Which of the following is most responsible for global warming?

Options

A. CFC
B. `CH_(4)`
C. `CO_(2)`
D. `N_(2)O`

Answer

To determine which gas is most responsible for global warming, we can follow these steps:

### Step 1: Identify the Gases
First, we need to identify the gases that are commonly associated with global warming. The options provided are:
- A) CFC (Chloro Fluoro Carbon)
- B) CH4 (Methane)
- C) CO2 (Carbon Dioxide)
- D) N2O (Nitrous Oxide)

### Step 2: Analyze Each Gas
Next, we analyze the role of each gas in global warming:
- **CFCs:** These gases are primarily responsible for ozone depletion, not global warming.
- **CH4 (Methane):** This gas is indeed a greenhouse gas and contributes to global warming. It is significantly more potent than CO2 in terms of heat retention.
- **CO2 (Carbon Dioxide):** This is a major greenhouse gas and is known for its role in global warming. It is present in the atmosphere in larger quantities than methane.
- **N2O (Nitrous Oxide):** While this gas can contribute to global warming, it is more commonly associated with acid rain.

### Step 3: Compare CH4 and CO2
Since both CH4 and CO2 are responsible for global warming, we need to compare their impacts:
- **Potency:** Methane (CH4) is approximately 25 times more effective than carbon dioxide (CO2) at trapping heat in the atmosphere over a 100-year period.
- **Concentration:** However, CO2 is present in the atmosphere in much larger quantities. The concentration of CO2 is about 0.02% of the total air, which is significantly higher than that of methane.

### Step 4: Conclusion
Given that CO2 is present in much larger amounts in the atmosphere compared to CH4, it is concluded that carbon dioxide (CO2) is the most responsible gas for global warming, despite methane's higher potency.

### Final Answer
The gas most responsible for global warming is **C) CO2 (Carbon Dioxide)**.

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