Greenhouse gases cause

Options

A. Trap UV rays
B. Increase in temperature of atmosphere
C. Prevents global warming
D. All of these

Answer

### Step-by-Step Solution:

1. **Understanding Greenhouse Gases**:
- Greenhouse gases are gases in the Earth's atmosphere that trap heat. They include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and others.

2. **Mechanism of the Greenhouse Effect**:
- These gases absorb and emit radiation in the thermal infrared range. When sunlight reaches the Earth, some of it is reflected back to space, and the rest is absorbed, warming the planet. Greenhouse gases then trap some of this heat, preventing it from escaping back into space.

3. **Impact on Temperature**:
- The trapping of heat by greenhouse gases leads to an increase in the Earth's average temperature, a phenomenon known as global warming. This is the primary effect of greenhouse gases on the atmosphere.

4. **Evaluating the Options**:
- a. Trap UV rays: This is incorrect as greenhouse gases primarily trap infrared radiation, not ultraviolet rays.
- b. Increase in temperature of atmosphere: This is correct as greenhouse gases lead to an increase in the Earth's temperature.
- c. Prevents global warming: This is incorrect; greenhouse gases contribute to global warming, not prevent it.
- d. All of these: This is incorrect as only option b is correct.

5. **Conclusion**:
- The correct answer to the question "Greenhouse gases cause" is **b. Increase in temperature of atmosphere**.