Why do Earth, Mars, and Venus lack any hydrogen and helium in their atmospheres?

Some of the hydrogen bonds with other elements, but most of it remains free hydrogen. Both hydrogen and helium are light elements, so they will tend to evaporate into space over time. ... But the gravity of Earth isn't strong enough, so Earth's early atmosphere of helium and free hydrogen evaporated into space.

Explanation:

Global warming increases the amount of carbon in the atmosphere.