What Makes a Molecule a Greenhouse Gas? A Case Study on Molecular Symmetry and Global Warming Potential

Greenhouse gases are atmospheric molecules that absorb and re-emit infrared radiation emitted from earth’s surface, a process known as the greenhouse effect, which contributes to rising global temperatures. A molecule’s ability to trap heat is fundamentally determined by its molecular structure and symmetry. Group theory provides a method for relating a molecule’s symmetry to its vibrational spectrum. By applying this treatment to greenhouse gases, it is possible to understand why some molecules are strong infrared radiation absorbers and connect their bonding properties with their contributions to global warming.