what gas made up most of the early atmosphere
carbon dioxide
+ nitrogen, water vapour
virtually no oxygen
greenhouse effect
greenhouse gases absorb long wavelength radiation that gets reflected back off earth
they re-radiate in all directions including back towards earth
longwave radiation
longwave radiation
thermal radiation, results in warming of the surface of the earth
human contributions to greenhouse effect
- deforestation
- burning fossil fuels
- agriculture (methane)
- creating waste (landfill etc)
carbon footprint
measure of the amount of CO2 and other greenhouse gases released over the full life cycle of something
incomplete combustion
not enough oxygen causing some of fuel not to burn
unburnt fuel as well as carbon monoxide produced
carbon monoxide cause for humans
stop blood from carrying oxygen around the body
binds to haemoglobin in blood that normally carries O2
Phases of earth’s early atmosphere
- Volcanoes release gases
- Oceans, algae and green plants absorbed CO2
- Green plants and algae produced oxygen
