This is possible only because most of this radiation is absorbed in the atmosphere, and what actually escapes out into space is mostly emitted from colder atmosphere. (skepticalscience.com)
The very cold atmosphere radiates the same energy back to space that is received from the Sun. (cfact.org)
That you think the very warm atmosphere close to the ground emits less thermal radiation than the very cold atmosphere higher up because you think molecules and atoms a sentient remains a perpetual point of hilarity. (cfact.org)