The problem with greenhouse gases, as I understand it, is that they absorb and emit radiation within the thermal infrared range leading to increased temperatures on Earth. According to some sources, there appears to be a large gap with lower atmospheric opacity for wavelengths between 10cm and 10m. Can we not convert significant amounts of thermal infrared radiation to longer wave radiation in an efficient way (especially since it is lower entropy)? I understand the radiation is pretty spread out, but couldn't we expel thermal radiation from volcanos or industry that way?

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    $\begingroup$ If it were possible, the transmitters used for this would give conspiracy theorists a field day. HAARP is nothing compared to the size of these things ;-) $\endgroup$
    – hdhondt
    May 3, 2021 at 9:49
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    $\begingroup$ So far as I'm aware, there is really no good method known for "converting frequencies" as you put it, though someone else could probably give a more authoritative answer there. I will also note that there is no notion of different frequencies of light corresponding to different entropies. $\endgroup$ May 6, 2021 at 6:26

1 Answer 1


One thing to keep in mind is that such conversion is itself a thermodynamic process, which necessarily has finite efficientcy. Thus, there will be heating effect due to the conversion itself.

When discussing global warming it is important to keep in mind the basic thermodynamics. The warming as a consequence of the efficiency of any human devices being elss than 1, as required by the second law of thermodynamics. The rejected heat is in essence the warming, and the realistic ways of reducing it is either reducing the energy consumption, or using more efficient technologies (which may produce some paradoxal results when comparing the "green energy" with the fossil or the nuclear).

The effective irradiation of the heat by earth is only a part of the picture, and unlikely the key to the permanent solution of the problem (since we may eventually run into other problems, if Earth is continuously to lose more and more heat).

If we however accept this as a solution, then the answer to the question depends on the balance between the efficientcy of (i.e., the warming due to) the frequency conversion vs. the improving the irradiation of energy by Earth.


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