There are approximately 1,386 million cubic kilometers (km3) of water on Earth. Approximately how much of that total is fresh water? 4,158,000 km3 41,580,000 km3 134,442,000 km3 415,800,000 km3 1,344,420,000 km3
There are approximately 1,386 million cubic kilometers (km3) of water on Earth. Approximately how much of that total is fresh water? 4,158,000 km3 41,580,000 km3 134,442,000 km3 415,800,000 km3 1,344,420,000 km3
The Correct Answer and Explanation is :
The correct answer is: 41,580,000 km³
Explanation:
Earth has an estimated 1,386 million cubic kilometers (km³) of water. However, only about 3% of Earth’s water is freshwater — the rest (approximately 97%) is salt water found in oceans.
To calculate the volume of freshwater: 1,386,000,000 km3×0.03=41,580,000 km31,386,000,000 \, \text{km}^3 \times 0.03 = 41,580,000 \, \text{km}^3
This matches the answer 41,580,000 km³, which represents approximately 3% of the total global water volume.
Breakdown of Freshwater:
While 3% may sound like a lot, most of that freshwater is not easily accessible:
- 68.7% of freshwater is locked in glaciers and ice caps
- 30.1% is found in groundwater
- 0.3% is in rivers, lakes, and swamps (surface water)
- 0.9% is in other forms like atmospheric water vapor and soil moisture
That means only about 0.3% of all freshwater (roughly 124,740 km³) is readily available for human use in rivers and lakes.
Importance:
Freshwater is essential for drinking, agriculture, sanitation, and industry. Despite its small proportion, it supports all terrestrial life. The relatively limited supply of accessible freshwater, coupled with increasing global demand and pollution, poses serious challenges for sustainable development.
Understanding the distribution of water resources helps policymakers and scientists manage water effectively, particularly in regions vulnerable to droughts, climate change, and population growth.
In conclusion, of the 1,386 million km³ of water on Earth, approximately 41.58 million km³ is freshwater, representing about 3% of the total — a vital yet finite and unevenly distributed resource.
