If `CO_(2)` is absent in the atmosphere of earth, then

Options

A. Temperature will decrease
B. Temperature will increase
C. Plants will flourish well
D. No effect

Answer

To solve the question "If CO2 is absent in the atmosphere of Earth, then...", we need to analyze the role of CO2 in the atmosphere and its impact on temperature.

### Step-by-Step Solution:

1. **Understanding the Role of CO2**:
- Carbon dioxide (CO2) is a significant greenhouse gas in the Earth's atmosphere. Greenhouse gases are responsible for trapping heat from the sun, which helps maintain the Earth's temperature.

2. **Greenhouse Effect**:
- The greenhouse effect occurs when the shortwave radiation from the sun reaches the Earth, and the Earth emits longwave radiation (heat) back into space. Greenhouse gases like CO2 trap some of this longwave radiation, preventing it from escaping into space, thus warming the atmosphere.

3. **Impact of Absence of CO2**:
- If CO2 is absent, the greenhouse effect would be significantly reduced. This means that less heat would be trapped in the atmosphere, leading to a decrease in the average temperature of the Earth.

4. **Conclusion**:
- Therefore, if CO2 is absent in the atmosphere, the temperature of the Earth will decrease. This is because the greenhouse effect, which is crucial for maintaining a habitable temperature, would be diminished.

### Final Answer:
If CO2 is absent in the atmosphere of Earth, then the temperature will decrease.

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