Answer:
The hydrosphere is the sum of all water on Earth and the water cycle. Water moves through the hydrosphere in a cycle. Water collects in clouds, then falls to Earth in the form of rain or snow. This water collects in rivers, lakes and oceans. Then it evaporates into the atmosphere to start the cycle all over again.
Global warming:
As the Earth warms, so too will the ocean. As water warms, it expands. Expansion of warming water makes up about half of the present rise in sea level. The rest of the sea level rise we are currently witnessing is the result of land-based snow and ice melting into the ocean.