Why does earth have a lower amount of carbon in the atmosphere than planets such as Venus and mars

Question

carbon is released into the air during plant decomposition
most of earths carbon can be found in the proteins and lipids of organisms
the carbon escapes earths atmosphere faster than it is absorbed
plants take in carbon dioxide from the atmosphere for photosynthesis

Answer 1

Venus and Mars have much less oxygen in their atmospheres, so the carbon dioxide is not broken down as quickly as it is on Earth. This means that the carbon dioxide accumulates in the atmosphere, leading to higher levels of carbon in the atmosphere than on Earth.