Select the odd one among the following options about the least possible adverse effect of global warming.

Options

A. Retreat of glaciers
B. An increase of UV - B - radiation
C. Sea - level rise
D. Extraordinary weather patterns

Answer

To solve the question about the least possible adverse effect of global warming, we will analyze the provided options and determine which one does not fit with the others in terms of being an effect of global warming.

### Step-by-Step Solution:

1. **Understand Global Warming**:
- Global warming refers to the long-term rise in Earth's average temperature due to human activities, primarily the emission of greenhouse gases like carbon dioxide and methane.

2. **Identify Common Effects of Global Warming**:
- **Weather and Climate Changes**: Global warming leads to increased chances of extreme weather events such as floods and droughts.
- **Sea Level Rise**: The melting of polar ice and glaciers contributes to rising sea levels.
- **Impact on Flora and Fauna**: Changes in temperature can lead to the extinction of temperature-sensitive plant and animal species.

3. **Evaluate the Options**:
- **Option 1**: Changes in weather and climate (e.g., floods and droughts).
- **Option 2**: Changes in sea level (e.g., melting of polar ice).
- **Option 3**: Impact on flora and fauna (e.g., extinction of temperature-sensitive species).
- **Option 4**: Increase in UVB radiation.

4. **Identify the Odd One Out**:
- The first three options (changes in weather and climate, changes in sea level, and impact on flora and fauna) are all direct consequences of global warming.
- **Option 4** (increase in UVB radiation) is not a direct effect of global warming. While UV radiation can be influenced by other factors, it is not a primary consequence of the greenhouse effect or global warming.

5. **Conclusion**:
- The least possible adverse effect of global warming among the options is **Option 2: Increase in UVB radiation**.

### Final Answer:
- The correct answer is **Option 2: Increase in UVB radiation**.