Question

Which among the following gases has the highest global warming potential?

• A. CO$_2$
• B. Water vapor
• C. Methane
• D. N$_2$O

Hint:

Relative GWPs: CO$_2 = 1$, CH$_4 \approx 25$, N$_2$O $\approx$ 298. Nitrous oxide is the most potent among these.

Answer 1

The Correct Option is D

Step 1: Recall Global Warming Potential (GWP).
- GWP is a measure of how much heat a greenhouse gas traps in the atmosphere relative to CO$_2$.
- CO$_2$ is taken as the reference = 1.
Step 2: Compare given gases.
- CO$_2$ → GWP = 1
- Water vapor → Strong greenhouse effect, but not assigned a GWP (short-lived, feedback gas).
- Methane (CH$_4$) → GWP ≈ 25 (over 100 years).
- Nitrous oxide (N$_2$O) → GWP ≈ 298 (over 100 years).
Step 3: Identify highest.
Among the given gases, N$_2$O has the highest global warming potential. Final Answer: \[ \boxed{\text{(D) N$_2$O}} \]