Of all the elements known to man, carbon is one of the most important for him. Diamond, the most valuable gem, is a form of carbon. Graphite is also a form of carbon which forms the lead of lead pencils. Again, coal which is a main source of heat and power in the present age is mostly carbon. The most important fact about carbon is that it is a necessary element for all living things. In fact, scientists believe that wherever carbon has been found in any quantity on the earth, life in all probability existed there. Carbon is the most widely distributed non-metallic element and it is a common constituent of all organic compounds. Do you know what Carbon Cycle is?
Carbon cycle is the process of constant circulation of carbon between living organisms and the atmosphere. It maintains a balanced percentage of carbondioxide in the air. The main source of carbon for all lives is the carbondioxide gas in the atmosphere. This gas is taken from air and returned to it by all organisms. In this continuous cycle, the limited carbondioxide in the air is being constantly re-used.
Green plants take in carbondioxide gas from the atmosphere; combine it with water from the soil, to make more complex carbon compounds. Carbondioxide is returned to the air by plants in two ways. Firstly during night they give off carbondioxide. And secondly, when they die and their remains decay, carbondioxide is released into the air.
Animals, including human beings, get some carbon from the carbondioxide in the air. However, most of their carbon is obtained from plants, vegetables, fruits or cereals. All animals return carbon to the air by breathing out carbondioxide during respiration. Like plants they also give out carbondioxide when they decay after death. Carbondioxide is also released when animals or plants are burnt. Again, when fossil fuels like coal, petroleum or natural gas are burnt, carbondioxide is released into the atmosphere.
Today, Carbon Cycle is in danger by the increased consumption and burning of fossil fuels and large tracts of tropical forests. As a result, carbondioxide is building-up in the atmosphere breaking the equilibrium and contributing to the global warming as termed by the scientists.