77.

What are the consequences of green house effect?
Or
What is the effect on the global warming due to the green house effect?

(i)  The green -house gases (namely carbon dioxide, methane, nitric oxides, water vapours, chlorofluorocarbons and ozone) are useful in keeping the earth warm with an average temperature of about 15°C. In the absence of these green- house gases, the average surface temperature will fall to about–18°C. As a result, this temperature will freeze all water and destroy most of the living beings. The escape of green -house gases in the atmosphere is equally harmful.

(ii)  Further, the amount of CO₂ increases in the atmosphere as a result of combustion of the fossil fuels or by human activities. Thus heat radiated back to the earth by CO₂ and H₂O vapours will increase. Consequently, the temperature of the earth’s surface will increase. Thus evaporation of surface water will increase which further helps in the rise of temperature.

This increase in temperature may result in the melting of glaciers and polar ice caps and level of sea water may rise thereby flooding the coastal lands and thus have a drastic effect on the climate. Also presence of green house gases has led to the warming of air called global warming.