You will find a host of articles that describe in detail the
process by which the great forests of the Cretaceous Period (circa 145 - 65 million years ago)
slowly develop into coal and how sea life
slowly developed into oil and
natural gas.
Natural processes in the atmosphere
slowly destroy these non-CO2 GHGs over time, mainly
by oxidation in the troposphere (0 - 20 km high), and
by «photolysis» with UV rays in the stratosphere (> 20 km).