Why is it important to distinguish between major gases and trace gases in the atmosphere?

Distinguishing between major gases and trace gases is important because it helps us understand the composition of the atmosphere and its effects on climate and life. Major gases like nitrogen and oxygen are essential for life, while trace gases can have significant impacts on greenhouse effects and air quality.

A strong answer should directly address the approved learning objective to distinguish the major gases in the present atmosphere from trace atmospheric gases. This question belongs to The proportions of different gases in the atmosphere within The composition and evolution of the Earth's atmosphere, so the response should use that exact curriculum context rather than a generic statement. The answer is correct when it names the key idea, explains the link to atmosphere, and keeps the wording specific to AQA GCSE revision.