File talk:1000 Year Temperature Comparison.png

Concerns Over Bias of Graph

Presumably the intended purpose of this graph is to demonstrate that independent temperature reconstructions prove the existence of 'hockey sticks' However, of the 10 reconstructions the first 7 are by Mann himself or coauthors or direct collaborators of Mann. And so is reconstruction 9.

Reference here: http://www.climate2003.com/blog/hockey_team.htm

And here: http://www.climateaudit.org/?p=499

Question: Mann’s group’s work surely cannot be used as independent validation of Mann’s work? Should there perhaps be added advisory text warning that the reconstructions are based primarily on Mann's group's work only?

"These curves are a fair representation of the range of results appearing in the published scientific literature."

Question: Can this statement be verified? Where is the citation to support it? Has Mann's and his coauthors and collaborators in fact published 70% of all temperature reconstructions in the published scientific literature?

Question: Are there any composite graphs similar to this available that are not completely dominated by the research work of one particular group of authors, so that better balance may be achieved?

Presumably the intended purpose of this graph is... to present all plausible well-sourced reconstructions. If you know any that have been omitted, be kind enough to list them. And don't trust CA to provide an unbiased view William M. Connolley (talk) 23:46, 14 January 2008 (UTC)[reply]

As requested a small selection of alternate reconstructions here:

http://www.climateaudit.org/?p=2393

And also here:

http://www.ncasi.org/Publications/Detail.aspx?id=3025 —Preceding unsigned comment added by 220.237.11.42 (talk) 05:04, 22 January 2008 (UTC)[reply]

CA should not be trusted to provide unbiased information any more than Realclimate or any other group. (Double-blind experiments are performed exactly because it is well understood that scientists inevitably introduce bias into their work.) William Connolley please provide links that readers can study that back up your opinions. Although I realise you have some type of connection with Realclimate, which is itself closely aligned with the Mann group, any factual evidence supporting your assertions would still be of potential great interest to most readers. —Preceding unsigned comment added by Will Nitschke (talk • contribs) 23:05, 16 January 2008 (UTC)[reply]

Which of my opinions are you looking for a source for? William M. Connolley (talk) 19:14, 18 January 2008 (UTC)[reply]

This Graph is now used for articles on how to not make a graph. Or better yet how to artificially create a hockey stick. Here: An illustration where the single year 2004 for observed temperature data explicitly is used in comparison with the super averaged medieval temperature data. http://wattsupwiththat.com/2010/04/04/ipcc-how-not-to-compare-temperatures/#more-18201 I know the classical Connolley reply is that these articles are not peer reviewed but neither is this graph. Please address the issues raised in the article or remove the graph from wikipedia. LucVC (talk) 09:16, 5 April 2010 (UTC)[reply]

How many data points were available in each curve?

Was the sampling uniform?

Why was Gaussian weighted averaging with the given width parameter chosen to smooth? What are the tradeoffs involved in the parameter selection and the smoothing method?

Are approximate confidence intervals available for the supplied data? If so, please include CI's for the smoothed curves.

Thanks! 71.214.99.239 (talk) 01:17, 13 July 2008 (UTC)[reply]

Oh: I see you provided a link to the site where you obtained the data. Still, it would be convenient if you summarized things such as # of data points, sampling frequency, etc. 71.214.99.239 (talk) 01:21, 13 July 2008 (UTC)[reply]

Could someone please explain the rationale for showing the 'single, unsmoothed annual value for 2004' as part of the black series. I would naively think that it's either of the same series, or it is separate and should show up as a single data point. That sudden blip upwards towards a data point 'shown for comparison' looks odd to me. Thanks, Campingcar (talk) 10:07, 1 February 2010 (UTC)[reply]

I think it was the last data point available when the graph was made William M. Connolley (talk) 10:28, 1 February 2010 (UTC)[reply]

I may have misread the * for 2004 as being the last data point of the black line. I take it there is a data point at the end of the black line, separate from the 2004 figure.Campingcar (talk) 17:32, 1 February 2010 (UTC)[reply]

Hello,

I am just writing to ask if there is any news on new data being made available on a similar spaghetti graph. It's 2008, not 2004, after all, so that black "2004*" looks odd.

1. When is new data usually available to Wikipedia on global temperatures? 3. When is new data expected for this particular(ly) hot topic? 2. Why does such a long (4 years and counting for this one anyway) gap exist? Is it just that difficult to put all the information together?

Thanks fogus (talk) 07:08, 20 October 2008 (UTC)[reply]

Any chance of getting this image updated with the latest data? Cheers ^Khukri 08:02, 19 September 2010 (UTC)[reply]

At first glance, this graph is quite complicated and confusing. You need to thorougly read the summary (Which is several paragraphs long and has two other related graphs) to even understand what each of the myriad of lines mean. When shown on an article, it means absolutely nothing to the average reader. There isn't even a graph key on the image! Jedibob5 (talk) 17:02, 5 January 2010 (UTC)[reply]

The graph is complex, but inevitably so. Removing the complexity by simplifying the picture would lose information. This is not a simple subject; a graph that makes that point is appropriate William M. Connolley (talk) 22:31, 5 January 2010 (UTC)[reply]

"when the earth used to be all tropical" Uh...citation needed. -- SEWilco (talk) 21:30, 11 March 2015 (UTC)[reply]