If you put on a heavy coat, and go out for a run, the coat makes you warm faster.
If you come back from the run, and do not remove your coat, the coat makes you cool slower. The distinction between warming and cooling is meaningless with respect to the insulating properties of the coat. The coat makes you warmer than you would be without the coat. The direction of warming or cooling is controlled by the heat source, not by the fixed insulator.
The ugly anti-greenhouse gas argument which keeps popping its head up here is so stupid, it had to have been a plant from alarmists designed to make skeptics look stupid.
Anyone who attempts to bring that argument up again after this thread, will be spammed. It is making it impossible to have any serious scientific discussion.