wirebender
Senior Member
Well, I was interested in finding 2010 co2 forcing...So I looked and found the equation and did the math.
ΔF = αln(C/Co)
a=constant, which is 5.35
So a=5.35
Natural log=ln
^F=5.35In(c/co)
Now we figure for c,
well c for 2010 was 389. 87 ppm
and the co is 278 ppm, which I think would be for 1750
Matthew, I believe your math is a little behind the times. The number 5.35 is a fudge factor, and nothing else and I am afraid that it isn't constant. 5.35 In C/CO is used to justify the claim that the ratio of C-now to C-originally, can be multiplied by a constant (5.35) to get increase of heat. If you use the constant 5.35, you get a result of 3 degrees C increase in global average temperature when the CO2 in the atmospherewhen the ration of C/CO equals two.
3C increase resulting from a doubling of CO2 was the desired result, however, way back in 1988. In the interim, the 3C number has become less than credible because the global termperatures weren't rising anywhere near that fast.
The originally desired 3C was reduced to 1.2C average increase for a doubling of CO2. In order to get that result, the constant has to be 2.31 instead of 5.35. Then not so long ago, the claim of 1.2C for doubling was reduced to 1C. Now the constant has to be changed again to 1.92. (sure changes a lot for a constant doesn't it?). Then the constant was reduced again by about 15% (I believe) to account for an overlap with H2O vapor.
In short Matthew, the constant is the result of reverse engineering. They begin with the result they want and work backwards to arrive at the necessary constant. There is no physical basis for those equations. They are simply convenient.