Role of dipole moments in climate change

[DMauricio34]

A very interesting example of the role of a dipole moment I saw recently in another class I’m taking was in the greenhouse gases that trap the Earth’s outgoing radiation and emit it back in.
The dipole moment plays its role in the absorption of infrared radiation by greenhouse gases because for a molecule to absorb IR radiation, the vibrations must cause fluctuations in its dipole moment. The oscillating electric field of the radiation interacts with these fluctuations in such a way that it allows energy to be absorbed if the vibration frequency of the molecule matches the frequency of the radiation. This is why asymmetric molecules like CO₂ and H₂O, which exhibit dipole moment changes during certain vibrational modes, effectively absorb IR radiation. In contrast, symmetric molecules like O₂ don’t actually have a dipole moment change and what’s why they don’t interrupt the outgoing IR radiation.

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