michael_nielsen

What I don't understand: the IR that's being blocked by the GHGs is energy which has already been absorbed by the Earth. So this shouldn't change the Earth's overall absorbivity, and I don't see how it could change the Earth's temperature.

Twitter may not be the best medium for this(??) But if someone who understands this well can point me to a good explanation, I'd appreciate it. Thanks!

@AndrewDohertyQu @dabacon @worrydream @patrickc Do you know?

I omitted the technical details, but it's this: the temperature should be set by: incoming energy flux = epsilon sigma T^4, where epsilon is the emissivity, sigma is the Stefan-Boltzmann constant, and T is the temperature.

Since anything absorbed by the GHGs has already been absorbed by the Earth, the absorptivity (and thus the emissivity) shouldn't be changed by the GHGs, and so I don't see how T can be changed by the GHGs.

I should have said earlier in the thread, but the key thing I'm worried about: why is epsilon in the Stefan-Boltzmann relation changed, since net absorptivity apparently isn't? Or is S-B the wrong way to be thinking?

Michael, complicating things is the parallel thermodynamic heat transfer of convection. The atmosphere is a heat pump, of Carnot & ‘steam’ cycles. Increased convection-shear has been documented and thought a disruptive reason behind decrease in cyclone #’s. Ocean heat x DWLR ???

I'm happy to neglect that. If I can't understand the simple model I described there's no hope of understanding more complex models.