Earth's Freshwater and Atmosphere

Freshwater

Freshwater is essential for life on Earth. It is found in lakes, rivers, streams, and underground aquifers. The majority of Earth's freshwater is stored in glaciers and ice caps.

Sources of Freshwater

• Surface water (lakes, rivers, and streams)
• Groundwater (aquifers)
• Glaciers and ice caps

Usage of Freshwater

Freshwater is used for drinking, agriculture, industry, and sanitation. It is important to conserve and protect freshwater sources to ensure a sustainable supply for future generations.

Atmosphere

The atmosphere is the layer of gases that surround the Earth. It is composed of nitrogen, oxygen, carbon dioxide, and other trace gases. The atmosphere plays a crucial role in regulating Earth's temperature and protecting life from harmful solar radiation.

Layers of the Atmosphere

• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere
• Exosphere

Composition of the Atmosphere

The atmosphere is primarily composed of nitrogen (78%) and oxygen (21%), with trace amounts of other gases such as carbon dioxide, argon, and water vapor.

Role of the Atmosphere

The atmosphere helps regulate Earth's temperature by trapping heat from the sun (greenhouse effect) and protecting the planet from harmful solar radiation such as UV rays and cosmic rays.

Study Guide Questions

1. What are the primary sources of freshwater on Earth?
2. Why is it important to conserve and protect freshwater sources?
3. List and describe the layers of the Earth's atmosphere.
4. What are the primary gases that make up the Earth's atmosphere?
5. Explain the role of the atmosphere in regulating Earth's temperature and protecting life.