CO2 is a good absorber of infrared radiation because it can absorb energies with a wavelength of 15 micrometres. This makes it easy for absorbing infrared radiation. The energy from the photon causes the CO2 molecule to vibrate.
- Sometime later, the molecule gives up this extra energy by emitting another infrared photon. Once the extra energy has been removed by the emitted photon, the carbon dioxide molecule stops vibrating.
- This ability to absorb and re-emit infrared energy is what makes CO2 effective heat-trapping greenhouse gas.
- The infrared radiation strikes a molecule such as carbon dioxide and causes the bonds to bend and vibrate – this is called the absorption of IR energy.