For the 'greenhouse effect' consider statements I to III

(I) Sunlight is recived by earth. Some incomintg radiations are reflected back into space by the atmosphere and some is aborbed such as certain UV light by stratosphere ozone.
(II) Earth's surface emits IR radiations.
(III) Emitted `IR` radiation are less intense than that emitted by earth's surface. `CO_(2)` along with `IR` radiations warm the atmosphere.
Select the correct statement:

Options

A. Both I and II
B. Both I and III
C. I,II and III
D. Boht II and III

Answer

C

Explanation

`CO_(2)(g)` is not assumed to be an air pollutant because it is non-toxic. However, a buildup of `CO_(2)(g)` in the atmosphere may disturb energy balance on earth. Its atmosphere is transparent to visible and UV radiation from the Sun. Infared radition is absorbed energy is reradiated as `IR` radiation. Certain atmospheric gases as `CO_(2)` and water vapour absorb these `IR` radiations. Energy retained in the atmosphere produces a warning effect. Thus, thermal energy is retained in a greenhouse-greenhouse effect.