Question

explain why the greenhouse effect is not entirely a man - made phenomenon.

Explanation:

The greenhouse effect occurs naturally. Gases like water vapor, carbon - dioxide, and methane are present in the Earth's atmosphere from natural sources such as volcanic eruptions, plant respiration, and evaporation. These gases trap heat from the sun, warming the planet even without human influence. Human activities have enhanced the greenhouse effect, but it existed long before human civilization due to these natural processes.

Answer:

The greenhouse effect is not entirely man - made because natural sources of greenhouse gases (e.g., water vapor from evaporation, carbon - dioxide from volcanic eruptions and plant respiration) have been present in the atmosphere since long before human activities, and these gases naturally trap heat from the sun, warming the Earth.