Earth
Aerosols
Erosion
Ozone layer
Waste
Engines
Pollution
A suspension of small particles in a gas; the particles may be solid or liquid or a mixture of both.
Region of the stratosphere containing relatively high concentrations of ozone
Waste material such as garbage, refuse, rubbish, and trash.
A machine that converts energy into mechanical force or motion.
The act or process of polluting or the state of being polluted, especially the contamination of soil, water, or the atmosphere by the discharge of harmful substances.