The montreal protocol on Substances that Deplete the Ozone Layer is the international environmental agreement designed to protect the stratospheric ozone layer, which shields the earth's surface from radiation in the ultraviolet spectrum. An increase in the intensity of UV-B rays reaching the surface may augment skin cancer rates in humans, decrease plankton production in the oceans, and negatively affect agricultural production throughout the world.

The Montreal Protocol, as it is often referred to in short, provided the framework for phasing out the production of the main ozone depleting chemicals (chlorofluorocarbons [CFCs], halons, carbon tetrachloride, methyl chloroform, hydrofluorocarbons, and methyl bromide). These chemicals were widely used as refrigerants, coolants, aerosol propellants, and industrial solvents.

CFCs were invented in 1928 by Thomas Midgley, Jr. (who also invented the ...