Infrared Absorption by Carbon Dioxide Molecule

CARBON DIOXIDE CO2 & THE GREENHOUSE EFFECT: a photon (shown as a whitish elongated ovoid) from the sun strikes the land. The land warms and emits an infrared photon (shown as a pink elongated ovoid). This IR photon strikes the carbon dioxide molecule and, as it is captured, sets up a flexing motion in the molecule. Soon afterwards, the molecule emits an infrared photon that is shown travelling to the ground. After emission, the molecule stops flexing and returns to its original state.

GREENHOUSE EFFECT this repeated absorption and re-emission by carbon dioxide effectively scatters the infrared radiation and so causes the heating known as the greenhouse effect. Without an atmosphere containing greenhouse gases this heat would be radiated back into space. However, carbon dioxide and other greenhouse gases absorb and re-emit this infrared in various directions. Some IR will ultimately escape back into space after taking a tortuous route from molecule to molecule but the overall effect is to heat the atmosphere.