On Feb 25, 1:06 pm, Robert I Ellison <[email protected]>
wrote:
> ...
The Arrhenius formula is
k(ln(CO2 now) - ln(CO2 start))
where the start is best treated as an interval fairly
near equilibrium and k is a constant to be determined.
It is ordinarily reported as k*ln(2) for 2xCO2 as a
matter of convention.
One way to estimate k is using the known concentrations
of CO2 from Law Dome and the Keeling curve and global
temperature anomlies from GISTEMP. I did this using
decades and a sngle decade lag so that the average CO2
concentration for one decade is used to estimate GISTEMP
average for the following decade. This means not ony
is k=OGTR estimated but it is then possible to offer
a prediction for the decade just now starting. Here it
is
OGTR for 2xCO2 = 2.33 RMS= 0.05 R2= 0.96
decade GTA AE residual
1880s -0.28 -0.28 +0.00
1890s -0.25 -0.23 -0.02
1900s -0.26 -0.20 -0.05
1910s -0.28 -0.17 -0.10
1920s -0.18 -0.13 -0.04
1930s -0.04 -0.09 +0.05
1940s +0.03 -0.05 +0.08
1950s -0.02 -0.03 +0.01
1960s -0.01 -0.00 -0.01
1970s -0.00 +0.07 -0.07
1980s +0.18 +0.18 -0.01
1990s +0.31 +0.33 -0.02
2000s +0.51 +0.47 +0.04
2010s ??.?? +0.64
with the value of R squared (R2) indicating that
all but 4% of the variance is explained.
Since the climate is now far from equilibrium,
the value of OGTR is for the Observed GISTENP
Response to date. There are some rules of thumb
which suggest a range for the equilibrium climate
sensitivity (ECS) based on OGTR; these hint at a
value for ECS in the range 3.3--3.7 K but this
range is not to be taken as more than indicative.
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