Which layer of the atmosphere is the closest to the earth's surface?

The troposphere is the closest layer of the atmosphere to the Earth's surface. It extends from the Earth's surface up to about 8 to 15 kilometers (5 to 9 miles) high, depending on geographical location and weather conditions. This layer is significant because it contains most of the atmosphere's mass, including the air we breathe, and is where nearly all weather phenomena occur, such as clouds, rain, and storms.

In the troposphere, temperature decreases with altitude, which contributes to the various weather patterns we experience. The presence of life, along with essential weather processes, underscores the importance of this layer. The layers above the troposphere—such as the stratosphere, mesosphere, and thermosphere—are at greater altitudes and have different characteristics and functions, but they do not play the same role in weather and life on Earth as the troposphere does.