Greenhouse Effect

The trapping of heat radiated from the earth’s surface within the earth’s atmosphere by the gases present in the environment like carbon dioxide, methane, nitrous oxide etc. is referred to as greenhouse effect.

Origin of the term:

The term ‘greenhouse effect’ is named by analogy to greenhouses. Greenhouses are basically built with materials like glass or plastic because these materials trap the radiation from the sun and help heat the surface inside the greenhouse. Greenhouses are mostly built up in places having temperature lower than the normal, such as the places at high altitudes, thus aids the growth of the seedlings required for vegetation and also planting.

Greenhouse Gases:

For the better understanding of the term greenhouse effect we should first learn about the gases that are present in the atmosphere and are responsible for both the absorption and emission of radiation within the thermal infrared range.The primary greenhouse gases are water vapour, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and ozone (O3).

These gases are emitted into the atmosphere due to respiration, combustion of fossil fuels like coal and petroleum from automobiles and industries and also due to burning of papers, dry leaves, wood etc.

Role played by water vapour:

The largest percentage of the greenhouse effect is mainly due to water vapour present in the atmosphere. However according to the Clausius-Clapeyron relation the air is capable of holding more per unit volume of water vapour when it’s warm.
Hence it can be said that the heating up of the air by other greenhouse gases also contributes to the concentration of water vapour in the atmosphere, ultimately causing greenhouse effect.

Effect on climate change:

Greenhouse effect is the major contributing factor to the cause of global warming. Due to the entrapment of heat the temperature of the earth’s atmosphere is increasing which is leading to many devastating affects, one of such being the melting of the ice caps.

In sum it can said that greenhouse effect has both contributing and confiscating attribute to earth’s atmosphere.