How Much Of The Earth's Surface Is Land And How Much Is Water?
I believe that the percentage of land is closer to 20% rather than 30. Land covers around 20% of the earth's surface and water the other 80%.
97% of the world's water is seawater, and only 3% is fresh water.
Only 1% of the earth's water is suitable for drinking.
And only about 0.08% of the world's drinkable water is accessible to humans.
Land covers 29.22 percent of the Earth's surface. This is about 57.5 million square miles (149 x 106 square kilometers). Water covers the other 70.78 percent of the Earth's surface. This is about 139.4 million square miles (361 x 106 square kilometers).
Source: Barnes-Svarney, Patricia. The New York Public Library Science Desk Reference, p. 372.