(a) Ozone hole : The large depletion of ozone layer in certain parts of the atmosphere is called Ozone hole. 

(b) Tropopause : The upper limit of the troposphere is called Tropopause. 

(c) Global warming : Gradual rise in Earth’s average temperature is called Global Warming.

(d) Greenhouse effect : The warming up of the atmosphere due to trapping of the solar radiation reflected by the earth by gases like carbon dioxide is called Greenhouse effect. 

(e) Stratosphere : The layer of the atmosphere above the troposphere is called Stratosphere. 

(f) Troposphere : The atmospheric layer closest to the earth is called Troposphere. 

(g) CFC’s : These are chloro-fluoro carbons and are used as propellants in aerosol cans, refrigerants in refrigerators, air conditioning and as solvent cleaners in the microelectronic industry. 

(h) Mesosphere : The layer of th® atmosphere which extends to a height of 80 km above the stratosphere is called Mesosphere. 

(i) Exosphere : The topmost layer of the atmosphere is called the Exosphere. 

(j) Thermosphere : Ionosphere, which extends from 80 km to 480 km is known as the Thermosphere