Human activities in the recent past have caused the increased concentration of carbon dioxide in the atmosphere, but a lot of it does not remain in the lower atmosphere because of

1. its escape into the outer stratosphere.
2. the photosynthesis by phytoplankton in the oceans
3. the trapping of air in the polar ice caps.

Which of the statements given above is/ are correct?

[UPSC Civil Services Exam – 2011 Prelims]

(a) 1 and 2

(b) 2 only

(c) 2 and 3

(d) 3 only

Answer: (b)        

Explanation:

• The photosynthesis by phytoplankton in the oceans is natural carbon Sequestration.
• The trapping of carbon dioxide by polar ice caps is not known. Also, carbon dioxide does not escape into the stratosphere. Hence, statements 1 and 3 are incorrect.