1.2 Deforestation - Trees cut down to make products like paper or wood.
When the trees are cut down, the carbon dioxide trapped in the trees are
released and the fewer trees they are then less oxygen can be produced.
1.3 An increase in cattle farming and rice growing.
Methane is released from the animals along
with wetlands where rice is grown.
1.4 The burning of fossil fuels causes
global warming. Carbon dioxide
and sulphur dioxide is released.
2 Time scale of the earth
2.1 Volcanoes released water vapour and
carbon dioxide which condensed the earth
and cooled it down. The water vapour fell
as rain filling up hollows in the crust
2.2.2 Primitive plants such as single-celled
algae began to photosynthesise, taking
in carbon dioxide and releasing oxygen
2.3 Carbon from carbon dioxide in the air
was locked up in sedimentary rocks as
carbonates and fossil fuels. The carbonates
were formed when carbon dioxide dissolved
in oceans.. These compounds became
concentrated in the shells of sea creatures.
When the sea creatures died their remains
eventually formed carbonate rocks, locking
away the carbon.
3 Carbon Cycle
3.1 1) Carbon dioxide is taken in by trees
and plants through photosynthesis.
3.2 2) Plants and animals respire,
releasing carbon dioxide.
3.3 3) Micro-organisms feed on dead
plants and animals to break them
down. They respire while feeding.
3.4 4) The burning of fossil fuels also release
carbon dioxide into the atmosphere.
4 Present Gasses
4.1 Measuring Oxygen
4.1.1 If copper is heated while a fixed volume of air
passes over it, then the volume of air will gradually
reduce as the oxygen is used up in the chemical
reaction. Eventually the volume of air will stop
changing because all the oxygen will have been used