009 (UTC)

Actually, it's stuck in 2000 or earlier for most of the reconstructions. The instrumental temperature record is updated frequently, but, as you might have notices, this article is about the middle ages. Has someone invented a time machine and gone back to change the climate in 1231? --Stephan Schulz (talk) 09:13, 29 October 2009 (UTC)

RFC: renaming of article according to WP:STYLE?

I contest the changes — either it should actually go according to the MoS: medieval warm period (or Medieval warm period for the title), or (better) it should stay Medieval Warm Period as it is used almost consistently throughout literature. Lars T. (talk) 23:23, 28 October 2009 (UTC)

• It denotes a singular event and hence is a proper name. Medieval Warm Period it is - not only due to the MOS, but due to plain English language. --Stephan Schulz (talk) 22:49, 29 October 2009 (UTC)

• • Both Medieval Warm Period and medieval warm period are used in the literature; the capitalization of "Warm" is strange. It should be moved to one of Lars' two suggestions; from his comment and Stephan's, returning it to its fully-capitalized state is the current preference. Awickert (talk) 00:10, 30 October 2009 (UTC)

• I agree with Awickert, particularly that capitalizing "Warm" but not "period" is strange. --Tryptofish (talk) 16:53, 30 October 2009 (UTC)
• This doesn't need a RfC. Just fix it. -Atmoz (talk) 17:26, 30 October 2009 (UTC)
• The name of an article which has been around for some time should not have been tweaked in the first place. The article is a well-established one and the Rfc should have come before any changes were made. I don't feel confident in the renaming mechanics. Perhaps Avalik would be so kind as to change it back? BobKawanaka (talk) 18:00, 30 October 2009 (UTC)

Moved to the fully capitalized version. --Stephan Schulz (talk) 20:05, 30 October 2009 (UTC)

Sentence not supported by citation - propose deletion or at least correction

The article leads the reader to believe that a number of scientists refer to the Medieval Warm Period as the "Medieval Climatic Anomaly":

Some refer to the event as the Medieval Climatic Anomaly as this term emphasizes that effects other than temperature were important.

It seemed interesting, so I read the actual reference, but it says no such thing. The reference is from what appears to be either an unpublished working paper or an informal presentation. Nevertheless, the only reference in it that is relevant to the above sentence propsed for deletion is as follows from page 3 (emphasis added):

This led Stine to argue that a better term for the overall period was the “Medieval Climatic Anomaly” (MCA), which removes the emphasis on temperature as its defining characteristic.

Here we see that it isn't "some" but a single thinly referenced person Stine making the claim, and the claim is characterized as an argument. Clearly, the reference provided not only fails to support the sentence, it actually serves to argue against its inclusion. I don't want to remove it until others have a chance to comment. -- Knowsetfree (talk) 05:11, 15 December 2009 (UTC)

There are now two cites, the second added by Kim, citing a book, if he could be so kind as to check the wording as to how "Medieval Climatic Anomaly" is framed in the book, as Knowsetfree makes a valid point that (our text) "this term emphasizes that effects other than temperature were important" is not the same as (the source) "which removes the emphasis on temperature as its defining characteristic" although it is close. Without knowing what is in the second source, it is impossible to tell if that rephrasing is close enough or not. Kim, let this remind you that no good deed (adding another source) goes unpunished (PITAs like me asking what they say) :p Gerrard Winstanley (talk) 17:59, 24 December 2009 (UTC)

Check the diff :-) I only changed the reference format, i don't have the Le Roi book. But the Stine in question is Scott Stine - and is referring to this paper:

Stine, Scott (1994). "Extreme and persistent drought in California and Patagonia during mediaeval time" (PDF). Nature. 369 (6481): 546-549. doi:10.1038/369546a0.

I'll request the book and check it possible - but that will be at some time in the next year. --Kim D. Petersen (talk) 22:45, 24 December 2009 (UTC)

Sheesh these diffs are tricky things :-) Sorry for not spotting that you expanded the two cites. I found that Uncle uncle uncle spotted that there were two references in one and separated them, but when the original two-in-one was put in, I don't know. It took many clicks to find where they split into two and I've already had enough hunting for tonight, so whoever added gets away with not being hassled for info by me... for now :p Thanks for requesting the book, I think it's important to ensure absolute veracity of what it is that make some prefer this term to MWP, but it's not urgent. I'll stop being a pain in the aerosol now and not ask anything else until after the festivities are done.Gerrard Winstanley (talk) 23:30, 24 December 2009 (UTC)

Medieval Climatic Anomaly and Medieval Climate Anomaly both have more than 15000 hits on Google Scholar, so the term is certainly in significant use. --Stephan Schulz (talk) 08:03, 15 December 2009 (UTC)

15000 hits is rather small, and since when did "Google" become a valid reference for whether an term is popular in the scientific community? —Preceding unsigned comment added by 60.56.161.188 (talk) 15:45, 19 December 2009 (UTC)

Note Google Scholar, not Google. Google Scholar is certainly a good source for prevalence in the recent scientific literature, and 15000 is significant. --Stephan Schulz (talk) 15:59, 19 December 2009 (UTC)

I agree in part with the objection raised in this section. Please see my article edits here and here, taking note to read the 1st edit summary in particular. I do not think we should be polarizing the introduction. There is no need to make the introduction a political football. This issue is already too politicized. Misplaced Pages should stay above the fray. 216.153.214.89 (talk) 05:37, 21 December 2009 (UTC)

From GeoRef:

• 279 peer-reviewed journal sources for "Medieval Warm Period"
• 6 peer-reviewed journal sources for "Medieval Climatic Anomaly"
• 18 peer-reviewed journal sources for "Medieval Climate Anomaly"

The latter examples are clearly used, especially recently, but are also clearly in the minority. I would keep them for clarity's sake. But I don't like the explanation given by the article. A better explanation would be, Although Europe, where the term originated, experienced warming, other parts of the world experienced different changes in climate. This has led some researchers to instead use the term "Medieval Climate Anomaly". Then some refs, of course, probably from around the Pacific. Awickert (talk) 16:01, 21 December 2009 (UTC)

FWIW the textbook that I use for my intro course calls it "Medieval Climate Anomaly." (But I emphasize to the students that MWP is the more common term.) Short Brigade Harvester Boris (talk) 18:30, 24 December 2009 (UTC)

biographies of living persons

I've removed extended discussion concerning a reference to a website that contains claims that breach our biographies of living persons policy. Obviously we won't be citing that website because it's contrary to policy. All editors are reminded that extended discussion and defence of such sources is not to be undertaken on Misplaced Pages. Simply remove the source material when and where it appears. --TS 14:29, 21 December 2009 (UTC)

Ice Core Data Graph

It would be nice to add this ice core data graph that shows Medieval Warm Period very well:

http://www.foresight.org/nanodot/wp-content/uploads/2009/12/histo5.png

References:

1. Alley, R.B. 2000. The Younger Dryas cold interval as viewed from central Greenland. Quaternary Science Reviews 19:213-226

2. http://www.ncdc.noaa.gov/paleo/metadata/noaa-icecore-2475.html

3. Vostok Ice Core Data: http://www.ncdc.noaa.gov/paleo/metadata/noaa-icecore-2453.html

—Preceding unsigned comment added by VotusW (talk • contribs) 02:30, 22 December 2009 (UTC)

The Foresight graph is not from a reliable source (and it's quite unclear what it shows). The Alley paper is on the younger Dryas and talks about Greenland only, as does the data from NOOA. I don't know how the Vostok data comes into this - it's from the other side of the world. I've looked at the Alley GISP data set, and it really is useful for long-term developments only - it has no data from the last 100 years, and it also seems to be very raw, in that there are e.g. unexplained doublets in them. --Stephan Schulz (talk) 08:34, 22 December 2009 (UTC)

-This is Ice Core Data - it's important for the raw information / data. This is why people come to Misplaced Pages - not for someones opinion, but for the raw info. This graph show the Medieval Warm Period very clear. It's missing around 60-70 years. But, I do not understand why do you need to compare Medieval Warm Period to the last 100 years? Source is reliable. I don't understand why graph that made from NOOA Ice Core Data, by the Foresight Institute is not reliable? --VotusW (talk)

No, raw data is not what people come too Misplaced Pages for. Please see WP:PRIMARY. We need to be very careful about using primary sources - they typically need expert interpretation. In this case, the data gives some evidence for temperatures in one single location, not about a global or hemispherical MWP. The Foresight Institute is not a RS for climate science, and it is unclear if they plotted the data in the first place - all we can say is that the plot is on their server. I replotted the last 1500 years of the GISP data, and my plot looks only somewhat similar to the one on the Foresight site. It's not clear what they did to produce this graph- its certainly not a direct plot. --Stephan Schulz (talk) 16:35, 22 December 2009 (UTC)

-This graph was made by Foresight Institute & by J. Storrs Hall: http://en.wikipedia.org/J._Storrs_Hall Source - "Alley, R.B. 2000. The Younger Dryas cold interval as viewed from central Greenland. Quaternary Science Reviews 19:213-226" & NOOA. http://nsidc.org/data/docs/agdc/nsidc0121_alley/index.html Do you have any graph with Ice Core Data in "all locations"? Why don't use this one also? --VotusW (talk)

The graph has no attribution and no legend, unless there is another page than the one you link to. I don't know J. Storrs Hall, but the article looks like a fan biography - it certainly does not meet our standards for reliable sources. But that's neither here nor there. We have no evidence that the graph was produced by him, and even if it were, it would still be self-published by someone who is not an expert in a relevant field. No, Alley is not a source for this plot, it's a description of the full 50000 year reconstruction. --Stephan Schulz (talk) 11:01, 23 December 2009 (UTC)

Article protected?

Any particular reason why this article is proteced? 216.153.214.89 (talk) 07:58, 22 December 2009 (UTC)

As it says: Note: This page has been semi-protected so that only established users can edit it... 2009-12-22T00:43:46 Stephan Schulz (talk | contribs) protected Medieval Warm Period (expires 00:43, 25 December 2009 (UTC)) (expires 00:43, 25 December 2009 (UTC)) ‎ (Excessive vandalism) (hist) William M. Connolley (talk) 09:15, 22 December 2009 (UTC)

For purposes of clarity and impartiality can I ask: Who are the 'established' editors and what political organisations on the web are they affiliated with? For example, you are a member of realclimate.org which is funded by an eco-energy company.Greg hill (talk) 09:38, 22 December 2009 (UTC)

I'm not. It isn't William M. Connolley (talk) 09:44, 22 December 2009 (UTC)

In this context, the term "established editors" simply means autoconfirmed editors. To edit the article you need to have held the account for at least four days (that's right, days, not weeks or months), and to have made at least ten edits anywhere on Misplaced Pages in those four days. --TS 10:31, 22 December 2009 (UTC)

...and you need to set your secret decoder ring to C-A-B-A-L! --Stephan Schulz (talk) 10:47, 22 December 2009 (UTC)

Suggested changes

The sentence that begins with "Studies by Michael Mann et al. find that the MWP..." seems to suggest the broad conclusion is only from Mann studies. Others appear to concur (Esper et al., Moberg, etc.).

Also, the recent Mann et al. study is cited. It would be nice to include an image from ths study showing regional variation.

Gmb92 (talk) 20:54, 22 December 2009 (UTC)

I've corrected "studies" into the singular; there is only one. Arguably we shouldn't ref that; it is too new. Don't blame me guv (well not much). As for Esper/Moberg etc - do they do patterns? I didn't think so, just a global total William M. Connolley (talk) 23:18, 22 December 2009 (UTC)

Since the section is titled "Globally", it seems it would apply at least in part to the global average. Maybe there should be two separate paragraphs, one discussing global (or hemispheric) averages which has been covered extensively in the peer-reviewed journals and one for the regional variation as covered in the recent Mann et al. study. At the same time, the global or hemispheric average is discussed in the Initial Research section and includes a graphic of northern hemisphere reconstructions, so that might be redundant. It just seems the "Globally" section is lacking given the body of multi-proxy studies covering hemispheric and global average reconstructions. Gmb92 (talk) 00:24, 23 December 2009 (UTC)

Proposed article update

I am going to update this part of the text in the article as it is no longer correct.

The Medieval Warm Period (MWP) or Medieval Climate Optimum was a time of warm climate in the North Atlantic region, lasting from about AD 800–1300. It was followed by a cooler period in the North Atlantic termed the Little Ice Age. Some refer to the event as the Medieval Climatic Anomaly as this term emphasizes that effects other than temperature were important

Bold highlights are the parts i would like to change. The first is to extend the area from just the north Atlantic based on this peer reviewed paper It clearly shows the mwp was a world wide climate event and not a localized one as is suggested in the opening paragraph.

I also take exception the the term "some refer" (medieval climatic anomaly) To the best of my knowledge only michael mann has used this term. Plus 600 odd years should not be called an "anomaly". Thoughts on the above please --mark nutley (talk) 10:19, 26 December 2009 (UTC)

Please read previous discussions before proposing changes; e.g., see the "Sentence not supported by citation..." section above where your second point is addressed. Short Brigade Harvester Boris (talk) 13:53, 26 December 2009 (UTC)

Seen it now thanks, i see no consensus there for the text to remain the same as it currently stands. We can move this part of my proposed edits to there though.

any thoughts on the first point? mark nutley (talk) 14:16, 26 December 2009 (UTC)

Singular focus on a single paper is never worth anything. It is about a specific location, and thus doesn't reflect the globe. What does the assessment reports say? (IPCC, US CCSP) As for your "only mann" thing - that is rather easy to show wrong --Kim D. Petersen (talk) 18:38, 27 December 2009 (UTC)

I`m not focusing on a single paper, this is the third study from new zealand which shows it too went through the MWP.

This is definate evidence that it was more than likely a global event and not confined to the north atlantic as is written in the lead of the article. And could you tell me please which study is used to state the the MWP was confined to the north atlantic regions only? --mark nutley (talk) 19:23, 27 December 2009 (UTC)

ANY evidence of the MPW outside of the region the MPW is supposed to have been localized to, tends to falsify the hypothesis I would think. It's not our call to say which is correct, but at the very least we shouldn't be taking the side which seems to have been proven false. Edgespath24 (talk) 12:14, 29 December 2009 (UTC)

And that is the actually interesting thing about this "New Zealand MWP" paper — not only is the MWP hard to tell apart from where the Little Ice Age should be, it also has the absolute minimum at around 1010 — right where the European MWP has its peak. Lars T. (talk) 00:36, 31 December 2009 (UTC)

Honestly, why do we use Mann's information??? His hockey stick was shown not to work. There is much more supportive data supporting the medevil warm period being just as warm as today, or around that. I think a new graph supported by many times more scienctist should be posted showing the med-evil warm period and the little ice age define as should be. Can you tell me why or why not. —Preceding unsigned comment added by Matthurricane (talk • contribs) 00:56, 28 December 2009 (UTC) Matthurricane (talk) 01:00, 28 December 2009 (UTC)

On the contrary. Mann's methods have received some criticism, some of it even justified, but the reconstruction (especially with the error bounds) has been generally vindicated. That said, we don't show "Mann's Hockey Stick", but rather an ensemble of 10 different reconstructions, only one of which is "the Hockey Stick", and 7 of which have no input by Mann. See the description at File:2000 Year Temperature Comparison.png. --Stephan Schulz (talk) 22:29, 28 December 2009 (UTC)

It's undue weight and asserting that the MWP was local, rather than global, is the extraordinary claim which needing extraordinary proof. I'll remove it. Edgespath24 (talk) 11:14, 29 December 2009 (UTC)

You might want to discuss that first, i believe with the new paper i have posted we can say that the mwp covered more than just the north atlantic, but removing stuff without talk leads to revert wars. And on that note does anyone actually have any input to this proposal? mark nutley (talk) 11:32, 29 December 2009 (UTC)

Well I agree with you. Given that there is evidence world-wide for the MWP, it's incorrect to say it was just local. We should certainly say that Mann thinks it was. As for the issue re: the "Medieval Climatic Anomaly" term, I don't have a problem with it and the linked citataion attributes the term to Stine, not Mann - "This led Stine to argue that a better term for the overall period was the “Medieval Climatic Anomaly” (MCA), which removes the emphasis on temperature as its defining characteristic." Edgespath24 (talk) 12:07, 29 December 2009 (UTC)

No, it is not undue weight - since that is what the parity of references say: the MWP was most likely a NA phenomenon. The trouble here is that you are confusing issues, a NA phenomenon may have global impacts, but the impacts are not by necessity of the same kind. (ie. some places show cooling, drying, flooding ...) The signal is strongest in the NH and slight in the SH, and has a significant impact in the NA area, and a smaller in other areas. Cherry-picking single sources can and will always give the result that you want, but a review of the literature, which takes all sources into account, show differently. --Kim D. Petersen (talk) 13:00, 29 December 2009 (UTC)

OK well it's obviously your position that it was localized, but it is still undue weight. We can't definitively say it was localized when there is clear contraindicating evidence and ongoing research on the matter. Edgespath24 (talk) 21:13, 29 December 2009 (UTC)

This isn't a question of whether Kim or you or I say it's localized. Our positions don't matter. The only question Misplaced Pages asks is what do the reliable sources say. --TS 21:32, 29 December 2009 (UTC)

I agree. As reliable sources have found evidence of it in NZ (and other places) we should not be saying it was localized. Edgespath24 (talk) 00:05, 30 December 2009 (UTC)

If you can find evidence not in single papers, but in reviews of the literature, then I'll concede that we have a reliable source to challenge the orthodoxy. --TS 00:13, 30 December 2009 (UTC)

So now peer reviewed papers aren't enough? Sounds like you're proposing a novel standard to avoid NPOV on this issue. Edgespath24 (talk) 00:18, 30 December 2009 (UTC)

One, two or even three peer reviewed papers have never been enough. This isn't the place for original research. --TS 00:28, 30 December 2009 (UTC)

Wow. So citing papers appearing in the peer reviewed literature (which happen to contradict some editor's preferred view) have now somehow become original research. That's another novel interpretation of WP rules. Edgespath24 (talk) 00:39, 30 December 2009 (UTC)

Citing papers in the peer reviewed literature is fine. Citing some outliers to overrule the result of reviews of the field is not. --TS 00:41, 30 December 2009 (UTC)

Which is why I rewrote without picking sides. Your objection only makes any sense if I'd written it to say it was global. Edgespath24 (talk) 01:01, 30 December 2009 (UTC)

The paper you like so much is an example of the effect already discussed in the article: "Palaeoclimatologists developing region-specific climate reconstructions of past centuries conventionally label their coldest interval as "LIA" and their warmest interval as the "MWP"" -- in this particular case, the reconstruction (Fig. 3 in ) shows distinct cold period at around the time the MWP was at it's warmest in Europe, and it's warm period very much to the end, when temperatures in Europe were mostly back to normal. That's not a global MWP, if anything it's evidence for the suspected see-saw between the hemispheres. --Stephan Schulz (talk) 03:35, 30 December 2009 (UTC)

If you can cite that analysis, then add it to the article. However, unless you can provide strong evidence that the MPW is universally considered to be a localized phenomenon, it's inappropriate to present it as such. Edgespath24 (talk) 05:32, 30 December 2009 (UTC)

You have things reversed. You will have to document that it was world-wide by citing papers that say that it was world-wide. A methodology that consists of editors looking at regional or local reconstructions, and concluding by themselves that it must be global is original research. --Kim D. Petersen (talk) 02:21, 31 December 2009 (UTC)

I've added a NPOV tag until this is sorted out. Edgespath24 (talk) 05:34, 30 December 2009 (UTC)

Overkill, mate. All we have to do is to be careful to distinguish what we know for certain (the MWP was a fairly pronounced warm climate anomaly in the North Atlantic) from what is is a bit less certain (the MWP extended to other parts of the world). And keep in mind that even if it was global it could be manifested in different ways in different regions: Broecker, while arguing that the MWP was a global event, notes that Antarctica was substantially colder during the MWP. How about a sentence like "The Medieval Warm Period (MWP) or Medieval Climate Optimum was a time of warm climate in the North Atlantic region that may have been part of a global climate anomaly." Short Brigade Harvester Boris (talk) 05:49, 30 December 2009 (UTC)

Not bad boris, if i may add a bit? "The Medieval Warm Period (MWP) or Medieval Climate Optimum was a time of warm climate in the North Atlantic region and which new research (cite above paper here) shows it may have been part of a global climate anomaly." mark nutley (talk) 09:09, 30 December 2009 (UTC)

The "new research shows" bit doesn't belong because people have suspected the MWP may have been global for a long time. Short Brigade Harvester Boris (talk) 14:36, 30 December 2009 (UTC)

Good compromise. --Kim D. Petersen (talk) 02:22, 31 December 2009 (UTC)

If it has been suspected that the MWP was a global event then why does the article lead focus on the NA? why does it not say it was a global event? And i hate the word Anomaly for the MWP 600years is not an anomaly :) --mark nutley (talk) 11:29, 1 January 2010 (UTC)

Carbon dioxide levels

Why does this article not mention what atmospheric carbon dioxide levels were 1000 years ago? That would seem a crucially important bit of data. Recent studies have shown current CO2 levels the highest in 15 million years, when temperatures were 5 to 10 degrees Fahrenheit higher than they are today, and sea levels 75 to 120 feet higher than today. Badagnani (talk) 07:28, 29 December 2009 (UTC)

This is yet another article that needs some serious research applied to it. • Ling.Nut 08:35, 29 December 2009 (UTC)

I'm sure this information can be found; it's just surprising that no one has mentioned or added it yet. Badagnani (talk) 10:16, 29 December 2009 (UTC)

Around 280ppm ± 4ppm - just about the same as it has been for the rest of the Holocene. The reason it hasn't been added is that it isn't mentioned or considered relevant in reliable sources on the subject. --Kim D. Petersen (talk) 10:50, 29 December 2009 (UTC)

Not to sure were you get 280ppm kim, i have read upwards of 400ppm in a paper by Ernst-Georg Beck. —Preceding unsigned comment added by Marknutley (talk • contribs) 12:18, 29 December 2009 (UTC)

And if you believe Beck, then i have a bridge that i want to sell :-) My figures are from the Law Dome ice-core - but could have been from any other such proxy measurement. (sediment, stomata, sponge, ..) --Kim D. Petersen (talk) 12:52, 29 December 2009 (UTC)

Beck is an academically acceptable source. Nothughthomas (talk) 14:35, 29 December 2009 (UTC)

No, sorry - neither is it peer-reviewed nor is it published in a reliable source (not to mention that it is non-sense, and contradicted by all academic sources on this subject that i've seen. Jaworowski's publication record for this, seems to be in LaRouche magazines (which aren't reliable sources either, in fact they are practically banned on WP)) --Kim D. Petersen (talk) 18:02, 29 December 2009 (UTC)

But beck`s findings correspond with Zbigniew Jaworowski`s findings, or is he also not any good :) (what bridge btw?) mark nutley (talk) 15:58, 29 December 2009 (UTC)

Sorry, but Beck is a biology school teacher with no particular competence on climate or CO2 measurement. I also don't think he has published anything on the MWP (if yes, do you have a ref or a link?), but his 200 year CO2 concentration is completely discredited -see . --Stephan Schulz (talk) 16:02, 29 December 2009 (UTC)

Beck does not understand that surface measurements in vegetated or urban areas are not representative because of the diurnal cycle of the atmospheric boundary layer. The primary sources and sinks are at the surface, so that when mixing is limited (as by an inversion) concentrations fluctuate greatly. Or may be he does understand, and... Short Brigade Harvester Boris (talk) 16:12, 29 December 2009 (UTC)

Consensus appears to be in favor of using Beck. Now let's move on. Nothughthomas (talk) 17:38, 29 December 2009 (UTC)

Try pulling the other one. --Kim D. Petersen (talk) 18:03, 29 December 2009 (UTC)

Sorry Nothughthomas, i see no consensus in favor of beck, i see two in favour and three against, current consensus is against i`m afraid. I see no objections to Zbigniew Jaworowski however. mark nutley (talk) 18:01, 29 December 2009 (UTC)

Both Beck and ZJ are jokes, but this isn't the place to discuss why. If you want to retain any kind of credibility, you need to drop them. If for some reason you don't understand this well enough to know why, then by all means ask on my talk page William M. Connolley (talk) 21:05, 29 December 2009 (UTC)

Naturally WMC you think them a joke, as you do anything which may oppose agw :) so tell me how about Segalstad he backs up jaworowski does he not? mark nutley (talk) 08:46, 30 December 2009 (UTC)

Would you mind listing actual sources instead of name-dropping? I have yet to see a source by Beck discussing CO2 concentrations during the MWP - in fact, I still don't believe it exists. So please provide the sources by Jaworowski and Segalstad (and Beck, if you really want to adopt him). Thanks. --Stephan Schulz (talk) 09:08, 30 December 2009 (UTC)

Sure mate, give me some time to look them up and post though as i`ve a lot on today :) mark nutley (talk) 09:23, 30 December 2009 (UTC)

Sorry it has taken so long to reply, as requested here are the links to the studies i mentioned above.

• Statement written for the US Senate Committee on Commerce, Science, and Transportation by Prof. Zbigniew Jaworowski
• Becks paper(so yes stephen it exists :) )
• Segalstad`s paper

I Hope this helps the discussion move along --mark nutley (talk) 10:37, 8 January 2010 (UTC)

There is just the trouble that you actually confirm Stephan's disbelief. None of these papers address the MWP. And i still have a bridge to sell :-) --Kim D. Petersen (talk) 10:51, 8 January 2010 (UTC)

As I suspected, this is Beck's well-known (and deeply flawed) paper discussing chemical CO2 measurements during the 19th and 20th centuries. It does not make any claims about CO2 levels during the time period of the MWP, as far as I can tell. Indeed, the word "medieval" does not appear. None of the plots goes back further than 1700, and none of his plots (as opposed to referenced data) goes back further than 1810. --Stephan Schulz (talk) 10:51, 8 January 2010 (UTC)

Strange, the article i got those from had an image credited to beck which went back to 1000 and up to the present day. Let me recheck that article again, i suspect they may have lead me astray :) mark nutley (talk) 11:18, 8 January 2010 (UTC)

Beck and ZJ are both crap (insofar as their views on past CO2 go). On the off chance that you're interested in why, then is for JZ; for Beck. Or if you prefer more invective, William M. Connolley (talk) 12:05, 8 January 2010 (UTC)

Isn't this article about the Medieval Warm Period?

This article should reflect the fact that it's about the MWP?! In stead there's a lot of information about the MWP's relationship to global warming- perhaps we need another article about this issue? What's really missing from this article though is a discussion about what caused the MWP? And then perhaps a broader description of its effects during this period (the vikings are very interesting, but I'm sure their settling of Greenland wasn't the only significant effect of the MWP.) Joe Gain 95.113.5.250 (talk) 11:21, 31 December 2009 (UTC)

Is there? We have on small section on that topic, and one or two comparisons of MWP temperature to 20th century temperatures. That does not seem excessive to me. I don't think we understand the MWP very well - we don't even know if it was global, and I don't think there is a good understanding of what caused it. Climate records are sparse and we are just now beginning to model global climate in the relevant time frame. --Stephan Schulz (talk) 12:18, 31 December 2009 (UTC)

Per Stephan: other than speculation, I don't think there is much good stuff on the origin. Probably we need more on its reality - the current mish-mash of "evidence" is poor William M. Connolley (talk) 12:25, 31 December 2009 (UTC)

Article probation

Please note that, by a decision of the Misplaced Pages community, this article and others relating to climate change (broadly construed) has been placed under article probation. Editors making disruptive edits may be blocked temporarily from editing the encyclopedia, or subject to other administrative remedies, according to standards that may be higher than elsewhere on Misplaced Pages. Please see Misplaced Pages:General sanctions/Climate change probation for full information and to review the decision. -- ChrisO (talk) 02:46, 2 January 2010 (UTC)

Rewrite - Relation to modern climate issues

I think this section has to be rewritten. Taken alone, a niave reader may take this section to mean that this issue creates significant and credible evidence against anthropogenic global warming. This is WP:UNDUE. I suggest rewording There are credible arguments both for and against such a hypothesis to While there have been acadmic arguments both for and against such a hypothesis, the debate has had little impact on the general scientific consensus for man-made gobal warming. Objections? NickCT (talk) 20:10, 4 January 2010 (UTC)

As this article is about the MWP and not AGW i think rewriting it to what you say is wrong, this is about facts, not spin. --mark nutley (talk) 22:54, 6 January 2010 (UTC)

I took this out:

The Medieval Warming Period has been the subject of political and scientific debate, over the possibility that the occurence of such warming in the past might indicate that modern global warming might not be a product of manmade factors. There are credible arguments both for and against such a hypothesis. A scientific study begun in 2009 aims to examine evidence both for and against that hypothesis.

on the grounds that it isn't acceptable. This is far too much "false balance". The idea that cliamte is 50-50 on whether this argument makes sense is wrong: the balance is that pretty well everyone agrees that the MWP isn't the slightest evidence against current GW being anthro? Who put this stuff in? (I do hope it won't turn out to be me) William M. Connolley (talk) 23:12, 6 January 2010 (UTC)

I discover that this text came in quite recently just before Christmas William M. Connolley (talk) 08:59, 7 January 2010 (UTC)

Have you actually got a reliable source for that claim? the balance is that pretty well everyone agrees that the MWP isn't the slightest evidence against current GW being anthro if not i would have to suggest a revert mark nutley (talk) 09:36, 7 January 2010 (UTC)

Could we please not waste time on nonsense? Just look at the sci-op articles, or anywhere else. And even by your own logic you're wrong: you certainly don't have a RS for opinion being 50-50 so have no grounds for a revert William M. Connolley (talk) 09:52, 7 January 2010 (UTC)

Where is the credible evidence? Can you cite some? The references certainly do not support it - and as far as i know, neither the NAS, US CCSP or the IPCC even remotely indicate such a possibility. (in fact quite the opposite is the case). --Kim D. Petersen (talk) 12:03, 7 January 2010 (UTC)

I do think the onus is on the editor to support the edit. --TS 12:51, 7 January 2010 (UTC)

per what tony just wrote, WMC until such a time as you can post reliable sources proving what you have said above i would ask you to replace the removed text, thank you. --mark nutley (talk) 14:02, 7 January 2010 (UTC)

You've got Tony backwards. He said, until the original edit can be supported it should be out. At least that is what I think he said. Tony? William M. Connolley (talk) 14:16, 7 January 2010 (UTC)

Suggestion-- Removal of Image

There is previous discussion above in the talk page regarding issues with the current graphic image. I suggest a vote on whether or not remove the image. People who support removal should vote Support - Removal of Image and people who support retention should vote Oppose -- Removal of Image. Please include your wiki username with the 4 tildes after your vote.

It should be noted that the current image was created by a[REDACTED] editor from multiple sources (see File:2000_Year_Temperature_Comparison.png), unfortunately most of the sources are referenced only by abstract links. Thus the situation is that no one can verify that the graphic was correctly generated. Please follow the link I provide in this paragraph, review the sources referenced for the image, and verify for yourself that you cannot actually validate the data. Because the image itself is neither directly available from a secondary source, nor can the data used to generate the image be verified (and thus we cannot exclude WP:OR), I vote to remove.

Support - Removal of Image SunSw0rd (talk) 22:20, 6 January 2010 (UTC)

Votes are evil. See WP:VOTE. And what do you mean with "described by abstract links"? All the sources are clearly described and available via any good library. Also see Misplaced Pages:OR#Original_images - images are explicitly allowed under WP:OR. Moreover, it's substantially the same as Fig. 6.10 in the IPCC AR4 (, page467). --Stephan Schulz (talk) 22:58, 6 January 2010 (UTC)

Votes are evil. Note that Misplaced Pages:OR#Original_images states that images can be excluded if they introduce original ideas. I'm not convinced that's happening here, and I'm willing to give the creator the benefit of the doubt. For kicks and giggles I'm going to Oppose -- Removal of Image NickCT (talk) 23:19, 6 January 2010 (UTC)

If the has not been published in some other journal or publication then it is by definition self-published and not acceptable. If it is, as has been suggested, it would be synthesis of material. One only has to ask if this was text would it be viewed as synthesis of material and/or self-published. If the answer to that is yes, then there is no question that it should not be used. Arzel (talk) 00:44, 7 January 2010 (UTC)

I seriously suggest you read the previous discussion, where both the general and the specific claim have been rebutted. Creating original images is actually encouraged, and this graph is equivalent to a similar one in the AR4. --Stephan Schulz (talk) 00:54, 7 January 2010 (UTC)

I've removed references to "Vote". We don't vote (nor for that matter do we "!vote".) --TS 10:27, 7 January 2010 (UTC)

The grounds for removal appear to be most of the sources are referenced only by abstract links. Thus the situation is that no one can verify that the graphic was correctly generated. This is incorrect, obviously. Anyone can follow the abstract links, retreive the data and check William M. Connolley (talk) 11:17, 7 January 2010 (UTC)

There is even a direct link to the data given in the text for the image (aside the paper refs). --Kim D. Petersen (talk) 12:05, 7 January 2010 (UTC)

CO2 levels

Can the atmospheric CO2 levels during the Medieval Warm Period please be added? Is it possible that they are not known? Badagnani (talk) 04:15, 8 January 2010 (UTC)

The answer to that was already produced in the other thread: around 280ppm. --Kim D. Petersen (talk) 07:01, 8 January 2010 (UTC)

1. ^ Cite error: The named reference bradley(2003d) was invoked but never defined (see the help page).
2. Velasquez-Manoff, Moises (Dec 20, 2009). "If humans didn't cause global warming and cooling in the past, is that evidence they also aren't now?". Christian Science Monitor.
3. Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1126/science.291.5508.1497, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1126/science.291.5508.1497 instead.
4. Cite error: The named reference broecker_kunzig(2009) was invoked but never defined (see the help page).
5. Cite error: The named reference mann_etal(2009) was invoked but never defined (see the help page).
6. "Past regional cold and warm periods linked to natural climate drivers". Penn State University. Nov 27, 2009.

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