tisdag 2 december 2014

Prediction of Global Temperature May Well Be Possible

The recent "hiatus" of global warming, with slightly falling global temperature over now two decades under rising CO2 levels, in total contradiction to steadily rising temperature predicted by all of the complex climate models underlying the CO2 alarmism propagated by IPCC, has given support to a populistic view that "mathematical modeling of climate is impossible because the evolution of climate is chaotic". Both skeptics and alarmists have shown enthusiasm for such a scientific defaitism.

But it is not at all necessary to draw this conclusion, since chaos can sometimes be very predictable, for example as a null result of small stochastic perturbations.

For example, a simple climate model stating a balance between incoming radiation from the Sun, which is observed to be nearly constant, and outgoing radiation from the Earth system, which is observed to be nearly constant, can give the prediction that global temperature will stay nearly constant over forseeable time, say a couple of hundred years.

Such a model would be in excellent agreement with observations over the last two decades, and would also be within measurement accuracy since the start of recorded observations (with maybe half a degree Celsius nominal increase).

Climate as long-time-average of weather may thus be predictable, by the same mathematical reasons that mean-value aspects of turbulent flow like total drag and lift of an airplane are predictable (as shown in Computational Turbulent Incompressible Flow).

What may be impossible is a precise prediction of a very small effect of a small perturbation of atmospheric radiation from a change of concentration of a trace gas as CO2. But a precise prediction of something so small that it has no observable effect, is of course meaningless and thus the perceived impossibility is not real.

It is only if you like IPCC want to send an alarm of an effect of a vanishingly small cause, that you need a precise climate model supporting your case. The fact that such model is basically unthinkable is then something to hide, together with the fact that a prediction of no-change is certainly thinkable and may well be correct.

10 kommentarer:

  1. What do you think about a "model" which assumes the gravito-thermal 33C greenhouse effect is constant, since atmospheric mass/gravity are constant, but solar activity changes slightly, which if change the solar constant in the equation


    1 W/m2 from 1367 to 1368 W/m2, the calculated surface temperature increases from T=288.433K to 288.486K, an increase of 0.056C (this includes the division by 4 to convert solar insolation from a flat disk to a sphere)

    and if we change the albedo 1% in the same equation we get a 1C temperature change at the surface

    and since albedo/clouds could be one of many solar amplification mechanisms described in the literature, the chaotic climate system in effect bounded by what the sun does?

  2. Any model predicting no change can show up to be pretty correct, I think.

  3. Hi Claes,

    I'm now able to reproduce the atmospheric temperature profile in a physically-derived 1-D vertical profile from the surface all the way to edge of space by computing the "ERL" height from the well-known barometric formula & center of mass.

    The only assumption made about temperature is the equilibrium temp with the Sun 255K, but otherwise all temperatures are calculated by the model, including the surface temperature and gravito-thermal temperature gradient in the troposphere. Above the troposphere, I can then adjoin with the physical 1976 US Standard Atmosphere 1-D model up to the edge of space.

    What do you think? Any interest in collaborating on this?



  4. Sounds good. Do you compute the lapse rate as well? Or do you put in the observed value?

  5. Yes the lapse rate is calculated in the symbolic "greenhouse equation" by g/Cp

    The 1976 US Standard Atmosphere 1-D model was physically derived assuming the dry adiabatic lapse rate from measured Cp of dry air.

    After the dry atmosphere physical model was complete, they changed the Cp of air to the average observed at each atmospheric level (and if I recall they also calculated from physical chemistry - but I'll have to read the document again to verify the latter) to determine the lapse rates at each level and connect them together with the preceding lapse rates at lower levels as summarized here:


  6. My point is that the effective (observed) lapse rate set by an interaction of convection, phase change, gravitation and radiation and that this determines the Earth surface temperature. To determine the effect of a small change of radiative properties of the atmosphere, that is the effect on the lapse rate, may be difficult, but there is nothing that indicates that the effect would be observable. What does your model say?

  7. I've worked out a much better model of the entire atmosphere, and it says no warming effect of greenhouse gases whatsoever, and rather the opposite of cooling as passive IR radiators. Derived from 1st law to ensure conservation of energy, thus I firmly believe demonstrates no warming from GHGs nor effects on lapse rates, etc.

    I haven't posted on it yet while refining it, but please give me your thoughts, criticisms, or suggestions when I post it soon.

    Best regards

  8. Claes, what do you think about this?
    Case 1 - a solid spherical body heated only passively by solar radiation an otherwise free to radiate to space should have a core temperature dependent only on the solar constant and not on any other physical property of the sphere. This phenomenon requires only that absorptivity = emissivity at radiative thermal equilibrium.

    Case 2 - a spherical body with internal heat source not heated by any external source, but still radiating to space has a continuously falling termperature over time.

    The (earth + atmosphere) in space is a combination of cases 1 and 2. Therefore, the (earth+atmosphere) in the presence of constant solar radiation will only cool gradually over time.

    Within the (earth+atmosphere), there are complex chaotic thermodynamic stmopheric effects caused by cyclical heating and cooling, which you have described mathematically in the past. But all of that can only occur within the bounds of net cooling as determined by (Case 1 + 2).

  9. I do'nt see that net cooling must occur.