Courtesy NASA Goddard

Chlorofluorocarbons (CFCs) contain atoms of chlorine, fluorine, and carbon that are arranged in a stable chemical structure. They were invented in the 1920s and have been used for propellants, refrigerants, and foaming agents. Manufactures have unwittingly used CFCs for decades because of their stability and inertness (non-reactivity) with other atmospheric constituents in the lower atmosphere. Little did they know at the time, the CFCs were actually finding their way into the higher reaches of the atmosphere. It wasn’t until the 1970s that humans were finally aware of their destructive nature in the stratosphere.