Planetary Energy Balance

What does this chair have to do with the atmosphere?

In this picture, we can see the sun, a window, and a chair.

The sun’s radiation—in the form of visible light—passes through the window. Because the window is transparent.

The wooden slats on the chair block the light. Because the wood is opaque. The wood will even absorb some light and reflect some too.

The resulting pattern on the floor has dark areas, where the light is blocked. It also has light areas, where the light could pass through.

Our atmosphere is sort of like the chair. It is transparent to some forms of radiation and opaque to other forms.