How much CO2 is Present in Our Atmosphere?

A. 0.03 to 0.04% CO2
B. 0.3 to 0.4% CO2
C. 3 to 4% CO2
D. None of these

Explanation:

Carbon occupies about 0.03% of the earth’s atmosphere. In the pre-industrial time, the level of carbon dioxide was only about 280 parts per million.