Without greenhouse effect the average temperature at surface of Earth would have been a chily ______ C rather than the present average of _________ C.

Answer

To solve the question regarding the average temperature at the surface of the Earth without the greenhouse effect, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Greenhouse Effect**:
- The greenhouse effect is a natural process that warms the Earth’s surface. It occurs when the sun's energy reaches the Earth – some of this energy is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.

2. **Identifying the Average Temperature Without Greenhouse Effect**:
- Without the greenhouse effect, the Earth's average surface temperature would be significantly lower. The typical value cited for this temperature is around -18 degrees Celsius.

3. **Identifying the Present Average Temperature**:
- The current average temperature of the Earth, with the greenhouse effect, is approximately 15 degrees Celsius.

4. **Filling in the Blanks**:
- Therefore, the complete statement would read: "Without greenhouse effect the average temperature at the surface of Earth would have been a chilly -18°C rather than the present average of 15°C."

### Final Answer:
Without greenhouse effect the average temperature at surface of Earth would have been a chilly **-18°C** rather than the present average of **15°C**.

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