What specific aspect of Earth's atmosphere is crucial for sustained life beyond simply having a gaseous layer?

Answer

Its composition, rich in nitrogen and oxygen, provides necessary gases for respiration and metabolic functions.

The composition matters immensely; Earth's atmosphere, being rich in nitrogen and oxygen, supplies the specific gases required for respiration and other metabolic functions necessary for sustained life.

What specific aspect of Earth's atmosphere is crucial for sustained life beyond simply having a gaseous layer?
scienceHabitabilityLife supportEarth conditionsenvironmental factors