Why is the atmosphere essential for life?
Atmosphere is essential for life because of the following masons : (i) It keeps the average temperature of the earth fairly steady during the day and even during the course of the whole year. (ii) It prevents the sudden increase in temperature during the daylight hours. (iii) It contains all the important gases which are required for sustaining life on earth. These gases are : (a) Oxygen for respiration of living organisms and oxidation. (b) Carbon dioxide for photosynthesis in plants and for making food. (c) Nitrogen for providing inert atmosphere and making proteins. (iv) The stratosphere region (16-23 km from the surface of Earth) of atmosphere contains a thick layer of ozone which filters the harmful UV radiation from Sun. If these radiations reach on the surface of Earth, then they may cause cancer in animals and are also harmful for plants.
