Question

Why does Earth's mean surface temperature differ from -15 degrees Celsius in the absence of the atmosphere?

a) Absorption of ultraviolet radiation by the ozone layer
b) Scattering of visible radiation by aerosols
c) Absorption of infrared radiation by atmospheric gases
d) Breakdown of oxygen molecules in the thermosphere

Answer 1

The mean surface temperature of Earth differs from -15 degrees Celsius in the absence of the atmosphere primarily due to the absorption of infrared radiation by atmospheric gases. The greenhouse effect, caused by greenhouse gases in the atmosphere, plays a crucial role in maintaining Earth's surface temperature around 15 degrees Celsius.

Step-by-step explanation:

The mean surface temperature of Earth differs from -15 degrees Celsius in the absence of the atmosphere primarily due to the absorption of infrared radiation by atmospheric gases.

When there is no atmosphere, the infrared radiation emitted by the Earth escapes directly into space, causing a much colder temperature. However, the presence of greenhouse gases such as carbon dioxide and water vapor in the atmosphere absorb and re-radiate the infrared radiation back to the Earth, creating a warming effect known as the greenhouse effect. This phenomenon raises the surface temperature of the Earth to about 15 degrees Celsius, maintaining a suitable environment for life.