File talk:2000 Year Temperature Comparison.png

Smoothing behaviour at boundaries not defined

Image description says "the raw data has been decadally smoothed with a σ = 5 yr Gaussian weighted moving average". How was the data smoothed on the boundaries? Obviously people are going to be looking at this graph and particularly interested in the recent trend. But, since no information has been given on how the last decade or so of data was smoothed, no conclusions can or should be drawn from the data on this graph.

22nd November 2019 — Preceding unsigned comment added by Myridium (talk • contribs) 23:07, 21 November 2019 (UTC)

The description claims that "100009" different published reconstructions were used for the graph. There are not that many lines in the graph! Even if that many studies were published, which would seem rather odd (it would give a mean of 1000 publications on the subject in the last century), they are not shown in the graph. Could someone who knows this figure please correct the caption? Or replace it with a valid figure.

20th march 2015

I think inserting black line representing instrumental measurements into the spaghetti graph of cliamte reconstructions is highly misleading, because there is a divergence between the two - almost all proxy reconstructions show cooling or flat trend for the last 30 years while temperature measurements show warming. The reason for this discrepancy is not clear, but you cannot have it both ways: either you believe instrumental record in which case you cannot mix it with proxy reconstructions, or you believe reconstructions in which case you must reconsider instrumental data. Instead this apples and oranges mixture, you should use say proxy data until 2008. If you don't have proxy updates since 1980 (as most of reconstructions do not have them) you should remove misleading instrumental graph and show proxy data up to 1980. you cannot use proxies as evidence of th epast climate, while in the same time reject proxies as an evidence of recent climate. The only purpose of that "Frankenstein" graph is to strengthen impression of "unprecedented" warming in XX century. Once you remove instrumental graph and insert only proxy data to make apples to apples "spaghetti", that impression dramatically weakens. IPCC uses that trick with instrumental data as propagandistic tool. Wikipedia should have NPOV.

Apart from that you should include in spaghetti new reconstruction by Leohle (2007). --Djovani (talk) 17:54, 24 July 2008 (UTC)

This is quite dishonest. Two data sets (at least) are not temperature records but selected temperature eigenvectors. The black line should be removed and if you do you will see that current temperatures are not obviously above the med. warm. period.

This file has been used in:   Dana Desonie (July 10, 2009). "Climate". CK-12 Flexbooks.

Agreed. The Hockey Stick lives on, despite the stake through its heart. Fraudulent.

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There is no way it's warmer now than during the Medieval Warm Period, because much of southern Greenland was suitable for growing crops by the Vikings at that time, which it clearly isn't now. The Vikings had a successful colony there from roughly 1000 CE until about 1350 CE at which point it started to get colder. There's clearly something wrong with this graph. 97.125.18.72 09:29, 8 December 2009 (UTC)

You are confusing two things. These are global temperature reconstructions (for the whole world), but what you are talking about was a local effect. There is no contradiction. Samohyl Jan (talk) 13:30, 1 January 2010 (UTC)

"Much of southern Greenland" was not suitable for growing crops by the Vikings - very little was (and is now). --Stephan Schulz (talk) 23:06, 6 January 2010 (UTC)

Are some references valid for global reconstructions?

I don't like inclusion of work Moberg et al. (2005), without comment, because it clearly states in the title of their work that it's a reconstruction for northern hemisphere only. Samohyl Jan (talk) 13:30, 1 January 2010 (UTC)

Ditto for Esper and Cook reconstruction. It also seems to obsess with northern hemisphere only. Samohyl Jan (talk) 13:33, 1 January 2010 (UTC)

That's because most temperature reconstructions are NH - the proxy situation is better (more land). This is, however, clearly described. --Stephan Schulz (talk) 23:05, 6 January 2010 (UTC)

Journal reference Template

I was seeing multiple Error: journal= not stated messages instead of references. The Journal refrence template didn't seem to like the upper case fields so I corrected those. If that causes issues in other views feel free to revert and let me know and I'll try to find some more technical support as to why the references don't appear. Qgaliana (talk) 14:17, 3 December 2011 (UTC)

Labeling that doesn't visually exaggerate ups and downs

ping: Saperaud~commonswiki, JeffyP

Great work on the generation and development of the 1000 year and 2000 year files. I'm hoping that it might be possible to place all of the labels consistently either above or below the data curves. Placing some above and the other below creates an artificial exaggeration to the upward and downward swings. An edit might also make the image, unless you stretched the whole thing horisontally, more compact.

Thanks.

GregKaye (talk) 08:42, 23 April 2018 (UTC)

Update

Please update this chart. It even shows 2016 in the future. We need 2020 in the future. Ratel (talk) 04:54, 10 January 2019 (UTC)

What is the reference temperature ?

Hello,

The unit of the y-axis is the temperature anomaly. Anomaly in relation to what? What is the reference temperature?

Bibar (talk) 21:33, 16 November 2019 (UTC)

According to [1] this is the average of 1951-1980 temperatures. Ruslik (talk) 19:01, 17 November 2019 (UTC)

Thanks for the quick reply ! Bibar (talk) 20:23, 17 November 2019 (UTC)