Carbon monoxide is a colorless, odorless gas.
CFC is an abbreviation for the compound formed from chlorine, fluorine, and carbon.
Smog is formed when fossil fuels or turpentine are incompletely burned in the presence of sunlight.
Air pollution results when substances contaminate the air.
Acid rain is formed by the gases released when burning fossil fuels, such as coal and oil, combined with rain.
The Greenhouse effect is the reduced rate at which the earth loses heat, causing an increase in the earth's temperature.