Final answer:
The majority of Earth's water is in the oceans, making up about 97% of the hydrosphere, while most freshwater is stored in glaciers and ice caps. However, access to drinking water remains a significant issue due to the geographical distribution and very small proportion of accessible, clean freshwater.
Step-by-step explanation:
The majority of water in the hydrosphere is found in the oceans. The distribution of Earth's water shows that about 97% of it is contained in the oceans, which makes them the largest reservoir of the planet's water. However, this water is saline and not directly usable for drinking or agriculture without desalination.
When considering freshwater, the majority is found in glaciers and ice caps, specifically representing about 68.7% of the world's freshwater. Groundwater is another significant reservoir, which is more accessible for use. Despite the abundance of water in the form of oceans, ice caps, and glaciers, access to clean drinking water is a critical issue because a very small fraction of the Earth's total water is accessible and suitable for human use without treatment.