Competition for natural resources The case of water

1. Competition for natural resourcesThe case of water 2nd FAO Consultation on bioenergy and food security Rome, 5-6 February 2008 Jean-Marc Faurès FAO Land and Water Division

2. Water and agriculture today

3. Irrigation expansion 1950-2000 • Irrigation key element of Green Revolution “tripod”: water, fertilizers, seeds: • Need for rapid food production increase • Massive investments in irrigation (particularly in Asia) • Investment peak in late 1970s • Focus on large scale, public, surface irrigation schemes

4. Investments in irrigation 1960-2005

5. Irrigation in the world today • 275 Million hectares • 70% of all freshwater appropriation • 20% of cultivated land • 40% of agricultural production • 60% of cereal production

6. Where irrigation matters

7. The impact

8. Increased water withdrawal

9. Environmental water stress Source: Comprehensive Assessment of water management in agriculture, based on a study by IWMI, WRI, Kassel University, CA RR #2, 2007

10. The loss of biodiversity

11. Main driving forces for AWU • Demography • Population growth (although slowing down) • Urbanisation and changes in diet preferences • Economic growth • Trade and globalisation • accelerated pressure on water • Increasing concern for environmental sustainability • Competition for water (incl. other sectors) • Pollution (see agriculture in MA) • Climate change • Bioenergy ?

12. Projections for 2030 • Without accounting for CC and biofuels: • Irrigated production to increase by 36% • Irrigated area to increase by 20% • Irrigated water requirements to increase by 12-14% • Source: AT2030 and FAO-NRLW estimates, refers to developing countries only

13. Which water are we talking about ? • “Blue water”: freshwater from rivers, aquifers and lakes: •  45,000 km3/yr, 12,500 “available” •  irrigated agriculture • “Green water”: rainwater stored in the soil and available for biomass production: •  75,000 km3/yr •  rainfed agriculture

14. Dependencyon “green” and “blue” water Areas in green: agriculture mainly under rainfed Areas in blue: agriculture mainly under irrigation Circles depict total crop depletion August 2006

15. “Blue” and “green” water in the water cycle

16. What is the potential ?

20. Climate change

21. Impact on runoff Source: IPCC report on water, foprthcoming

22. Projected impacts of climate change Global temperature change (relative to pre-industrial) 0°C 1°C 2°C 3°C 4°C 5°C Food Falling crop yields in many areas, particularly developing regions Falling yields in many developed regions Possible rising yields in some high latitude regions Water Significant decreases in water availability in many areas, including Mediterranean and SouthernAfrica Small mountain glaciers disappear – water supplies threatened in several areas Sea level rise threatens major cities Ecosystems Extensive Damage to Coral Reefs Rising number of species face extinction Extreme Weather Events Rising intensity of storms, forest fires, droughts, flooding and heat waves Risk of Abrupt and Major Irreversible Changes Increasing risk of dangerous feedbacks and abrupt, large-scale shifts in the climate system

23. Asia: Major issues: Water availability & flooding Flooding/melting of glaciers • Coastal areas, esp. megadelta regions in S/E/SE-Asia at greatest risk due to flooding • Example 1 m SLR Mekong River delta  50% loss of mangrove area, ~100,000 ha of arable land becoming salt marsh; floods affecting 3.5-5 million people • Decay of glaciers: e.g. Tibetan Plateau; Himalayan glaciers to 1/5 by 2030s ↑Water stress • 0.12-1.2 billion people affected by 2020s/2050s • AG irrigation demand +10% in arid/semi-arid E-Asia for ↑temp +1°C • Crop yields up to 20% in E/SE-East Asia, ↓crop yield up to 30% in C/S-Asia by 2050s; due to rapid population growth risk of hunger remains high in several countries • Ex: India – ↓freshwater availability by 47% in 2025 due to CC and pop. growth, ↑intense rain and frequent flash floods during monsoon  more surface runoff, less groundwater recharge -> need for further storage (dams)

24. Biofuels

25. Trends in biofuel production Source: Earth Trends 2007 Earth Policy Institute

26. Corn-based ethanol

27. Sugarcane-based ethanol

28. Sugar: the price link Data: Nymex and EIA, J. Schmidhuber (2005)

29. Water requirements of biofuels Source: Hoogeveen, FAO-NRLW

30. A few numbers • Water needed to produce: • 1 kilo of wheat: 1 000 litres • 1 kilo of meat (beef): 15 000 litres • Daily water requirements per person: • Drinking: 2-3 litres • Domestic needs: 20–300 litres • Food: 2 000-3 000 litres • with 2 500 litres of water, we can produce: • food for one person for one day • 1 litre of biofuel

31. Biofuel and water use (2005) Source: de Fraiture, IWMI, 2007

32. Projections for water demand - 2030 Source: de Fraiture, IWMI, 2007

33. Rainfed agriculture: Pressure on land resources Irrigated agriculture: Pressure on water resources Impacts of biofuels

34. NAS report on water and biofuels in the United States (2007): • Currently, biofuels are a marginal additional stress on water supplies at the regional to local scale. However, significant acceleration of biofuels production could cause much greater water quantity problems depending on where the crops are grown. Growing biofuel crops in areas requiring additional irrigation water from already depleted aquifers is a major concern. • The growth of biofuels in the United States has probably already affected water quality because of the large amount of N and P required to produce corn. If projected future increases in the use of corn for ethanol production do occur, the increase in harm to water quality could be considerable.

35. Conclusions • World water system already under heavy stress due to agriculture and other uses • Agriculture main water user (70%) • Future water demand for agriculture in the rise • Climate change likely to result in increased demand for irrigated water • Bioenergy likely to add to pressure on water: • depending on type of crop • depending on farming system: rainfed/irrigated • depending on region • China, India, already facing serious water constraints • Keep an eye on sugarcane

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