Water scarcity concerns the lack of adequate available water resources to satisfy the water requirements of a society or region. Scarcity of water is a significant factor in socioeconomic development and in the context of continuous concerns about the sufficiency of food to feed the growing world population. Owing to recognition of its value as the most important resource for life, water has been a vital issue on the agenda of the international community for a number of decades (Mancosu et al 976). Many parts of the world have experienced on-going water scarcity challenges that have coincided with problems in the sufficiency of food. The most constraining factors in farming, generally, and especially the production of crops, are the availability and accessibility of water, thus making the issue of addressing water scarcity critical in promoting crop production and ensuring the sufficiency of food.The U.N. projects an increase in the world population to 8.5b by 2030 and 9.7b by 2050, implying that the demand for food is likely to increase and leading to direct effects on the rates of water use in the agricultural sector (UN World Population Prospects Report 2).This means that the problems of increasing water scarcity and prevalence of drought conditions, due to climate change, are likely to present continuing problems for global food security (Bita and Gerats 1).
In one of its “Water Reports” released in 2012, the UN’s Food and Agricultural Organization (FAO) notes that unconstrained use of water has increased across the world to a level that is above twice the rate of population increase in the 20th Century. The organization notes that the outcome of this rise in water use rates has been the inability to provide reliable water services in most regions of the world. Processes in the modern world, including demographic pressures, urbanization, pollution, and high rates of economic development, have resulted in unprecedented pressure on water as a renewable but finite resource, especially in arid and semi-arid areas (FAO 11).Waterscarcity is most relevant in agriculture, among all economic sectors in a society. The report notes that agriculture is responsible for 70% of the withdrawal of global freshwater and 90% of consumption or use of the resource (FAO 11). In the context of rising per capita demand for food (because of rising population and economic growth), the worsening water scarcity problem presents a critical threat to global food security.
Defining Water Scarcity and Factors underlying it
Debate on the global water crisis and water scarcity is puzzling considering the arguments of geographers and scientists that water makes up about 71% of the earth. In fact, the world contains millions of tons of water in oceans, inland lakes, and in other forms such as ice, water vapor, rivers, aquifers, glaciers, in living beings, and in the soil as moisture (USGS para. 1). The problem in water scarcity reflects the shortage of water resources that can satisfy the water needs of specific regions. The FAO defines water scarcity as the prevalence of a gap between the accessible supply and expressed demand for freshwater in a particular locality and under prevalent institutional environments and arrangements, including infrastructural conditions, resource “costs”, and retail charges (FAO5). This implies that scarcity of water is dependent on contextual factors, including the levels of water needs, levels of availability of water, relevant costs of obtaining the resource, and the ease of obtaining the resource in terms of prevailing conditions. Scarcity is evident in terms of unsatisfied demand, prevalence of tensions among users, competition for the resource, over-extraction of water from sources such as groundwater sources, and inadequate flows to the natural environment (FAO 6). In Yemen, an arid country, a worsening water shortage crisis is one of the factors that have facilitated conflict in the society, evident in tribal, sectarian, and political hostilities (Glass 25).
The Natural Hydrological Cycle
While the causes of water scarcity are varied, analysts, geographers, and ecologists consider human interference with the natural water cycle as the fundamental cause (FAO 6). Water scarcity is essentially dynamic, meaning that it varies in time owing to variability in the natural hydrological cycle and a complexity of other factors such as economic policy, applied approaches in management and planning, and the capacities of individual societies to anticipate changing supply and demand patterns and enforcing effective measures to address foreseen shortages. The FAO observes that water scarcity can be the outcome of shortsighted economic and management policies such as over-allocations of licenses for the use of water in a particular catchment or the excessive expansion of areas of irrigation with cheap or free water for farming (FAO 6). The underlying cause of shortage is increasing demand among users of water resources and decreasing quality and accessibility of the resources. Related concepts in water scarcity are water shortage, which concerns deficiency in the supply of water of an acceptable quality at a particular locality, and water stress, which refers to symptoms of such shortage and scarcity, such as conflict among users, declining standards in the reliability and service of the resource, food insecurity, and rising competition for water (FAO 6).
As stated above, the quality of water is a relevant aspect of the scarcity or availability of water, especially in the context of agricultural production (FAO 6). In response to water scarcity, reuse, along with recirculation, is a common policy or strategy that, however, leads to deterioration in the quality of the resource. Continued reuse of water reduces the availability of water that is of a sufficient quality for specific uses. In some areas, the problem of natural contaminants such as fluoride adds to the scarcity of water in terms of reducing the quality of available water resources for specific uses (Haering et al 3). Another issue that relates to water scarcity, in terms of both causing and worsening it, is climate change. The progressive warming of the planet has the effect of altering the hydrological cycle and availability of freshwater. In general, climate change causes reduced precipitation in semi-arid areas, higher variations in the distribution of rainfall, increased frequency of extreme events such as droughts, increased surface temperatures, and increased precipitation in temperate regions (FAO 13).
The FAO identifies human (anthropogenic) factors as the sole determinants of the levels of demand for water in the society. Population levels, population growth, and changes in the patterns of consumption affect demand for services and products directly, and hence the levels of use of water that applies in production, processing, and delivery of the products(FAO 13). The sectors of the economy that utilize water include agriculture, industrial sector, and municipal (including domestic) uses.
Increasing Need for Food and rising Pressure on Water Resources in the World
Population levels and patternsaffect water resources directly through changes in the patterns of water and land use. Pressure on water resources rises as incomes and levels of socioeconomic development rise, since economic growth correlates with increased levels of consumption of services, energy, manufactured products, etc. (FAO 14). Along with increasing population, increasing levels of income around the world have influenced rises in the per capita demand for food. Generally, higher incomes imply more diversified diets in the lives of individuals, families, and societies. The FAO notes that increased incomes lead to higher consumption of meat and dairy products, whose production requires higher levels of water than that necessary in diets based on staple crop products such as root crops and cereals (FAO 14). On average, per capita consumption of food has continued to increase around the world, with analysts expecting the average level of global food supply to increase from 2,650kcal per person per day in 2006 to over 3000kcal per person per day by 2050 (FAO 14). This evaluation of per capita figures includes food waste and post-harvest losses in production, which means that the global agricultural sector has to produce an additional 1 billion tons and 200m tons of cereals and meat respectively on an annual basis (FAO 14).
Rising Population, Urbanization, and Economic Growth
Alongside rising population, economic growth, and per capita demand for food, the FAO identifies urbanization as another important factor influencing rises in the levels of food consumption. Urbanization has led to the rising importance of restaurants, supermarkets, and convenience foods (foods prepared commercially with special focus on ease of consumption). The FAO argues that this involves lengthening of the food chain, resulting in higher levels of wastage of food (FAO 14). In such context, the FAO estimates that global agricultural production shall need to expand by 60% between 2006 and 2050 to satisfy the rise in food demand. The organization expects both the share of farmland under irrigation for crop production and the share of irrigated production in the global agricultural sector to increase, which would imply higher levels of demand for water. Adding to the heavy pressure on water resources in agriculture is the problem of climate change, which is likely to affect the demand for water in the agricultural sector and alter the distribution of agriculture internationally (Thornton and Lipper 2; Edame et al 207-208).Rising frequency and severity in extreme weather, including droughts and floods, are likely to undermine local agricultural production in different areas of the world, especially in societies at low latitudes that largely practice subsistence agriculture and those in areas of food insecurity that are dependent on rainfall for agricultural production. The outcome of these effects is likely to be rising demand for food in markets around the world and rising pressure on irrigated agricultural production (FAO 15). Alongside these effects, rising temperatures and shifts in hydrological patterns around water catchment areas and major rivers are likely to raise the global demand for water in agricultural production.
Reflecting the huge significance of water scarcity in global food shortage, authors Hanjra and Qureshi observe that food policies in different societies should not lose sight of worsening water scarcity since water is a critical driver and facilitator of agricultural production (Hanjra and Qureshi 365). The authors note that scarcity of water can cut production and have an adverse impact on food security. They observe that irrigation has been vital in boosting agricultural yield in arid and semi-arid areas, assisting in stabilizing the production, supply, and prices of food. They observe that less than a fifth (19%) of irrigated farmlandsupplies two-fifths (40%) of food worldwide (Hanjra and Qureshi 365). This is strong evidence that water, along with its availability and adequacy in the agricultural sector, is a critical factor for global food security towards the future.Hanjra and Qureshi further note that persistent increase in the demand for water for uses other than agriculture (such as industrial and urban uses) and broader concerns about the quality of the environment have fostered inquiry into the demand for irrigation water and threatened global food security (Hanjra and Qureshi 365).Once considered unlimited in supply, water has developed into a scarce resource, even in developed economies that feature advanced water recycling and reuse systems.
Considering the expected effects of global warming, water scarcity is likely to worsen as a problem in the future even with the possibility of new supplies, thus exacerbating the insufficiency of water to meet increased food demand worldwide. Such severity in the water crisis has prompted the United Nations to identify water scarcity, rather than the scarcity of arable land, as the leading constraint to future improvements in global food production (Hanjraand Qureshi 365). As examples of the significance of water scarcity in global food shortage, Hanjra and Qureshi cite the effects of recent drought periods in Australia, Europe, and the U.S. on levels of food production. In Australia, which is one of the major food producing and land-abundant countries worldwide, land use data reflected a 40% decline in the production of cereals and rice in the Murray-Darling Basin due to drought. Drought in some parts of the U.S. and Europe, which are also major food producing countries, contributed to the global crisis in food prices in 2008 (Hanjra and Qureshi 366; UN Social Report 71).
Immense Significance of Water in Agricultural Production
Noting that water is vital for the preservation of sufficient food supply, Pimentel et al observe that majority of nutrients that human beings obtain from livestock and crops require water, alongside land and energy, for production. The authors note that per capita food supplies, primarily cereal grains, dropped by 17% in the 20 years to 2004 because of the related events of an increasing human population and simultaneous shortages in cropland and freshwater. Food shortages have contributedpartlyto the global problem of a malnourished population, which totaled 3b by 2004 (Pimentel at al 909). Important factors limiting the availability of water in agricultural production include soil quality, type of vegetation, evaporation rates, low rainfall, and high temperature. Noting that agriculture consumes about 70% of fresh water globally, the authors observe that the increasing demands of human and economic activities on the global supply of water threaten the availability, adequacy, quality, and usefulness of water for food production (Pimentel at al 909).Plants need water for photosynthesis, reproduction, and growth, while the resource is also an essential component of the chemical make-up of the plant (Petersen, Sack, and Gabler 299).Pimentel et al observe that crops utilize water at rates ranging between 300 and 2000 liters per kilogram of dry matter of produced crops, while minimum soil moisture necessary for crop growth varies widely, from 25-50% for potatoes to 50-70% for corn. The authors observe that a growing season for corn requires approximately 800mm of rainfall (or 8m liters of water per hectare), while high-yielding rice requires 11m liters of water per hectare for a 7-metric ton yield per hectare (Pimentel at al 911).
These assessments portray the immense significance of water in agricultural production and the huge cost, in terms of global food shortage, that water scarcity would influence, especially in the context of rising global demand for food due to increases in world population, economic growth, per capita food demand, and industrial and domestic pressure on existent freshwater resources.
Water scarcity concerns the deficiency of quality water resources that can meet the specific needs of a society at a particular time. Among all economic sectors, agriculture is the one in which water scarcity has the greatest relevance owing to the importance of adequate water in agricultural production. As noted in the assessment above, agriculture is responsible for 70% of the withdrawal of global freshwater and 90% of consumption or use of the resource. This means that water scarcity, owing to shortage in quality freshwater that can be useful in agricultural production, represents a critical factor in global food shortage. With the world population increasing, a decreasing capacity in available water resources to support necessary increases in agricultural production to meet the rising per capita food requirements reflects the immense significance of water scarcity as a factor in global food shortage. As the examples of significant declines in food production owing to droughts in Australia, Europe, and the U.S. demonstrate, the lack of adequate water resources that can meet the water needs of the global agricultural sector in food production is a critical factor in global food insufficiency.
“The Global Social Crisis: Report on the World Social Situation 2011”. UN Social Report, 2011.
“World Population Prospects: Key Findings and Advance Tables”. UN World Population Prospects Report, 2015.
Bita, Craita, and Gerats, Tom. “Plant Tolerance to High Temperature in a changing Environment: Scientific Fundamentals and Production of Heat Stress-tolerant Crops”. Frontiers in Plant Science vol. 4, no. 273, 2013
Edame, Greg, Ekpenyong, Anam, and Fonta, William. “Climate Change, Food Security, and Agricultural Productivity in Africa: Issues and Policy Directions”. International Journal of Humanities and Social Sciences, vol. 1, no. 21, 2011, pp. 205-223
Food and Agriculture Organization of the United Nations (FAO). Coping with Water Scarcity: an Action Framework for Agriculture and Food Security. FAO Water Reports, 2012.
Glass, Nicole. “The Water Crisis in Yemen: Causes, Consequences, and Solutions”. Global Majority E-journal, vol. 1, no. 1, 2010, pp. 17-30.
Haering, Kathryn, Evanylo, Gregory, Benham, Brian, and Goatley, Mike. Water Reuse: Using Reclaimed Water for Irrigation. Virginia State University Article, 2009.
Hanjra, Munir, and Qureshi, Ejaz. “Global Water Crisis and Future Food Security in an era of Climate Change”. Food Policy, vol. 35, 2010, pp. 365-377.
Mancosu, Noemi, Snyder, Richard, Kyriakakis, Gavriil, and Spano, Donatella. “Water Scarcity and Future Challenges for Food Production”. Water, vol. 7, 2015, pp. 975-992.
Petersen, James, Sack, Dorothy, and Gabler, Robert. Physical Geography. Cengage Learning, 2016.
Pimentel, David, Berger, Bonnie, Filiberto, David, Newton, Michelle, Wolfe, Benjamin, Karabinakis, Elizabeth, Clark, Steven, Poon, Elaine, Abbett, Elizabeth, and Nandagopal, Sudha. “Water Resources: Agricultural and Environmental Issues”. Bioscience, vol. 54, no. 10, 2004, pp. 909-918
Thornton, Phillip, and Lipper, Leslie. How does Climate change alter Agricultural strategies to support Food Security? International Food Policy Research Institute article, 2014.
United States Geological Survey (USGS). “How much water is there on, in, and above the earth?” USGS Water Science School article, 2016.