Airbourne fraction (again, again)

Posted by William M. Connolley on April 29, 2011
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Still no new science (is there any? Jules and James didn’t find much to post about at EGU), but Tamino posted on AF, which prompted me to look up some of my earlier posts. Tamino shows the CO2 growth rate from 1960, and they look upwards, which was rather less obvious when I drew them from 1990 on.

If you want to think happy thoughts, you can notice that the dCO2 rates are ~a bit less than 2 ppm on average, which is to say rather closer to 0.5% than 1% (1% gets you CO2 doubling in 70 years; but even 0.5% will get us above 600 ppm by the end of this century).

Update: this is an experiment (in two senses). Firstly, can I make a paypal “donate” button? And secondly, will anyone use it ;-? Don’t worry, I won’t be offended if you don’t.





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Comments

  1. #1 Nicolas Nierenberg
    2011/04/29

    WMC,

    I think your last paragraph uses the correct measurement which is percentage rate of growth since the effect should be order logarithmic. I haven’t done the math, did you notice from Tamino’s trend which direction the percentage rate of growth is going?

    [It must be close to constant. The absolute value only changes slowly after all -W]

  2. #2 crandles
    2011/04/30

    Well if you really want it back to 1960 (instead of 1980 which may be worldwide data) you can have the Mauna Loa data curtesy of NOAA:

    http://farm6.static.flickr.com/5148/5672137124_8f7d46e784_b.jpg
    ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt

    Using the linear trend, the 1959 increase of .754 ppmv over level then of 316ppmv is an increase of .24%. 2011 increase of 2.123ppmv on 391ppmv is an increase of .54%.

    The increases do seem to vary quite rapidly: Jan 10 to Jan 11 has an increase of 2.7ppmv while Mar 10 to Mar 11 is only 1.39ppmv

  3. #3 James Annan
    2011/04/30

    I thought there was quite a lot of science, but maybe you had to be there…

    [Maybe I'm doing you (and it) an injustice. But it seemed to me that you were rather listing things, than talking about what was done -W]

    And despite the “again, again” you still haven’t learnt how to spell it :-)

    [Hmm, you may be right, and not just colonial. Still, I like it my way -W]

  4. #4 Gareth
    2011/05/01

    James *is* right, y’know.

    [About the spelling? Yes, I do know. But I still like mine, so ner-ner -W]

  5. #5 supratall
    2011/05/01

    I thought there was quite a lot of science, but maybe you had to be there…

  6. #6 Alan
    2011/05/01

    Crandles #2 – “The increases do seem to vary quite rapidly: Jan 10 to Jan 11 has an increase of 2.7ppmv while Mar 10 to Mar 11 is only 1.39ppmv”
    CO2 oscillates with the seasons.

  7. #7 Alan
    2011/05/01

    Bugger, my random link (in #6) explaining the seasonal CO2 cycle was from a bunch of anti-AGW lobbyists, sorry about that! As usual for lobbyists the description is reasonably factual but the conclusions are bizzare.

    [As well as the seasonal cycle, there are year-to-year variations clear too. In fact, Tamino made some efforts to "clean up" the signal by removing ENSO-type co-variance, as I recall -W]

  8. #8 David B. Benson
    2011/05/04

    I favour creative spelling.

  9. #9 Steve L
    2011/05/05

    Off-topic comment brought about by despair, the latest from NSIDC, and the fact that Stoat was the last place I’ve read about the negative feedback provided by autumn open ocean releasing heat following a low late season minimum ice area in the Arctic:

    [Latest from NSIDC? Have I missed something exciting? -W]

    Can we encourage that negative feedback? I don’t particularly like geo-engineering solutions (band-aids), but what if somehow ice was piled up during the winter (thickening it in some places) and some areas opened to permit more loss of heat? You get some extra loss of heat from the ocean that has just warmed from extra sunlight, and the next summer there is more thick ice resisting melt to repel some of that sunlight.

    How to do that without adding heat? My stupid idea is gigantic sail boats that sit on the ice. I don’t have a non-stupid idea. But if the principle makes sense, then maybe somebody smart could come up with a realistic way to do it.

    [I think the answer is that we care about the Earth's overall radiative balance more, and so (if we were going to geo-engineer) would probably go for increasing overall albedo by whitening clouds or somesuch; I can't see sails on sea ice as being efficient -W]

    Sorry for the off-topic.

  10. #10 Steve L
    2011/05/05

    Just their usual monthly report on sea ice, nothing particularly dramatic this month. Despair was generally just a result of not being able to contribute to progress on this issue. Thanks for the replies.