1. Earth's temperature is maintained by re radiated infra red radiation by green green house gases and slightly by water vapors in atmosphere. These gases prevent heat from escaping to outer space, so are functionally comparable to glass panel of green house. Thus, this heating effect is referred to as green house effect. Carbon dioxide is a green house gas so increased amount of this gas in the atmosphere will result in increased atmospheric temperature and global warming.
2. Three sources of atmospheric carbon dioxide are:
Volcanic eruption
Respiration by plants and animals
Decomposition of organic substance.
Explanation:
<u>Overall rise in temperature </u>of the Earth due to excessive amount of green house gases in atmosphere that trap heat radiating from Earth's surface is called Global warming.
Global warming can cause melting of ice caps, alteration of seasons, destruction of forest and increase in deserts.
Green house gases include carbon dioxide, methane, ozone, nitrous oxide, and nitrogen dioxide etc.
Among all these gases Carbon dioxide is the major component that is responsible for global warming.
Carbon dioxide is added to the atmosphere by burning of fossil fuels, volcanic eruption and respiration. But Burning of fossil fuels itself adds about 18 X 10¹² tonnes of CO₂ anually.
Global warming has become a major environmental concern now and needs to be controlled immediately.
