An effective measure to prevent global warming is

Options

A. Carbon tax system
B. Emission of green house gases
C. Afforestation
D. cut down `O_2` and CO in atmosphere

Answer

To answer the question "An effective measure to prevent global warming is," we need to evaluate the provided options carefully.

### Step-by-Step Solution:

1. **Understanding Global Warming**:
- Global warming is primarily caused by the accumulation of greenhouse gases (GHGs) in the atmosphere, which trap heat and lead to an increase in Earth's average temperature.

2. **Evaluating the Options**:
- **Option 1: Cut down CO2 and O2 in the atmosphere**:
- This option suggests reducing oxygen (O2) levels, which is not feasible or beneficial since oxygen is essential for life. Thus, this option is incorrect.

- **Option 2: Afforestation**:
- Afforestation refers to planting trees in areas where there were none previously. Trees absorb CO2, which helps mitigate global warming. However, if this option is misinterpreted as cutting down forests (deforestation), it would be wrong. Therefore, this option is also not effective if it implies cutting down forests.

- **Option 3: Emission of greenhouse gases**:
- This option suggests that increasing emissions would help prevent global warming, which is incorrect. Higher emissions of greenhouse gases lead to more global warming.

- **Option 4: Carbon tax**:
- A carbon tax is a financial charge on companies that emit carbon dioxide and other greenhouse gases. This measure incentivizes industries to reduce their emissions to avoid higher taxes. Therefore, this option is effective in reducing greenhouse gas emissions and combating global warming.

3. **Conclusion**:
- After evaluating all options, the most effective measure to prevent global warming is **implementing a carbon tax**.

### Final Answer:
An effective measure to prevent global warming is **carbon tax**.

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