In Spain, storks' trash diet driven by climate change

The storks float and swoop in formation, circling over a landfill in the foothills of the Sierra de Guadarrama mountains north of Madrid. Then a garbage truck pulls up and disgorges its contents. One by one, they dive to ...

Antarctica's ocean brightens clouds

The teeming life in the Southern Ocean, which encircles Antarctica, contributes to brightening the clouds that form there, according to a study published today in Atmospheric Chemistry and Physics. The clouds are bright because ...

Study shows tropical reefs grow faster in cooler waters

For thousands of years, cold waters in tropical upwelling zones have hindered the growth and survival of coral species which thrived in warm seas. New research from Florida Tech shows that corals living in cooler waters are ...

Sounding the alarm on microplastic pollution

There are four basic ingredients in beer: grain, hops, yeast and water. The water often introduces a fifth, which passes unfiltered into a typical pilsner.

Why icicles are rippled

Winter is coming to an end; the last nights of below zero temperatures are here. In the morning, one still spots the occasional icicle on a gutter or car bumper. When you look at these icicles carefully, you may notice that ...

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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.

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