“The origin of all matter is water.”
Thales (624-546 BC), a pre-Socratic Greek philosopher.
Water is the essential part of every living system; forming two thirds of the earth and our bodies, it forms the greatest part of our World. Like the capillaries, veins and arteries of our bodies, the courses of water on Earth operate as a circulatory system; transfering between liquid and vapour. This system, most often described as the hydrologic (or water) cycle, perpetuates the essential flow of water from the undrinkable salted sea water to the drinkable mountain streams; providing the only means through which fresh water can be naturally replaced. It is thus of incredible importance to the temperature of our Planet and the availability of drinking water that this cycle is maintained and that the fresh water created is effectively managed and protected. For despite the huge abundance of water on Earth only 2.75% is fresh water, of which 2.05% is frozen in glaciers.
“Water is a vital resource not just for humans, but for a variety of aquatic ecosystems, including wetlands, watersheds, riparian zones, estuaries, and coastal areas. These critical habitats, in turn, supply surrounding communities with a variety of valuable ecosystems goods and services, such as sustaining biodiversity, moderating floods and droughts, filtering water-borne contaminants, and forming the foundation of coastal and aquatic food chains. However, misuse and abuse of the water resources on which these ecosystems depend is hastening their degradation, threatening human settlements as well as nature.” (http://www.usaid.gov/our_work/environment/water/index.html)
http://landsat.gsfc.nasa.gov/images/archive/f0012.html - aral sea decline (image)