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

Water and agriculture today

Irrigation expansion ► 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

Investments in irrigation

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

Where irrigation matters

The impact

Increased water withdrawal

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

The loss of biodiversity

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 ?

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 %  Source: AT2030 and FAO-NRLW estimates, refers to developing countries only

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

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

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

What is the potential ?

Climate change

Impact on runoff Source: IPCC report on water, foprthcoming

Projected impacts of climate change 1°C2°C5°C4°C3°C Sea level rise threatens major cities Falling crop yields in many areas, particularly developing regions Food Water Ecosystems Risk of Abrupt and Major Irreversible Changes Global temperature change (relative to pre-industrial) 0°C Falling yields in many developed regions Rising number of species face extinction Increasing risk of dangerous feedbacks and abrupt, large-scale shifts in the climate system Significant decreases in water availability in many areas, including Mediterranean and Southern Africa Small mountain glaciers disappear – water supplies threatened in several areas Extensive Damage to Coral Reefs Extreme Weather Events Rising intensity of storms, forest fires, droughts, flooding and heat waves Possible rising yields in some high latitude regions

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 million people ► Decay of glaciers: e.g. Tibetan Plateau; Himalayan glaciers to 1/5 by 2030s ↑Water stress ► 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)

Biofuels

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

Corn-based ethanol

Sugarcane-based ethanol

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

Water requirements of biofuels crop: fuel product: (energy density: Bio-diesel 35 MJ/l Ethanol 20 MJ/l) annual obtainable yield in l/ha (indicative):I/R Evapo- transpiration in litre / litre fuel (indicative) Irrigation water withdrawn in litre / litre fuel (indicative) Sugar cane Ethanol (from sugar)6000I/R Sugar beet Ethanol (from sugar)7000I/R Cassava Ethanol (from starch)4000R2250- Maize Ethanol (from starch)3500I/R Oil palmBio-diesel5500R2364- Rapeseed / MustardBio-diesel1200R3333- SoybeanBio-diesel400R Source: Hoogeveen, FAO-NRLW

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

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

Projections for water demand Source: de Fraiture, IWMI, 2007

► Rainfed agriculture:  Pressure on land resources ► Irrigated agriculture:  Pressure on water resources Impacts of biofuels

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.

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

THANK YOU