The Earth has 1,386,000,000 cubic kilometers (km3) of total water resource, counting all the oceans, lakes, rivers, aquifers, glaciers, icecaps and icebergs. But the world's freshwater glass is less than half-full and becoming increasingly scarce. Scarcity of freshwater isn't a new thing. Throughout history, civilizations have fallen due to lack of water and droughts. These include ancient Egyptian, Hittite, Mycenaean civilizations more than 3,200 years ago that irreparably suffered from a 150-year drought beginning in 1250 BC, and the Anasazi people in the American Southwest during the 12th century AD. "Water security" is now a growing concern in many places.
The importance of water for all life forms
on Earth cannot be overstated. Without water, especially freshwater for
creatures like us who don't live in the seas, there can be no life on the
Earth. Humans can stay alive for only 3 to 5 days without water. It is the
basis of Leonardo da Vinci's apt observation, "Water is the driving force
of all nature." This truism is reflected in Samuel Taylor Coleridge's fluid words from
his Rime of the Ancient Mariner:
Water, water, every where,
And all the boards did shrink;
Water, water, every where,
Nor any drop to drink.
"Nor any drop to drink"
references that only 2.5% of all water on the Earth (total water) is freshwater.
Of that, glaciers and ice caps account for 1.7% of total water; fresh ground
water accounts for 0.75% of total water. Fresh river and lake water accounts
for 0.0009% of total water. There are 34.6 million km3 of fresh water on our
planet, which seems like a lot, but.
There are 2 reasons for the growing
scarcity of freshwater. First, human population continues to increase. More
than 7.1 billion humans now live on the Earth, every one of whom requires daily
potable water to survive. The world’s population has doubled in the last 40
years; its use of fresh water has quadrupled.
Second, every human not only needs
water, he/she also needs food stay alive. Agriculture consumes more freshwater
than any other single use. Irrigation of cropland, first used by Sumerian farmers
more than 7,500 years ago, is how agriculture uses water, often lots of it. In the
proverbial average year, the UN's Food & Agriculture Organization believes 1,000
m3 of water per inhabitant is considered as a minimum to sustain life and ensure agricultural production in
countries with climates that require irrigation for agriculture. According to
David Suzuki, an environmental advocate, more than one billion people lack
adequate access to clean water.
In the US, irrigation accounts for 37%
of all freshwater withdrawals, the single largest use. That's 67% of all US groundwater
withdrawals and 28% of all surface water withdrawals. California is the largest
consumer of irrigation water in the nation, representing 19% of all US
irrigation use. Within California, irrigation accounts for 73% of the State's total freshwater usage.
The world's freshwater resources are
not distributed evenly. Nine "water-rich" nations account for 60% of
world's natural freshwater resources (listed in order of their internal
freshwater resources, biggest first): Canada, Brazil, Peru, Columbia, Russia, Indonesia,
US, China and India. At the other end of the world's water glass, 33 countries
depend on other nations for over 50% of their renewable freshwater resources,
including; Argentina, Egypt, Israel, the Netherlands, Pakistan, Syria and Viet
Nam.
Asia, which has 60% of the world's
population, has 28% of its freshwater resources. Africa, with 15% of the
world's population, has 9% of its freshwater resources. By contrast, the
Americas (North, Central and South) are relatively awash in water with 13% of
world population and 45% of its water. A fair amount of North America's water
lies frozen in Alaska's and Canada's far north (although now melting more and
more into the Arctic sea).
Consumption of water also varies
significantly by nation. India withdraws the most water for its use than any other
country (761 km3/yr), followed by China (579 km3/yr) and the US (482 km3/yr). The
ordering of water withdrawal/consumption by nation is much different when
considering per capita usage.
On a per capita basis, the world's largest
water user is Turkmenistan (4,762 m3/p/yr); who'd of guessed? Turkmenistan is a
central Asian nation of 5 million people. It uses 98% of its total freshwater for
irrigation, mostly thirsty cotton plants – it is the world's 9th
largest cotton producer. The US' per capita water usage is ranked 10th highest (1,518 m3/p/yr).
Throughout recorded history, nations
that can afford it have sponsored massive and costly water projects that have
brought freshwater from afar to its citizens. The Romans famously built
aqueducts. In the arid West, Americans built canals, aqueducts and captured
entire rivers for drinking and irrigation water – Los Angeles' controversial
expropriation that drained the Owens Valley's water in the early 20th
century (at a cost of more than $557M in current dollars). Subsequently, LA
managed to get a substantial portion –about 50% – of its water needs from the
Colorado River that allowed the parched LA basin to dramatically grow. Other
water-grabs by semi-desert Southern California include 2 aqueducts begun in the
1960s that start in the San Joaquin-Sacramento River delta near the San
Francisco Bay and transport water southward for 700 miles.
Like California, China's water dilemma
is mostly founded on geography but also behavior. Eighty percent of
China’s water is in the south, principally the Yangzi River basin. Half the
people and two-thirds of the farmland are in the north, including the Yellow
River basin. Beijing has the sort of water scarcity usually associated with
Saudi Arabia: just 100 m3 per person a year is locally available. The water
table under Beijing has dropped by nearly 1,000 feet since the 1970s. Because
of massive, unchecked industrial pollution, only 50% the water sources in Chinese
cities are now safe to drink. More than 70% the groundwater in the north China
plain is unfit for any human contact, even for washing.
To remedy this calamity China has wholly
focused on increasing available water supplies for its dry northeastern region,
where Beijing lies. Thus, the nation has been busy constructing dams (including
the world's largest, the Three Gorge Dam) and a gigantic series of engineered waterways
– called the South-North Water Diversion Project – that will link the Yangzi River
with the Yellow River and transport water over 1,800 miles northward. Will
these hugely expensive efforts work? At least 600 million parched people hope
so.
More generally, what alternatives
should we consider to slack our growing thirst? Aside from offering alms to Lono
and Chaac (the Hawaiian and Mayan gods of rain, respectively), there are 3 related
actions that should be carried out. The first 2 focus on reducing demand for
water, one via technology, the second through our tried-and-true economic
stand-by, prices. The last action addresses increasing the supply of water.
1.
Improve the water-efficiency of
agricultural irrigation, and industrial and residential usage (in that order of
importance);
2.
Raise the price of water, especially
for non-residential consumption; and
3.
Continue searching for new freshwater
resources.
Improving water efficiency (also
called water productivity) is necessary to "stretch" existing water
resources. Efficiency can include process improvements that use less water as
well as improved recycling and treat water methods so it can be used again
"downstream." Industry and agriculture account for 87% of
total water use in the US. For agriculture it means getting rid of traditional,
water-inefficient irrigation methods such as flooding and high-pressure (e.g., center-pivot)
spraying methods. Instead, crop irrigation needs to use much more efficient
low-pressure (e.g., drip) systems. Such changes can save 25 to 50% of water
used for crop irrigation.
Why haven't industrial and
agricultural water users already adopted these efficiency options? Because the
cost of using water is nonsensically low, so new water-efficient techniques and
technologies aren't cost-effective. Thus, these users stick with the water-wasting
status quo. This leads to the next action.
The second action is founded on Ben
Franklin's quote given at the beginning of this blog. Our collective well isn't
yet completely dry, but as water volumes from aquifers, lakes and rivers are
reduced, users and policy-makers need to recognize the value of water now all
too often exceeds its price. The price of water, especially for non-residential
users, should increase, probably substantially.
With few exceptions, water is
distributed in the US (and beyond) by public agencies – the US Bureau of
Reclamation and local water boards, irrigation districts and municipal
utilities. These agencies have pricing authority for virtually all water sold
to the public. For most of their history these agencies practically gave away
the public's water to users. Reflecting the unstated but adhered-to motto of
the Bureau of Reclamation – "economics be dammed" – the Bureau was
compelled by the 1926 Omnibus Adjustment Act to set water prices according to
the then mostly dry dirt-poor farmers' "ability to pay," not the actual
cost of providing the water. Electricity sales revenues from the Bureau's
multitude of hydroelectric dams were used to substantially subsidize water
prices. Many irrigating farmers – meaning virtually all farmers in Arizona,
Utah, Idaho and California – have benefited enormously.
In recent years a small but growing
number of these agencies have revised their give-away policies, moving from
being quite benthic, to raising water's price to better reflect its worth. More
agencies should to do this. Freshwater remains a seriously under-priced resource.
With higher water prices, first for non-residential customers, users will have real incentive to install
technologies that employ this precious resource more efficiently
and effectively.
Finally, efforts should continue to
search for new water resources. Just like oil and natural gas companies devote
money, time and effort to discovering more reserves, so too should governments
look for "new" water. And I don't mean building more dams or lassoing
glaciers. I mean discovering new aquifers, like recently happened in Kenya. It
was announced in September that the just-located Lotikipi Basin Aquifer in northern Kenya may hold 250
billion m3 of water. This and several other aquifers were discovered in Kenya
using satellite and drilling technologies. Hopefully, these techniques can add
supply in other drought-prone areas of Africa and beyond.
With some luck, these demand- and
supply-side actions will provide more vital drops of water for us to drink. We
need every one of them.
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