The atmospheric CO2 levels at Hawaii’s Mauna Loa observatory have declined since 2004?

Posted by William M. Connolley on March 31, 2009
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Well no, of course they haven’t. It is yet more septic twaddle from Avery; David Appell has a screenshot, since he expects the original is so blatantly stupid that it will be taken down. And he was right, it is now gone, though not silently: *Apologia: I deeply regret my misstatement that CO2 levels are Mauna Loa were declining. They are not. Nor is there clear evidence that the increase in atmospheric CO2 is yet slowing. In the past, I have demanded a higher standard of evidence than I had for the first edition of this column, and will return to that policy. says The American Daily, and the piece now has a new title. But it is a mistake that can only be made by wishful thinking; everyone else knows that CO2 is up year on year, and doesn’t even need to look at the figures.

But if you *are* going to look at the figures, it is a good idea to do it properly. Try a little test: what is wrong with Joe Romm’s takedown of Avery?

Yes, that’s right: in attempting to refute the idea that CO2 has declined since 2004, Romm shows a graph that doesn’t include any 2004 data. Doh! as he might say. Oh look, he did say it :-). The Wonk Room has a usable version of the same graph.

BTW, to include a tiny bit of actual science, it is worth noting that the growth rates that Romm quotes (quite likely correctly) are ~2 ppm/y recently, which is a about 0.65%, since CO2 is at ~380 ppm. And that is rather less than the 1% that gets you to CO2 doubling in 70 years. So we’ll have to work hard to stay on IS92a. Back in the days when I had access to decent graphical software I could do stuff like this. Ah well.

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Comments

  1. #1 dreikin
    2009/03/31

    Hm – that yearly CO2 cycle looks interesting. I wonder how well it correlates to weather/climate variation on the small scale..

    [The yearly cycle is well understood, it is due to there being more vegetation in the NH than the SH -W]

  2. #2 blf
    2009/04/01

    [T]hat yearly CO2 cycle looks interesting.

    The depth and warmth of the waters and volcanos around the islands make them a favourite sleeping grounds for Godzilla, Kraken, and other monsters. All you’re seeing is the results of their slow breathing: A spike when they exhale.

  3. #3 dreikin
    2009/04/01

    Cool. Although, I was more interested in its effects than it’s cause (which I had, apparently incorrectly, thought likely to be associated with more direct effects on the atmosphere’s dynamics with regard to the temperature).

  4. #4 Boris
    2009/04/02

    So we’ll have to work hard to stay on IS92a.

    I think we’re up for the challenge.

  5. #5 Aidan
    2009/04/02

    You need decent graphical software? (Who doesn’t?).

    You need R. It is an opensource version of S/S-plus and, in my opinion, now exceeds the original.

    It has a nice matrix/vector based manipulation model and programming ability. It is the business.

    Get it here:

    http://www.r-project.org/

  6. #6 Chris O'Neill
    2009/04/20

    BTW, to include a tiny bit of actual science, it is worth noting that the growth rates that Romm quotes (quite likely correctly) are ~2 ppm/y recently, which is a about 0.65%, since CO2 is at ~380 ppm. And that is rather less than the 1% that gets you to CO2 doubling in 70 years. So we’ll have to work hard to stay on IS92a.

    0.65% is the fraction of total (natural + anthro) CO2. If the anthro part grows exponentially then the growth fraction of the total will increase. e.g. if the anthro part is 100 ppm then it is growing at 2% p.a. of the anthro part which, under an exponential growth assumption, will mean 4 ppm per annum in 35 years with a total anthro part of 200 ppm. The annual growth will then be 0.83% of the total.

    It’s hard enough to get people to realize this when they don’t have a denialist attitude. With such an attitude they haven’t got a hope. They don’t want to understand.