What is the most important natural substance to humans? Water! In its liquid state, water is the most abundantly found element in the biosphere-and is also the most important element for life itself. It dissolves substances without chemically reacting to them, it has high "latent heat," and has several other extremely important characteristics for sustaining life. Learn about the seas' role in the biosphere, details about fresh water resources, and the threat of water shortages.

Originally released by Cerebellum Corporation, 2013. Streaming video file encoded with permission for digital streaming by Infobase on July 10, 2018.

Fresh Water: Introduction (1:32); --Qualities of Water (2:59); -- Water and Living Beings (1:23); -- Fresh Water Distribution (3:57); -- Rainwater is No Longer Enough (3:15); -- Fresh Water: Summary (3:11); -- Credits: Fresh Water (2:23); .