Atmosphere: the mixture of gases around the earth
Noun: These factories are releasing toxic gases into the atmosphere.
Biosphere: a part of a planet's environment where life exists
Noun: With a massive impact, a biosphere gets another chance.
Geosphere: any of the almost spherical concentric regions of matter that make up the earth and its atmosphere, as the lithosphere and hydrosphere.
Noun: These are called, respectively, the geosphere, biosphere, and noosphere.