The significant greenhouse gases are water vapor (H2O, 36-70%), carbon dioxide (CO2, 9-26%), methane (CH4, 4-9%), ozone (O3, 3-7%), nitrous oxide, sulfur hexafluoride, hydrofluorocarbons, perfluorocarbons and chlorofluorocarbons.
Sunlight that penetrates the atmosphere and is absorbed by the lands and oceans of the Earth warms its surface. In turn, the Earth’s surface radiates heat in the form of infrared radiation up into the atmosphere. Greenhouse gases absorb and retain this heat, and this effect is due to their molecular nature.

Many types of molecules will develop a slight electrical charge imbalance when their heavy nuclei rotate and vibrate relative to each other as seen along the directions of their chemical bonds. These charged oscillations can have frequencies and energies that match those of a quantum of infrared radiation. So, such molecules readily absorb incident infrared photons (”particles” of infrared electromagnetic energy), and they apply the added energy to boost themselves into a higher state of rotational and vibrational excitation.

Nitrogen (N2) and oxygen (O2), the major gas species in Earth’s atmosphere, do not develop a significant charge imbalance when they rotate and vibrate, because of the symmetry of their chemical structure (one end of the “dumbbell” never looks more nor less positive that the other). Molecules of this type do not absorb nor emit (very much) infrared radiation. Molecules with more chemical bonds, and nuclei from several chemical elements will have more heat storage capacity, a good example being the CFCs, chlorofluorocarbons, highly volatile fluids devised as refrigerants.

Another factor to consider is the buffer effect. A large contributor is the algae in the oceans.

The cynical view is that the concentration on this is that solutions can be proposed that will damage the economies that are targeted. This allows propaganda to be spread and good science hard to come by.