Question

If there was no $C{O}_2$ in the earth’s atmosphere, the temperature of the earth’s surface would be ______

• A. the same
• B. less than the present level
• C. more than the present level
• D. dependent upon the oxygen amount of the environment

Answer 1

The correct option is B

less than the present level

When sunlight is absorbed by the surface of the Earth, the surface heats up and emits a different kind of radiation, known as infrared radiation. Carbon dioxide is a special compound which is transparent to solar radiation and yet it absorbs infrared radiation. Thus, the presence of carbon dioxide in our atmosphere allows sunlight to penetrate to the surface but inhibits the emission of infrared radiation to space.