1. Oil, coal and gas are fossil fuels - so-called because they were formed from the remains of prehistoric plants and animals.

Oil and Gas were formed over millions of years and come from the remains of tiny animals that lived in the seas in prehistoric times. As the animals rotted they were covered by more and more layers of animals and finally by mud and sand. The rotting animal matter gradually turned into oil and also produced methane much the same as our rubbish tips do now. The gas was trapped under the successive layers of silt and mud on top of the oil layer and formed huge pockets containing many millions of litres.

Oil is reached by drilling holes in the ground which may have to go down thousands of metres. Once the oil is reached, it may gush out under pressure or may have to be pumped out and up to the surface. Looking for Oil and Gas?

Nearly half the world’s oil is found under the sea floor which can add even more length to the drilling operation. Huge oil rigs are towed out from the shore and anchored in place over the drilling site. Once the supply is tapped they send oil ashore through sea-bed pipelines or use tankers to ship it to the refineries, where it is split into many useful components - petrol, aviation fuel, oil for heating, diesel, petrochemical products for the chemical and plastics industries etc.

Gas is also tapped using rigs and is piped back to huge storage tanks on land.

Coal was formed from plants and animals which died when the Earth was covered with swamps. About 300 million years ago these swamps were home to giant plants and many animal species lived there. Over millions of years the plants and animals lived and died and got buried under the mud at the bottom of the swamp.

The mud gradually hardened into rock and the layers of rotting plant and animal material were squashed between heavy layers of rock and heated by the Earth. Over millions of years they changed into coal.

Coal seams are also associated with pockets of gas which can make them very dangerous to mine. Coal can be very deep under the ground in which case huge tunnels are bored and the coal mined out or it may lie just under the surface and can be mined using open-cast methods.

Fossil fuels are finite - we will run out of them one day and since they take many millions of years to form there is no possibility of making more.

When fossil fuels are burned they produce lots of heat and a variety of chemicals and gases. The main pollutants are carbon monoxide - produced from burning gas and liquid fuels, and sulphur dioxide produced from burning coal.

Carbon monoxide is very dangerous because if you breathe it in, it can pass through the membrane in your lungs and attach itself to your red blood cells in place of oxygen. Unlike oxygen, your cells cannot get rid of it and so if all your red blood cells start carrying carbon monoxide you will soon die. Many people have suffered carbon monoxide poisoning from gas fires which do not have sufficient venting through the chimney.

Sulphur dioxide rises in the atmosphere and mixes with water vapour to form acid rain which destroys plant life and damages metal and stone.

These fuels also produce a range of other waste gases and materials, many of which are carcinogenic or toxic.

Worksheet D10 (G), which gives the children chance to make a flow diagram for coal and oil, can be used here.