Earth's temperature remains fairly steady, which means that Earth must return nearly the same amount of energy to space that it receives from the Sun. In what form (s) does Earth return most of this energy to space?

1) Visible light reflected by clouds

2) Infrared light emitted by the surface and atmosphere

3) Reflection of visible light by the surface

Explanation:

The primary source of heat for the Earth is Sun. The heat is transferred in the form of light from the Sun.

Now, for the Earth to maintain nearly the same temperature some amount of this light must be returned.

The heat or the energy is returned by the Earth through

1) Visible light reflected by clouds

2) Infrared light emitted by the surface and atmosphere

3) Reflection of visible light by the surface