Global warming and The scientific method

Discussion in 'Earth Science' started by Andre, Apr 14, 2008.

  1. Andre Registered Senior Member

    The scientific method is about

    1. observation of a phenomenon
    2. think out a mechanism that could cause it
    3. make a prediction that follows from the mechanism
    4. test the prediction against reality

    1: Observations
    1.1: it's warming
    1.2: carbon dioxide is increasing
    1.3: in the geologic past there seems to be a correlation between the two

    2: think out a mechanism that could cause it
    2.1. greenhouse effect of CO2

    3.1. make a prediction that follows from the mechanism
    According to Hansen et al 1988:

    Page 7 Fig 3:

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    Notice about scenarios Hansen et al '88 Section 4,

    A: "the assumed annual growth averages about 1.5% of current emissions, so the net greenhouse forcing increases exponentially"

    B: "decreasing trace gas growth rates, such that the annual increase of the greenhouse climate forcing remains approximately constant at the present level"

    C: drastic reduction in GH gas growth.

    See also appendix B with more assumptions on other GH gasses.

    4. test the prediction against reality:

    CO2 emission trends continue to accelerate in 21st century .

    So Hansen was too optimistic and he should also have included a scenario even higher than A. So if we compare nowadays reality we certainly can disregard scenario B and C.

    Of course with start point bias:

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    No way of a A+ scenario. Who can possibly maintain that Hansens prediction was correct, implying that climate was mostly about greenhouse gasses and very little about anuything else.

    yes of course there is the solar variability and La Nina but there is also El Nino of 1998, (a nice end point bias of the IPCC). So what is really driving the climate? The CO2 or the sun and the ENSO?

    Hence all the reason for this open letter to the UN:

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  3. iceaura Valued Senior Member

    In the book "How To Lie With Statistics" there's a chapter on graphs with incommensurable scales.

    Note that the graph above does not plot absolute temperature and CO2 concentration, but temp variation from some mean against the very upper range of the CO2 chart.

    There's two immediate problems: the rise in CO2 is exaggerated compared with the temp variation as a percentage of the height of the graph, and the temp mean is sensitive to outlying or anomalous values, both visually and arithmetically. Do we have such values? Yes, around 1998 - right where the graph begins, the most deceptive place (along with the end).

    There's a third problem: the information charted by plotting variation is of a different kind than the info plotted by absolute values, and the graph can easily confuse. For example, if the mean is recalculated with each new year's data, a constant high new temperature would produce a negative slope on the variation graph - the difference between the measured value and the mean would be shrinking as the years went by. That would look, to the eye, like a "falling" temp. Likewise an apparent "plateau" on a rolling mean variation graph in the positive direction would signify a rising temp, as the new temps rise away from a rising mean.

    Hopefully they weren't quite that screwed up, and fixed the mean identically for all measurements ?

    That still confuses the eye. A more honest graph would plot absolutes against absolutes, temperature against CO2 concentration on comparable scales. I would suggest degrees Kelvin with the ppm, using the temp range attributable to CO2 in the first place and the absolute (from 0) Co2 concentration scale.

    And of course there's the usual problem with assigning false arguments to the alarmists, and using bad arguments to contest them. But that's standard.
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  5. Andre Registered Senior Member

    okay lets do some absolute plots:

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    Notice that the satellite plot of the MSU 2LT of UAH is pulled up tp the GISS value at the starting point in 1979 and also that the last plot of the UAH is merely the first three months of 2008, not a complete plot.

    Other than that, a picture is worth a thousand words.
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  7. iceaura Valued Senior Member

    Rising temps, rising CO2, relative slope completely dependent on the relative scale of the plot.

    You need a graph whose vertical temp range includes the entire effect of CO2 on atmospheric temps - the whole difference, and nothing but the difference, between no CO2 (and its associated water vapor, etc) and a nitrogen/oxygen/water atmosphere with it - and whose associated vertical CO2 range starts at 0.

    Meanwhile, the last point of the temp scale, which includes almost the entire visual effect of the graph (end it on the next to last point, and compare) is likely deceptive to some extent, unless the rest of 2008 goes exactly as the first three months went.

    And when that is done, the likely existence of visible lag or damping effects - lower temp regression slope, negative feedbacks, acknowledged as likely by all - don't mean much without mechanism and predictions from it. What is mysterious is not therefore inevitable, and the CO2 has not gone away,nor has it stopped behaving as CO2.
  8. TheCareTaker BBUURRIITTOOSS!!! Registered Senior Member

    Global warming is all lies
    if u know anything the north is actually getting colder

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