Sunday, April 19, 2009

The Dogleg in the Keeling Curve



The Keeling curve is the one you always see with the rising level of CO2. It is that curve of doom that marks, according to the global warming hysteriacs, the demise of human civilization and the earth. The line is a wiggly upward trending line of CO2, starting at 315 parts per million in 1958 and rising now to the now horrific level of 385 parts per million. All of this increase in CO2, we are told, is due to human influences which must be stopped.

Well, not so fast. Consider this, partly touched on in a previous bloghere:

"Wind-driven upwelling in the ocean around Antarctica helps regulate the exchange of carbon dioxide (CO2) between the deep sea and the atmosphere, as well as the supply of dissolved silicon to the euphotic zone of the Southern Ocean. Diatom productivity south of the Antarctic Polar Front and the subsequent burial of biogenic opal in underlying sediments are limited by this silicon supply. We show that opal burial rates, and thus upwelling, were enhanced during the termination of the last ice age in each sector of the Southern Ocean. In the record with the greatest temporal resolution, we find evidence for two intervals of enhanced upwelling concurrent with the two intervals of rising atmospheric CO2 during deglaciation. These results directly link increased ventilation of deep water to the deglacial rise in atmospheric CO2." R. F. Anderson, et al " Wind-Driven Upwelling in the Southern Ocean and the Deglacial Rise in Atmospheric CO2," Science, 323(2009), p. 1443

What has now come to my attention is a Lamont-Doherty press release that goes with that article. It says:

"The faster the ocean turns over, the more deep water rises to the surface to release CO2," said lead author Robert Anderson, a geochemist at Lamont-Doherty. "It's this rate of overturning that regulates CO2 in the atmosphere." In the last 40 years, the winds have shifted south much as they did 17,000 years ago, said Anderson. If they end up venting more CO2 into the air, manmade warming underway now could be intensified." Source


Bolding mine

Now, this is 2009. If the winds changed 40 years ago, shouldn't we see the deep CO2 that this study speaks of? Shouldn't we see some impact on the world's CO2 level?

Yes. So, I took the Keeling Curve and put a straight line fitting the rate of change between 1958 and 1969. That is the blue line on the photo at the top. You can see that in about 1969, CO2 started increasing at a faster rate. That is probably due to the winds shifting south, as they did in the era of deglaciation spoken of by Anderson.

If Anderson et al are right, much of the increase in CO2 is natural, not due to man and his evil life style.

7 comments:

  1. Seems like you could trace this somehow. To determine if, indeed, the source of the CO2 is the deep ocean or from the burning of fossil fuels.

    From what I've read it appears that a great deal of the CO2 being released into the atmosphere lately is depleted in 14-C and probably largely due to the burning of fossil fuels (SOURCE: http://scitation.aip.org/journals/doc/PHTOAD-ft/vol_58/iss_5/16_1.shtml)

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  2. I knew someone would come up with this objection, and I am ready for it.

    Oceanic CO2 is also partly depleted in C14 because it has been down there for up to 5000 years, or basically 1 half life

    ""Ages of up to 5000 years have been reported for glacial deep waters near New Zealand (41), but more northerly sites in the Pacific show little difference from today, at least at depths shallower than ~2 km (40). We infer that the greatest 14C depletion of the glacial deep ocean was probably concentrated in the Southern Ocean region (and deepest Pacific), coincident with the highest densities (22) and lowest d13C values (24)."
    Thomas M. Marchitto, et al."Marine Radiocarbon Evidence for the Mechanism of Deglacial Atmospheric CO 2 Rise,"Science 316, (2007) p. 1459;"

    The waters being upwelled are from quite deep. I also have a picture of the vertical C14 quantity which shows that even 1000 meters down, the water has 40% of the c14 that the surface waters have. Maybe some time I will post it.

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  3. Depleted on an order of 1 half life is very different from depletion based on hundreds of half-lives, I should think.

    Carbon from a Pennsyvlanian aged coal will have an extremely small 14-C signature while 5000 year old carbon will be depleted by only half of its original 14-C.

    A Carboniferous aged coal would, presumably, have undergone something like 52,356 half-lives leaving only 1/2^52,356 th the original 14C. This is significantly different from 40% (a little more than 1 half-lives worth), right?

    So even allowing for the carbon to be sourced from the deep ocean and then in those conditions mentioned here (5000 years) only puts it at about 50% of it's original content.

    But again, this would be a good test of your hypothesis that the "dogleg" is oceanic-sourced.

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  4. Sorry, but after 10 half-lives it is all gone for all practical purposes, so your math is incredible overkill. Between the 52356 and 52355th half-life, you might (and I do mean might) lose one atom of C14). That isn't measureable. The biggest effect happens in the first half life when half of it decays.

    Remember after the first half life one loses 50% of the original. Only 25% of the original is lost in half-life #2 and only 12.5% is lost in half live #3. But that means that the C14 coming out is 50% depleted after the first, 75% depleted after the 2nd and 87.5% depleted after the third.

    Deep ocean waters not involved in the thermohaline circulation may remain down there for thousands of years.

    I agree it would be good to test it. There is a dog-leg just when Anderson says the winds shifted. I find that interesting.

    Just out of curiousity would you care to comment on some of the posts below where I show that all the things the global warming advocates fear have already happened in the HOlocene? A good place to start would be in the Holocene denial blog.

    What I am interested in is why we should fear that which we have already experienced just 5000 years ago

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  5. I understand the largest impact occurs within the first few half-lives (I'm familiar enough with 1st order rate laws, which is why I posted that..it was intended to be overkill), but my point was precisely that even by the reference you posted, at 1 half-life there is significant amount of 14-C compared to the amount one would expect from many, much older fossil fuel sources. If, however you find a reference that indicates that the residence time for CO2 in parts of the deep ocean was on the order of 57,000 years then you most certainly would have a relatively strong argument for the proposed hypothesis.

    As for your other points, I just found the site. I will read through them as time permits.

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  6. With 1 half life there is only 50% of the C14.

    As for the other points, fair enough

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  7. interesting way to redact this information, I think you're an expert in thins type of informations, but you should add something important: Concentrations of carbon dioxide fall during the northern spring and summer as plants consume the gas, and rise during the northern autumn and winter as plants go dormant, die and decay. 23jj

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