Elsevier

Food Policy

Volume 35, Issue 5, October 2010, Pages 365-377
Food Policy

Global water crisis and future food security in an era of climate change

https://doi.org/10.1016/j.foodpol.2010.05.006Get rights and content

Abstract

Food policy should serve humanity by advancing the humane goals of eradicating extreme poverty and hunger. However, these goals have recently been challenged by emerging forces including climate change, water scarcity, the energy crisis as well as the credit crisis. This paper analyses the overall role of these forces and population growth in redefining global food security. Specifically, global water supply and demand as well as the linkages between water supply and food security are examined. The analysis reveals that the water for food security situation is intricate and might get daunting if no action is taken. Investments are needed today for enhancing future food security; this requires action on several fronts, including tackling climate change, preserving land and conserving water, reducing the energy footprint in food systems, developing and adopting climate resilient varieties, modernising irrigation infrastructure, shoring up domestic food supplies, reforming international food trade, and responding to other global challenges.

Introduction

“When the well is dry, we know the worth of water” (Benjamin Franklin).

Food policy must not lose sight of surging water scarcity. Water is a key driver of agricultural production. Water scarcity can cut production and adversely impact food security.1,2 Irrigation has helped boost agricultural yields and outputs in semi-arid and even arid environments and stabilized food production and prices (Hanjra et al., 2009a, Hanjra et al., 2009b, Rosegrant and Cline, 2003) and the revenue from the agriculture sector (Sampath, 1992). Only 19% of agricultural land cultivated through irrigation supplies 40% of the world’s food (Molden et al., 2010) and has thus brought substantial socioeconomic gains (Evenson and Gollin, 2003). Water for agriculture is critical for future global food security. However, continued increase in demand for water by non-agricultural uses, such as urban and industrial uses and greater concerns for environmental quality have put irrigation water demand under greater scrutiny and threatened food security. Water scarcity is already a critical concern in parts of the world (Fedoroff et al., 2010). Further, there are growing public concerns that the footprints (i.e. negative impacts) of food security on the environment are substantial (Khan and Hanjra, 2009, Khan et al., 2009a, Khan et al., 2009b). Continued increase in demand for irrigation water over many years has led to changed water flows, land clearing and therefore deteriorated stream water quality. Addressing these environmental concerns and fulfilling urban and industrial water demand will require diverting water away from irrigation. This will reduce irrigated area and its production and impact on future food security.

New investments in irrigation infrastructure and improved water management can minimise the impact of water scarcity and partially meet water demand for food production (Falkenmark and Molden, 2008). However, in many arid or semi-arid areas and seasonally in wetter areas, water is no longer abundant. The high economic and environmental costs of developing new water resources limit expansion in its supply (Rosegrant and Cai, 2000). Once assumed unlimited in supply, now even in developed countries water is considered scarce. Further, it is believed that climate change will increase water scarcity in the coming decades (Lobell et al., 2008). Even if new supplies are added to existing ones, water might not be sufficient for increased food demand (Brown and Funk, 2008).

The severity of the water crisis has prompted the United Nations (UNDP, 2007) in concluding that it is water scarcity, not a lack of arable land, that will be the major constraint to increased food production over the next few decades. For instance, Australia is one of the major food producing and land abundant countries but recent drought reduced its agricultural and food production substantially (Goesch et al., 2007). According to 2001 and 2006 land use data by the ABS (2008), in the Murray–Darling Basin (MDB) of Australia, there was a decline of about 40% in rice and cereals production. Drought in other food producing countries such as parts of the United States of America and Europe is regarded as one of the major factors that contributed to the global food price crisis of 2008 (Piesse and Thirtle, 2009). Inequitable distribution of available food supplies, poverty, and inequality result in entitlement failure for the poor to exacerbate the food security issues because those lacking water entitlements are often food insecure (Molden et al., 2007, Sen, 1989, Sen, 2001). The high and widening inequality and income gap between the rich and the poor is a serious concern; though it is amazing that while one billion people are hungry in the developing world (Barrett, 2010), a significant proportion of the population in the developed countries is obese (Schäfer-Elinder, 2005).

This thematic paper examines the current and future global situation of water and food in terms of supply and demand, and their impacts on food security in the context of climate change. Food production and demand in the global market are investigated, and the impact of increasing water scarcity in redefining global food security is examined. This paper juxtaposes the findings of the existing models including PODIUM (Mu et al., 2008), WATERSIM (de Fraiture et al., 2007) and IMPACT-WATER (Rosegrant et al., 2005) as well as other empirical studies published in topical journals to distil global water and food projections, and provides a comprehensive assessment of the global water and food security challenges.

Section snippets

Global water supply and demand

Global demand for water has tripled since the 1950s, but the supply of fresh water has been declining (Gleick, 2003a). Half a billion people live in water-stressed or water-scarce countries, and by 2025 that number will grow to three billion due to an increase in population. Irrigated agriculture is the dominant user of water, accounting for about 80% of global water use (Molden et al., 2007). Population and income growth will increase the demand for irrigation water to meet food production

Global food supply and demand

Current global food production comes from 1.5 billion ha of cultivated land, representing 12% of the total land area (Schultz and de Wrachien, 2002). About 1.1 billion ha are rainfed with no irrigation systems. Thus rainfed agriculture is practiced on about 80% of world’s physical agricultural area and generates about 60% of the world’s staple food (FAO, 2008). Irrigated agriculture covers only 279 million ha or 19% of cropland (Thenkabail et al., 2010) – (it becomes 400 million ha when

Water scarcity and food security linkages

With continued increase in population, limits are being met on the basic resource needed to produce food, as shown in Fig. 2 (Khan and Hanjra, 2009 and references therein). World food production is now consistently outpacing consumption. In 2008, world food security came at its lowest ebb in half a century. Grain carryover stocks in mid-2007 were the lowest since records began in 1960; in 2007 the stocks were only 53 days of grain supply or only half of what was available in 2002 (FAO, 2008).

Global food trade and food security linkages

International food trade is vital for global food security. Food trade improves physical and economic access to food by increasing food availability and lowering food prices for domestic consumers. Food trade and aid also enable the global exchange of surplus food. In other words, they improve entitlements of water through exchange and, in so doing, widen the range of food available for consumption, improving diets and satisfying food preferences. For instance, from 1961 to 2000, the worldwide

Future food security and investment policy

Future food security depends on investments decisions made today for tackling climate change, conserving water and energy resources, developing and adopting new seeds, renewed investments in agricultural water, shoring up domestic food production, reforming international trade, and diversification of food production away from farming. Future food security requires governments and the public to deal forcefully with the issues critical in food production and food security, including population

Conclusion and implications

Debate about global water scarcity and food security has intensified in recent times, and precise estimates of future water and food demand are elusive. Climate change is adding another layer of complexity. The global human population may hit a record 9 billion people by 2050. The much needed increase in food production is not forthcoming. Crop yields are not increasing fast enough either. Instead, limits are faced due to carrying capacity in some areas of the world. Public investments in

Acknowledgements

The authors wish to thank two anonymous reviewers of this journal for their recommendations and constructive comments, which have helped us in improving the quality of this manuscript.

References (155)

  • P. Droogers et al.

    Adaptation strategies to climate change and climate variability: a comparative study between seven contrasting river basins

    Physics and Chemistry of the Earth Parts, A/B/C

    (2005)
  • S. Fan et al.

    Returns to investment in less-favored areas in developing countries: a synthesis of evidence and implications for Africa

    Food Policy

    (2004)
  • G. Fischer et al.

    Climate change impacts on irrigation water requirements: effects of mitigation, 1990–2080

    Technological Forecasting & Social Change

    (2007)
  • L.J. Gordon et al.

    Managing water in agriculture for food production and other ecosystem services

    Agricultural Water Management Comprehensive Assessment of Water Management in Agriculture

    (2010)
  • M.A. Hanjra et al.

    Reducing poverty in sub-Saharan Africa through investments in water and other priorities

    Agricultural Water Management

    (2009)
  • A.Y. Hoekstra et al.

    Globalisation of water resources: international virtual water flows in relation to crop trade

    Global Environmental Change

    (2005)
  • J. Huang et al.

    Biotechnology boosts to crop productivity in China: trade and welfare implications

    Journal of Development Economics

    (2004)
  • M.A. Kahlown et al.

    Effect of shallow groundwater table on crop water requirements and crop yields

    Agricultural Water Management

    (2005)
  • S. Khan et al.

    Footprints of water and energy inputs in food production-global perspectives

    Food Policy

    (2009)
  • D. Knowler et al.

    Farmers’ adoption of conservation agriculture: a review and synthesis of recent research

    Food Policy

    (2007)
  • R. Lal

    Residue management, conservation tillage and soil restoration for mitigating greenhouse effect by CO2-enrichment

    Soil and Tillage Research

    (1997)
  • A. Mahal et al.

    Adequacy of dietary intakes and poverty in India: trends in the 1990s

    Economics & Human Biology

    (2008)
  • L. Mancino et al.

    Getting consumers to eat more whole-grains: the role of policy, information, and food manufacturers

    Food Policy

    (2008)
  • D. Molden et al.

    Improving agricultural water productivity: between optimism and caution

    Agricultural Water Management, Comprehensive Assessment of Water Management in Agriculture

    (2010)
  • R.E. Namara et al.

    Agricultural water management and poverty linkages

    Agricultural Water Management, Comprehensive Assessment of Water Management in Agriculture

    (2010)
  • J. Niosi et al.

    Biotechnology and nanotechnology: science-based enabling technologies as windows of opportunity for LDCs?

    World Development

    (2007)
  • M. Parry et al.

    Millions at risk: defining critical climate change threats and targets

    Global Environmental Change

    (2001)
  • P. Pingali

    Westernization of Asian diets and the transformation of food systems: implications for research and policy

    Food Policy

    (2007)
  • B.M. Popkin

    Technology, transport, globalization and the nutrition transition food policy

    Food policy

    (2006)
  • ABS, 2008. Australian Water Account. Australian Bureau of Statistics,...
  • N. Alexandratos

    Food price surges: possible causes, past experience, and longer term relevance

    Population and Development Review

    (2008)
  • J.A. Allan

    Virtual water: a strategic resource. Global solutions to regional deficits

    Groundwater

    (1998)
  • R.B. Alley et al.

    Abrupt climate change

    Science

    (2005)
  • T.P. Barnett et al.

    Potential impacts of a warming climate on water availability in snow-dominated regions

    Nature

    (2005)
  • C.B. Barrett

    Measuring food insecurity

    Science

    (2010)
  • M.E. Brown et al.

    Food security under climate change

    Science

    (2008)
  • C. Brown et al.

    Water and economic development: the role of variability and a framework for resilience

    Natural Resources Forum

    (2006)
  • R. Chand

    The global food crisis: causes, severity and outlook

    Economic and Political Weekly

    (2008)
  • W.R. Cline

    World Agriculture Faces Serious Decline from Global Warming

    (2007)
  • CSIRO, 2008. Water Availability in the Murray–Darling Basin: A report from CSIRO to the Australian Government. CSIRO,...
  • C. de Fraiture et al.

    Looking ahead to 2050: scenarios of alternative investment approaches

  • C. de Fraiture et al.

    Facing Climate Change by Securing Water for Food, Livelihoods and Ecosystems

    (2008)
  • J. Deckers

    Vegetarianism, sentimental or ethical?

    Journal of Agricultural and Environmental Ethics

    (2009)
  • J. Deckers

    What Policy Should Be Adopted to Curtail the Negative Global Health Impacts Associated with the Consumption of Farmed Animal Products?

    Res Publica

    (2010)
  • P. Döll et al.

    Global modeling of irrigation water requirements

    Water Resources Research

    (2002)
  • D. Dudgeon

    Large-scale hydrological changes in tropical Asia: prospects for riverine biodiversity

    BioScience

    (2000)
  • A. Eide

    Human rights requirements to social and economic development

    Food Policy (Special Issue on Nutrition and Human Rights)

    (1996)
  • EPA, 2008. National Water Program Strategy: Response to Climate Change. Office of Water, US EPA, United States of...
  • R.E. Evenson et al.

    Assessing the impact of the Green Revolution 1960 to 2000

    Science

    (2003)
  • M. Falkenmark

    Shift in thinking to address the 21st century hunger gap: moving focus from blue to green water management

    Water Resources Management

    (2007)
  • Cited by (915)

    View all citing articles on Scopus
    View full text