Greenhouse gases

Greenhouse gases

The greenhouse effect - These gases act like a blanket that trap heat emitted by the Earth. As the heat cannot escape it the atmosphere heats ups
Carbon Dioxide CO2
1. Released by ocean evaporation, respiration, soil processes and the Earth's interior.
2. Conversely, dissolved into the ocean and taken in by plants for photosynthesis
3. part of the complex global carbon cycle
Methane CH4
1. produced mainly by anaerobic processes
2. Rice paddies, biomass burning, animal digestive processes and natural wetlands
3. destroyed in the troposphere by the reaction with hydroxyl OH
Nitrogen oxides
1. produced biologically in oceans and soils
  1. Also by industrial processes, cars, biomass burning and chemical fertilisers
Ozone O2
1. created by the breakup of oxygen by solar ultraviolet radiation - high up in the atmosphere, usually over the tropics
2. destroyed by CFC's and Nitrogen oxides
Chlorofluorocarbons CFC's
1. man-made not seen in atmosphere before 30's
  1. used for refrigerator coolants, air conditioners and aerosol propellants
    1. considered responsible for the ozone holes above the Artic and Antarctic
Water vapour
1. most important greenhouse gas
  1. makes up 1% of volume of the atmosphere
  2. part of the complex hydrological cycle
2. highly variable in time and space
Aerosols
1. Mainly, sea salt, dust (mainly silicates), smoke and organic matter
2. Height at which they are introduced will determine whether they cause regional cooling or warming

Resource summary

	Created by Sharondeep over 10 years ago