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DESALINATION AND THE CONTINUITY OF HUMAN CIVILIZATION
Water, Population and Development
To support the growing
human population, which has already crossed the 6
billion mark and is expected to reach 8.3 billion in
2025, and 10 - 12 billion in 2050, humanity must rely on
industrial development within a framework of
socio-economic development. The Dublin Principles and
also Agenda-21, particularly its Freshwater Chapter,
make it clear that water is a key to sustainable
development. The World Health Organization (WHO) has
estimated that 1000 cubic meters per person per year is
the benchmark level below which chronic water scarcity
is considered to impede development and harm human
health.
97.5% of the total global stock of water is saline and
only 2.5% is fresh water. Approximately 70% of this
global freshwater stock is locked up in polar icecaps
and a major part of the remaining 30% lies in remote
underground aquifers. In effect, only a miniscule
fraction of freshwater (less than 1% of total
freshwater, or 0.007% of the total global water stock)
that is available in rivers, lakes and reservoirs is
readily accessible for direct human use. Furthermore,
the spatial and temporal distribution of the freshwater
stocks and flows is hugely uneven.
Hydrologists estimate the average annual flow of all the
world's rivers to be about 41,000 km3/yr. Less than a
third of this potential resource can be harnessed for
human needs. This is further reduced by pollution such
as discharges from industrial processes, drainage from
mines and leaching of the residues of fertilizers and
pesticides used in agriculture.
Sun is the Source of Renewable
Energy and the Oceans are a Major Alternative Source of
Water
Just as the sun is an alternative source of energy to
meet future demands, the oceans are an alternative water
resource. However, extraction of fresh water from the
oceans requires significant development of desalination
infrastructure. Desalination is very energy-intensive,
and sustainable energy systems urgently need to be
developed. The most arid lands are also those blessed
with abundant solar energy and this needs to be
exploited for large-scale production of freshwater from
the oceans.
Human engineered desalination systems actually mimic the
hydrologic cycle, which is itself a grand process of
distillation. If these systems are driven by the sun,
they will augment the fresh water supplies of the global
hydrologic cycle. The resulting process will add a human
engineered, sustainable and very controllable,
contribution to the natural hydrological cycle. There is
a clear need for further research and development, and
adequate funding towards this end. The oil-rich and
water-poor Arab nations must, and they can afford at
present, take significant steps in this direction. They
are strangely living in a false paradise without
adequate concern about the inevitable crisis they will
have to face in the not too distant a future when their
oil reserves will be exhausted.
Commercial Potential of
Desalination
The world has seen a 22-fold increase in desalination
capacity since 1972 and the figure continues to rise.
Desalinated water is still expensive and one way of
bringing down the cost is by building large-scale units
with appropriate technology. There were ambitious
studies in the 1960s and 1970s on large-scale thermal
desalination units with a capacity of 50 million gallons
per day, but little came of this. Economics of
desalination continues to be based on a flawed
accounting system, which disregards fundamental life
support systems.
Remember that main stream
economists (neoclassical economics) are still unwilling
and unable to internalize external costs in marketprices.
However 'natural capitalism' would certainly mean that
natural ressources and environmental costs need to be
part of the economic calculations. See The Economics
of Life and Death (John McMurtry ) and Energy
Economics: Deep Breath or http://www.eroei.com/articles/the_chain/energy_economics/
The 'dismal science' of economics has developed in
isolation from other sciences, in particular those that
concern the living world. As a result, what is necessary
to preserve our planet's life processes is all too
likely to be 'irrational' from an economic standpoint.
The choice is simple: to rewrite economics or to destroy
the natural world". (Goldsmith, 2003)
The current structures of the energy market and domestic
energy prices are major barriers to increasing the use
of renewables. However, policy dimensions, and cultural
issues all are challenges confronting decision makers
worldwide at local, regional and global levels.
As it is well known that oil and gas are running out and
soon or later, every type of fossil energy will run out
– including fossil uranium ore which is used by nuclear
power plants.
According to the findings of the Intergovernmental Panel
on Climate Change (IPCC), climate gases will have to be
reduced by at least 60 per cent by 2050 if earth
ecological system collapse is to be avoided.
The sun, with its by-products (renewable and
non-renewable resources) supplies our planet with many
times more energy per day than the earth consumes, as
for example if we assume the world energy demand for
electric power in 2004 is about 14.5 Terawatts and
considering the total solar energy potential of earth is
about 165000 Terawatts the result is about 11400 times
the world energy demands. If we consider just 3% of the
Arab region surface area, it is equivalent to about 127.7
Terawatts. This is indeed what may be classified as true
sustainable wealth of the Arab region, however the sad
story is that Arab governments have unfortunately failed
to realize the proper utilization of this enormous clean
energy.
The apparent abundance of fossil fuels brings the energy
prices deceitfully to low levels that are surely
unsustainable. This is tantamount to robbing future
generations, and is in breach of the principle of
intergenerational equity. The result is a situation in
which decision makers have been satisfied with a
performance ratio of around 6 to 10. With suitable
motivation, the industry should be capable of achieving
performance ratios of 20 or even 30 for thermal
desalination processes.
Market forces tell us that the costs of conventional
water supplies from freshwater flows are expected to
rise sharply. In urban water management, most of the
cost goes into distribution and sewage treatment,
whereas a significant decline has been noticed in recent
years in the costs of desalination. In the last fifty
years, a reduction of nearly 90% has been achieved in
energy usage for seawater desalting. By 2025 the costs
of desalination are likely to be of the same order as
those of urban water supply and sanitation. Furthermore,
water quality improvement can be achieved at the local
level as well as by means of large industrial plants. Of
late, there has been an increasing focus on the
installation of small-scale distillation plants at the
community and household level, in order to remove
contaminants in supply lines. Thus small-scale
distillation units for water purification (particularly
solar based ones) offer good commercial potential.
Desalination and Sustainable
Development:
Desalination has already made a major contribution to
quality of life in the most arid regions of the world,
particularly the Arab region and North Africa. Without
desalination, many of these regions would have remained
uninhabited. With rising global demand, uneven
distribution of freshwater and increasing population,
Malthusian apocalypse would have already come true.
Desalination technology is providing safe drinking water
even to some 'water-rich' nations where pollution
reduced the quality of natural waters. Thus, as a means
of augmenting fresh water supplies, desalination
contributes significantly to global sustainability.
The desalination associations and institutions have a
pivotal role to play here, encouraging the scientific
and industrial communities to make efforts to meet world
water requirements through environmentally sustainable
technologies. Investments in this direction are not
impossible; the annual global expenditures for arms and
advertisement are currently about US$780 billion (SIPRI
1998) and US$435 billion respectively. Just 1% of this
over ten years would be a prudent diversion of resources
enough to provide safe water and decent sanitation
facilities for all human beings.
Solar Energy for Desalination
in the Arab World
The Arab World (AW) stretches across well over 12.9
million square kilometers of area including North Africa
and the part of Western Asia known as the Arab Region.
This is a region of highest water scarcity and arid
climate with annual precipitation ranging from 100 mm to
400 mm. The total annual renewable water resources (TARWR)
vary tremendously between the different Arab countries
ranging between 0.1 km3/yr for Qatar and 75 billion
m3/yr for Iraq. With a current total population of
around 325 million people and a very high growth rate of
2.7%, the per capita share of TARWR has dropped well
below the UN threshold for water poverty (1000 m3 per
year) with most of the Gulf Arab countries reaching per
capita TARWR below 200 m3/yr.
In order to meet the rising water demand required by an
expanding population and developing economy and to fill
the gap between supply and demand, it was found that
desalination of seawater and brackish water could
provide a portion of the shortfall in water supply. The
growing technology of desalination is currently
providing enormous quantities of water to meet the
escalating needs for domestic and industrial sectors in
many water scarce Arab countries. Based on recent
published estimates, the current water
deficit in the region amounts to 60 billion m3/year and
this is expected to grow to 160 billion m3/year by 2050.
A significant amount of the current 60 billion m3/year
deficit is provided by desalination and it is expected
that desalination will also provide more to make up for
the 160 billion m3/year needed by 2050.
Desalination processes, however, are energy intensive
and are responsible for a good portion of GHG emissions
in the region. To produce 1 m3 of desalted
water from a typical cogeneration plant results in 12 kg
of CO2 gas emission (at an energy consumption rate of 24
kWh/m3 using thermal processes). The current
CO2 emission due to desalination can therefore be
estimated as 720 million ton CO2 per year. With
business-as-usual, this amount is expected to increase
to 1600 million ton CO2 by 2050. This is an
unacceptable situation and cannot be allowed to continue
from both population health viewpoint and from the
global warming point of view.
Fortunately, the AW is blessed with a renewable energy
resource that is matched only in very few areas of the
world, namely, Solar Energy. The region lies in the so
called “sun belt” area which is the area of the globe
that has the highest solar radiation intensity. The
solar radiation intensity in the region lies in the
range 2000 – 2800 kWh/m2 yr. The major advantage of
using solar energy for desalination is that the GHG
emissions produced by solar desalination plants is
almost zero and the resource is available almost
everywhere in the AW. The current issue of high capital
cost for solar collectors and solar PV fields is a
temporary problem that will be eventually solved by new
technology, mass production and engineering innovation.
The total installed capacity of desalinated water
systems in the world in 2006 was about 37 million m3/d,
which is expected to increase drastically in the next
decades. The dramatic increase in desalinated water
supply will create a series of problems, the most
significant of which are those related to energy
consumption. It has been estimated that production of 25
million m3/d requires about 338.4 million barrels of oil per year
(considering specific energy consumption 24 kWh/m3).
Even if oil were much more widely available, could we
afford to burn it on the scale needed to provide
everyone with fresh water? Given the current
understanding of the greenhouse effect and the
importance of CO2 levels, this use of oil is debatable.
Thus, apart from satisfying the additional energy
demand, environmental pollution would be a major
concern. If desalination is accomplished by conventional
technology, then it will require burning of substantial
quantities of fossil fuels]. Fortunately, the Arab world
(AW), as many other regions of the world, is blessed
with a non-polluting resource of energy and is
renewable, namely Solar Energy.
Problems relevant to the use of fossil fuels, in part,
could be resolved by considering possible utilization of
renewable resources, such as solar energy. In fact, most
developing countries, with vast areas but having no
access to the electric grid, appear to be well versed in
renewable energies. Such sources, able to be used
directly even at far remote and isolated areas, could be
exploited to power low to medium scale desalination
plants. A meaningful contribution from the above
mentioned environmentally friendly energy resources
would certainly be to extend the foreseen duration of
fossil fuels store as well as attenuate the socially
negative impacts caused by sudden increases in oil
price. It is to be noted that nearly 3 kg of CO2
generated for each m3 of water produced
(at an energy consumption rate of 6 kWh/m3
with the alternative desalination technology currently
used on large scale) could be avoided if the
conventional fuel is replaced by a renewable one.
Security policy should be Renewable Energy Policy
Our dependency on exhaustible fossil and uranium
resources leads to the vulnerability of societies.
Remember that there are many hidden costs associated
with fossil and nuclear energy such as, undermining
health, destabilizing the climate system, disposal of
radioactive nuclear waste and pollution of water
resources. This may lead to irreversible damage to
Earth's Life Support Systems. Global life-support
systems, incorporate the environmental resources
(healthy environment) that sustain the economy as well
as those - such as water and air , that support life on
earth . At present, critical stress suffered by our
environment is manifest in the air, water, and soil, our
climate, and plant and animal species. Should this
deterioration be allowed to continue, we can expect to
alter the living world to the extent that it will be
unable to sustain life as we know it. Just imagine the
enormous expenditures on international security
associated with safeguarding of fossil and atomic fuels
including processing. All these are bad enough but an
even worse aspect of nuclear technology is the creation
of massive security risks such as nuclear weapons
proliferation and nuclear terrorism. All of the
financial expenditures should wisely be used to promote
the use renewable energy resources for eternal peace and
protection of life support systems.
Therefore humanity should consider seriously the total
replacement of fossil and atomic energy by renewable
energy in the next 40-50 years. Atomic and fossil energy
prices will inevitably increase due to the exhaustion of
natural resources as well as the additional costs from
environmental damages. Renewable energy prices will
continue to drop due to the increase in mass production
and improvement of technology. As there are no fuel
costs for wind, solar, the renewable energy system is
more cost effective, perhaps exception to this is
biomass. However Most of biomass is the energy source
for the bottom half of the global economic ladder, three
billion people or so. A great deal of that was
unsustainably burned vegetation, cow dung, and other
materials that are used where modern energy is not
available or affordable (Richard Smalley).
See also
Solar Energy-The
Availability Perspective for Meeting the Future Energy
Demands of the Arab as well as the Entire World.
Let us
hope that the entire world rises to meet this
requirement of faith in the survival of life on earth.
Darwish Al Gobaisi
Please
download the
presentation by Prof. Richard E. Smalley (Nobel
Lauriate), on
Humanity's Top Ten Problems for next 50 years
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