The Earth’s Atmosphere

• The atmosphere consists mainly of nitrogen (78%) and oxygen (21%)
• Carbon dioxide, water vapour and trace amounts of other gases make up the remaining 1%
• Nitrogen is essential to all living organisms as it forms part of proteins and nucleic acids.
• Oxygen is also vital because it is used by plants during photosynthesis and animals when they respire.
• Water vapour is important because it helps regulate temperature on earth through evaporation and condensation.
• Oxygen is also essential to life because it is used by plants during photosynthesis and animals during respiration.
• Greenhouse gases trap heat from the sun within the atmosphere, contributing to global warming.
• Air pollution can be caused by natural sources like volcanoes or human activities like burning fossil fuels, industrial processes, transportation, and agriculture.
• Increased levels of atmospheric CO2 can lead to ocean acidification, which affects marine ecosystems and coral reefs.
• the early atmosphere ( 4.6 billion years ago ) was almost purely carbon dioxide much like mars and Venus today .