The biosphere is the global ecosystem that includes all living things on earth. The biosphere’s atmosphere is made up of several gases including argon, nitrogen, oxygen and carbon dioxide. Oxygen is necessary for us to breathe. Carbon dioxide is necessary for plants to perform photosynthesis. The biosphere can be broken down into many smaller ecosystems and habitats where different organisms live such as rainforests, deserts, boreal forests, prairies, etc. The biosphere gives us a place to live, food to eat and oxygen to breathe.