Pollution

• Global warming - The rise in overall temperature of the earth because of the green house effect is referred as global warming.
• Air pollution 
  • The layer of air present around the earth is called atmosphere.
  • Atmosphere is composed of 78% of nitrogen, 21% of oxygen, and 1% percent other gases such as carbon dioxide, ozone, water vapour, methane, etc.
  • The phenomenon of contamination of air with unwanted substances so that it becomes harmful for living organisms and non-living substances is known as air pollution.
  • The substances, which cause air pollution, are called air pollutants.
  • Sources of air pollution are
  • Power plants
  • Factories
  • Automobiles
  • Bu…