Answer: Troposphere
Explanation: The Troposphere: The Layer in Which We Live
The lowest layer of the atmosphere, which lies next to the
Earth’s surface, is called the troposphere. The troposphere is also
the densest atmospheric layer. It contains almost 90% of the
atmosphere’s total mass! Almost all of the Earth’s carbon dioxide, water vapor, clouds, air pollution, weather, and life-forms
are in the troposphere. As shown in Figure 4, temperatures vary
greatly in the troposphere. Differences in air temperature and
density cause gases in the troposphere to mix continuously.
