Question

which statement best describes the greenhouse effect?
it is a process by which plants are able to grow well in a warm, enclosed structure.
it is a process by which greenhouse gases block the suns light to penetrate the atmosphere.
it is a process by which greenhouse gases allow the suns light to penetrate the atmosphere but stop the heat from escaping.
it is a process by which prevailing winds bring moisture to the land, to the prevailing wind direction.

Explanation:

The greenhouse effect is when greenhouse gases (like CO₂, methane) in the atmosphere let the Sun's short - wave radiation (light) pass through to heat the Earth's surface. The Earth then emits long - wave (heat) radiation, and these greenhouse gases trap this heat, preventing it from escaping into space. Let's analyze each option:

• Option 1: Describes a greenhouse (the structure for plants), not the greenhouse effect.
• Option 2: Greenhouse gases do not block the Sun's light; they allow it through. So this is incorrect.
• Option 3: This matches the definition of the greenhouse effect. Greenhouse gases are transparent to incoming solar radiation (light) but absorb and re - emit the outgoing infrared radiation (heat), thus trapping heat.
• Option 4: Describes a process related to wind - borne moisture (like monsoons or prevailing wind moisture transport), not the greenhouse effect.

Answer:

The option "It is a process by which greenhouse gases allow the sun's light to penetrate the atmosphere but stop the heat from escaping." (the third option in the list)