Carbon cycle
Living things are made up of carbon. Carbon is found naturally in the atmosphere, rocks fossil fuels and dead organic matter.
Carbon enters the atmosphere as carbon dioxide during combustion of fossil fuels and respiration by living things carbon dioxide in the atmosphere is absorbed by plants during photosynthesis to make sugars the carbon becomes part of the plants Animals feed on the plants passing the carbon compounds along the food chain Some of the carbon in the animals and plants is exhaled as carbon dioxide during respiration.
Eventually the animals and plants die the dead bodies which are organic matter are broken down by decomposers and the carbon is returned to the atmosphere as carbon dioxide Not all organic matter is decomposed immediately Under certain conditions some of the organic matter is compressed and heated underground turning into fossil fuels after many, many years. When these fossil fuels are burnt most of the carbon enters the atmosphere as carbon dioxide The cycle repeats