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Tuesday, July 29, 2008

David Evans on GHGs

David Evans, a former carbon accountant, wrote a recent op-ed in The Australian that got some attention, "No smoking hot spot" (July 18th). Tim Lambert thoroughly critiques it here.

The first thing Evans wrote was
1. The greenhouse signature is missing. We have been looking and measuring for years, and cannot find it.
I thought this was one of the primary signatures of anthropogenic global warming...



IPCC 4th Assessment Report, WG1, Ch 9, FAQ 9.2, Fig 1, p. 703
(bottom three graphs)
http://tinyurl.com/27ocvp

so I asked him about it. He replied that he thought the climate models just got "lucky."
Comparing a model to observations doesn't prove the model works. It's encouraging to the model builders, but it's not proof. For instance, the model could just be lucky. (And I'm a model builder!)
I don't know how else you could prove a model works, but anyway. He went on:
The GCM models omit cloud complexities. They simply assume relative humidity is constant (observations in the last few decades shows in fact it drops steadily as the temp went up), so as temp rises there are more high clouds....

Also, the GCM models totally omit solar magnetic effects [ie. Svensmark]

Given their omissions, my guess is that the GCMs got "lucky" to get the Fig 9.2 results. For instance, I can make a model of plant growth predict global temperatures if you wish (obviously absurd), with sufficient tuning and funding :)
--

DeSmog blog notes that Evans has never published a single peer-reviewed paper in climate science, and that he earlier claimed "I am not a climate modeler." He has a Ph.D. in electrical engineering.

7 comments:

  1. GCMs do not assume constant relative humidity. Matehmatical analyses do, sometimes, partly because that is what the models tend to show and what in fact, despite his claims, has been observed. One could claim that such an analysis is a "model", but that would be confusing conceptual models with simulations, something an experienced modeler wouldn't do, right?

    Of course, relative humidity declines with temperature on a daily cycle, but bringing that in would just be confusing annual and daily time scales, something that someone writing a major article would be sure not to mess up, right?

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  2. It seems to me if one really believes co2 is harmful then more nuclear realistic alternative. Nations are not going to give up low cost energy.

    thorium is the green nuclear
    http://www.energyfromthorium.com/

    http://www.forbes.com/opinions/forbes/2008/0811/094.html

    "A number of influential people in Russia, China, India, Indonesia and Vietnam say the planet is now entering a 30-year cooling period, the second half of a normal cycle driven by cyclical changes in the sun's output and currents in the Pacific Ocean. Their theory leaves true believers in carbon catastrophe livid.

    To judge by actions, not words, the carbon-warming view hasn't come close to persuading a political majority even in nations considered far more environmentally enlightened than China and India. Europe's coal consumption is rising, not falling, and the Continent won't come close to meeting the Kyoto targets for carbon reduction. Australia is selling coal to all comers."

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  3. A number of influential people in Russia, China, India, Indonesia and Vietnam say the planet is now entering a 30-year cooling period, the second half of a normal cycle driven by cyclical changes in the sun's output and currents in the Pacific Ocean. Their theory leaves true believers in carbon catastrophe livid.

    Note they cannot give the names of these people or what they influence.

    *snork*.

    Best,

    D

    ReplyDelete
  4. dano,

    The operative paragraph is the second (independent of what you think about the first).

    Even Europe is building more coal plants.

    ReplyDelete
  5. charles, the operative paragraph does not take away the fact that your argumentation is conflating false cooling periods and nuclear advocacy to make some point.

    Best,

    D

    ReplyDelete
  6. Anonymous10:54 AM

    David Evans gave up too easily, those IPCC raphs conveniently end in 2000, lets see how they look in AR5, and moreover the black line showing claimed observations is greatly exaggerated by showing only anomalies, instead of actual GMST, using the latter the natural and anthro would not easily be separable.

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  7. Dano,

    The world is not sufficiently afraid of co2 to give up low cost coal. If you really think co2 is as dangerous as you say I suggest to find the cleanest low cost solution you can and promote it.

    I invite you to consider LFTR (liquid fluoride thorium reactor) technology. The "green" nuclear.

    Thorium based (rather than uranium based) nuclear power was demonstrate in the 50's and 60's but was abandoned because it was much harder to produce weapons grade material (compared to uranium). The military considerations favored the uranium fuel cycle.

    thorium LFTR compared to uranium reactors:

    have 100x more known fuel reserves (enough to power the USA for 1000s of yrs)
    burn fuel 100x more efficiently without reprocessing
    1000x less mining waste
    ~100x less radio active waste volume and waste needs storage for 10-300yrs not 10000yrs
    no weapons grade material
    are inherently safer (low pressure, can't explode)
    more efficient (high temp)
    should cost less (low pressure)
    can be air cooled (don't need water)
    can BURN UP URANIUM WASTE! no Yucca!

    Sound to good to be true?

    for more info see

    www.energyfromthorium.com/

    www.energyfromthorium.com/ppt/thoriumVsUranium.ppt

    ReplyDelete