Greenhouse effect is mainly caused by

Options

A. CFCs
B. `CH_(4)`
C. `CO_(2)`
D. CO

Answer

**Step-by-Step Solution:**

1. **Understanding the Greenhouse Effect**: The greenhouse effect is a natural process that warms the Earth’s surface. When the Sun’s energy reaches the Earth, some of it is reflected back to space and the rest is absorbed, warming the planet.

2. **Role of Greenhouse Gases**: Certain gases in the atmosphere, known as greenhouse gases, trap heat. The most significant greenhouse gases include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and water vapor.

3. **Identifying the Main Cause**: Among these gases, carbon dioxide (CO2) is recognized as the primary contributor to the greenhouse effect. It is released through various human activities such as burning fossil fuels, deforestation, and industrial processes.

4. **Mechanism of Heat Retention**: Once the Earth absorbs solar energy, it re-emits this energy in the form of infrared radiation. However, CO2 and other greenhouse gases absorb this infrared radiation and re-radiate it back towards the Earth, preventing it from escaping into space.

5. **Consequences of the Greenhouse Effect**: This process leads to an increase in the Earth's average temperature, contributing to global warming and climate change.

**Final Answer**: The greenhouse effect is mainly caused by carbon dioxide (CO2) in the atmosphere.

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