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CO2 and Global Warming Part II

Somewhat to my surprise, I didn’t get my ass totally handed to me when I posted on this subject last. But there were a couple of things I should respond to. Firstly, Ti’ (hi, Ti’!) rightly takes me to task for poor phrasing

“Causal links are one way”, indeed! Ha! If my house burns down, I shall have that as my epitaph. Ben says there are no chain reactions!

What I was trying to say was that the ice core evidence supports the hypothesis that warming causes an increase in CO2, and it does not support the hypothesis that CO2 increase causes warming. That doesn’t mean that CO2 increase doesn’t cause warming, it just means that you can’t use ice cores to prove it.

So, on that note, Danny points me at an explanation of the ice core data, which appears to explain that I’m right. So, my understanding is that we believe CO2 causes warming because climate models say so. Should I be cynical about climate models on the basis that the models I interact with on a daily basis (weather forecasts) appear to have almost no predictive power? Or is there evidence that climate forecasting is different from weather forecasting?

5 Comments

  1. Let kids decide if CO2 is the culprit
    Several months back a Dallas high school science teacher conducted a simple experiment for his class. They constructed a miniature biosphere with an airtight terrarium. Then periodically, they increased CO2 through a one-way valve and recorded the temperature.

    They finally stopped when they reached 20 times the normal CO2 atmospheric volume and were unable to achieve any increase in temperature.

    My question is, why don’t schools all over the country duplicate this simple experiment in their classrooms and science fairs?

    The results seem pretty open and shut to me. Yet the public argues about whose computer model is better, or whose political party is favored, or who is ahead in the polls of the ignorant, fear motivated public.

    gerald

    Comment by gerald — 28 Mar 2007 @ 19:03

  2. Well, y’know, we should always be *able* to say, “These apparently knowledgeable experts… could they be talking utter garbage?”, without suffering personal attack as a consequence. (The BCS, for example, think widespread use of ADA, rather than Java, would be a pretty good idea, though I suspect in *that* case one could easily find numerous other computing experts who would say “Hogwash”, or equivalent, loudly. Conversely, there’s something approaching a consensus of climate scientists…)

    The alternative, and perhaps reasonable, interpretation of the temperature/CO2 graph is “Oh, shit! Positive feedback”.

    I’m a little puzzled by Gerald’s experiment… after all, in orbit, at night, it’s many degrees below freezing. The extremely thick atmosphere largely insulates the ground from space’s ambient cold. How are you going to replicate this in a terrarium (where the glass or plastic largely takes over the visible light in, attenuated IR-out role)? What you’d be looking for would be a difference in IR-absorbancy between CO2 and N2/O2.

    BASC says:
    http://books.nap.edu/openbook.php?record_id=11175&page=30

    “radiative forcing due to CO2, CH4, N2O, and various halocarbons is due to absorption of infrared (IR) radiation. It is well characterized and well understood”. I suspect THAT constitutes an open and shut case; it sounds like fairly verifiable, fairly basic physics. The big question, then, is what other negative or positive feedbacks in the biosphere respond to CO2 concentrations, and how quickly (and, as Ben says, this boots us squarely into GIGO-computer-modelling territory).

    If the climate models are way out, of course, we could be in the clear, or in utterly deep shit, so doubt about their accuracy doesn’t seem to make the climate change problem go away…

    Conversely, I think spectacular energy-inefficiency has become hardwired into a lot of engineering and social practices, and a lot of fossil fuel consumption is utterly disproportionate to fuel’s scarcity, climate change aside. Look how long Intel was able to keep pouring more watts into servers, despite the associated HVAC plant costs of hauling every kWh back OUT of the data centre, for bob’s sake! Eventually, data centres caught on…

    Another example: Amory Lovins (in his book “Natural Capitalism”) claims that engineering practice when sizing pumps and pipe runs is to minimise the total capital cost of pump and pipe run, ie. disregarding the cost of electricity to run the pump for the lifetime of the installation. Oops!

    And even if climate change DOES go away, there are lots of reasons to worry about availability of fossil fuels, or at least, to think they’ll be more expensive. So. Being more careful about fossil fuel usage will yield a reliable return on investment, barring global disasters, or cold fusion.

    Comment by ti' — 28 Mar 2007 @ 20:52

  3. The answer is quite simple. If there was no CO2 in the atmosphere, we would all be frozen. If there was way too many CO2, it would be as hot as Venus. So CO2 does influence on climate, as a variable coupled with temperature. It does feedback, to provide temperature balance. Change the CO2 concentration, and it changes the balance. You could check this reference:

    http://gristmill.grist.org/story/2006/12/13/21360/608
    It has a link to the research made by Hansen et al.
    http://pubs.giss.nasa.gov/abstracts/1988/Hansen_etal.html
    They predicted current global warming with his 1988 model fairly accurately, with GHG as the forcing factor.

    Comment by ginin — 29 Mar 2007 @ 18:59

  4. I’m afraid that it is a sign of the times that people are frightened to publically challenge the prevailing doctrine of “global warming” for fear of the response.

    A recent documentary on the subject on Channel Four here in the UK challenged the finding of the IPCC and already one of the contributors has received a death threat. This shows that the debate has passed from the hands of scientists to the politicians. The IPCC is a trans-national political body set up by politicians for specific ends and some scientists who were originally signatories to the document have had to take legal action to have their names removed from it.

    They believe that the science behind the IPCC report is flawed. The reaction to this is instructive: could anyone imagine Leibnitz making a death threat to Newton in their dispute about who invented Calculus/fluxions?

    I agree that temperature appears to be rising but CO2 follows temperature not the other way around and there have been innunerable global warmings and cooling in Earth history: remember the “little ice age” between about 1645 and the 1740s and it coinciding with the Maunder minimum which was a measure of solar activity?

    I believe that whilst man made CO2 is making a contribution to warming the real culprits are water vapour and the complex interaction between solar flares, sunspots. cosmic rays and clouds.

    This is very detailed and complex science and the best thing I can do is to direct the reader to two very good books on the subject, both by a former editor of the New Scientist, Nigel Calder: The Manic Sun (1998) and The Chilling Stars (2007). The latter wad written in conjunction with the Danish Scientist, Henrik Svensmark. I believe it to be a very important distillation of the complex science which has appeared in peer reviewed scientific journals.

    Comment by Gary Richmond — 29 Mar 2007 @ 21:58

  5. While I am concerned about the fact that temperature leads CO2 during a warming, I am much more concerned about the fact that during a cooling temperature AGAIN leads. This means that when CO2 is highest, the earth has already started to cool, then CO2 goes down AFTER the onset of global cooling. How can this happen if CO2 is a temperature driver? The temperature should not be able to go down when CO2 is highest.

    Comment by Mark — 7 Apr 2007 @ 2:51

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