Greenhouse Effect The Greenhouse Effect
The vast majority of the heat entering the Earth/atmosphere system is in the visible range (about 0.2 to 5.0 um). In this frequency range, the atmosphere is virtually transparent. Heat reradiated from the Earth's surface, however, is mostly in the infrared band (about 5 to 40 um). In this frequency range, the atmosphere is relatively opaque, or absorbant so heat reradiated from the Earth's surface is reabsorbed in the atmosphere, leading to warming. This is known as the Greenhouse Effect.

greenhouse pic