Choose the correct statement from the following .

Options

A. The temperature of Earth has increased by `0.6^@C` in the past century.
B. `CH_4` contributes about 14% of all the greenhouse gases to global warming .
C. Clouds and gases reflect about one - third of the incoming solar radiation, and absorb some of it.
D. El Nino effect is referred to the melting of the ice caps of the Himalayan region.

Answer

To solve the question of identifying the correct statement regarding environmental changes and greenhouse gases, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understand the Question**: The question asks us to choose the correct statement from the options provided.

2. **Evaluate Option A**:
- The statement claims that "In the last century, the temperature of the earth has increased by 0.6 degrees Celsius."
- This statement is supported by scientific consensus, which indicates that the Earth's average temperature has indeed increased by approximately 0.6 degrees Celsius over the last century due to global warming and the greenhouse effect.
- **Conclusion**: This statement is correct.

3. **Evaluate Option B**:
- The statement claims that "the contribution of CH4 (methane) is 14% in global warming."
- While methane is a significant greenhouse gas, its contribution is generally estimated to be around 20% or more, not 14%.
- **Conclusion**: This statement is incorrect.

4. **Evaluate Option C**:
- The statement claims that "clouds and gases reflect one third of incoming solar radiation."
- In reality, about 1/4 (or 25%) of incoming solar radiation is absorbed by clouds, and only about half of the sunlight reaches the Earth's surface. Therefore, stating that one third is reflected is inaccurate.
- **Conclusion**: This statement is incorrect.

5. **Evaluate Option D**:
- The statement claims that "the El Nino effect in the Himalayan region is causing ice to melt."
- The El Nino effect primarily affects the Pacific Ocean and has global weather implications, but it does not directly cause ice melting in the Himalayas. The melting of Himalayan ice is more closely related to global warming and climate change rather than the El Nino phenomenon.
- **Conclusion**: This statement is incorrect.

6. **Final Conclusion**: After evaluating all options, only Option A is correct. The increase in Earth's temperature by 0.6 degrees Celsius over the last century is a well-documented fact.