ABSTRACT
The Earth System contains a great variety of bodies of water—great oceans that cover the majority of Earth’s surface, large and small lakes, and flowing freshwater ranging from small trickling streams to mighty rivers such as the Mississippi, the Nile, and China’s Yellow River. For each of us, though, the most crucial body of water is our own body, which is composed of approximately 60% water. This fact drives home the crucial importance of water to our own existence and the survival of the Earth System as one that is hospitable to life.
