Final answer:
Water from precipitation is freshwater due to the Earth's water cycle, which leaves salts behind during evaporation. Most freshwater is locked in ice caps or underground aquifers, and less than one percent is available for human use in rivers and lakes. Access to freshwater remains a critical issue, exacerbated by geographic inaccessibility and a dominance of saline water.
Step-by-step explanation:
Despite the fact that more than 70 percent of the Earth's surface is covered by oceans, the water from precipitation is freshwater. This is possible because the Earth's water cycle essentially distills seawater. When water evaporates due to the sun's heat, only the water molecules rise into the atmosphere, leaving salts and other impurities behind. This vapor then condenses to form clouds and falls back to Earth as rain, sleet, or snow, all of which are freshwater.
Most of Earth's freshwater is indeed trapped in ice caps and glaciers or located in underground aquifers. These freshwater reservoirs are crucial for supplying water to ecosystems and humans. Freshwater in rivers, lakes, streams, and groundwater makes up less than one percent of the world's freshwater, yet it is vital for human consumption and agricultural use. Climate plays a significant role, as it dictates the patterns of precipitation required for these activities.
Access to drinking water remains critical globally because the vast majority of water on Earth is saline. The small percentage that is freshwater is often inaccessible, being frozen in polar regions or stored underground. Technologies like rainwater harvesting, well drilling, and desalination help mitigate these challenges, aiming to provide sufficient fresh water for human needs.