Explain how the Earth's atmosphere helps in maintaining a suitable temperature for life to survive on the Earth.

The Earth's atmosphere plays a vital role in maintaining a suitable temperature for life by regulating the amount of heat received from and lost to space.

(1) Greenhouse Effect: The atmosphere contains greenhouse gases such as carbon dioxide (CO₂), water vapour, methane, and ozone. These gases allow most of the Sun's visible radiation to reach the Earth's surface. After absorbing this energy, the Earth re-radiates heat in the form of infrared radiation. Greenhouse gases absorb and trap a part of this heat, preventing it from escaping completely into space. This natural greenhouse effect keeps the Earth warm enough to support life.

Without the greenhouse effect, the average temperature of the Earth would be around -18 °C instead of about 15 °C.

(2) Protection from Harmful Radiation: The atmosphere protects life by absorbing

harmful radiation from the Sun. The ozone layer in the stratosphere absorbs most of the harmful ultraviolet (UV) rays, while the upper atmosphere blocks highly energetic gamma rays and X-rays.

(3) Moderation of Temperature: The atmosphere prevents extreme temperature variations.

During the day, clouds and gases reflect some solar radiation, reducing excessive heating.

At night, the atmosphere retains heat and prevents the Earth from becoming extremely cold.

(4) Redistribution of Heat: Atmospheric circulation distributes heat from the equatorial regions toward the poles through winds and weather systems. This helps maintain a more balanced global climate.

Thus, the Earth's atmosphere acts as a protective and insulating layer that regulates temperature, protects life from harmful radiation, and creates conditions suitable for the survival of living organisms.