Peak water is a concept that underlines the growing constraints on the availability, quality, and use of freshwater resources. Peak water was defined in 2010 by Peter Gleick and Meena Palaniappan. They distinguish between peak renewable, peak non-renewable, and peak ecological water to demonstrate the fact that although there is a vast amount of water on the planet, sustainably managed water is becoming scarce.
Lester R. Brown, president of the Earth Policy Institute, wrote in 2013 that although there was extensive literature on peak oil, it was peak water that is "the real threat to our future". An assessment was published in August 2011 in the Stockholm International Water Institute's journal. Much of the world's water in underground and in lakes can be depleted and thus resembles a finite resource. The phrase peak water sparks debates similar to those about peak oil. In 2010, New York Times chose "peak water" as one of its 33 "Words of the Year".
There are concerns about impending peak water in several areas around the world:
+ Freshwater sources (top 15 countries) |
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The amount of available freshwater supply in some regions is decreasing because of (i) climate change, which has caused receding , reduced stream and river flow, and shrinking lakes; (ii) contamination of water by human waste and ; and (iii) overuse of non-renewable groundwater aquifers. Many aquifers have been over-pumped and are not recharging quickly. Although the total freshwater supply is not used up, much has become polluted, salted, unsuitable or otherwise unavailable for Tap water, industry, and agriculture.
Agriculture represents 70% of freshwater use worldwide.
Agriculture, industrialization and urbanization all serve to increase water consumption.
India has the largest water withdrawal out of all the countries in the world. Eighty-six percent of that water supports agriculture. That heavy use is dictated in large part by what people eat. People in India consume a lot of rice. Rice farmers in India typically get less than half the yield per unit area while using ten times more water than their Chinese counterparts. Economic development can make things worse because as people's living standards rise, they tend to eat more meat, which requires much water to produce. Growing a tonne of grain requires 1,000 tonnes of water; producing a tonne of beef requires 15,000 tonnes. To make a single hamburger requires around 4,940 liters (1,300 gallons) of water. To produce a glass of orange juice requires 850 liters (225 gallons) of freshwater.
In western China's Qinghai, through which the Yellow River’s main stream flows, more than 2,000 lakes have disappeared over the last 20 years. There were once 4,077 lakes. Global climate change is responsible for the reduction in flow of the (Huang He) Yellow River over the past several decades. The source of the Yellow River is the Qinghai-Xizang Tibetan plateau where the glaciers are receding sharply.
In Hebei, which surrounds Beijing, the situation is much worse. Hebei is one of China's major wheat and corn growing provinces. The water tables have been falling fast throughout Hebei. The region has lost 969 of its 1,052 lakes. About 500,000 people are affected by a shortage of drinking water due to continuing droughts. Hydro-power generation is also impacted. Beijing and Tianjin depend on Hebei Province to supply their water from the Yangtze River. Beijing gets its water via the newly constructed South-North Water Transfer Project. The river originates in a glacier on the eastern part of the Tibetan Plateau.
The Ogallala Aquifer in the southern high plains (Texas and New Mexico) is being mined at a rate that far exceeds replenishment—a classic example of peak non-renewable water. Portions of the aquifer will not naturally recharge due to layers of clay between the surface and the water-bearing formation, and because rainfall rates simply do not match rates of extraction for irrigation. The term fossil water is sometimes used to describe water in aquifers that was stored over centuries to millennia. Use of this water is not sustainable when the recharge rate is slower than the rate of groundwater extraction.
In California, large amounts of groundwater are also being withdrawn from Central Valley groundwater aquifers. California's Central Valley is home to one-sixth of all irrigated land in the United States, and the state leads the nation in agricultural production and exports. The inability to sustain groundwater withdrawals over time may lead to adverse impacts on the region's agricultural productivity.
The Central Arizona Project (CAP) is a long canal that diverts a year from the Colorado River to irrigate more than of farmland. The CAP project also provides drinking water for Phoenix and Tucson. It has been estimated that Lake Mead, which dams the Colorado, has a 50-50 chance of running dry by 2021.
The Ipswich River near Boston now runs dry in some years due to heavy pumping of groundwater for irrigation. Maryland, Virginia and the District of Columbia have been fighting over the Potomac River. In drought years like 1999 or 2003, and on hot summer days the region consumes up to 85 percent of the river's flow.
As of 2010, the threat of running out of water was considered greater than that of Al-Qaeda or instability. There was speculation that Yemenis would have to abandon mountain cities, including Sana'a, and move to the coast. The cultivation of khat and poor water regulation by the government were partly blamed.
Vital aquifers everywhere are becoming contaminated with toxins. Once an aquifer is contaminated, it is not likely that it can ever recover. Contaminants are more likely to cause chronic health effects. Water can be contaminated from pathogens such as bacteria, viruses, and parasites. Also, toxic organic chemicals can be a source of water contamination. Inorganic contaminants include like arsenic, barium, chromium, lead, mercury, and silver. Nitrates are another source of inorganic contamination. Finally, Leachate radioactive elements into the water supply can contaminate it.
In West Africa and other places like Nepal, Bangladesh, India (such as the Ganges Delta), and Peru, major changes in the rivers generate a significant risk of violent conflict in coming years. Water management and control could play a part in future resource wars over scarce resources.
Water should be used more efficiently in industry, which should use a closed water cycle if possible. Also, industry should prevent polluting water so that it can be returned into the water cycle. Whenever possible, Graywater should be used to irrigate trees or lawns. Water drawn from aquifers should be recharged by treating the wastewater and returning it to the aquifer.
Water can be conserved by not allowing freshwater to be used to irrigate luxuries such as . Luxury goods should not be produced in areas where freshwater has been depleted. For example, 1,500 liters of water is used on average for the manufacturing of a single computer and monitor.
In Ladakh, a high plateau behind the Himalaya, villagers helped by an engineer and school students build ice stupa as water storage to favour water at spring as natural glaciers retreat.
Experience shows that higher water prices lead to improvements in the efficiency of use—a classical argument in economics, pricing, and markets. For example, Clark County, Nevada, raised its water rates in 2008 to encourage conservation. Economists propose to encourage conservation by adopting a system of progressive pricing whereby the price per unit of water used would start out very small, and then rise substantially for each additional unit of water used. This tiered-rate approach has been used for many years in many places, and is becoming more widespread. A Freakonomics column in the New York Times similarly suggested that people would respond to higher water prices by using less of it, just as they respond to higher gasoline prices by using less of it. The Christian Science Monitor has also reported on arguments that higher water prices curb waste and consumption.
In his book The Ultimate Resource 2, Julian Simon claimed that there is a strong correlation between government corruption and lack of sufficient supplies of safe, clean water. Simon wrote, "there is complete agreement among water economists that all it takes to ensure an adequate supply for agriculture as well as for households in rich countries is that there be a rational structure of water law and market pricing. The problem is not too many people but rather defective laws and bureaucratic interventions; freeing up markets in water would eliminate just about all water problems forever... In poor water-short countries the problem with water supply—as with so many other matters—is lack of wealth to create systems to supply water efficiently enough. As these countries become richer, their water problems will become less difficult". This theoretical argument, however, ignores real-world conditions, including strong barriers to open water markets, the difficulty of moving water from one region to another, inability of some populations to pay for water, and grossly imperfect information on water use. Actual experience with peak water constraints in some wealthy, but water-short countries and regions still suggests serious difficulties in reducing water challenges.
Loss of biodiversity can be attributed largely to the appropriation of land for agroforestry and the effects of climate change. The 2008 IUCN Red List warns that long-term droughts and extreme weather puts additional stress on key habitats and, for example, lists 1,226 bird species as threatened with extinction, which is one-in-eight of all bird species.
To produce that fresh water, it can be obtained from ocean water through desalination. A 17 January 2008 article in The Wall Street Journal stated, "World-wide, 13,080 desalination plants produce more than of water a day, according to the International Desalination Association". In 2005 Israel was desalinizing water at a cost of US$0.53 per cubic meter. In 2006 Singapore was desalinizing water for US$0.49 per cubic meter. In 2008 after being desalinized at Jubail, Saudi Arabia, water was pumped inland though a pipeline to the capital city of Riyadh.
However, several factors prevent desalination from being a panacea for water shortages:
At last resort, it is possible in some particular regions to harvest water from fog using nets. The water from the nets drips into a tube. The tubes from several nets lead to a holding tank. Using this method, small communities on the edge of deserts can get water for drinking, gardening, showering and clothes washing. Critics say that fog catchers work in theory but have not succeeded as well in practice. This is due to the high expense of the nets and pipe, high maintenance costs and low quality of water.
An alternative approach is that of the Seawater Greenhouse, which desalinates seawater inside a greenhouse, using evaporation and condensation powered by solar energy. Successful pilots have been conducted growing crops in desert locations.
China
United States
Per capita withdrawal of water
+ Freshwater withdrawal by country and sector (top 15 countries, per capita) 94 74 98 79 90 91 86 41 93 76 1 11 93 92 74 87 91
Turkmenistan
Kazakhstan and Uzbekistan
Water shortfall by country
+ Freshwater shortfall by country (top 15 countries) 14.9 3.7 2.5 2.2 0.4 0.4 0.4 0.2 0.2 0.1 0.0 0.0 0.0
Saudi Arabia
Libya
Yemen
United Arab Emirates
Consequences
Famine
Health problems
Human conflicts over water
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Solutions
Water conservation
Water management
Climate change
Backstop water sources
Nevertheless, some countries like Spain increasingly rely on desalination because costs of the technology continue to drop.
See also
External links
Books
Audio books
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