If all life on Earth were to cease, the atmosphere would revert to its primitive, oxygen-poor composition and become poisonous to modern plants and animals.

Question

Quizplus · Accepted Answer

Without living organisms, there would be no photosynthesis to replenish oxygen in the atmosphere. Eventually, the oxygen would be consumed by chemical reactions and the atmosphere would revert to its primitive, oxygen-poor composition, making it poisonous to modern plants and animals.

If All Life on Earth Were to Cease, the Atmosphere