Biosphere
From the Simple English Wikipedia, the free encyclopedia that anyone can change
The biosphere includes everything living on Earth, including humans, animals, and insects. In other words, it's everything that is alive on the earth. Currently the biosphere has a biomass (or amount of living things) at around 1900 gigatonnes of carbon. It is not certain exactly how thick the biosphere is, though scientists predict that it is somewhere around 12,000 meters.
biosphere consists of living beings specially.it is not exactly 12,000 mm thick. biosphere surrounds the earth.it is like an imaginary blanket which covers us.