An increasing demand
85% of the world population lives in the driest half of the planet.
783 million people do not have access to clean water and almost 2.5 billion do not have access to adequate sanitation.
6 to 8 million people die annually from the consequences of disasters and water-related diseases.
Various
estimates indicate that, based on business as usual, ~3.5 planets Earth
would be needed to sustain a global population achieving the current
lifestyle of the average European or North American.
Global
population growth projections of 2–3 billion people over the next 40
years, combined with changing diets, result in a predicted increase in
food demand of 70% by 2050.
Over
half of the world population lives in urban areas, and the number of
urban dwellers grows each day. Urban areas, although better served than
rural areas, are struggling to keep up with population growth
(WHO/UNICEF, 2010).
With
expected increases in population, by 2030, food demand is predicted to
increase by 50% (70% by 2050) (Bruinsma, 2009), while energy demand from
hydropower and other renewable energy resources will rise by 60% (WWAP,
2009). These issues are interconnected – increasing agricultural
output, for example, will substantially increase both water and energy
consumption, leading to increased competition for water between
water-using sectors.
Water availability is expected to decrease in many
regions. Yet future global agricultural water consumption alone is
estimated to increase by ~19% by 2050, and will be even greater in the
absence of any technological progress or policy intervention.
Water
for irrigation and food production constitutes one of the greatest
pressures on freshwater resources. Agriculture accounts for ~70% of
global freshwater withdrawals (up to 90% in some fast-growing
economies).
Economic growth
and individual wealth are shifting diets from predominantly
starch-based to meat and dairy, which require more water. Producing 1 kg
of rice, for example, requires ~3,500 L of water, 1 kg of beef ~15,000
L, and a cup of coffee ~140 L (Hoekstra and Chapagain, 2008). This
dietary shift is the greatest to impact on water consumption over the
past 30 years, and is likely to continue well into the middle of the
twenty-first century (FAO, 2006).
About
66% of Africa is arid or semi-arid and more than 300 of the 800 million
people in sub-Saharan Africa live in a water-scarce environment –
meaning that they have less than 1,000 m3 per capita (NEPAD, 2006).
The impact of climate change
The
IPCC predicts with high confidence that water stress will increase in
central and southern Europe, and that by the 2070s, the number of people
affected will rise from 28 million to 44 million. Summer flows are
likely to drop by up to 80% in southern Europe and some parts of central
and Eastern Europe. Europe’s hydropower potential is expected to drop
by an average of 6%, but rise by 20–50% around the Mediterranean by 2070
(Alcamo et al., 2007).
The
cost of adapting to the impacts of a 2°C rise in global average
temperature could range from US$70 to $100 billion per year between 2020
and 2050 (World Bank, 2010). Of this cost, between US$13.7 billion
(drier scenario) and $19.2 billion (wetter scenario) will be related to
water, predominantly through water supply and flood management.
A resource without borders
Water is not confined to political borders.
An estimated 148 states have international basins within their territory
(OSU, n.d., 2008 data), and 21 countries lie entirely within them (OSU,
n.d, 2002 data).
There
are 276 transboundary river basins in the world (64 transboundary river
basins in Africa, 60 in Asia, 68 in Europe, 46 in North America and 38
in South America).
185 out
of the 276 transboundary river basins, about two-thirds, are shared by
two countries. 256 out of 276 are shared by 2, 3 or 4 countries (92,7%),
and 20 out of 276 are shared by 5 or more countries (7,2%), the maximum
being 18 countries sharing a same transboundary river basin (Danube).
46% of the globe’s (terrestrial) surface is covered by transboundary river basins.
148
countries include territory within one or more transboundary river
basins. 39 countries have more than 90% of their territory within one or
more transboundary river basins, and 21 lie entirely within one or more
of these watersheds.
Russian
Federation shares 30 transboundary river basins with riparian
countries, Chile and United States 19, Argentina and China 18, Canada
15, Guinea 14, Guatemala 13, and France 10.
Africa
has about one-third of the world’s major international water basins –
basins larger than 100,000 km2. Virtually all sub-Saharan African
countries, and Egypt, share at least one international water basin.
Depending on how they are counted, there are between 63 (UNEP, 2010b)
and 80 (UNECA, 2000) transboundary river and lake basins on the African
continent.
Rich nations are
tending to maintain or increase their consumption of natural resources
(WWF, 2010), but are exporting their footprints to producer, and
typically, poorer, nations. European and North American populations
consume a considerable amount of virtual water embedded in imported food
and products. Each person in North America and Europe (excluding former
Soviet Union countries) consumes at least 3 m3 per day of virtual water
in imported food, compared to 1.4 m3 per day in Asia and 1.1 m3 per day
in Africa (Zimmer and Renault, n.d.).
Land
grabbing is another increasingly common phenomenon. Saudi Arabia, one
of the Middle East’s largest cereal growers, announced it would cut
cereal production by 12% a year to reduce the unsustainable use of
groundwater. To protect its water and food security, the Saudi
government issued incentives to Saudi corporations to lease large tracts
of land in Africa for agricultural production. By investing in Africa
to produce its staple crops, Saudi Arabia is saving the equivalent of
hundreds of millions of gallons of water per year and reducing the rate
of depletion of its fossil aquifers.
Nearly
all Arab countries suffer from water scarcity. An estimated 66% of the
Arab region’s available surface freshwater originates outside the
region.
Pollution
The treatment of wastewater requires
significant amounts of energy, and demand for energy to do this is
expected to increase globally by 44% between 2006 and 2030 (IEA, 2009),
especially in non-OECD countries where wastewater currently receives
little or no treatment (Corcoran et al., 2010).
Pollution
knows no borders either. Up to 90% of wastewater in developing
countries flows untreated into rivers, lakes and highly productive
coastal zones, threatening health, food security and access to safe
drinking and bathing water Over 80% of used water worldwide is not
collected or treated (Corcoran et al., 2010).
Cooperation, a contrasted reality
There
are numerous examples where transboundary waters have proved to be a
source of cooperation rather than conflict. Nearly 450 agreements on
international waters were signed between 1820 and 2007 (OSU, 2007).
Over 90 international water agreements were drawn up to help manage shared water basins on the African continent (UNEP, 2010).
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