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The Food and Water Paradox - Dr Colin Chartres
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Water for a food-secure world
The Food and Water Paradox
Colin Chartres International Water Management Institute
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Water for a food-secure world
The Global Food and Water Paradox
• Two key drivers:– Growing population, and– Growing wealth
• Climate Change creating uncertainty
Feeding c.2 billion more peoplewith less water for agriculture than we have now
in an era of climate change
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Water for a food-secure world
How has IWMI contributed?
A journey through time and into the future recognizing the contribution of past and present staff and partners
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Water for a food-secure world
Demography, Global GDP and Water Withdrawals 1900 - 2000
• Population increase about 3.6 times • Water withdrawals increased 6.8 times• GDP increased 19 times , about 3% per year (constant prices,
IMF)
Acknowledgements to Jan Lundqvist, SIWI
GDP
Pop.
Total
Agriculture
Industry
Municipal
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Water for a food-secure world
Poverty and Population
Pop. m2009
Pop. m2050
Growth
Africa 1010 1998 98%
Asia 4121 5231 27%
Europe 732 691 - 5%
LA and Caribbean 582 729 25%
Population growth,dietary change and poverty and malnutrition will be key drivers with respect to agriculture
Courtesy of Stan Wood, IFPRI
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Water for a food-secure world
Drivers paint a pessimistic picture even without climate change
• Food production to increase by 70% by 2050 (World Food Summit, Rome)
• Additional water required under BaU up to 6000 km3 (Comprehensive Assessment 2007) - from where?
• CC may reduce potential yields in SSA and SA by 30% by 2030 (Lobell et al, Science, 2008)
• Temperature increase may reduce yields of corn, soya beans and cotton by 30 – 46% in the US in a century (Schlenker & Roberts, PNAS, 2009)
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Water for a food-secure world
The Green Revolution was fuelled by fertilizer and irrigation, but at a cost
Irrigated Area
Food price index
World Bank lending for irrigation
2.5
2.0
1.5
1.0
0.5
01960
1965
1970
1975
1980
1985
1990
1995
2000
2005
320
280
240
200
160
120
80
40
0
Living Planet IndexFreshwater Species
?
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Water for a food-secure world
• IWMI work stressed that irrigation has to be considered in a basin context and that other competing uses and the environment need to be considered.
• This highlighted the significance of the IWRM approach that had been emerging for decades.
• Studies demonstrated that some basins were rapidly “closing” due to over extraction of water
• Water stress indicator
The River Basin approach
Areas in red are where environmental water requirements may not be met under current usage (Smakhtin et al. 2004)
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Water for a food-secure world
Where does all the water go?
Thanks to David Molden
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Water for a food-secure world
Water Scarcity in 2000
From the Comprehensive Assessment of Water Management in Agriculture, 2007
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Water for a food-secure world
More Crop Per Drop
From the Comprehensive Assessment of Water Management in Agriculture, 2007
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Water for a food-secure world
Global Water Withdrawals: historical and projected (after Peter Gleick)
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Water for a food-secure world
Approx. 2000 water withdrawals
n.b. consumptive demand is less than water withdrawals due to irrigation inefficiency
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Water for a food-secure world
Climate change impacts
• SRESA2 (A2) and SRESB1 (B1) IPCC scenarios show no clear trend in the total rainfall;
• Potential evapotranspiration (PET), which is dependent upon the temperature, increases, with sharper increase after 2040
• By 2050, for the irrigated area, the gap between PET and effective rainfall will be about 17% higher than the baseline for the A2 climate change scenario whereas it will be about 14% higher for B1 climate change scenario.
• This will put extra stress on demand for irrigation water.
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Water for a food-secure world
How can we respond to the paradox?
• Improving irrigation efficiency and water productivity
• Building resilience in terms of storage• Recycling and reuse• Industrial and urban efficiency• Water reform – policy, governance,
institutions and regulation• Reducing food waste• Enhancing supply chains for the benefit of
farmers, consumers and environment
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Water for a food-secure world
Increase Productivity
more crop per drop in irrigated and rainfed systems
0 200,000 400,000 600,000 800,000 1,000,000 1,200,0000
1000
2000
3000
4000
5000
6000
Arab World
Sub-Saharan Africa (developing only)
Burkina Faso
Bangladesh
India
Pakistan
China
Vietnam
Thailand
Brazil
Colombia
Area (Km2)
Cere
al P
rodu
ction
per
Are
a (K
g/ha
)
Courtesy Simon Cook
Participatory Irrigation Management(PIM)/Water Users Associations – its all about people, institutions and governance
• Irrigation Management Transfer (IMT) served as the cornerstone of the IWMI, research agenda for nearly a decade.
• PIM is now the paradigm for irrigation management, but there is emerging evidence that schemes are failing when financial support is withdrawn.
• The trend in South Asia from government canal schemes to individual boreholes has created anarchy and a major groundwater management headache.
• How do we reinvigorate PIM?
Region Success Failure
S Asia 18 20
E Asia 7 2
SE Asia 12 24
C Asia 4 14
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Water for a food-secure world
Wastewater Reuse
Can we develop effective business models that promote safe recycling and reuse?
Courtesy Pay Drechsel
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Water for a food-secure world
Sustainable intensification – the coming challenge across many scales
• Closing the actual vs potential yield gap (on farm issue)
• Twice the yield off half the area? (on-farm issue)• Capitalizing on natural infrastructure (national
policy issue)• Recognizing the value of ecosystem services
(river basin/regional level issue)• The water-food-energy-environment nexus
(national-transboundary issue)
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Water for a food-secure world
Sustainable intensification – the coming challenge across many scales
• Closing the actual vs potential yield gap (on farm issue)
• Twice the yield off half the area? (on-farm issue)• Capitalizing on natural infrastructure (national
policy issue)• Recognizing the value of ecosystem services
(river basin/regional level issue)• The water-food-energy-environment nexus
(national-transboundary issue)
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Water for a food-secure world
What does sustainable intensification mean?
• Minimal off-site movement of pollutants• Maintaining downstream flows and water quality• Utilizing natural infrastructure for water storage, flood
prevention• Maintaining habitat for pollinators and conserving
biodiversity, forest cover and grasslands• Sequestering carbon to improve
soils and mitigate climate change• Maximizing energy efficiency,
minimizing water consumption, resource reuse.
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Water for a food-secure world
Hot spots Many developing countries with high population growth and currently low agricultural productivity e.g. • India where water demand is forecast to exceed supply by 50% in
2030 and where the dry west has high productivity and the wet east, lower productivity
• Pakistan, where “feudal” land tenure and water scarcity are compounded by a predicted population increase from 169m
• to 295m in 2050
• Sub-Saharan Africa where yields continue to stagnate in the face of a predicted 98% population increase
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Water for a food-secure world
Conclusions• Food and water security issues are still
daunting in the developing world
• Business as usual paradigms have to be replaced
• Sustainable intensification is the way forward, but will require significant investment in R&D, capacity building, land and water reform
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Water for a food-secure world
Conclusions
If we combine these approaches with reductionof food waste we can feed 2 billion more people without significantly increasing agriculture’s footprint
