- An albedo decrease of only 1%, bringing the Earth’s albedo from 30% to 29%, would cause an increase in the black-body radiative equilibrium temperature of about 1°C, a highly significant value, roughly equivalent to the direct radiative effect of a doubling of the atmospheric CO2 concentration.
fredag 16 april 2010
On Climate Sensitivity 5
The basis of IPCC climate alarmism is presented in IPCC AR4 The Physical Science Basis as follows:
We have seen in the previous posts 1-4 on the topic that this comes from the formula
dQ = 4 dT
where dQ is change in radiative forcing and dT corresponding global warming. We have seen that the simple ("undeniable, undisputed") formula dQ = 4 dT comes out from Stefan-Boltmann's Black Body Radiation Law Q = cTTTT, by inserting Q = 273 Watts/m^2 and T = 273 Kelvin, which fixes the constant c = Q/TTTT. The formula then follows by differentiation:
dQ= 4 cTTT dT = 4 Q/T dT = 4 dT.
Now 1% change of albedo changes the total radiative forcing of 273 Watts/m^2 by 2.73 Watts,
say 4 Watts/m^2, which gives the alarming global warming of dT = 1 K = 1 C, then elevated to
1.5 - 4.5 C by feed backs.
So IPCC alarmism claims that we live in a highly unstable surface climate in which human civilization can get destroyed by a 1% change of albedo, or doubling of CO2.
But the climate does not seem that unstable, certainly the albedo has changed 1% by human activities without any climate catastrophy.
What is wrong is not Stefan-Boltzmann's Law or differentiation per se. What is wrong is to apply it to the coupled Earth-atmosphere system, where the atmopshere acts like an insulating window connecting the Earth surface temperature of 15 C to the top of the stratosphere at 0 C, just like an ordinary window connects the inside of a room to the outside.
The connection is a combined process of convection-diffusion-radiation-evaporation-condensation, which is not at all described by Stefan Boltzmann's Radiation Law. No engineer
would model the inside temperature of a house relying only of Stefan-Boltzmann's Law.
So the entire basis of IPCC alarmism appears to rest on a fundamenatlly incorrect application
of Stefan-Boltmann's Radiation Law. If this is true, it is remarkable. And so?
The posts on Climate Sensitivity 1-5 are summarized in the new report A Simple Climate Model.