Why is the atmosphere essential for life?
Atmosphere is very important for sustaining life: (1) It contains various gases like O2, CO2, N2 which are required for various life processes by plants and animals. (2) CO2 gas is used by plants to prepare food by the process called photos (3) Oxygen is required for burning, combustion and respiration. (4) Ozone layer is acting as a protective layer, which avoids/prevents U.V rays to enter the earth's atmosphere. (5) CO2 dissolved in water forms carbonates which is required by animals to form shells.