On Apr 21, 8:56 pm, Robert I Ellison <[email protected]>
wrote:
> > The formula used is quite clearly
> > AE(d) = k(lnCO2(d-1) - lnCO2(1870s)) - GTA(1880s)
> > but unfortunately the obvious right parenthesis was
> > missing. Now the conversion factor k is not that
> > orignally used by Arrhenius but is determined by the
> > best fit to the data, as is later explained in the link.
>
> The formula seems to have an observed temperature term on the right
> hand side but as the method derivation of k was unexplained
On the contray, k and A were determined by the best fit to the GTA
data, a standard method of estimating parameters. Then the parameter
k is reporteed as OGTR for 2xCO2 being equal to k*ln(2). I don't care
what IPCC AR4, etc., say, this is the observed global temperature
response from the GISTEMP data.
> ... this is a little confusing.
It shouldn't be so give me a hint as to how I might better rewrite it
for clarity.
> The formula calculates changes in temperature based on CO2
> concentrations.
Yes.
> The answers are then back correlated with observed
> temperature.
Huh? The residuals are the differences between GTA and the values
from the formula. Everythng is absolutely standard and there is no
circularlity whatsoever. The method of detrmining the values of A and
k is to minimize the RMS error; once again this is vinilla parameter
estimation.
> The Arrhenius formulation is used by the IPCC to derived 'forcing' of
> trace atmospheric gases from empirical data.
If so, I didn't see it; the big AOGCMs don't use this approximation
being too crude for careful work.
> The US National Academy of Science disagrees - 'Modern climate records
> include abrupt changes that are smaller and briefer than in
> paleoclimate records but show that abrupt climate change is not
> restricted to the distant past.'
So it depends upon the definition of abrupt. Fine. Then I'll say
that the global temperature change since the 1960s is abrupt. It
certainly is already impacting society, irrespective of definitions.
> The forcing from CO2 - easily calculated using gamma = 5.35 and CO2
> concentration changes over time - is 1.6 W/m2. The net forcing
> according to the IPCC is 2.4 W/m2. You also need - in order to
> plausibly model climate responses - to add in feedbacks of clouds and
> water vapour at a minimum.
All of that is treated as the Observed Global Temperature Resonse; all
of it.
> The only reason the correlation works is the assumption that all
> warming is from CO2 solely (implicit in the derivation of k)
Absolutely not. It is from CO2 and all fast feedbacks therefrom.
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