how does water contribute to life on earth?

Answer 1

In just about every way, shape and form.

Answer 2

It helps plants, vegetables, fruits, and animals grow and develope. These are vital for us to live. We also need to drink water to live, for if we didn't drink water we would dry out and die.

Answer 3

it helps us live and to the plants provides food to eat and we eat the plants if there was no water the earth would overheat

Answer 4

we have to have water to live for things to grow to clean the earth.we also need it bath basicly to do any out door work dealing with plants etc.

Answer 5

life

Answer 6

try living without it and find out

Answer 7

Effects on life
From a biological standpoint, water has many distinct properties that are critical for the proliferation of life that set it apart from other substances. It carries out this role by allowing organic compounds to react in ways that ultimately allows replication. All known forms of life depend on water. Water is vital both as a solvent in which many of the body's solutes dissolve and as an essential part of many metabolic processes within the body, since significant quantities of water are used during the digestion of food.

Aquatic life forms
Earth's waters are filled with life. Nearly all fish live exclusively in water, and there are many types of marine mammals, such as dolphins and whales that also live in the water. Some kinds of animals, such as amphibians, spend portions of their lives in water and portions on land. Plants such as kelp and algae grow in the water and are the basis for some underwater ecosystems. Plankton is generally the foundation of the ocean food chain.

Different water creatures have found different solutions to obtaining oxygen in the water. Fish have gills instead of lungs, though some species of fish, such as the lungfish, have both. Marine mammals, such as dolphins, whales, otters, and seals need to surface periodically to breathe air.

Effects on human civilization
Civilization has historically flourished around rivers and major waterways; Mesopotamia, the so-called cradle of civilization, was situated between the major rivers Tigris and Euphrates. Large metropolises like Rotterdam, London, Montreal, Paris, New York, and Tokyo owe their success in part to their easy accessibility via water and the resultant expansion of trade. Islands with safe water ports, like Singapore and Hong Kong, have flourished for the same reason. In places such as North Africa and the Middle East, where water is more scarce, access to clean drinking water was and is a major factor in human development.

Health and pollution
Water fit for human consumption is called drinking water or "potable water". Water that is not fit for drinking but is not harmful for humans when used for food preparation is called safe water.

This natural resource is becoming scarcer in certain places, and its availability is a major social and economic concern. Currently, about 1 billion people around the world routinely drink unhealthy water. Most countries accepted the goal of halving by 2015 the number of people worldwide who do not have access to safe water and sanitation during the 2003 G8 Evian summit.[4] Even if this difficult goal is met, it will still leave more than an estimated half a billion people without access to safe drinking water supplies and over 1 billion without access to adequate sanitation facilities. Poor water quality and bad sanitation are deadly; some 5 million deaths a year are caused by polluted drinking water.

In the developing world, 90% of all wastewater still goes untreated into local rivers and streams. Some 50 countries, with roughly a third of the world’s population, also suffer from medium or high water stress, and 17 of these extract more water annually than is recharged through their natural water cycles [citation needed]. The strain affects surface freshwater bodies like rivers and lakes, but it also degrades groundwater resources.

Human uses
For drinking
About 72% of the fat free mass of the human body is made of water. To function properly, the body requires between one and seven litres of water per day to avoid dehydration; the precise amount depends on the level of activity, temperature, humidity, and other factors. Most of this is ingested through foods or beverages other than drinking straight water. It is not clear how much water intake is needed by healthy people. However, for those who do not have kidney problems, it is rather difficult to drink too much water, but (especially in warm humid weather and while exercising) it is dangerous to drink too little. People can drink far more water than necessary while exercising, however, putting them at risk of water intoxication, which can be fatal. The "fact" that a person should consume eight glasses of water per day cannot be traced back to a scientific source.[5] There are other myths such as the effect of water on weight loss and constipation that have been dispelled.[6]

The latest dietary reference intake report by the United States National Research Council recommended (including food sources): 2.7 litres of water total for women and 3.7 litres for men.[7] Water is lost from the body in urine and feces, through sweating, and by exhalation of water vapor in the breath.

Humans require water that does not contain too many impurities. Common impurities include metal salts and/or harmful bacteria, such as vibrio. Some solutes are acceptable and even desirable for perceived taste enhancement and to provide needed electrolytes.

As a solvent
Dissolving (or suspending) is used to wash everyday items such as the human body, clothes, floors, cars, food, and pets. Sometimes water is not enough, and many chemicals can be added in order to improve the solvating power of water. These chemicals include saliva, soap, shampoo, alcohol, vinegar and various surfactants; these are all examples of emulsifying agents. When water will not do (to remove a nonwater-soluble substance such as paint), other solvents are used, such as ethanol (in meths) or acetone (in nail varnish remover).

As a thermal transfer agent
Boiling, steaming, and simmering are popular cooking methods that often require immersing food in water or its gaseous state, steam. Water is also used in industrial contexts as a coolant, and in almost all powerstations as a coolant and to drive steam turbines to generate electricity. In the nuclear industry, water can also be used as a neutron moderator.


Recreation
Humans use water for many recreational purposes, as well as for exercising and for sports. Some of these include swimming, waterskiing, boating, fishing, and diving. In addition, some sports, like ice hockey and ice skating, are played on ice.

Lakesides and beaches are popular places for people to go to relax and enjoy recreation. Many find the sound of flowing water to be calming, too. Some keep fish and other life in water tanks or ponds for show, fun, and companionship. People may also use water for play fighting such as with water guns or water balloons.

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Answer 8

think harder youll get it .,.,.,.,.,.,