If there was no carbon dioxide in the Earth's atmosphere so the temperature of Earth's surface would be :

Options

A. same as present
B. less than the present
C. higher than the present
D. dependent on `O_(2)` in atmosphere.

Answer

To solve the question regarding the effect of the absence of carbon dioxide (CO2) in the Earth's atmosphere on the temperature of the Earth's surface, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Role of Carbon Dioxide**:
- Carbon dioxide is a greenhouse gas, which means it has the ability to trap heat in the atmosphere. This process is essential for maintaining the Earth's temperature.

2. **Consider the Consequences of No CO2**:
- If there were no carbon dioxide in the atmosphere, the greenhouse effect would be significantly diminished. This means that less heat would be trapped.

3. **Evaluate the Impact on Temperature**:
- Without CO2, the heat that the Earth receives from the Sun would not be retained effectively. As a result, much of this heat would escape back into space.

4. **Predict the Resulting Temperature**:
- The loss of heat retention would lead to a decrease in the Earth's surface temperature. The oceans would likely freeze, and the overall climate would become much colder.

5. **Select the Correct Option**:
- Based on the analysis, the correct answer to the question is that the temperature of the Earth's surface would be "less than the present."

### Final Answer:
The temperature of Earth's surface would be **less than the present** (Option B).

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