Climate nutters

Originally posted by DanMachine: ↑

>Yup that's exactly what I'm claiming.
Oh that's funny.

>You need to educate yourself on blackbody radiation.

I well know about it, thank you. It's a special kind of fallacy to assume that the earth is a black body, it's a grey body. CO2 also definitely doesn't behave as a black body. I mean, for one, it's a gas, and therefore transparent. That sort of alters how the theory might apply.

>I've given you the good stuff - the equation for radiative equilibrium including Boltzmann's constant, blackbody radiation, even the albedo of the earth.

You can give all the equations you want. They don't mean anything if you don't explain how they apply in the manner I'm requesting.
Radiative equilibrium is just.. earth has to emit what it takes in. Duh. Of course it does. Your claim requires that the surface temperature somehow gets hotter - how is the extra energy getting into the earth?

None of those things offer an explanation for increased spot temperatures. Again, only trapping heat - which is not "amplifying heat" - and average temperatures - not "spot temperatures".

It is the case that the greenhouse effect increases the earths temperature.
It does not increase its maximum temperatures.

>You've only responded with hand-waving.
You can attempt to characterise me however you want, this only indicates your failure to mount a proper argument.

Anyway, regarding emissivity, CO2 gets worse at absorption and emissivity as the temperature increases (as do most greenhouse gases. Water may well be special as, eg, clouds are not optically transparent).

Over 280 odd Kelvin CO2's emissivity and absorption of IR approaches zero. In earth-like conditions (gas pressure/ radiation levels etc) it has been measured that the optimum temperature for absorption and release is about -60C.

Indeed most of the IR radiation is trapped and released by CO2 at an altitude of around 5km.

So, again. CO2 definitely affects the energy balance of the earth. No one, least of all me, denies this. Of course it does.

However.. you nor anyone else has explained how CO2 can increase the peak temperatures.
Because you can't. Because it can't. Well, okay. Maybe, possibly, in a very specific set of circumstances, - say, if the noon temperature was somewhere around -50c, and the surface was quite emissive, eg, a giant square of black tarmac.

Indeed, you will not find any climate literature which claims CO2 increases peak temperatures. The warming is the average temperature of the earth.

Water vapour is a much more potent greenhouse gas, and more humidity does not equal higher surface peaks. Again, think heatsink.

Also, I'm kind of bored now since I don't think you really understand how these things work, so I'll tell you why CO2 is not analogous to a glass greenhouse.

A glass greenhouse heats up because the solar energy penetrates the glass, which heats up the internal surfaces, which heat up the air. The heat from the air does not conduct out of the greenhouse.

Glass is a poor conductor of heat. CO2 is not. Glass is also a solid, I mean, a tad different.

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Ok, let's take a step back because you are hopelessly confused. I wonder if you'll accept an argument based on conservation of energy. This is about as simple as I can make it.

1) Do you accept the law of conservation of energy?

2) Given that, do you accept that on the day side of earth, the solar radiation that falls on the earth must equal what is a) reflected back from the earth, plus b) absorbed from the earth, plus c) transmitted through the earth?

3) Do you accept that the earth is pretty thick, and so we can ignore transmission for the purposes of this conversation, and assume for now that solar radiation is either reflected or absorbed?

4) Do you accept that if there was a hypothetical substance that reduced the reflectivity of the earth, it would increase the absorption of the earth and vice versa?

5) Do you accept that solar radiation that is absorbed by the earth is a strong driver of surface temperature?

If you accept these points, I'll talk about what such a hypothetical substance might look like, and what the consequences would be for radiation coming in off the sun and reflecting from the earth.