how does the composition of the Earth’s atmosphere affect life on Earth

Protection

Earths atmosphere is a combination of gases

the atmosphere has 7 layers

Breathing

78% nitrogen

21% oxygen

0.9% argon

0.1% other gasses

The earths atmosphere holds in oxygen

Protects from solar flares

Lessens UV Radiation

Lets animals and humans breathe

Bacteria released the oxygen

Almost killed all life as they were 'allergic' to oxygen

the exosphere

the mesosphere

the stratosphere

the troposphere

the thermosphere