How has the Earth's atmosphere changed over time, and why?Reducing air pollution
The Earth, its oceans and atmosphere are made of elements and compounds in different states. The particle model may be used to explain the different properties of the solid, liquid and gas states.
Power stations generate electricity. By reducing electricity use, everyone can reduce the emissionsSubstances that are given off, especially in the form of gas. of air pollutantA toxic chemical or object that causes damage to the land, air or water. from power stations.
Sulfur dioxide may be removed from the waste gases by a process called gas scrubbing.
Reducing air pollution from cars
The emission of air pollutants from cars may be reduced by people using their cars less by, for example:
walking
taking public transport
car sharing
cycling
Engineers are developing engines for vehicles that are more efficient. This means that the engine uses less fuel and so produces less air pollution.
A catalytic converterA device which when fitted to a car exhaust can change harmful nitrogen monoxide and carbon monoxide into nitrogen and carbon dioxide., fitted to the exhaust of a car, changes the pollutants carbon monoxide and nitrogen monoxide into less harmful carbon dioxide and nitrogen.
The use of low-sulfur fuels has reduced the amount of sulfur dioxide in car emissions.