File talk:Mauna Loa CO2 monthly mean concentration.svg

Smoothed mean

It worries me that the smoothed mean in the official graph goes up and up, ever steeper right to the end (i.e. the present time), but on our version, the smoothed mean looks quite straight towards the end, and actually ends with a noticeable downtick. I don't know enough about R programming to know why this is, but I think the difference is significant, given how important this trend is, and the widespread use of our graph. --Nigelj (留言) 12:28, 25 February 2016 (UTC)

The smoothing we use is a local regression which is strongly driven by the data ; so it depends when we make the plot : in summer (northern hemisphere) the data is at the yearly maximum so the smoothing will be steep and in winter the slope at the end of the curve will be flatter. On the NOAA page they use a moving average of SEVEN adjacent seasonal cycles centered on the month to be corrected, except for the first and last THREE and one-half years of the record, where the seasonal cycle has been averaged over the first and last SEVEN years, respectively (as of 2019-07) so the last part of the plot is more stable. Maybe we could use the same method or we could update the plot only at a determined date... --Oeneis (留言) 07:17, 24 July 2019 (UTC)

Something is wrong with the seasonal inset figure

Seems to me that there must be something wrong with the inset figure, because there is no wrap-around continuity over the New Year. To be specific, the December value is larger than the January value, this leads to a discontinuity in the graph over New Year -- surely, this must be a mistake? — 以上未签名的留言是由该用户加入的： Inference (留言 • 贡献) 19:58, 9 July 2019 (UTC)

Not really, because year after year the december value is always higher than the preceding january value. In the inset, we plot the departure from yearly average so it means that the january value is mostly below the yearly mean and the december value mostly equal to the yearly mean ; and it is not intended to connect december to january. --Oeneis (留言) 07:17, 24 July 2019 (UTC)

I guess it just depends on what you mean by seasonal effect. With your definition (deviation from annual mean), you are right. I had an alternative interpretation in mind, that there is a smooth underlying trend with time, plus an effect caused purely by season. In your interpretation, the trend and the seasonal effects are confounded in the graph, because every year, January comes before December. — Preceding unsigned comment was added by 92.29.226.50 (talk) 12:09, 10 June 2020 (UTC)

HTTP 301 Moved permanently

Looks like the source http://cdiac.ornl.gov/trends/co2/contents.htm was moved to https://cdiac.ess-dive.lbl.gov/trends/co2/contents.htm since Wayback Machine shows that the old website was returning HTTP 301 to the new website. --Saledomo (留言) 05:38, 14 November 2021 (UTC)

Larger font size

I was wondering if the font size of the most important data could be increased (year, concentration). It's an accessibility issue. Even if you click on the figure, it is likely difficult for older people to read the text. Consider deleting the text about NOAA, as this can be put in the image description on Commons instead. Femkemilene (留言) 11:02, 24 January 2022 (UTC)