Carbon dioxide is present in small amount in the earth’s atmosphere. It is nearly about 0.033 percent of all atmospheric gases. Though carbon dioxide is present in small proportion in the atmosphere, but it performs very important functions. Some of the important functions performed by carbon dioxide gas in the atmosphere are given below
- Carbon dioxide gas produces green-house effect, leading to the heating of earth and its atmosphere, which is essential for our survival.
- Carbon dioxide takes part in the photosynthesis process carried out by green plants to prepare food for plants and animals.
- Carbon dioxide dissolves in oceans to form carbonate works.
Some of the processes taking place in earth and its atmosphere release carbon dioxide gas whereas other processes consume carbon dioxide gas. So, the proportion of carbon dioxide gas in the atmosphere is maintained by a number of different processes. The major suppliers of carbon dioxide gas to the atmosphere are
- Eruption of volcanoes
- Respiration of living organisms
- Decay of dead organisms
- Burning of fossil fuels
- Cultivation of land
The carbon dioxide gas given to the atmosphere through volcanoes comes from the interior of the earth. The major consumers of carbon dioxide gas from the atmosphere are green plants and oceans. The green plants use carbon dioxide gas to prepare their food through the process of photosynthesis whereas oceans dissolve the carbon dioxide continuously exchange carbon dioxide with rocks, plants and higher organisms.
Carbon dioxide in the atmosphere does not absorb the incoming visible radiation coming from the sun. It blocks the outgoing infra-red radiation radiated by earth. By absorbing infra-red, the atmosphere gets heated. The heated atmosphere keeps the earth warm. So the carbon dioxide in atmosphere is important to keep earth warm. This is known as greenhouse effect.
Carbon dioxide is important for green plants to preparing their food through photosynthesis. Green plants convert carbon dioxide and water into food compounds such as glucose and oxygen. This is called photosynthesis. However during respiration process by animals and human beings the reverse of photosynthesis happens that is carbon dioxide is released. In this way the carbon dioxide is very important in the atmosphere and for living organisms like human being, animals and plants