Answer: short answer it provides the air we need to survive
Explanation: long answer
The troposphere is made up of several different gases. And, there are a couple of interesting things about the gases. The first is that the troposphere is made of 78% nitrogen, which is by far and away the most plentiful gas in our air. Also, oxygen, the gas that is so crucial to life on the planet, only makes up 21% of the air. All the other gases combined make up the remaining 1%, including carbon dioxide. Also regulates our weather and temperatures on a regular basis