Greenhouse effect: Green house is used for the cultivation of fruits and vegetables. It is used in countries where the sun radiations are not easily available. The Green house is made up of glass. It allows entering the Short wave radiations. These short wave radiations when strikes the inner surface of the greenhouse, converts the short wave radiations into long wave radiations. The long wave radiations are again reflected back but are not allowed by the glass to leave the green house and are entrapped. This trapped energy is useful to keep the plants green and for their growth.
In the same manner the earth atmosphere acts like a green house and keeps the earth green. The short waves radiations are allowed to enter the atmosphere but the long wave radiations are entrapped by the atmosphere surroundings. The earth’s surrounding atmosphere consists of gases containing N2 (79%), O2 (21%) and CO2, NOx, SO2 and He in small amounts. CO2 is the main gas responsible for maintaining the earth temperature constant. If there is a change in the CO2 level it can change the earth temperature. The presence of O2 in earth atmosphere is responsible for existence of human and plant life. Therefore it is essential to maintain the particular level of O2 and CO2 in atmosphere. The change in the level can give rise to the natural calamities.
CO2 has optical properties which absorbs the long wave radiations. Apart from CO2, gases like CH4, NO2 and CFCs have similar properties. All these gases are called Green House gases.
Effects of Greenhouse effects:
- Due to high temperature the glacier melts down and will raise the sea level.
- The water evaporation rate will increase and hence reduce the water run-off.
- The wheat and corn production will reduce due to warm conditions.
- Green house effect, gases, short, long wave radiations, earth, atmosphere, CFC