Like CO2 (carbon dioxide), H2O (water vapor) is a strongly heteropolar molecule — having one end with a positive electrical charge, and another end with a negative electrical charge — and absorbs outgoing Infrared Radiation (IR) from Earth’s surface, thus capturing heat in the atmosphere. Homopolar molecules like N2 (nitrogen) and O2 (oxygen) are transparent to IR. Inelastic molecular collisions redistribute that heat (as kinetic energy) to other atmospheric molecules (N2, O2, mainly) and atoms (Ar, He, trace components).
Most of Earth’s surface heat eventually diffuses into the oceans. Heat flows along the heat gradient in the negative direction from warmer air to colder water. The heat capacity (storage ability) of the oceans is IMMENSE (this is where ‘global warming’ ends up), and their heat content takes centuries to diffuse into a stable stratified distribution, rearranged by thermo-haline currents (a solar forcing effect) and by geometry (oceans as a spherical shell with warm equator and cold poles, so ocean heat diffuses poleward).
The fundamental problem of global warming is the ‘excess’ capture of outgoing IR (infrared radiation), reducing the rejection of Earth heat (originally delivered by incoming
— source counterpunch.org | Manuel Garcia Jr | Sep 13, 2021