C9 - Chemistry of the atmosphere

Nota:

• The Earth formed approximately 4.6 billion years ago. 

1. 200 mllion years ago, the atmosphere was; 80% nitrogien, 20% oxygen and the rest were other gases (Carbon dioxide, water vapour, noble gases).
2. Theory suggests that the early atmosphere came from intense volcanic activity, which released gases that made the early atmosphere very similar to the atmospheres of Mars and Venus today.

1. Carbon dioxide, methane & water vapour
2. Keeps the air warm
3. 1: Sun gives out short wavelength radiation. 2: Radiation reflects back by Earth as long wavelength radiation and absorbed by greenhouse gas. Greenhouse gases then give out radiation in all directions. Some of that radiation heads back to earth and warms up the surface
4. human activity
   1. Deforestation: Fewer trees, less photosynthesis
   2. Burning fossil fuels: releases carbon dioxide
   3. Agriculture: Farm animals produce methane when they digest food
   4. Creating waste: More landfills, more carbon and methane when waste breaks down