What are three ways in which the atmosphere is important to life on earth?
The three ways that the atmosphere is important to life in earth is because earths atmosphere makes conditions on earth suitable for living things
Free oxygen in your atmosphere is important to the development and maintenance of life on Earth because oxygen?
You have it wrong way round, the atmosphere of Earth was created by the life on Earth. 4000 million years ago the atmosphere had no oxygen and was full of CO2, Nitrogen and Methane. However life came into existence in this atmosphere and over time has altered the atmosphere to what we have today. Therefore the composition of the atmosphere would not appear to be critical to life.