The mechanism believed to maintain the energy balance at the top of the atmosphere (TOA).
For example, a rise in surface temperature causes an increase in outgoing long-wave radiation. This increase in long wave radiation cools the atmosphere which in turn cools the surface.
1. Note that only approximately 10% of the radiation emitted at the surface of the Earth reaches the TOA and so the part played by this mechanism in achieving a balance at the TOA is exaggerated.