There are 326 million cubic miles of endless blue sea occupying the expanse between our seven continents, making up 70% of the earth’s surface (Bureau of Reclamation, 2017).
Read our related article: 9 Viable Water Scarcity Solutions We Can All Work Toward
With merely 5% of the ocean floor having been discovered and mapped, and with the deepest part reaching almost 7 miles, water seems to be as abundant as it is ominous.
Yet, it wouldn’t take much of the mineral-rich ocean to dehydrate a human being if consumed. The amount of sodium in seawater is much more concentrated than what the body can safely process, requiring more water as salt is consumed. Eventually, death would come as a result of dehydration without ever having the thirst quenched (Ocean Service).
Of the waters occupying 70% of the earth’s surface, only 3% is considered freshwater. And most of this freshwater reserve is inaccessible to humans — locked up in polar ice caps or stored too far underneath the earth’s surface to be extracted. Furthermore, much of the freshwater that is accessible has become highly polluted.
This leaves us with roughly 0.4% of the earth’s water which is usable and drinkable to be shared among the 7 billion of its inhabitants (World Atlas, 2018).
How Much Water is On Earth?
- Oceans 97.2%
- Ice Caps/Glaciers 2.0%
- Groundwater 0.62%
- Freshwater Lakes 0.009%
- Inland Seas/Salt Lakes 0.008%
- Atmosphere 0.001%
- Rivers 0.0001%
And still, much of this 0.4% is hard to get to. Most of it flows through underground aquifers which can be accessed by digging wells; the rest are found in rivers and streams which we refer to as, surface water. Much of the global population is hard-stricken having access to such a small percentage of freshwater on the earth’s surface (Perlman, 2016).
The United States Geological Survey provides a visual illustration (represented in spheres) as to the amount of available water in comparison to the size of the earth.
The largest sphere represents all of the water on earth (oceans, ice caps, lakes, rivers, groundwater) and has a volume of 332,500,000 cubic miles.
The second-largest sphere, with a volume of 2,551,100 cubic miles, represents the earth’s freshwater supply in liquid form. 99% of the liquid freshwater is groundwater, much of which is far too deep to be accessible.
The remainder of the earth’s freshwater exists in lakes and rivers, represented by the tiniest sphere, with a volume of 22,339 cubic miles (Perlman, 2016).
0 billion gallons
of surface water per day
0 billion gallons
of groundwater per day
Since surface water is easier to reach, it’s become the most common way for humans to access clean water. Globally, we use about 321 billion gallons of surface water and about 77 billion gallons of groundwater per day. Contamination of these water supplies is a problem that further limits availability (Groundwater Association, 2012).
Read our related article: 12 Clean Water Charities the World is Counting On
Surface water is any body of water that is on the earth’s surface: lakes, rivers, streams, and reservoirs. 80% of the world’s daily water usage comes from surface water and makes up the majority of the water used for irrigation and public supply. Oceans are the world’s largest source of surface water and make up 97% of it, but due to its high salinity, it is unusable for humans (Postel, 2010).
The earth’s surface waters travel through a complex network of flowing rivers and streams. Rivers can obtain their water from two sources: base flow and runoff. Base flow is when the river collects its water from water-saturated areas in the ground, adding to its volume. Runoff is when the force of gravity naturally pulls water downhill from higher to lower altitudes. They usually start as small creeks in the mountains, and then gradually merge with larger streams as they flow downward, eventually forming large rivers which empty out into the ocean.
Groundwater is the water beneath the earth’s surface that is at 100% saturation. Anything less than 100% is considered soil mixture. 98% of the earth’s freshwater is indeed groundwater and it is about 60 times more plentiful than the surface water. Groundwater travels through holes and cracks in the bedrock. The amount of rock space and the ability for water to travel through it is known as porosity and permeability. Groundwater with high porosity and permeability value can travel quickly and are known as aquifers. An aquifer with high pressure can cause the groundwater level to rise to the surface once a well has been dug (Groundwater Association, 2012).
The Hydrologic Cycle
Water takes the form of liquid, gas, and solid and cycles through these in what is known as the earth’s hydrologic cycle. When water evaporates, liquid molecules become gas molecules as they rise through the atmosphere. Condensation begins when the moisture from these gas molecules becomes so great that they fall back to earth in the form of precipitation. Because the process of evaporation, condensation, and precipitation has essentially “distilled” the water, it is considered clean before it hits the ground. When the precipitation hits the ground, it collects into aquifers, rivers, or lakes, ready to be used again. Glaciers and icecaps cover 10% of the world's mass and exist primarily in Greenland and Antarctica. They are the storehouses for the world’s freshwater.
Water Conflicts Around the World
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Water Conflicts: Looking at Our World from Past to Future
There are 263 rivers and countless aquifers worldwide which either cross or demarcate geopolitical boundaries. The Atlas of International Freshwater Agreement states that 90 percent of the world’s countries share these water sources with at least one or two other governing bodies. The atrocities in Darfur are an example of conflict resulting from clean water shortages.
• Violence erupts in 1992 over a dispute between Uzbekistan and Turkmenistan regarding the contested Tyuyamuyun reservoir. It continues to be a highly disputed water source in the region today (Factbook).
• In 2010, dozens of people were killed in Pakistan’s tribal region due to a water dispute which lasted over two weeks. According to a senior government official in the Kurram district which borders Afghanistan, the Mangal tribe stopped water irrigation on lands belonging to the Tori tribe. In total, 116 people were killed and 165 were injured (CNN, 2010).
• Four farmers were hacked to death in northeast Tanzania over the disputed Pangani River Basin in 2013 (Factbook).
• In 2016, 18 people were killed and 200 more were injured when the Indian Army clashed with economic protestors surrounding the highly-contested Munak canal, a water source that supplies New Dehli with three-fifths of its freshwater supply (Factbook).
• The drought-stricken conditions of major parts of Somalia often force herders to sell more of their livestock than they can afford to make a living with. This lack of economic stability fuels recruitment appeal with militant groups such as Al Shabaab, which provide cash incentives and other benefits to their soldiers. Other illicit activities such as pirating and livestock raiding are seen as reasonable alternatives to the declining stability of animal herding (Factbook).
Change is Needed
Water is finite. The amount of water circulating through the earth’s hydrologic cycle is the same amount that has been there since the earth’s beginning, not a drop more or less. What has changed is the number of people living on earth, and thus, the amount of drinkable water required for human sustenance. The United Nations reports that in the last century alone, water consumption has grown at more than twice the rate of population increase.
70% of the earth is covered in water, yet only 3% of it is fresh. Of that 3%, 2.6 of it is locked away in glaciers and polar ice caps. That leaves us with 0.4% of the earth’s water, in the form of rivers and underground aquifers, to try to utilize for our consumption and societal development. It is no wonder that in developing regions where clean water sources cross national boundaries, it often finds itself in conflict among those trying to secure a means to a healthy living.
With humans being made up of 60% water, our natural instinct might be to fight for it. But by collaborating to find ways to access the untapped groundwater beneath us, helping to conserve clean water use, and preventing further pollution of our clean water sources, it is possible for all peoples to have access to clean water.
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0.5% of the earth's water is available fresh water. If the world's water supply were only 100 liters (26 gallons), our usable water supply of fresh water would be only about 0.003 liter (one-half teaspoon). In actuality, that amounts to an average of 8.4 million liters (2.2 million gallons) for each person on earth.Is 1% of the Earth's water available for human use? ›
The Earth might seem like it has abundant water, but in fact less than 1 percent is available for human use. The rest is either salt water found in oceans, fresh water frozen in the polar ice caps, or too inaccessible for practical usage.Is the Earth 70 percent water? ›
The Earth is a watery place. But just how much water exists on, in, and above our planet? About 71 percent of the Earth's surface is water-covered, and the oceans hold about 96.5 percent of all Earth's water.Which is Earth's largest source of drinkable water? ›
US and Canadian researchers recently calculated the total amount of the world's groundwater and estimated that it is equivalent to a lake 180m deep covering the entire Earth. This makes groundwater the largest active freshwater resource on the planet.What is 97% of the water on Earth making it undrinkable for humans? ›
Oceans are the world's largest source of surface water and make up 97% of it, but due to its high salinity, it is unusable for humans (Postel, 2010). The earth's surface waters travel through a complex network of flowing rivers and streams. Rivers can obtain their water from two sources: base flow and runoff.Is 99% of water on Earth available to humans for drinking? ›
Only about three percent of Earth's water is freshwater. Of that, only about 1.2 percent can be used as drinking water; the rest is locked up in glaciers, ice caps, and permafrost, or buried deep in the ground.Where is about 20% of Earth's fresh water found? ›
Lake Baikal in Russia is considered the deepest, oldest freshwater lake in the world. It holds about 20 percent of the Earth's unfrozen surface fresh water, the largest volume in the world.Does the earth make new water? ›
Over millions of years, much of this water is recycled between the inner Earth, the oceans and rivers, and the atmosphere. This cycling process means that freshwater is constantly made available to Earth's surface where we all live.How many years of fresh water left? ›
Unless water use is drastically reduced, severe water shortage will affect the entire planet by 2040. "There will be no water by 2040 if we keep doing what we're doing today".Are humans 98% water? ›
Up to 60% of the human adult body is water. According to Mitchell and others (1945), the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64% water, muscles and kidneys are 79%, and even the bones are watery: 31%.
Boiling seawater does not make it safe to drink because it doesn't remove the salt. Freshwater on the other hand - say from a river - can be boiled to make it safe enough to drink.Can you drink water from rain? ›
To lower your risk of getting sick, consider using rainwater only for uses such as watering plants that you don't eat or washing items that are not used for cooking or eating. Avoid using rainwater for drinking, cooking, brushing your teeth, or rinsing or watering plants that you intend to eat.Where is the purest water in the world? ›
While there are a few places that boast extremely clean water, such as Canada, Iceland, Antarctica, or even Upstate New York, the team of scientists determined that the cleanest water in the world was in the Patagonia region of Chile, Puerto Williams.Is about 3% of water on Earth usable? ›
3% of the earth's water is fresh. 2.5% of the earth's fresh water is unavailable: locked up in glaciers, polar ice caps, atmosphere, and soil; highly polluted; or lies too far under the earth's surface to be extracted at an affordable cost. 0.5% of the earth's water is available fresh water.Why is 99 of the water on Earth unusable? ›
Currently, more than 99 percent of all water on Earth is unavailable for human use because it is too saline (in the form of seawater) or is frozen as glaciers, ice, or snow. With a stored volume of about two million cubic miles, groundwater remains the largest component of freshwater available for humans.What bodies of water cover almost 70% of the earth? ›
About 97 percent of Earth's water is in the ocean.
The ocean covers more than 70 percent of the surface of our planet.
For most people, there is really no limit for daily water intake and a gallon a day is not harmful. But for those who have congestive heart failure or end stage kidney disease, sometimes water needs to be restricted because the body can't process it correctly.What is the most water you should drink in a day? ›
The U.S. National Academies of Sciences, Engineering, and Medicine determined that an adequate daily fluid intake is: About 15.5 cups (3.7 liters) of fluids a day for men. About 11.5 cups (2.7 liters) of fluids a day for women.What is considered drinking too much water? ›
But how much water is too much? "Drinking more than the kidneys can eliminate could cause hyponatremia in some people," says Hultin, noting that the kidneys can eliminate 27 to 34 ounces of water per hour, or a total of 676 to 947 ounces (20 to 28 liters) per day. More than that might put you in the danger zone.Are the Great Lakes cleaner than the oceans? ›
Fresh water isn't stinky and crusty
So you know how when you go for a dip in the ocean and you come out covered in salt crust and with the distinct stench of rotting seaweed? Yeah, that doesn't happen in the Great Lakes. The water may be colder, but it's wonderfully clean.
Lake Superior is the largest, cleanest, and wildest of all the Great Lakes.What country has the largest fresh water supply? ›
Brazil has highest freshwater resources in the world which is accounts for approximately 12% of the world's freshwater resources. It is just because Amazon region this country contains 70% of the total freshwater. Russia has second largest freshwater reserve which is approximately 1/5 of freshwater in the world.Will we run out of water by 2050? ›
Says. Five billion people, or around two-thirds of the world's population, will face at least one month of water shortages by 2050, according to the first in a series of United Nations reports on how climate change is affecting the world's water resources.Will we ever run out of oxygen? ›
Oxygen makes up one-fifth of the air we breathe, but it's the most vital component – and it does seem to be declining. The main cause is the burning of fossil fuels, which consumes free oxygen. Fortunately, the atmosphere contains so much oxygen that we're in no danger of running out soon.Will Earth eventually be all water? ›
The simple answer is no. The whole world will never be underwater. But our coastlines would be very different. If all the ice covering Antarctica , Greenland, and in mountain glaciers around the world were to melt, sea level would rise about 70 meters (230 feet).Which state is least likely to run out of water? ›
By this scoring system, the most vulnerable states are Oklahoma, Montana, and Iowa, while Delaware, Massachusetts, Connecticut, and California are least vulnerable to drought.How long before California runs out of water? ›
Over 90% of the Western US is currently experiencing different severities of drought. However, California is being hit the hardest as it goes through the areas first megadrought in 1,200 years.What state has plenty of water? ›
Alaska has the most water
The state with the largest total area of water is Alaska, which has 94,743 square miles of water.
Blood is made up of about 55% blood plasma and about 45% different types of blood cells. Blood plasma is a light yellow, slightly cloudy liquid. Over 90% of blood plasma is water, while less than 10% consists of dissolved substances, mostly proteins.How much of the female body is made up of water? ›
Body composition varies according to gender and fitness level because fatty tissue contains less water than lean tissue. The average adult male is about 60% water. The average adult woman is about 55% water because women naturally have more fatty tissue than men.
adult will have approximately 1.2-1.5 gallons (or 10 units) of blood in their body. Blood is approximately 10% of an adult's weight.Why won t California build desalination plants? ›
A salty dispute: California Coastal Commission unanimously rejects desalination plant. Unlike Poseidon's proposed Huntington Beach plant to the north, the Doheny plant would suck in seawater from wells buried beneath the ocean's floor — putting a natural barrier between the intakes and marine creatures.Which ocean is not salt water? ›
The least saline ocean, by comparison, is the Arctic Ocean, which has a typical salinity of 28–30 g/kg owing to the low rate of evaporation and meltwater from the ice-caps.Why don t they use sea water to put out forest fires? ›
Explanation: Yes, salt water can be used to put out wildfires. However, salt water can harm plant life: some species are sensitive to salinity levels. Thus, using salt water may not be a wise first choice in firefighting methods in certain environments.Is it safe to drink snow water? ›
Freshly melted snow is generally considered to be safe to drink without further treatment, however it should not be assumed that because water is frozen that it is safe to drink. Exercise the same caution for melted Ice as you would for standing water, and if in doubt boil the water for 10 minutes.Can you drink distilled water? ›
Distilled water is safe to drink. But you'll probably find it flat or bland. That's because it's stripped of important minerals like calcium, sodium, and magnesium that give tap water its familiar flavor. What's left is just hydrogen and oxygen and nothing else.Can you live off of seawater? ›
Human kidneys can only make urine that is less salty than salt water. Therefore, to get rid of all the excess salt taken in by drinking seawater, you have to urinate more water than you drank. Eventually, you die of dehydration even as you become thirstier.Is water in caves drinkable? ›
Don't drink cave water. Bring enough water that it will last beyond the estimated length of your expedition. Pack high-energy foods that can survive the tight confines of a cave. Remember to never leave your trash in a cave.What is the most holy water in the world? ›
Lourdes water is water which flows from a spring in the Grotto of Massabielle in the Sanctuary of Our Lady of Lourdes, France. The location of the spring was described to Bernadette Soubirous by an apparition of Our Lady of Lourdes on 25 February 1858.What is the world's cleanest river? ›
River Rhine (Switzerland)
Thanks to this program to eliminate river pollution and more than 15 billion dollars invested in it, the waters of the Rhine were recovered. There is still work to do, but presently 95% of wastewater from factories is treated and there are now 63 species of fish living in the river.
Unfortunately, we can't use most of that as drinking water. Over 97% of the Earth's water is salt water in oceans and seas. Another 2% is frozen in icecaps and glaciers. That leaves less than 1% of the Earth's water for everyone to drink.How much of the human body is made up of water? ›
Up to 60% of the human adult body is water. According to Mitchell and others (1945), the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64% water, muscles and kidneys are 79%, and even the bones are watery: 31%.Why is ocean water not fit for human consumption? ›
Drinking seawater can be deadly to humans.
Seawater contains salt. When humans drink seawater, their cells are thus taking in water and salt. While humans can safely ingest small amounts of salt, the salt content in seawater is much higher than what can be processed by the human body.
This is because only 2.5% of the hydrosphere is freshwater, with the rest being saltwater in the oceans. Of this 2.5%, only a tiny fraction is available to humans, most stored in ice sheets, glaciers, or deep underground aquifers.Can you make ocean water drinkable? ›
Today, desalination plants are used to convert sea water to drinking water on ships and in many arid regions of the world, and to treat water in other areas that is fouled by natural and unnatural contaminants.What organ contains the most water? ›
Some organs contain much more water than others. The brain and kidneys possess the highest percentage of water; the bones and teeth contain the lowest proportion.What percentage of water is blood? ›
Over 90% of blood plasma is water, while less than 10% consists of dissolved substances, mostly proteins.Where does water go when you drink it? ›
The water we drink is absorbed by the intestines, and circulated throughout the body in the form of body fluids such as blood. These perform various functions that keep us alive. They deliver oxygen and nutrients to the cells, and take away waste materials, which are then eliminated with urination.What happens if you drink salt water on an empty stomach? ›
Drinking salt water on an empty stomach may cause nausea and vomiting. You may also experience cramping, bloating, and dehydration. Colon cleansing in general may cause an electrolyte imbalance due to the rapid loss of sodium and fluids.How long does it take water to digest and pee? ›
If you're dehydrated, the water will be absorbed and sent to maintain vital functions before it eventually reaches the kidneys to remove toxins. It generally takes your body 9 to 10 hours to produce 2 cups of urine.
Drink salt water to replace lost sodium
While electrolytes generally help the body function, sodium is especially important for muscle and nerve functions. It plays an integral role in ensuring muscles contract and relax, your neurons fire, and even help regulate your bodily fluid balance.
3% of the earth's water is fresh. 2.5% of the earth's fresh water is unavailable: locked up in glaciers, polar ice caps, atmosphere, and soil; highly polluted; or lies too far under the earth's surface to be extracted at an affordable cost.What is the water on the earth's surface called? ›
The hydrosphere includes water that is on the surface of the planet, underground, and in the air. A planet's hydrosphere can be liquid, vapor, or ice. On Earth, liquid water exists on the surface in the form of oceans, lakes, and rivers. It also exists below ground—as groundwater, in wells and aquifers.What happens to rainwater when it reaches Earth surface? ›
When rainwater reaches the surface of the Earth, it gets absorbed and contributes to the water table.