What is the largest source of freshwater on Earth?

• A. Glaciers and ice caps
• B. Lakes and rivers
• C. Groundwater
• D. Atmospheric water vapor

Answer: (A)

Verified step by step guidance

1. Understand the context of the question: The problem is asking about the largest source of freshwater on Earth. Freshwater is water with low concentrations of dissolved salts, essential for life and ecosystems.
2. Review the options provided: Glaciers and ice caps, lakes and rivers, groundwater, and atmospheric water vapor. Each represents a different reservoir of freshwater on Earth.
3. Recall the distribution of freshwater on Earth: Approximately 68.7% of Earth's freshwater is stored in glaciers and ice caps, primarily in polar regions and high-altitude areas. Groundwater accounts for about 30.1%, while lakes and rivers make up only about 0.3%. Atmospheric water vapor is a very small fraction.
4. Compare the sizes of these reservoirs: Glaciers and ice caps are the largest source of freshwater, followed by groundwater. Lakes, rivers, and atmospheric water vapor are much smaller contributors.
5. Conclude that glaciers and ice caps are the largest source of freshwater on Earth, based on their significant contribution to the global freshwater supply.