The term reradiate is a nonsense term which should never be used to explain anything. This too is nonsense. The radiation was not reflected, it was absorbed and different radiation was subsequently emitted. A las no. As rapidly as the atmosphere absorbs energy it loses it.
Nothing is trapped.
If energy were being trapped, i.e. retained, then the temperature would of necessity be steadily rising. Rather, on average, the temperature is constant and the energy courses through the system without being trapped within it. T he name, greenhouse effect is unfortunate, for a real greenhouse does not behave as the atmosphere does. Thus, a real greenhouse does act like a blanket to prevent bubbles of warm air from being carried away from the surface. As we have seen, this is not how the atmosphere keeps the Earth's surface warm.