Approximately what percentage of the world's total water inventory is contained in the oceans?

• A. 50
• B. 97
• C. 70
• D. 25

Answer: (B)

The main idea is that water is not evenly distributed on Earth—the oceans hold by far the largest share. About 97% of the world’s total water inventory is in the oceans as saltwater, forming the planet’s biggest reservoir. The remaining roughly 3% is freshwater, found in glaciers and ice caps, groundwater, lakes, rivers, the atmosphere, and soil moisture. Because most freshwater is locked away in ice or underground, the amount readily available for immediate use is a small fraction, which is why freshwater resources can be relatively scarce even though there is a lot of water overall.