Questioning the Science Behind AGW: Wikipedia as a Source

[D H]

Wikipedia has been uniformly denounced as a non-reputable source for discussions on science of any kind, let alone discussions in this Earth sciences forum. Here is a nice little graph from Wikipedia showing an apparent strong correlation between global temperature and atmospheric CO₂ concentration:

So if Wikipedia is a disreputable source, why did I use it as a source in this post? The reason: The United Nations Environment Programme used this very image in its "Climate Change Science Compendium 2009" report. See figure 1.3 on page 5 of the report, with attribution "Hanno 2009".

McMullen, C.P. and Jabbour, J. (2009). Climate Change Science Compendium 2009. United Nations Environment Programme, Nairobi, EarthPrint. http://www.unep.org/compendium2009/PDF/compendium2009.pdf

At least the authors of this compendium could have been honest and cited the source as Wikipedia.
http://commons.wikimedia.org/wiki/File:CO2-Temp.png

Source: graph drawn by Hanno using data from different sources​

With junk like this, is it any surprise that people question the science behind AGW?

 

[mgb_phys]

It depends where the original data from the chart came from.
In this case wiki is simply reformatting the data (assuming the author of the graph didn't edit the data). Is kinko's a reliable source? If I photocopy "On the Electrodynamics of Moving Bodies" does that make E=mc^2 wrong?

If somebody took the data from a reputable source, created a graph and included it in wiki then it is as reputable as the original source - that another report simply took the graphic is probably un-profesional but they did credit the source.

 

[D H]

but they did credit the source.

No, they didn't, at least not in any professionally recognized form. That report ends with nine pages of references. The source for the cited graph is nowhere to be found in those references.

 

[mgb_phys]

Sorry I misunderstood - I thought you meant they had listed wiki as the source of the graph rather than the original report it was from.

There is a lot of lazy report writing out there - especially for outfits like the UN which seem to exist to give work to report writers. It's not necessarily malicous just cheap!
Still at least they didn't invade Iraq because of some 'intelligence' they foun on the internet.

 

[Xnn]

DH;

Just because Wikipedia cited the same source as the UN report did does not mean UN report (or the original source) is not reputable.

In this instance the original source was Hanno, which the UN cited; so there is nothing wrong with the UN's report.

Actually, it would have been wrong for the UN to cite Wikipedia as a soure, since Hanno was the originator.

 

[D H]

Actually, it would have been wrong for the UN to cite Wikipedia as a soure, since Hanno was the originator.

That's pure crap. I'm surprised your computer didn't undergo spontaneous combustion after you typed nonsense like that into it.

Just browsing the report, figure 2.1 on page 15 cites "Source: WGMS 2008a". Looking in the list of references I see

WGMS (2008a). Global glacier changes: facts and figures. UNEP/World Glacier Monitoring Service, Zurich​

A random paragraph from that page says

Documentation of this trend has been building for the last century and studies of glaciers and ice caps are becoming more sophisticated with new satellite-based observation technologies and attempts to distinguish glacier responses to multiple variables (WGMS 2008a, WGMS 2008b, Braithwaite et al. 2009). Evidence from increasing loss rates is becoming stronger. In the European Alps, for instance, overall glacial volume reduced by about one per cent per year from 1975 to 2000 and between two and three per cent since the turn of the millennium (Haeberli 2007).​

I can find each of WGMS 2008a, WGMS 2008b, Braithwaite et al. 2009, and Haeberli 2007 in the list of references. So why don't I find Hanno 2009 in the list of references? Answer: The graph did not come from a reputable source. In fact, even the 2009 part isn't correct.

 

[Xnn]

DH;

I'll let you in on a little secret: Wikipedia isn't a real person.

 

[D H]

I'll let you in on another little secret: Neither is the Annals of Glaciology, or any of the other multitude of publications that the bibliographic references in the main body of the report link to in the references section.

I'll let you in on another little secret: Scientists in fields other than climatology have lost their jobs and have been essentially blacklisted for acts just like this. Fabrication of evidence is scientific fraud.

BTW, I retract part of what I said in post #6. Braithwaite et al. 2009 is not listed in the references, either.

 

[billiards]

It seems that Hanno is a Wikipedia user who can be found in the Norwegian and sometimes the German Wikipedia, lol. http://commons.wikimedia.org/wiki/User:Hanno"

 

[D H]

It seems that Hanno is a Wikipedia user who can be found in the Norwegian and sometimes the German Wikipedia, lol. http://commons.wikimedia.org/wiki/User:Hanno"

Correct. That of course is the user's wikipedia handle. His full name is Hanno Sandvik. If Hanno Sandvik was a professional soccer player, referring to him by his first name only would be fine. Last I read, referencing someone by first name only in a supposedly scientific work is not standard practice.

 

[Count Iblis]

Wikipedia has been uniformly denounced as a non-reputable source for discussions on science of any kind

Not true.

So if Wikipedia is a disreputable source, why did I use it as a source in this post?

I suspect that the person who uploaded the graph is himself the scientist who made that graph for the scientific report itself. Wikipedia has a lot of professional scientists as its contributors. Since 2005/2006 a huge number of professional scientists have started to conribute to wikipedia and the quality of wikipedia articles (in the sense of being scientifically accurate, not necessarly w.r.t. being "encyclopedic") has improved so much that it is the best easy to access, scientific source of information.

I have myself corrected errors in wiki articles before the cited article's erratum was published (and even before the arXiv version was corrected). So, in some cases, it is the only source that will give you the correct information.

 

[D H]

Not true.

Name one scientific journal that accepts wikipedia references amongst the citations.

I suspect that the person who uploaded the graph is himself the scientist who made that graph for the scientific report itself.

I suspect that the person who uploaded the graph is a long-time contributor to wikipedia and uploaded the graph almost four years ago, on 6 December 2005. Look at the timetag on the reference.

 

[Count Iblis]

I'm sure that I could get away with a Wikipedia reference to a specific article version (instead of linking to the current version which could be affected by temporary vandalism or temporary quack edits) in the Physical Review.

I have never done this, but I have a few times before given links to webpages, so I don't see what would be so problematic about giving a wiki link, if the text on the wiki page is better suited for the readers than some standard review article or book.

Also, from my personal experience, journals such as the Physical Review do not strictly enforce any guidelines about what is allowed or not. If you as the Author write a good article, the Referee is unlikely to object on some minor irrelevant point, just because the journal guidelines are not met.

 

[mheslep]

... has improved so much that it is the best easy to access, scientific source of information...

In no objective way can you defend using 'best' as a modifier of 'scientific' here, only 'easiest'. BTW, we have scientists on PF that refuse to participate in Wiki.

 

[mheslep]

Wikipedia has been uniformly denounced as a non-reputable source for discussions on science of any kind, let alone discussions in this Earth sciences forum. Here is a nice little graph from Wikipedia showing an apparent strong correlation between global temperature and atmospheric CO₂ concentration:
[...]

So if Wikipedia is a disreputable source, why did I use it as a source in this post? The reason: The United Nations Environment Programme used this very image in its "Climate Change Science Compendium 2009" report. See figure 1.3 on page 5 of the report, with attribution "Hanno 2009".

McMullen, C.P. and Jabbour, J. (2009). Climate Change Science Compendium 2009. United Nations Environment Programme, Nairobi, EarthPrint. http://www.unep.org/compendium2009/PDF/compendium2009.pdf

At least the authors of this compendium could have been honest and cited the source as Wikipedia.
http://commons.wikimedia.org/wiki/File:CO2-Temp.png

Source: graph drawn by Hanno using data from different sources​

With junk like this, is it any surprise that people question the science behind AGW?

Good catch DH. Outrageous that the Compendium allowed this, though their first name basis friend 'Hanno' must be pleased.

 

[ideasrule]

In no objective way can you defend using 'best' as a modifier of 'scientific' here, only 'easiest'. BTW, we have scientists on PF that refuse to participate in Wiki.

And, on the other hand, we have scientists who graduated from Ivy League schools contributing to Wikipedia for the benefit of others. Some people are willing to sacrifice hours every day to make Wikipedia the best it can be, even though they can't hope to get any career or monetary benefit from it. It's quite an insult to these volunteers to denounce an article or a piece of information simply because it happened to be on Wikipedia.

The graph in question was based on reputable sources, which Hanno cited, and is no less reliable than those sources. That said, the journal's use of the image is highly questionable. First of all it violates Wikimedia Commons' license on the image (http://creativecommons.org/licenses/by-sa/3.0/legalcode), which says:

"You may Distribute or Publicly Perform the Work only under the terms of this License. You must include a copy of, or the Uniform Resource Identifier (URI) for, this License with every copy of the Work You Distribute or Publicly Perform."

"You must...keep intact all copyright notices for the Work and provide...to the extent reasonably practicable, the URI"

Second, how hard could did possibly have been to check Hanno's sources and redraw the graph? I agree that this belies the author's extreme laziness.

 

[D H]

Good catch DH. Outrageous that the Compendium allowed this, though their first name basis friend 'Hanno' must be pleased.

Not my catch. The "denier" crowd is all over this. Interesting, the only denialism going on is that being perpetrated by the true believers.

 

[mheslep]

And, on the other hand, we have scientists who graduated from Ivy League schools contributing to Wikipedia for the benefit of others. Some people are willing to sacrifice hours every day to make Wikipedia the best it can be, even though they can't hope to get any career or monetary benefit from it. It's quite an insult to these volunteers to denounce an article or a piece of information simply because it happened to be on Wikipedia...

Not at all. The thesis here is not that Wiki is all trash, on the contrary it is wonderfully handy quick resource. The thesis is that Wiki is flawed, because along with all the expert contributions crackpot and agenda driven themes remain, as I'm sure the expert contributors and you are well aware. Thus when the scientific standard needs to be very high, as for published journals, Wiki doesn't cut it.

 

[D H]

It's quite an insult to these volunteers to denounce an article or a piece of information simply because it happened to be on Wikipedia.

Encyclopedias are fine as a reference for little kids. They are fine as a starting point for research by older kids. However, every student reaches a point in their education when using any encyclopedia as a reference is no longer allowed. Using an encyclopedia is anything but fine for a scientific paper. The reason is simple: Encyclopedias are not supposed to be the place for publishing original research. Wikipedia is first and foremost an encyclopedia, and it has a very strong rule against publishing original research.

http://en.wikipedia.org/wiki/Wikipedia:No_original_research

• Wikipedia does not publish original thought: all material in Wikipedia must be attributable to a reliable, published source.
• Articles may not contain any new analysis or synthesis of published material that serves to advance a position not clearly advanced by the sources.

Emphasis mine. More on this below.

The graph in question was based on reputable sources, which Hanno cited, and is no less reliable than those sources.

The graph is less reliable than those sources. From http://commons.wikimedia.org/wiki/File:CO2-Temp.png, "Source: graph drawn by Hanno using data from different sources." In other words, the graph is a clear violation of Wikipedia's No Original Research rule. It is a synthesis of published material that advances a position not clearly advanced by the sources.

Before I posted the original post I looked at the global warming pages in the English version of Wikipedia to find the article in which the graph is used. I couldn't find one. A likely reason is that someone at Wikipedia removed the graph from whatever pages used to reference it They did not delete the graph itself from the Wikipedia commons.

 

[ideasrule]

The graph is less reliable than those sources. From http://commons.wikimedia.org/wiki/File:CO2-Temp.png, "Source: graph drawn by Hanno using data from different sources." In other words, the graph is a clear violation of Wikipedia's No Original Research rule. It is a synthesis of published material that advances a position not clearly advanced by the sources.

Before I posted the original post I looked at the global warming pages in the English version of Wikipedia to find the article in which the graph is used. I couldn't find one. A likely reason is that someone at Wikipedia removed the graph from whatever pages used to reference it They did not delete the graph itself from the Wikipedia commons.

The policy on original research has a section devoted to synthesis, which states: "Do not combine material from multiple sources to reach or imply a conclusion not explicitly stated by any of the sources." "Imply a conclusion" is the key phrase; using multiple resources is not synthesis by itself because every good article references more than one source. Hanno's graph is borderline because on one hand, the sources might have been chosen for a reason, but on the other, the graph doesn't advance any clear position. It doesn't tell us whether CO2 concentration influences temperature or whether temperature influences CO2 concentration; it doesn't say whether one causes the other or is merely correlated with the other. Since the correlation between CO2 concentration and temperature is not controversial, the graph is good for illustration purposes.

 

[ideasrule]

Before I posted the original post I looked at the global warming pages in the English version of Wikipedia to find the article in which the graph is used. I couldn't find one. A likely reason is that someone at Wikipedia removed the graph from whatever pages used to reference it They did not delete the graph itself from the Wikipedia commons.

An easy way to see what articles use the graph is to use the CheckUsage app: http://toolserver.org/~daniel/WikiSense/CheckUsage.php?i=CO2-Temp.png&w=_100000#end

You're right in saying that no Wikipedia articles use it, but wikis in other languages do.

 

[sylas]

I agree that the use of this graph was pretty dreadful.

There's all kinds of problems with it. The referencing is inadequate in the compendium, and also in the wikipedia page. I had a quick try at sorting out the paper trail, and it's not easy. "Hanno" cites the temperature data to Jones and Mann (2004). It's easy enough to find the data; it is in figure 5 of that paper. Except that the scale is different. For some reason, Hanno used an absolute temperature scale. I have no idea why. Furthermore, Hanno omitted the error bars which were in the original... and they are quite significant. The particular data in Jones and Mann is properly cited, back to Jones and Mann (2003).

There's another problem: the graph by Hanno also shows a CO₂ trend. But then how are the two vertical axes aligned? I presume he's picked out a scale that gives the best correlation.

The problem here is, however, that the association of CO₂ with temperature is not based on correlation; and there are other factors than CO₂ to consider.

All told, yuck! This is pretty lazy by the authors of the compendium. It would have been straightforward to give a proper primary reference with the same basic information, and a better graph.

----

On the other hand; neither Wikipedia not the compendium are primary sources, and neither one is an instance of the "science behind" anthropogenic global warming (AGW). That science stands or falls on its own merits; and not on how well it is described in secondary summaries.

The biggest issue here is that this use of the graph was lazy; not that the science is actually suspect. I realize some people here are suspect about various aspects of the science behind global warming; but that is a different discussion, and should be considered by looking at primary sources. This use of a badly sourced graph is not a case of bad science, but of poor science writing. The science behind the graph stands up just fine. To disagree with that would require looking at the science itself.

In this case, the science to consider is as follows:

• The various attempts to reconstruct global temperature trends over the couple of millenia.
• The reconstruction of atmospheric CO₂ over the last couple of millennia.
• The physics behind the association of CO₂ and temperature -- the strong correlation is not the primary evidence for this association, but stands rather as a test of the correlation that is expected given the underlying science.

This would mean considering the following references, or others like them:

• Mann, M. E., and P. D. Jones (2003), http://www.agu.org/pubs/crossref/2003/2003GL017814.shtml, in Geophys. Res. Lett., 30(15), 1820, doi:10.1029/2003GL017814. (Publicly accessible preprint).
  Figure 2c shows the temperature data used by Hanno; how this is obtained is described in the paper.
• Jones, P. D., and M. E. Mann (2004), http://www.agu.org/pubs/crossref/2004/2003RG000143.shtml, in Rev. Geophys., 42, RG2002, doi:10.1029/2003RG000143.
  Source given by Hanno for temperatures. Data shown in Figure 5c, cited to Mann and Jones (2003).
• Climate Reconstructions repository at NCDC (NOAA), with data available for hundreds of papers, including the Mann and Jones (2003), and Jones and Mann (2004). You can use this to obtain numbers and play around yourself, with this and a lot of other data.
• Etheridge, D.M. et al. (1998). Historical CO2 records from the Law Dome DE08, DE08-2, and DSS ice cores. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A.
  This is the source of CO₂ data used by Hanno. Linked page includes datasets.
• Knutti, R., and L. Tomassini (2008), http://www.agu.org/pubs/crossref/2008/2007GL032904.shtml in Geophys. Res. Lett. 35, L09701, doi:10.1029/2007GL032904. (Publicly available preprint)
  This estimates the transient climate response (TCR; per 2xCO2) as being from 1.11-2.34, with a best estimate of 1.6 degrees. The IPCC 4th AR estimates 1-3 degrees. (All 90% confidence bounds.) The difference between TCR and equilibrium sensitivity is briefly explained in [post=2362326]msg #69[/post] of thread "Playing Devil's advocate on climate", with references.

See also plenty of references and background on the physical basis for quantifying the link between temperature and CO₂ in the thread [thread=307685]Estimating the impact of CO2 on global mean temperature[/thread].

A more meaningful comparison of CO₂ with temperature would compare the logarithm of CO₂ with anomalies. The jump in CO₂ shown by Hanno is from 280ppm to 380ppm. As logarithms, this is log₂(380/280) = 0.44. Using a TCR of 1.6 (range 1.1 to 2.4) gives a temperature response of about 0.7 degrees (range 0.5 to 1.0). Hanno's graph uses about 0.67 degrees between 280ppm and 380ppm, which is reasonable enough. So actually the graph is not a bad guide to the expected link of temperature and CO₂... except that it omits all error bounds, all justification of the scale link, and the logarithmic nature of the relation.

It's not that the science is bad, or even that the graph is particularly misleading. Its fair enough as a simple non-technical illustration. But the compendium would have been much better to actually USE the science, rather than the image they chose.

Cheers -- sylas

 

[Galteeth]

I think wikipedia is an extremely useful resource for general knowledge purposes. If i see something on wikipedia unsourced, i know to ignore it. If something sounds questionable, I can check the source, see for myself, google that source, read more on the subject, etc. I think an overview of the discussion on an article is essential to understanding what might be controversial. It is not a final source, but it's a great starting point. From what the OP described, the graph was a clear violation of wikipedia's policies. I think it might be the case that an article on global warming attracts a lot of cracpot editors, so it it locked more so then a normal article would be.

 

[D H]

You missed the point of the original post, Galteeth. The graph in question was used in an official UN report. To make things worse, it was not properly cited. To make things even worse, that graph appears to contravene wikipedia rules against original research.

There is a larger issue here, and that is what constitutes a valid reference for the purposes of this particular part of Physics Forums. [thread=280637]The PF Earth Sciences policy[/thread] states

Controversial claims must be supported by evidence that comes from a scientific, peer-reviewed journal or a similarly reliable source, i.e., unsubstantiated claims are not allowed.

The problem with this policy is that the reputable sources are not all that reputable. This latest UN report is but one example of that.

 

[vanesch]

The problem with this policy is that the reputable sources are not all that reputable. This latest UN report is but one example of that.

Of course, and even in peer-reviewed literature (which a UN report is not really) there are errors and even outright wrong claims.

Peer-review IS NOT a guarantee for quality. But it should have, on average, a higher level of quality. At least a lot of junk is rejected in peer-review. Not all. There are no guarantees. Just some means to try to elevate the level of quality. That's all.

Moreover, the UN report is not a scientific report, as it talks about policies. From the moment you talk about policies, you left the area of pure, investigating, science. In other words, this UN report is not a scientific publication.

 

[sylas]

Many forms of Government have been tried and will be tried in this world of sin and woe. No one pretends that democracy is perfect or all-wise. Indeed, it has been said that democracy is the worst form of government except all those other forms that have been tried from time to time.

-- Winston Churchill (1947)​

This thread reminded me of this quote; and mentally I substitute "peer review" for "democracy"...

Controversial claims must be supported by evidence that comes from a scientific, peer-reviewed journal or a similarly reliable source, i.e., unsubstantiated claims are not allowed.

The problem with this policy is that the reputable sources are not all that reputable. This latest UN report is but one example of that.

What do you think is the objective of this policy? Is there a better policy you have in mind?

When peer review fails

Peer review is only the first hurdle for a scientific idea. It doesn't ensure correctness. It is better thought of as a check that the work is worth looking at. The public at large often fails to grasp this; but hopefully most folks here will get it. Publication does not mean that scientific evaluation and criticism has been completed and the result is now confirmed. Publication is only the start of evaluation by the scientific community. The initial hurdle of review by a couple of often rather rushed journal reviewers is a check that it is worth putting the work up for consideration by the scientific community.

Sometimes the peer review process fails quite spectacularly, and let's through material that is unworthy of any consideration. It's not common, but it happens. I know a couple of breath taking examples. Here's one from a different field entirely. See the thread "[thread=322690]Understanding Einstein's Twin Paradox, past the usual level?[/thread]" This thread was prompted by a paper published in International Journal of Theoretical Physics, a legitimate but low impact peer-reviewed physics journal (citation and link in [post=2343185]msg #7[/post] of that thread); and the paper is a sophomoric failure to understand special relativity. Complete and utter trash from start to finish. I know a few more such cases. The peer review requirement is not a panacea; but a very helpful heuristic.

By comparison with this relativity paper, the issues that have been raised here are trivial!

So why require peer review?

So why is the policy in place? I can't speak for Greg or the staff, but obviously there is a lot of material out there relating to climate in particular, which is not reviewed and is complete trash; but which still gets passed around certain circles as if it was credible science. The mentors here don't have standing as expert reviewers; and given the heat of discussion and the low quality of so much circulated material, it's sensible to have a readily manageable guideline to deal with this.

Sticking to material that has passed peer review strips out an awful lot of trash. It will also remove some perfectly good writing on the subject. But if the ideas expressed have any credible scientific basis, you should be able to find someone who has published about those ideas in the scientific literature. If it hasn't been published, that's a strong indication that the argument might not actually be as good as it appears to a general reader.

As I understand it, the requirement for peer-reviewed scientific sources is not a way to ensure that sources are beyond question. It's a hurdle which (almost always) means that the information in the source is worth considering. It's also a hurdle which is very easy to pass for any credible scientific argument. If the argument is any good, you should be able to find someone who has managed to publish it.

Even bad papers are usually worth looking at. Peer review nearly always stops the trivial or nonsensical; but it still let's through a range of ideas and arguments, with many contrasting and mutually inconsistent ideas on various open research questions. Discussion in PF consistent with the guidelines still allows us to give a critical evaluation of published research, or examine the potential problems with new ideas.

What is the problem with the compendium cited here?

The problem that has been identified with the compendium cited in this thread is pretty trivial, by comparison with a real error. The main issue is very poor referencing; also the lack of error bounds, and a lack of discussion of the vertical scales.

However, no problem with the underlying science has been shown; and in fact the underlying science is legitimate peer reviewed science in good standing. The compendium is a secondary source.

Contrary to what has been said in preceding discussion, the image source is NOT "Wikipedia". It is "Wikimedia Commons", which is not the same thing at all; and the actual data sources for the image ARE peer reviewed scientific information in good standing. There's no prohibition on "original research" in wikimedia commons (see the Project Scope policy), and no issue with the artist choosing to display the two curves together. The biggest problem is bad referencing in the compendium. The correct way to reference it (IMO) would be to give a credit to the artist (not a citation) combined with a citation to the data used by the artist.

The aim of the graphic was specifically to illustrate the correlation of a sharp rise in CO₂ with a sharp rise in temperature, as discussed in the main text of the compendium. This is a good graphic to illustrate that point. It would have been much better to reference it properly. It would have been even better to use images (with permission) from the primary sources directly.

The text of the compendium describes this correlation as prompting a question which is subsequently explored using more careful multidisciplinary analysis.

... But correlations between the curves of carbon dioxide in the atmosphere and the average global temperature appeared to be very strong: Over a 1000-year period, a fairly level trend seemed to start a sharp rise since the late 1800s. Was the climate changing—and, if so, how? And could human activity possible have anything to do with it? To answer such questions, researchers needed to use innovative approaches working with interdisciplinary teams that could incorporate data, information, and knowledge from many sources.

-- http://www.unep.org/compendium2009/PDF/compendium2009.pdf , McMullen and Jabbour.​

[/color]​

One minor criticism I have is that the compendium suggests the observed correlation was the impetus for the physical theory; in fact the theory came first.

Implications for PF policy

None. Wikipedia is still not a legitimate source for controversial claims in this forum.

Note that the original post got this wrong; there is no indication that wikipedia is used as a source. The actual source is simply a media repository, not the encyclopedia. The information behind the image is not wikipedia, but legitimate peer reviewed scientific papers.

But let's think about wikipedia anyway. If some other reliable source uses an image from wikipedia, that does not discredit the reputation of the source or disqualify it according to the guidelines. Other sources DO have expert oversight which may not be easily accessible or recognized at physicsforums. A reliable source is free to evaluate images and decide if they are appropriate, subject to their own review requirements. If so, we then may use the reliable source, including the images it has deemed useful.

As to whether the Compendium considered here is actually a reliable source consistent with the guidelines quoted at the start of this post; that is for the mentors to decide. It's not technically peer reviewed scientific literature, I think; but (IMO) it is "similarly reliable". This does not mean perfect. I don't think any meaningful case has been given for saying that the compendium is not "reputable" or "reliable" in the same sense as a peer reviewed scientific article.

On the other hand, I am aware that some of the mentors and readers may see it differently. For my own part, I nearly always prefer to go back to the references in the scientific literature, unless there is some definite benefit in accessibility to use a source like this compendium.

Felicitations -- sylas

 

[Mk]

The authorial attribution is not just, "graph drawn by Hanno using data from different sources." Hanno is not just a first name, or his third-grade niece. Hanno is the username of an individual who is known on the Commons and on no.wikipedia. http://no.wikipedia.org/wiki/Bruker:Hanno

Second, he lists the sources of data that he has used to create the graph. Care should be taken to review those sources instead of just saying "Wikipedia is open to anybody—it's wrong."

This would mean considering the following references, or others like them:

• Mann, M. E., and P. D. Jones (2003), http://www.agu.org/pubs/crossref/2003/2003GL017814.shtml, in Geophys. Res. Lett., 30(15), 1820, doi:10.1029/2003GL017814. (Publicly accessible preprint).
  Figure 2c shows the temperature data used by Hanno; how this is obtained is described in the paper.
• Jones, P. D., and M. E. Mann (2004), http://www.agu.org/pubs/crossref/2004/2003RG000143.shtml, in Rev. Geophys., 42, RG2002, doi:10.1029/2003RG000143.
  Source given by Hanno for temperatures. Data shown in Figure 5c, cited to Mann and Jones (2003).
• Climate Reconstructions repository at NCDC (NOAA), with data available for hundreds of papers, including the Mann and Jones (2003), and Jones and Mann (2004). You can use this to obtain numbers and play around yourself, with this and a lot of other data.
• Etheridge, D.M. et al. (1998). Historical CO2 records from the Law Dome DE08, DE08-2, and DSS ice cores. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A.
  This is the source of CO₂ data used by Hanno. Linked page includes datasets.
• Knutti, R., and L. Tomassini (2008), http://www.agu.org/pubs/crossref/2008/2007GL032904.shtml in Geophys. Res. Lett. 35, L09701, doi:10.1029/2007GL032904. (Publicly available preprint)
  This estimates the transient climate response (TCR; per 2xCO2) as being from 1.11-2.34, with a best estimate of 1.6 degrees. The IPCC 4th AR estimates 1-3 degrees. (All 90% confidence bounds.) The difference between TCR and equilibrium sensitivity is briefly explained in [post=2362326]msg #69[/post] of thread "Playing Devil's advocate on climate", with references.

Third, I sense a slight misunderstanding of Wikipedia's Original Research policy. Wikipedia strongly encourages editors to construct their own diagrams, drawings, graphs, and maps. Diagrams and drawings can be done by hand, but of course graphs and maps need to be done using precise software with accurate datasets. Take a look at the Global Warming article to see how many Wikipedian original graphics there are... all but one! This brings consistency and style, and does not violate copyright.

Also, page 5 figure 1.3 is a graph by Hansen et al., not Hanno.

Regardless, the IPCC would have done better to cite a graph (if they do, your post sends me to the wrong page) from User:Dragons_flight. His graphs are thoroughly annotated and he has his own site for them. Take a look at the description, technical notes, and references section for this one:
http://globalwarmingart.com/wiki/File:Deglaciation_png

 

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Also, page 5 figure 1.3 is a graph by Hansen et al., not Hanno.

That is the case now, after IPCC expunged the graph by "Hanno" from their report. Below are the pre- and post- update versions of page 5 of the report: