Chemistry of the Atmosphere

• The air we breathe is made of lots of different gases predominately nitrogen gas with about 20 21% oxygen and then lots of other gases including a small amount of carbon dioxide
• The early atmosphere was mainly formed by things coming out of volcanoes, with a large amount of ammonia, methane, water vapor, and carbon dioxide
• The early atmosphere would have been a pretty unpleasant place to be, with ammonia smelling like hair dye or really old baby nappies, and methane smelling like farts
• Changes in the early atmosphere

  1. Decrease in water vapor levels

  2. Rainfall

  3. Decrease in carbon dioxide levels as it dissolved in the newly formed oceans and became locked up in rocks

  4. Photosynthesis started to take place with the evolution of green plants, increasing oxygen levels
• Main greenhouse gases

  • Carbon dioxide
  • Water vapor
  • Methane
• Carbon dioxide

  The bonds in carbon dioxide are really good at absorbing infrared or heat radiation, which traps it inside the atmosphere and warms the planet
• Heat and light energy from the Sun comes to Earth

  It would normally be reflected back out into space, but is trapped by the greenhouse gases, heating up the atmosphere
• Global warming is a slightly confusing term because not everywhere is getting hotter
• Deserts, countries, and farmland are drying out completely, and the ice poles are getting hotter, which is bad for polar bears
• As the ice caps melt, we are seeing increased levels of flooding in other places as the sea levels go up
• Climate change affects animals and plants as well, as the temperature changes cause their habitats to change
• Levels of carbon dioxide in the atmosphere are increasing, and this is being sped up by human activities like burning fossil fuels, deforestation, and reliance on petrol cars
• Carbon footprint

  How much carbon your daily activities contribute to the atmosphere, impacted by things like transportation and food choices
• Sulfur dioxide dissolves in water in the atmosphere and comes down as acid rain, which can harm animals, plants, and even dissolve limestone statues
• Too much carbon in the air can lead to large levels of smog and global dimming, particularly in developing countries
• Carbon monoxide is a toxic gas, and nitrogen oxides contribute to smog and acid rain