Explain the following in detail.
Global Warming.

Explanation

Greenhouse effect or Global warming : Gases like `CO_2, CFCs, O_3, NO` and water vapour absorb I.R. radiations coming to the earth and reflect them back to the earth's surface. Due to this, The surface of the earth gets heated. This is called greenhouse effect or global warming. The gases which are responsible for this effect are called greenhouse gases.
Effect of global warming :
1) For a `1^(@)`C rise in temperature, the ice caps of polar regions melt and level of the sea water increases. Thereby many coastal coutries get submerged.
2) Due to global warming, the rate of evaporation of water from the seas, rivers, ponds will increase. This leads to unwarranted rains, cyclones and hurricanes.
3) Due to global warming, shortage of water supply for agriculture occurs.
Global warming can be prevented by growing trees, forests, stopping production of CFCs etc.