water desalination as a long-term sustainable solution to alleviate global freshwater scarcity? a...

ELSEVIER Desalination 169 (2004) 287-301

DESALINATION

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Water desalination as a long-term sustainable solution to alleviate global freshwater scarcity?

A North-South approach

Gregor Meerganz von Medeazza* Institut de Ci~ncia i Tecnologia Ambientals, Universitat Autbnoma de Barcelona, Edifici Ci~ncies,

Torre Area 9, 4a planta, C5-438, 08193 Bellaterra (Barcelona), Espa~a Tel. +34 (93) 581-2974; email: [email protected]

Received 16 February 2004; accepted 26 April 2004

Abstract

The direct per capita availability of freshwater resources decreases as the world population continues its growth. This fact threatens the well-being and subsequently the survival of humanity as a whole. In this article, the North-South approach is used to raise certain questions on the significance of scarcity. Indeed, the issue of water for tourists might seem far removed from water scarcities for poor people in the South. If we assume a technological trajectory of decreased monetary costs, decreased energy costs per cubic metre, and moreover increased share of renewable energies in desalination (a kind of win-win-win scenario), does this mean that water for urban use of poor people in the world will cease to be a problem? Will not the energy costs remain too high? An approach based on the "basic needs" scenario is relevant to address these questions. The Canary Island of Lanzarote (Spain) and the city of La~youne, (Moroccan Sahara) are taken as explanatory case studies.

Keywords: Water scarcity; Basic human needs; Oil peak; Strong sustainability; Water demand management

1. Introduct ion

In the scientific community, the belief that knowledge and human ingenuity will ultimately

*The opinions expressed herein are the author's alone and do not necessarily represent either the views of the Institute for Environmental Science and Technologies or the Auto- nomous University of Barcelona.

solve water scarcity problems through the efficient improvement o f freshwater production is widely held. In this vision, the sea- and brackish water desalination by reverse osmosis (RO) technologies seems very promising. However, this non-conventional alternative delivers solutions on a local and short-term scale. Indeed, with ever-

Presented at the EuroMed 2004 conference on Desalination Strategies in South Mediterranean Countries: Cooperation between Mediterranean Countries of Europe and the Southern Rim of the Mediterranean. Sponsored by the European Desalination Society and Office National de l'Eau Potable, Marrakech, Morocco, 30 May-2 June, 2004.

0011-9164/04/$- See front matter © 2004 Elsevier Science B.V. All rights reserved

doi:10.1016O.desal.2004.04.001

288 G. Meerganz yon Medeazza / Desalination 169 (2004) 287-301

decreasing cheap energy resources, desalination technologies, as well as other energy-intensive water supply systems, might well fail to fulfil their long-term expectations. As sustainability cannot be imposed in a dictatorial manner but only learnt, society requires methods to make such learning effective at the societal level. Therefore, under such perspective, sustainability could be viewed as a "reflexive learning process" [1]. This is exactly what this paper intends to deliver, especially to the scientific community striving to alleviate the freshwater scarcity crisis.

In order to embrace fully the concept of sustainable water management, one should look beyond the limits of technology. This work therefore freely overshoots the scope of the "desalination technology" as such: it both intends to address a warning by questioning the sustainability of the desalination alternative and wishes to lay the foundations for future debates within the framework of cooperation among the Medi- terranean countries of Europe and the southern rim of the Mediterranean.

2. Water accounts

The presence of water characterises our planet. Thanks to the unique properties of its hydrogen bonds, water has a high heat capacity, distributing heat around the globe. Entropy studies related to ecology and economy carried out by Tsuchida et al. [2,3] have emphasized the vital role that the hydrological cycle plays in maintaining the earth's open steady-state condition as well as the renewable and regenerative ability of its living systems. From this perspective, the world's oceans help to regulate and moderate the planet's climate and are a major habitat for many of the planet's living creatures. Moreover, water's superiority as a solvent enables the dilution of a variety of compounds and degrades some of our wastes.

Water covers about 71% of the earth's surface and the earth's organisms are made up mostly of

water (by weight, 60% of a tree, 50-70% of most animals, 80% of the human brain). Freshwater is a vital resource for humanity. However, in the planet's water budget only a tiny fraction (0.014%) of the world's total water supply is directly readily available freshwater [4-7]. The hydrologic cycle, powered by solar and gravitational energy, continuously collects, purifies and distributes this fixed supply of available freshwater. This purification process provides plenty of freshwater as long as we do not either overload it with persistent pollutants and non- degradable wastes or withdraw it from underground supplies faster than it is replenished. Unfortunately, we are currently doing both.

3. Population growth

Nevertheless, this relatively tiny fraction of freshwater that constitutes our survival support, satisfied during millennia, is humanity's desire to unfold itself. However, for the first time in history human population doubling time reaches such rates. World population has literally exploded, starting to grow exponentially, especially during the past couple of centuries. This demographic boom, combined with current consumption patterns, indirectly triggered the major environmental and social conflicts we are exper- iencing worldwide today.

Through the extensive use of fossil fuel energy, the industrial revolution enabled rapid scientific advances that led to an explosion of agricultural food production and impressive medical care improvements. Worldwide, this has drastically decreased mortality rates. Following the current demographic trajectory, the human population will surpass 10 billion by the year 2030 [8,9]. Moreover, since living standards - - represented in classical economics by global growth trends - - also increased, general consumption patterns and, in particular, demand for freshwater, has grown rapidly (withdrawal pro- jections are shown in Fig. 1), yet faster than the

G. Meerganz von Medeazza / Desalination 169 (2004) 287-301 289

6000 ) . . . . . . . . . . . . . . X ~ 500~1 '[ ~ Agrieniture .... Municipal

-- - / ~ Total x CDS Low ,..,'~7"~ 4000 ? l,~uSt~ ~ Reservoh's ~ . . . . ~ .....

= 2000t - _~* * ~" i000

0 'I I

1900 1920 1940 t960 1980 2000 2020 Year

Fig. 1. Global water withdrawals, 1900-I995, with projected future total withdrawals to 2025, according to a few Conventional Development Scenarios (CDS) [IPCC (2001); data from Shiklomanov et al., 2000 (after Raskin et al., 1997)].

population I, with less than 35 years as a doubling time since the 1950s [10]. Thus, the biosphere is being required to accommodate not just more, but in Carton's terms, effectively "larger" people.

4. Human appropriation and global freshwater scarcity

The demographic factor combined with the increasing per capita demand and the decreasing readily available resources (due to rising overall pollution) result in the era of global freshwater scarcity we are facing nowadays. As shown in the Fig. 2, the 25 countries currently suffering from water stress (withdrawals exceeding 20% of renewable water supply) are mostly located in the MENA regions and South Africa. This number is expected to rise to 90 by 2025 [11]; with about three-quarters of the world's major river systems being transnationally shared, water is likely to become the burning foreign policy and environmental security issue of this century. This trend will be exaggerated even further by projected global warming, altering rainfall patterns which might lead to dramatic flood and drought events, as well as water supply disruptions [12].

Through the solar-powered hydrological cycle, every year around 500,000 km 3 of water (86% from oceans and 14% from land) evaporate, and from this approximately 110.000 km 3 preci-

pitate back onto the continents [13]. Roughly 70,000 km 3 of this amount evaporates again from the continents, which leaves about 40,000 km 3 flowing annually towards the oceans [ 14]. Thus, this flow can be considered to constitute the earth's renewable freshwater stock. From this flow, however, only slightly more that 10,000 km 3 are accessible to us. When accounting for both the consumed and the contaminated vol- umes, the total appropriation of this flow in the year 2000 was well over 5,000 km 3. As Postel [15] points out, this is approximately eight times the yearly flow of the Mississippi River. Finally, of this water withdrawn worldwide each year, about 69% is used for irrigation purposes and 23% for energy production (oil and gas production and power plant cooling), industrial food processing, manufacturing, cleaning and waste removal. Domestic and municipal use accounts for about 8% of worldwide water withdrawal [5]. These general trends are turned upside down in the case of Lanzarote, likewise Lagyoune. In these arid regions, domestic water accounts for around 80% of the total consumption. These are cases where the concept of"virtual water", developed by Allan [16,17], plays a decisive role in agricultural production.

On the one hand, human appropriation of these considerable water masses enabled the rapid development of our modern society with its numerous beneficial facets. On the other hand, as argued by Buenfil [ 18], this massive "extraction and diversion of freshwater for human use has induced a large array of social and environmental problems." Indeed, falling water tables, seawater intrusion, biodiversity loss, eutrophication, irre- versible contamination and stressed ecosystems, to name just a few, are some of the direct conse- quences of poor and unsustainable freshwater resource management.

What scarcity are we talking about? For cli- matic reasons, differences in average annual precipitation divide the world into water-scarce and water-sufficient regions. Similar divides exist

290 G. Meerganz von Medeazza / Desalination 169 (2004) 287-301

Fig. 2. Availability of freshwater in 2000.

within countries themselves. For instance, we must distinguish between the humid and dry Morocco. The kingdom features an evident divide between two "hydraulic regions". Northem river basins such as Sebou or Loukous, where water surpluses can be observed, are relatively humid (800-900 mm/y), as opposed to the arid south, with the basins 2 of Souss, Errachidia and Sahara (in which the province of Lafiyoune is located, having an average annual precipitation of around 60 mm). Similarly, in the Spanish case, only in the northern river basins and in Galicia, does precipitation exceed the potential evapotrans- piration [19]. Meanwhile, in all other national river basins there is a net water deficit as precipitation fails to provide sufficient supplies for a permanent vegetation to cover their entire territorial sections [20]. The Canary island of Lanzarote is an extreme example of the "dry Spain".

However, the poverty factor playing a sigm- ficant role in the case of Morocco, the vision of scarcity itself lies at another level. Hence, its "ecological perception" also changes. Indeed, as a general trend, the issue of water scarcity is fundamentally different in Europe than it is in North Africa, for instance. This becomes evident when considering that the hydraulic potential of a European country, such as France, is around 1000 billion m 3, while that of Morocco 3 is approximately 20 billion rn 3, with "per capita" availability decreasing from 3500 m3/y (1960) to 950 m3/y (2003) and an estimated 490 m3/y for 2020 [21]. Although some of the wealthier and more humid regions present similar perceptions as in Europe, the ecological visions nourished in the North turn into an unreasonable luxury when dealing with physical scarcities.

In Morocco, the real issue at stake is quantity rather than quality (the water delivered in Lags-


youne for instance, with a salinity of 1988/zS/cm, fails to meet Western standards, while considered as perfectly safe under the Moroccan norm). The situation is especially urgent in rural areas where direct access to drinking water is still strongly lacking 4.

Notwithstanding, as explained by Naredo [22], it is the human demand for available water in a given region and its associated consumption patterns that eventually tums a physical scarcity (of climatologic and territorial origin) into a social one, perceived by the local population. In the middle of the Sahara Desert, there is an evident physical water scarcity, yet not a social one if nobody inhabits that particular spot. Oppo- sitely, the area of Barcelona in Spain does not, relatively speaking, present a fierce physical scarcity. However, important demography, combined with high water demands and heavy con- taminating uses led to the construction of a desalination plant in order to provide sufficient supplies. In this case, scarcity can therefore be seen as the lack of enough resources to satisfy infinite and insatiable wants (as opposed to the "basic needs" that Max-Neef[23 ] defines as finite and few).

In this view, the notion of "water scarcity" must also be distinguished between its two senses, in a way similar to how Lotka [24] (in the 1910s) separated endo- and exosomatic uses of energy. Scarcity below 20 or 30 L/person/d is a physical scarcity where health indicators, such as cholera, may appear. Tourists in Lanzarote or "non-residents" in Laftyoune require daily 460 and over 310 L/person, respectively. Comparing this to the average daily consumption rates of the local population of Lanzarote (120 L/p) and Laftyoune (61 L/p, 58% of which consume 29 L/p), they consume, respectively, 3.8 and 5.1 times more water than the residents, despite efforts undertaken to inform visitors about the precarious water situation and reducing their consumption by installing water-saving devices 5.

It is also striking to see how tourism and the

water desalination industry simultaneously developed on the island of Lanzarote. Desalination production rose from 0.45 hm 3 in 1968 to 17.21 hm 3 in 2002 (a 3724% increase). Between the same period the number of tourists visiting Lanzarote rose from 10,205 to over 1.87 million per annum. The tourist industry - - t h e island's major economic income - - is therefore highly dependent on desalination processes and ultimately the availability of oil, the main energy provider. Furthermore, Lanzarote's water market is presently somewhat perturbed in the sense that domestic water consumption is highly subsidised, whereas the industry (tourism sector in the first place) is subject to certain eco-taxes. As a conse- quence, illegal or unregulated small-scale desalination plants are built by the private sector to meet the high water demands of the tourist industry. This results in unmonitored water consumption, an uncontrolled disposal of the saline brine residue and high induced social costs [25].

Population and economic growth, as well as climate change in the longer term, have the greatest influence on the present and future situation. This is why Lanzarote's strategy on the Biosphere (1997) was implemented. It served as a proposal to alter the development model of the island through a "tourism moratorium" with the view of alleviating environmental pressures by limiting the proliferation of new accommodation facilities.

Furthermore, the principal imbalance between water availability and its uses originates when human activities are imported to zones without any consideration for their inherent capability to host such social habits. Playing golf in the lush vegetation of the humid European North might certainly be a pleasing activity. Yet sprinkling entire hectares of arid soils in Lanzarote and Morocco (with environmentally costly water) or building a big-size swimming pool in a hotel establishment of La~youne in order to satisfy a desire for entertainment seems somewhat unreasonable. The same argument applies when


striving to grow tomatoes in the desert of Almeria or importing the H a m h a m culture into the Sahara. These communal hot bathing facilities, which represent a key custom of the Moroccan culture, were practically nonexistent in the southern regions before 1975 due to their large water requirements. Indeed, one single H a m h a m in La~youne consumes on average around 9,500 L/d. Since La~youne's water network has been developed, they started to appear on a massive scale. Modern society, thirsty for unconsidered progress and growth, further exacerbates the imbalance between the earth's natural capital and the ever-more demanding requirements for water.

5. D e s a l i n a t i o n as a s h o r t - t e r m a l t e r n a t i v e

With an annual precipitation average of around 60 mm/m 2 and its increasing water demand, desalination is, according to the National Office for Drinking Water (Office National de l'Eau Potable, ONEP) [21 ], the only solution for Laftyoune, as well as other Moroccan regions. It could additionally become an interesting flexible emergency back-up solution for providing drinking water for many other communities. Facing this situation, Morocco began using desalination in 1976 with the Tarfaya brackish water distillation plant and has developed since then fair expertise in this field.

Morocco's greatest facility is located in Lagyoune, with 7,000 m3/d of desalinated water since its inauguration in 1995 (an additional 5,600 m3/d are "mined" from the local aquifer). This desalinated volume is produced with an average energy cost of approximately 5.3 kWh/m 3. The total monetary cost (i.e., including energy, maintenance, amortisement, etc.) for 1 m 3 of desalinated water produced in this plant is approximately 2.78. However, users in Lagyoune pay less than 0.37/m3; the "real" cost is about six times higher than the actual price. This is only feasible due to a national "solidarity" policy

where deficit tariffs allowed in La~tyoune are compensated for by surpluses from other "water- rich" river basins. Nevertheless, the plant is currently being extended to produce a further 6,500 m3/d by April 2004. Similar plants can be found in Tarfaya, Boujdour, Smara and Tan-Tan, all located in the Sahara region; and a 43,000 m3/d plant is planned to be built in Agadir by 2008 (see Table 1 for further information).

Similarly, Lanzarote's water availability is among the lowest in the European Union. Indeed, precipitation values are around 111 hm3/y (i.e., less than 200 mrn/m2); and with 89% of it lost by vapour-transpiration, the island does not feature any significant sources. Moreover, irregularities in these precipitation rates, the aquifers' great depths as well as their overexploitation causing saline intrusion, produce the result that the island is currently 100% dependent upon desalination processes. Average daily consumption has increased from 7,808 m 3 (1985) to 12,188 m 3 (1991) to 31,399 m 3 (2002): that is an increase of 56% and 302%, respectively, far higher than the population growth. In view of satisfying this demand, desalination technology has been mas- sively introduced on the island. Furthermore, as demonstrated by Naredo [22], in the case of Spain in general, desalination could effectively provide an economically and environmentally more viable alternative to the current trend of massive inter- basin water transfers, further encouraged by the National Hydrologic Plan (Plan Hydrol6gico National, PHN).

In order to thwart the undesired side effects of freshwater scarcity and considering the immense volume of available seawater as well as the technological advances at hand, for the past 30 years desalination has been increasingly perceived as a feasible, nonconventional solution to meet the ever-growing freshwater demand. As a result, during the past 15 years, daily water production has increased from approximately 13 million m 3

to 23 million m 3 in the 12,500 desalination plants operating worldwide. These are mostly located in

G. Meerganz yon Medeazza / Desalination 169 (2004) 287-301

Table 1 Production of current and future desalination in Morocco [21 ]

293

Town Process Brut water Capacity, m3/d Operation s tar t Current extensions

Tarfaya Distillation Brackish 75 1976 Boujdour MCV Sea 250 1977 Tarfay RO Brackish 120 1983 Smara RO Brackish 330 1986 Boujdour RO Sea 800 1995

Lagyoune RO Sea 7,000 1995 Tarfaya RO Brackish 800 2001 Tan Tan RO Brackish 1,728 2002 Tan Tan NA Sea 11,300 By 2006 Agadir NA Sea 43,200 By 2008

1,600 m3/d or 2,400 m3/d 6,500 m3/d

Project Project

the oil-rich Gulf countries where desalination accounts for 40% of the municipal and industrial water used. This figure seems indeed promising for the desalination industry, which estimates 10 years as a doubling time for desalinated water demand, especially in the MENA countries, with the demand of the Mediterranean rim growing to 10 Mm3/d by 2010 [26]. However, despite con- centrated efforts and real efficiency improvements, the desalination process still remains highly energy-intensive and expensive, and it currently accounts for less than 0.17% of the global water supply.

6. Potential of renewable energies

The highly energy-intensive desalination technology remains a very costly solution, especially for developing countries, such as Morocco, that do not possess fossil fuel resources. In order to escape from this foreign energy dependency, Morocco should certainly be encouraged to take advantage of its own energy potential. Indeed, along the 3.500-km-long coastline (representing the main target regions for the desalination sector), this country is characterised by abundant

wind and high solar radiation (annual normal direct radiation averages between 1,500 and 2,400 kWh/mZ). The wind power sector seems especially promising. It has been on a decreasing cost trajectory for the past 15 years, and at the end of 2001, nearly 25,000 MWe of wind capacity was operational worldwide. Moreover, when energy is produced through renewable resources, the grid is readily available as a capacity storage or a topping-up electricity source. Hence, considering the country's assets, the ONEP views the utilisation of renewable energies in the desalination sector as an interesting, although still very unexplored, solution [21 ]. Indeed, Morocco benefits from an important wind power potential, with certain zones featuring average wind speed exceeding 10 m/s. The northern region of Tanger and Tetouan as well as the Atlantic coast strip between Tarfaya and Lagouira present excep- tional sites with regular winds of sufficiently high speeds to develop profitable projects (see Fig. 3).

As theoretically evaluated, the baseline levelised water cost for RO technology using renewable energies is around 1.5/m3; the combination of RO and wind turbines is said to deliver the most promising solution [27].


Fig. 3. Qualified sites (Mdaghri, 2003).

Regarding the utilisation of available solar energy, a system of MSF distillation units coupled to a solar lake (approximately 90 kWhth/m 3) also seems to offer a potential alternative. Another suggestion is to use gravitational energy in a RO process. For a 7,000 m3/d facility, this would require a specific energy consumption of 4.2 KWh/m 3 [21 ], hence a more efficient solution than the one currently used in La~youne (5.3 kWh/m3). In the case of Lanzarote, the desalination processes have (relative to the other sectors) a high wind-generated energy share (12%, compared to just over 2% for the island's average).

7. From physical to social scarcity: a cultural change

The massive introduction of desalination technology subsequently triggered a fundamental cultural change in both cases. Namely, it trans- formed a, up to then, rare good into an apparently endless resource; dismissing in this way the cen- miles-old, traditional, water-saving consciousness developed by the local population. In the case of Lanzarote, one of the best examples can be seen in the agricultural sector where watering techniques had been adapted to these resource-scarce conditions. A valuable part of this lay knowledge


has been replaced by an unconsidered over- consumption and squandering of water.

Although, as acknowledged earlier, non- residents in La~tyoune have a high comparative consumption, their number is currently relatively insignificant. In this case, however, it is rather the distinction between autochthones (Sahraouies) and immigrants (mostly Moroccans coming from the northern provinces) that mark the water consumption divide. For the past few decades, an immigration wave has taken place, mainly originating from northern industrialised cities such as Agadir, Casablanca and Rabat. The cultural differences amongst Moroccans are especially evident when their water consumption pattems are observed. The autochthones of the Sahara region, like the inhabitants of La~youne, have a well developed, long-term, water-saving consciousness. They are not accustomed to drink water but rather their habits comprise essentially drinking beverages such as tea and milk. Before the introduction of desalination technology in 1995, brackish water was naturally used for all domestic purposes excluding alimentation uses. One further example: Muslim customs require that, prior to the five daily prayers, one's hands, forearms, mouth, nose, face, ears, head and feet are washed in a specific manner. However, water being scarce in the Sahara, the Koran allows it to be replaced by a similar purification ritual, but utilising a rock (Tayammounm) instead.

In La~youne, three different drinking water sources can be distinguished: one provided by the ONEP network (mix between desalinated water and groundwater pumped from the local aquifer), bottled water and rain water. The latter needs further explanation as it is still a typical custom of the Sahara, very representative of the local water culture. This so-called Ma Laghdir (meaning "brook water") is collected whenever irregu- lar precipitation occurs, either locally (obtained from the temporal "puddles" and distributed by canister or donkey-tanker) or lately also by tanker coming from as far as the Tan-Tan region

(300 km away from La~youne). Following a centuries-old custom, this water is then stored in the house's Matfya, which is an underground tank having a capacity of a few cubic metres, used as a reserve stock for drought periods. Similar reser- voirs can also be found in the Canary Islands, the so-called aljibe. For the Sahara autochthones this domestic device is paramount. Indeed, in their eyes, the Laghdir water has a high cultural value, almost of sacred connotation. For instance, the tea ritual, omnipresent in Morocco as it is in other Maghreb and West African regions, highly de- pends on this water. If not immediately available, Laghdir water will be replaced by bottled water.

Similarly, there are two water networks run- ning parallel to each other: the "technological" and the "cultural". On the one hand, the official governmental heavy infrastructure, managed by the ONEP, provides tap water (of desalinated origin). And on the other hand, the impalpable, culturally deeply embedded network in which the Laghdir water flows in an uncontrolled manner. It is evident to see how the water scarcity problem seems to vanish as soon as the (invisible) technological solution artificially provides an apparently endless resource. Prior to the installa- tion of the freshwater network in 1995, the inhabitants of Lahyoune were supplied by tanker, likewise the remaining significant part of the population that are still unconnected. This water costs approximately 2.3/m 3 compared to 0.23/m 3 (for the tariff category comprising 58% of the population). People not connected to the network strongly limit their own consumption; this habit slacks as soon as they get connected. On the one hand, they finally benefit from more viable prices but inevitably become "larger" consumers with increased expectations. Therefore, the fact that the quantity of water purchased over time increases is partly the result of falling costs of supply (a shift in the supply curve) rather than an increase in demand (shift in the demand curve). Hence, the need to regulate water prices further while focusing on demand-side-based strategies.


Also, taking the consumption ratio of tourists/ locals as a reference point may be a way of quan- tifying how much the "water-abundant" habit has been absorbed by the local population. In this perspective, authochtones in Lanzarote have been effected significantly more than in La~tyoune. As ethnodiversity constitutes a basis ofsustainability learning [ 1 ], conservation of the Sahraouy culture should be taken seriously, especially since it represents the ancient knowledge of a deeply embedded water-saving paradigm.

Finally, there are two general approaches to water management. On the one hand, the old- fashioned, unsustainable, "increased supply" focuses predominantly on providing technical support enforced by policies promoting large- scale hydraulic engineering works such as dam- ming, transfers, desalinating, pumping, etc. On the other hand, sound "demand management" such as the full-cost recovery principle in the European Water Directive or the Nueva Cultura deIAgua [28] in Spain strives towards integrating both socioeconomic and environmental aspects. The aim is to render the regime more flexible by reconverting programmes for more efficient uses [29]. Such changes can, for instance, be implemented through so-called "water banks" [30], as done in California. Even though demand-side- based managerial strategies are widely advertised and actively encouraged, under the perspective of the previously quoted figures, Lanzarote remains a triumph of the increased supply approach. In the case of La~youne, considering the above- mentioned socially constructed consumption patterns, the high dependency on non-renewable energy providers and groundwater "mining", combined with the intention of increasing daily desalination production from 7,000 m3/d to 26,000 ma/d by the year 2007: can this really be called sound "demand management"?

8. Desalination in an oil-based society

The seawater desalination industry is Lanza-

rote's greatest individual energy consumer, accounting for 14% (2002) of the total electricity demand. Almost 98% of the total energy consumed on Lanzarote originates from oil. Simi- larly, the ONEP desalination plant is Laglyoune's greatest individual energy consumer 6. In both cases the oil is imported, meaning an almost absolute energy dependency on the exterior with production impact located outside national limits and emission impact diverted to the atmosphere, i.e., the global environment.

Considering the Moroccan example, desalination could currently offer a financially viable solution to many countries around the world. However, in the long term, it is a matter of energy, not money. Indeed, at current extraction rates, oil being a non-renewable resource, we will be reaching its exhaustion point within the next 50 years [31]. Oil feeds our current socioeconomic system, and while it is inevitably becoming scarcer, not only does its own cost, but also the cost of all other energy forms, increase too. For instance, oil provides close to 50% of the fuel used for coal extraction. However, in the feasibility analysis carried out prior to the construction of the desalination plant of Lagyoune and the ones in Lanzarote (likewise most of the ones built worldwide), the rising energy costs due to oil scarcity were not taken into account.

Many perceive renewable energies as the ultimate solution to the forthcoming energy crisis. As acknowledged earlier in this paper, they represent indeed a great potential to satisfy part of the current demand at a lower environmental cost. Their implementation should therefore be encouraged. However, although omnipresent and inexhaustible, renewable resources are very diluted, and it takes vast amounts of energy to concentrate these highly site-specific flows to carry out useful work. Indeed, as emergy (i.e., energy memory) studies show, these renewable energy devices became beneficial largely due to the massive quantities of"cheap" oil mobilised to produce them. A significant part of any photo-


voltaic cell or wind turbine is embodied fossil fuel. At what cost will they be produced when this oil, gas, uranium runs out in respectively 50, 50 and 80 years [31]? Will the earth's biosphere be able to bear such additional amounts of emissions anyway? Moreover, with their smaller energy return on energy input (EROI) values, they will never provide an equally cheap source of energy and will therefore not be able fully to substitute the non-renewable resources that currently enable us to quench our thirst for growth and development. Indeed, even though the sun is our ultimate energy source, these solar-derived technologies will be unable to provide us with the same luxurious living standards to which we have become accustomed in the West [32].

Is there a trend towards an increasing cost of obtaining energy [3 3]? Do we use more energy as it gets cheaper? And "cheap" in terms of what? In terms of energy efficiency or in monetary terms? Jevons, in his book on the Coal Question (see Martinez-Alier [34]), pointed out back in 1865 that the efficiency of steam engines did para- doxically lead to an increasing use of coal by making it cheaper relative to output. Therefore, "as energy efficiency increases, more energy is used" (see Tables 2 and 3 for Morocco). Like- wise, do we automatically use more water as desalination gets cheaper? Furthermore, desalination in Lanzarote and in Lagyoune, tending towards being 100% 7 fossil-fuel driven, do these processes in some ways not merely shift problems from one scarce resource (water) to another (non- renewable energy provider)?

Finally, according to the thermodynamics of reversible systems, the theoretical minimal energy cost per m 3 ofdesalinised water produced is 0.7 kWh. Today, under the most efficient and novel techniques that use RO processes, water can be desalinated at a cost of approximately 2 kWh/m 3. However, since the real cost is approaching its theoretical minimum, future improvements of efficiency become limited and evermore costly. Although they are generally

Table 2 Energy price - - Morocco, in DH/kWh

Off-peak Plain Peak hours hours hours

1/1996 0.782 1.0714 1.1657 11/1997 0.7038 1.0071 1.1657 8/1998 0.6369 0.9245 1.1657 10/2000 0.4844 0.7216 1.0614

Source: ONEP-Boughriba (2003).

Table 3 Energy consumption - - Morocco

Net energy consumer, TWh

1997 11.8 1998 13.3 2002 15.5 2005* 18 2010" 24

*Averaged forecast. Source: Mdaghri (2003).

designed for less, once the average consumption is calculated, most modern desalination plants actually operate with an energy consumption of around 4 to 5 kWh/m 3 (even with energy recovery devices).

9. Water scarcity in a consumption society

The so-called developed countries (accounting for around 20% of the world 's population) consume about 80% of the world 's total resources. At the same time, water demand of the developing countries is the fastest growing in the world due to exploding population growth rates and their industrialisation-driven, increasing living standards. Although general managerial trends are said to have swung around from supply-side towards demand-side-based strategies, there is


still a lot of room to actively reduce freshwater demand.

This becomes apparent when considering that out of the 69% mobilised for irrigation purposes, 70-80% is wasted either through evaporation or by seeping into the ground before reaching crops. Furthermore, out of the billions oflitres produced each year by the desalination plants in Lagyoune and Lanzarote, less than 2% are consumed as drinking water. Thus, besides the freshwater required for cooking, this means that a considerable amount of the energy-intensive desalinised water is actually used to flush toilets, to clean or is wasted in leakage. Hence, not only is this water itself being wasted, but also the energy and material resources as well as the human effort necessary to satisfy this high demand. Addi- tionally, the controversial environmental impact due to direct brine and indirect greenhouse gas emissions (further exacerbating climate change, a denounced water-stressing factor) is not accounted for in those monetary costs. As argued by Buenfil [18], "the environment continues to bear the cost as new water supply systems are developed to keep up with the rapid growth of the population and the economy". Considering the case of Lagyoune, as the total annual energetic consumption of the desalination plant is 13.14 GWh, the equivalent of 747,000 trees or 824 hectares of forest 8 would have to be planted in order to provide a sufficiently large carbon sink for the total mass of greenhouse gases produced annually by this process.

Moreover, acknowledging that 75% of the current population can be understood as the direct result of oil availability, water scientists should question what will happen when this energy source runs out: any myopic vision offering short-term and therefore unsustainable solutions should be examined critically. In other words, besides improving our technologies (providing end-of-pipe solutions), we should focus on the initial drivers of the issue at stake; namely our

consumption and growth paradigms, which are in fact becoming uneconomical. Indeed, according to Daly [35] and with reference to the "full world", there is a maximum scale of the economic subsystem, a point beyond which further physical growth, while possible, costs more than it is worth. He clearly distinguishes between economic and uneconomic growth. Indeed, once economic growth increases ecological costs faster than production benefits, it becomes a true uneconomic growth, impoverishing rather than enrich- ing, and its measure, GNP, indeed becomes "a gilded index of far-reaching ruin" [35]. As population continues to grow and current economic trends demand ever-increasing amounts of flesh- water to produce necessary food and goods, will desalination ever be able to satisfy such a growing demand on a limited planet? Even though desalination may contribute to alleviate tempor- ally a local lack of water, can places such as La~youne or Lanzarote ever be sustainable (in the sense o f s trong sustainability [36-38]) as long as they are entirely dependent on desalination for their domestic water uses? Reaching sustainability in a finite system such as the earth is a challenging task due to the complexity of the interconnection between the various factors playing a role in defining this concept. Surely enough, human need is a fundamental constituent of it, and is therefore a key aspect of the current most widely used definition of "sustainable development" [39]. Indeed, this factor plays a central role. Yet interpreting its meaning is often neglected as it seems to be taken for granted. However, the meaning of "human need" (and its associated level of satisfaction) is relative to the historical and cultural context and casts therefore important doubts upon the validity and legitimacy of current development thinking and subsequently of our entire modem society. Indeed, as the interpretation of a need is embedded in its respective cultural scheme, the needs of one who lives within a reality change as soon as their real-


ity is altered. Hence, when dissecting the original question of what human beings really n e e d -

contrarily to what they are pushed to w a n t - - the modern myth of economic growth driven by "productivism and consumerism", expanded through globalised"development" soon becomes apparent. In modern (and still to some extent, in post-modern) society logic, consumerism is often associated with the standard of living and ultimately confused with the quality of life. This misconception leads, however, to carrying out uneconomic growth, weakening our social system, exhausting natural resources and over- shooting the planet's capacity to digest our pollution burden.

Scarcity is a fundamental problem facing all societies that results from a combination of scarce resources and people's virtually unlimited wants. By (classical) definition, economics is the science of efficient allocation of scarce resources; also, additional resources can be provided through human ingenuity and demand can be voluntarily decreased through reflexive behaviour. It is a matter of assessing up to which point the given scarcity situation is predominantly of physical or social nature. City planners and water experts should therefore emphasise resource conservation and demand management that actively curbs rapid consumption take-offs by altering the main- stream growth ideology and slowing down the frenetic "production-consumption carousel" [40]. This is the most cost-effective way of meeting water demand in a long-term sustainable manner.

As fossil fuel availability decreases, the prevailing growth paradigm - - especially under Western standards of living - - will have to be altered. We pride ourselves on being biologically more advanced than other species since we are self-reflexive. We should indeed urgently use this gift to regulate and redirect our own societal organisation. Society, blinded by neo-classical economic ideology, praises unlimited growth as the remedy to all fouls. However, under the

principle of responsibility [41], the utopia of abundance should be dismissed, and a certain form of voluntary simplicity and ecological austerity should be adopted. We should embark upon the "prosperous way down" by consciously stabilising the global population and questioning our wasteful consumerism and ever-growing appetite for exhaustible resources because in the long term, "either we adapt with deliberate process or have these changes forced on us with damaging repercussions" [42].

Acknowledgements

The author wishes to acknowledge the financial funding granted by the International Graduate School of Catalonia (IGSOC) that enabled the realisation of this paper.

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2Out of the nine Moroccan river basins, only the Errachidia and the huge Sahara ones account for highly deriding receipts due to their lack of water and therefore do not use a so-called Basin Agency for their financial matters. 3Although its potential global resources are accounted for as 29 billion m 3, only 20 of them can be mobilised. Out of these 16 billion m 3 are surface waters (of which 12 billion m 3 are already mobilised), and 4 billion m 3 are groundwaters (3 billion m 3 of which are already mobilised). 4Nevertheless, the country's general situation has improved. In 2002, 14.5 million people had direct access to drinking water in Morocco (that is, 88% of the total urban population), the remaining part being supplied through public fountains [43]. The national water authorities now concen- Irate their efforts on supplying rural areas and developing the wastewater treatment sector in view of actively protecting the national water resources, increasingly polluted through industrial development. 5This has proven to be particularly efficient in the Massira Hotel in Lagyoune, which saves approximately 13,000 L/d of water just by installing a drop-by-drop irrigation device to water its garden. Yet its consumption per visitor is still about 2.5 times higher than other hotels in its category, which do not have a garden at all nor offer a swimming pool. 6Together with the Office Chfrifien du Phosphate (OCP), a major phosphate mining exploitation group. 7La~youne currently receives all its energy through the national grid. Therefore, its desalination plant can be considered around 90% fossil-fuel driven, the rest originating from renewable resources, mainly hydro and wind power. (The country's four most important dams have a capacity of around 600 MW each, and the wind park in the Tetouan region provides another 57 MW.) However, this percentage will rise to 100% by 2005 as a 3×33 MW thermal power station is to be installed in the Lagyoune harbour. This facility will satisfy the energy demand of the entire southern region connected to the grid, and consequently will be the full provider of the desalination plant. 8These values have been calculated on the basis of figures obtained in Enzili [44], assuming that the process is 90% fossil-fuel driven since the electricity is provided by the national grid.

Notes

1Since 1990, the global rate of water withdrawal from surface and groundwater sources has increased seven-fold, while the world population increased only three-fold. Water withdrawal rates are projected to at least double in the next two decades.

Values about La~youne given herein were calculated from the consumption statistics (year 2002 and fourth trimeter of 2003) given by the ONEP. For Lanzarote, reference is made to both Centro de Datos: Consejeria de ciencia y tecnologia- anuario estadistico 2002 - - Cabildo de Lanzarote; Inalsa, Datos Estadisticos 2002, Oficina tfcnica; and Guia de la exposicidn (1996) by Cfsar Manrique: Nueva York, Fundacifn Cfsar Manrique.

water desalination as a long-term sustainable solution to alleviate global freshwater scarcity? a...

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