Most of Australia’s energy comes from coal. The energy stored in coal to turned into electrical energy.
But what are fossil fuels? Contrary to what most people think, dinosaur fossils aren't used to make fossil fuels, in fact animals which lived millions of years before the dinosaurs are used in fossil fuels.
They are formed for animals and plants which lived over 100 million years ago.
Thus, once we use the fossils to create energy, they take a very long time to re-occur.
When these living things died they became buried under layers of mud, rock and sand. Eventually they were covered by hundreds if not thousands of feet of the earth.
Over millions of years the dead plants and animals slowly decomposed into organic materials and formed fossil fuels.
Depending on the type of animals and plant debris present, time it was buried, temperature and pressure, different types of fossil fuels can be formed.
E.g. Crude oil and natural gas were created from organisms that lived in water and buried under ocean or river sediment. Ancient rivers which were present millions of years ago have now dried up.
Heat, pressure and bacteria combined to cook the organic material under the earth. In most cases Oil formed first, but the deeper we go the hotter it gets, and natural gas is formed.
Over time the gas and oil rose, seeping through the earths crust, until it was eventually stopped by a thick layer called ‘Caprocks’.
Coal is formed in roughly the same way. However, coal is formed from dead trees, ferns and other plants (over 300 million years).
This coal was formed from swamps covered by sea water. However millions of years ago some sea water contained large amounts of sulphur and the sulphur was absorbed into the coal.
This means when we burn coal a large amount of sulphur is released as an air pollutant.
Other coal produced in fresh water swamps have very little sulphur in them.
As the world grows in population so does its energy demands. It is estimated that we only have another 50 years of Oil left, 70 years of Natural gas and 250 years of Coal left.
