Definition: Atmospheric contamination involves the emission of materials or energy forms that pose risks to living beings or have environmental consequences.

Example: Natural pollutants include volcanic eruptions and forest fires, while artificial pollutants come from industrial activities and fossil fuel combustion.

Highlight: The ozone layer in the stratosphere intercepts 90% of the Sun's ultraviolet radiation, protecting the biosphere.

Quote: "CFCs used in refrigerators, air conditioners, and aerosols significantly damage the ozone layer."

Definition: The atmosphere is the gaseous layer surrounding Earth, held in place by gravity and composed primarily of nitrogen, oxygen, and other gases.

Highlight: The atmosphere's composition is crucial for life: 78.1% nitrogen, 21% oxygen, and 1% other gases including carbon dioxide and argon.

Example: The troposphere contains most of Earth's weather phenomena, including cloud formation, precipitation, and wind patterns.

Vocabulary: Troposphere - The lowest layer of Earth's atmosphere where most weather phenomena occur.