Which is a plausible explanation for the presence of carbon dioxide in Earth's early atmosphere?
A) Volcanic eruptions could have released carbon dioxide into the atmosphere.
B) Cyanobacteria were present on Earth 3.5 billion years ago.
C) Retroviruses could have catalyzed the formation of carbon dioxide.
D) Geysers may have produced Earth's early environment.
E) Chemical reactions with water would have resulted in the formation of carbon dioxide.

Question

Quizplus · Accepted Answer

Volcanic eruptions could have released carbon dioxide into the atmosphere. Volcanoes can release large amounts of carbon dioxide and other gases into the atmosphere. Estimates suggest that volcanic outgassing was a major contributor to the early atmosphere of the Earth, and could have led to the presence of carbon dioxide.

Which Is a Plausible Explanation for the Presence of Carbon