Would trading in pollution credits be the best way to curtail emissions of all pollutants? Will emissions other than carbon be treated similarly in the future if or when they start to threaten the future of the planet?

Legislation already exists to protect the environment from many pollutants. Why can’t carbon emissions be controlled in the same way? It seems that legislation is used to control your everyday backyard type of pollution, but when a pollutant starts to threaten the planet, a market to trade in is developed.