4 ms·

I think air pressure (the weight of air above us at sea-level) compresses the air sufficiently for it to reach a temperature much greater than you would expect,

I think air pressure (the weight of air above us at sea-level) compresses the air sufficiently for it to reach a temperature much greater than you would expect, e.g around negative 20 degrees Celsius. (This figure needs verification, I'm going from memory).

Someone 6y ago
But earth would still be radiating out heat, would it? If so, where would the energy come from to maintain that temperature?