Of Heat Engines and Refrigerators
The atmosphere is less a heat engine than a collection of many self-running refrigerators/dehumidifiers operating in different ways to carry heat largely from surface to tropopause locally and the balance from equator to poles. An important, but perhaps underappreciated, effect of dehumidification is to make the atmosphere broadly more amenable to cooling by LWIR.
Source: wattsupwiththat.com