Atmosphere

• Composition of the air (now)

  • Nitrogen 78%
  • Oxygen 21%
  • Argon 0.9%
  • Other gases 0.1%
• Role of Atmosphere

  • Support life
  • Protects us from the Sun
  • Traps heat in
• How oxygen levels increased

  Algae & primitive plants photosynthesise releasing oxygen as a product
• How CO₂ levels decreased

  1. CO₂ dissolved in the oceans

  2. Plants & algae photosynthesise (CO₂ is a product) and trapped in sedimentary rock
• Early Atmosphere components

  • Made up of Hydrogen , water vapour and ammonia
• Pollutants of the atmosphere

  • Sulfur dioxide
  • Combustion of sulfur in fuels
  • Combustion of nitrogen
  • Carbon monoxide
  • Carbon dioxide
  • Incomplete combustion
  • Complete combustion
• Main greenhouse gases

  • CO₂, H₂O, CH₄ (Methane)
• Effects of global warming

  • Glaciers melt
  • Sea levels rise
  • Rainfall patterns change
• Greenhouse effect

  • Main greenhouse gases(carbon dioxide, water vapour and methane)
  • Earth emits infrared radiation
  • This is trapped by thick layer of greenhouse gases
  • warming the atmosphere up
• Early atmosphere

  • Algae and plants began to photosynthesise
  • levels of co2 goes down(reactant)
  • Oxygen levels increase(product)
  • Earth cools and water vapour condenses
  • Oceans and the crust form
  • Ammonia reacts with oxygen to produce nitrogen