Water

Water moves continually Over land, evaporation and transpiration common chemical substance essential to all forms of life the substance has a solid state, ice, and a gaseous state, water vapor. About 1,460 teratonnes (Tt) of water covers 71% of the Earth's surface, in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation. Can cause hurricanes when global warming extends entire villages left submerged as in people's streets submeerged. Earth's water is contained within man-made and natural objects near the Earth's surface as water towers, animal and plant bodies, manufactured products, and food stores. Water moves continually Saltwater oceans hold ing 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers and lakes 0.6%. Water moves continually Water moves continually through a cycle of evaporation or transpiration, precipitation, and runoff, reaching the sea. Water moves continually over land Winds carry water vapor over land at the same rate as runoff into the sea, about 36 Tt per year. Over land, evaporation and transpiration contribute another 71 Tt per year to the precipitation of 107 Tt per year over land. Some water is trapped for varying periods in ice caps, glaciers, aquifers, or in lakes, providing fresh water for life on land. Clean, fresh water is essential to human and other life. In many parts of the world, it is in short supply. Many organic molecules as well as salts, sugars, acids, alkalis, and some gases (especially oxygen), are soluble in water. Water is essential for all life on Earth. Humans can survive for several weeks without food, but for only a few days without water. more than one billion people in low and middle-income countries lack access to safe water for drinking, personal hygiene and domestic use. more than 20 percent of the world’s people. close to 2 billion people did not have access to adequate sanitation facilities. leading causes of morbidity and mortality in low- and middle-income countries, frequently called developing countries. over 1.1 billion people are currently without safe drinking water.