hydrosphere

This term describes the global system of water, encompassing all liquid, solid, and gaseous states. It is primarily used in scientific contexts such as geology, ecology, and climatology to discuss the interaction between water and other planetary spheres. As a mass noun referring to a singular global system, it is typically used in the singular. While it can be pluralized when discussing the hydrospheres of multiple different planets, in a terrestrial context it functions as an uncountable entity.