Final answer:
Of Earth's total water, 97% is salt water in oceans, and just 2.5% is freshwater. A majority of freshwater is trapped in ice, leaving less than 1% as liquid and accessible for consumption and ecological use. This scarcity has serious implications for global water availability.
Step-by-step explanation:
Earth's water composition is predominantly saline, with approximately 97% being salt water in the oceans. Only a small fraction, about 2.5%, is freshwater. However, much of this freshwater is locked away in ice caps, glaciers, and the ground, rendering it largely inaccessible. The amount of liquid and accessible freshwater is less than 1% of the earth's total freshwater reserves, making it a precious resource for all living things, particularly humans.
The vast majority of the freshwater is contained within ice sheets, icebergs, and glaciers. This leaves a minute fraction that is available in the form of surface water, such as lakes, rivers, and streams, which is essential for supporting life's needs. The scarcity of accessible freshwater has significant implications for communities worldwide, especially in terms of drinking water and agriculture.