Question

Which of the following is not a greenhouse gas?

• A. ${\mathrm{CO}}_2$
• B. ${\mathrm{CH}}_4$
• C. ${\mathrm{O}}_2$
• D. $\mathrm{CFCs}$

Answer 1

The correct option is C

${\mathrm{O}}_2$

The correct option is C.

Explanation of the correct option

1. Oxygen $\left({\mathrm{O}}_2\right)$ is an essential gas that cannot capture heat from the air space.
2. It does not cause the greenhouse effect as it is mono-atomic.
3. Oxygen contains two same atoms of oxygen in its molecule.

Explanation of the incorrect options:

Option A:

1. ${\mathrm{CO}}_2$ is a primary greenhouse gas responsible for the greenhouse effect and ultimately global warming.

Option B:

1. ${\mathrm{CH}}_4$ refers to Methane which is another major component affecting the atmosphere.

Option D:

1. $\mathrm{CFCs}$ are Chlorofluorocarbons. They contribute to the greenhouse effect as well.

Final answer: Oxygen is not a greenhouse gas.