Question

based on the passage, which of the following best describes the greenhouse effect? a the process by which radiant heat from the atmosphere heats up the earth’s surface, making it warm enough for humans b the method by which electromagnetic waves carry heat through air or water, leading to balanced temperatures c a type of gas that lets radiant heat escape through holes in the atmosphere, making the earth cool d a system that allows the sun to absorb enough radiant energy from the earth to stay hot

Explanation:

To solve this, we analyze each option based on the definition of the greenhouse effect:

• Option A: The greenhouse effect involves greenhouse gases in the atmosphere trapping radiant heat (from the sun, after it warms the Earth's surface) and radiating some back to the Earth's surface, keeping it warm for life. This matches the basic concept.
• Option B: Describes heat transfer via electromagnetic waves (radiation), but the greenhouse effect is about trapping heat, not just heat transfer through air/water for balance. Eliminate.
• Option C: Greenhouse effect traps heat, not let it escape to cool the Earth. This is the opposite. Eliminate.
• Option D: The sun emits energy to the Earth; the greenhouse effect is about Earth's heat retention, not the sun absorbing Earth's energy. Eliminate.

Answer:

A. The process by which radiant heat from the atmosphere heats up the Earth’s surface, making it warm enough for humans