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( Article Type: Explanation )

Carbon is a building block of the molecules, which make up living cells and is an essential element for life on earth. It is a basic ingredient of bones, carbohydrates, connective tissue, hormones, nerve cells and proteins. As an important component of carbohydrates such as sugar and starch, carbon is a key component of photosynthesis and respiration, the mechanisms used to convert the sun’s energy into forms that can be used by life on earth. Fossil fuels (natural gas, oil and coal) are all carbonaceous compounds, which at a previous time in the earth’s evolution were built up by living cells through photosynthesis.

Carbon, in gas, liquid or solid form, moves between the atmosphere, oceans, rivers and landmass via chemical processes and through geophysical means. It moves through the atmosphere as carbon dioxide and carbonic acid, forms bicarbonates and then flows into the oceans. The oceans absorb carbon dioxide from the Earth’s atmosphere and organisms absorb carbon from the atmosphere.

There are complex balances that are continually changing as a result of short, medium and long-term actions, both natural and man-made. A clear example of how excessive changes in carbon in the biosphere can impact on the environment is that of global warming. Excess releases of carbon from fossil fuel burning create a build up of carbon dioxide in the atmosphere, which results in increased global temperatures.