_________can lead to melting of the polar ice caps.

Options

A. Global warming
B. Greenhouse effect
C. Eutrophication
D. Oil spill

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks what can lead to the melting of the polar ice caps. This implies we need to identify a phenomenon or factor that causes this effect.

2. **Identifying the Cause**: One of the major causes of the melting of polar ice caps is an increase in global temperatures. This increase is primarily due to the accumulation of greenhouse gases in the atmosphere.

3. **Recognizing Greenhouse Gases**: Greenhouse gases, such as carbon dioxide (CO2), trap heat from the sun in the Earth's atmosphere. This leads to an increase in temperature, which contributes to global warming.

4. **Explaining Global Warming**: Global warming refers to the long-term rise in the average temperature of the Earth’s atmosphere due to human activities, particularly the burning of fossil fuels which increases the concentration of greenhouse gases.

5. **Connecting Global Warming to Ice Caps**: As global temperatures rise, the polar ice caps begin to melt. This melting contributes to rising sea levels and can disrupt ecosystems.

6. **Final Answer**: Therefore, the answer to the question is **global warming**.

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