Question

Define green house effect. Write its adverse effects and how to control it?

Answer 1

A green house is a structure with walls and roof made chiefly of transparent material, such as glass, in which plants are grown. These structures range in size from small shed to large building. The interior of a green house exposed to sunlight becomes significantly warmer than the external temperature.

Earth is covered by a dense covering of atmosphere upto the height of 30 km though it is found upto 800 to 1000 km heights The atmosphere is mixture of many gases which are as follows—

1. Nitrogen 78%
2. Oxygen 21%
3. Argon 0.93%
4. CO₂ 0.04% (0.03 to 0.07%)
5. Others 0.03%

[Methane, Water vapors, N₂O, CFC, 03 etc]
The atmosphere around the earth acts as a glass wall of the green house. The CO₂, Methane, N₂O, CF. water vaporous etc. absorb the heat radiations and generate a specific atmospheric temperature (global temperature), i.e. the atmosphere is warmed by absorption of infrared thermal radiations (shorter wavelength radiant energy from the Sun and and convective heat fluxes from the surface). These gases in the atmosphere radiant energy, some of which towards the earth surface. This phenomena is termed as green house effect and these gases are called as green house gases.

Green House Gases :
The green house gases include CO₂, CFC, N₂O, CH₄, Water vapors O₃. Increase in the green house gases will increase the global temperature and the earth will become like boiling mass. For example, the atmosphere of Venus planet contains 90% CO₂ (3% N₂ and 0.5%. O₂). therefore there temperature is 477°C.

Causes of green house effect :
The increase in the green house gases in the atmosphere increasing the atmospheric temperature. The major green house gas is CO₂. (contribute 60% in green house effect) is increasing continuously because of the following reasons—

• Green plants perform photosynthesis in presence of chlorophyll to synthesize the food. The photosynthesis is the only biological process that consumes CO₂. According to a report, there is deforestation at a rate of 38 acre per minute. Moreover, there is combustion of the forests. As a result, the CO₂ is increasing due to its less consumption. Therefore, deforestation is the primary cause of increase in CO₂.
• Burning of coke and wood also generate CO₂.
• Increased industrialization and motor vehicles are another good sources of increase in CO₂.

Side effects of green house effect –

1. Increase in the green house will increase global temperature. It will cause heavy rains and flood in coastal regions and droughts in average rainfall regions. It is reported that if the temperature continues to rise than it will increase by 3.6°C up to 2100. It will lead to drought,  cyclones, hurricanes, flood, epidemics and may lead to final destruction of the Universe.
2. The green house effect will decrease production of agricultural products and fish production in India and other developing countries.
3. The sea level will rise due to melting of polar ice because of increased temperature. As a result, the coastal regions will be merged under sea water.

Increase of CO₂ in the atmosphere causing green house effect. As a result the atmospheric average temperature is increasing. It is called as global warming. The increase in temperature will cause many problems. Significant melting of old glaciers is already observed. The incoming water will cover fresh water marshlands, low-lying cities and islands with sea water. There will be change in the rainfall and vegetation patterns. The increase in CO₂ is to be checked to prevent increase in global temperature. Otherwise it is bound to have very serious and very negative effects.