News tagged with water
Related topics: drinking water , climate change , water molecules , liquid water , ocean
Water is a ubiquitous chemical substance, composed of hydrogen and oxygen, that is essential for the survival of many known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly 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. Saltwater oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earth's water is contained within biological bodies and manufactured products. Other water is trapped in ice caps, glaciers, aquifers, or in lakes, sometimes providing fresh water for life on land.
Water moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Winds carry water vapor over land at the same rate as runoff into the sea. Over land, evaporation and transpiration contribute to the precipitation over land.
Clean, fresh drinking water is essential to human and other lifeforms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world. There is a clear correlation between access to safe water and GDP per capita. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. Water plays an important role in the world economy, as it functions as a solvent for a wide variety of chemical substances and facilitates industrial cooling and transportation. Approximately 70 percent of freshwater is consumed by agriculture.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
(HealthDay)—When it comes to the care of your children's teeth, dentists aren't the only experts who can help.
Dentistry May 21, 2013 | not rated yet | 0
(Medical Xpress)—The feared Legionella pneumophila is responsible for legionellosis, an infectious disease that can lead to pneumonia. To infect humans, this pathogen has developed a complex method that allows it to camouflage ...
Diseases, Conditions, Syndromes May 20, 2013 | not rated yet | 0
(HealthDay)—There are few things more inviting than a cool, clear pool on a hot summer day. But a new federal report will have you thinking twice before dipping a toe in the water.
Health May 16, 2013 | not rated yet | 0
(AP)—The mayor of Portland, Ore., has conceded defeat in an effort to add fluoride to the city's drinking water.
Health 14 hours ago | not rated yet | 0