What percentage of freshwater is accessible and usable by humans?

Approximately 2.5% of the Earth's water is freshwater. However, much of this is trapped in glaciers, ice caps, and underground, or is otherwise inaccessible. It is estimated that only about 0.3% of total freshwater, or 0.007% of total global water, is readily accessible and usable by humans.

Here are the steps to get this answer:

1. Identify the total percentage of Earth's water that is freshwater: 2.5%.
2. Determine the percentage of this freshwater that is inaccessible because it is trapped in glaciers, ice caps, and underground: the majority of it.
3. Subtract the inaccessible freshwater from the total freshwater to find the percentage that is accessible: about 0.3% of total freshwater.
4. To find the percentage of total global water that is accessible freshwater, multiply the percentage of total water that is freshwater (2.5%) by the percentage of freshwater that is accessible (0.3%). This gives 0.0075%, or approximately 0.007% when rounded to three decimal places.