Question

Arrange the following greenhouse gases in ascending order of their contribution to global warming.
(A) CH\(_4\)
(B) N\(_2\)O
(C) CFCs
(D) CO\(_2\)
Choose the correct answer from the options given below:

• A. (A), (B), (C), (D)
• B. (B), (C), (A), (D)
• C. (C), (B), (A), (D)
• D. (A), (C), (B), (D)

Hint:

Don't confuse "Global Warming Potential" (GWP) with "total contribution". While gases like CFCs and methane have a much higher GWP per molecule than CO\(_2\), the sheer atmospheric concentration of CO\(_2\) makes it the number one contributor to global warming. The order of contribution is generally CO\(_2\) > CH\(_4\) > N\(_2\)O > F-gases.

Answer 1

The Correct Option is C

 

Step 1: Understanding the Concept: 
The question asks to arrange greenhouse gases in ascending order (least to most) of their total contribution to the enhanced greenhouse effect (global warming). This contribution depends on both the gas's atmospheric concentration and its Global Warming Potential (GWP) per molecule. 
 

Step 3: Detailed Explanation: 
The overall contribution of each gas to global warming is a product of its abundance and warming efficiency. Based on current data from sources like the IPCC, the approximate contributions are: 

\[\begin{array}{rl} \bullet & \text{(D) Carbon Dioxide (CO\(_2\)): By far the largest contributor, responsible for the majority of the warming (typically cited as over 60-70\%).} \\ \bullet & \text{(A) Methane (CH\(_4\)): The second largest contributor, responsible for approximately 16-20\% of the warming.} \\ \bullet & \text{(B) Nitrous Oxide (N\(_2\)O): The third largest contributor, responsible for about 6\%.} \\ \bullet & \text{(C) Chlorofluorocarbons (CFCs) and other fluorinated gases: As a group, they contribute the least among these options, though their GWP per molecule is extremely high. Their concentrations are very low.} \\ \end{array}\] Arranging these in ascending order of their total contribution (from least to most): CFCs \(\rightarrow\) N\(_2\)O \(\rightarrow\) CH\(_4\) \(\rightarrow\) CO\(_2\). This corresponds to the sequence (C), (B), (A), (D). 
 

Step 4: Final Answer: 
The correct ascending order of contribution to global warming is (C) CFCs, (B) N\(_2\)O, (A) CH\(_4\), (D) CO\(_2\).