the dual challenge: doubling yields in the face of water scarcity and climate change - dr david...
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The dual challenge: doubling yields in the face of water
scarcity and climate change
Dr David MoldenIWMI
Water for a food-secure worldWater for a food-secure world
About IWMIIWMI is one of 15 research centers supported by the Consultative Group on International Agricultural Research (CGIAR).
Mission: To improve the management of land and water resources for food, livelihoods and the environment.
Where we work:Headquarters: Colombo, Sri LankaIn Africa : Ghana, Southern Africa, EthiopiaIn Asia: India, Pakistan, Nepal, Laos, Vietnam, Central Asia, Syria
Water Scarcity 2000
1/3 of the world’s population live in basins that have to deal with water scarcity
More People – 6.5 to 9 billion people by 2050
More calories & more meat, fish, milk
More food production – need to double grain production by 2050
More water for food – if practices don’t change, double water needs
This equation doesn’t work – something has to change
Will there be enough water?More people – 6.5 to 9 billion people by 2050
More calories & more meat, fish, milkMore food production – need to double grain production by 2050
More water for food – if practices don’t change, water needs for agriculture will double
Something has to change
Climate Change
Mitigation is about gases.Adaptation is about water.
Some areas will be wetter, others drier
Source: Arnell, 2003 – IWMI, FAO, ADB report on revitalizing irrigation.
Water Scarcity and Climate Change
Some areas wetter, some areas drier
Water for a food-secure world
Hydrological Modeling (SWAT)
Rainfall-Runoff simulation to determine impacts of CC on flow regimes and groundwater recharge
Rainfall Evapotranspiration
Runoff
Results – one scenario (A1B), one sub-catchment in the Volta
Variability in Precipitation
Thornton et al 2006
likely to increase with climate change
- Costs 1/3rd of growth potential- Occurs as prolonged dry spells, drought and floods
Impact of rainfall variability on GDP and Agricultural GDP growth
-80
-60
-40
-20
0
20
40
60
80
19
82
19
83
19
84
19
85
19
86
19
87
19
88
19
89
19
90
19
91
19
92
19
93
19
94
19
95
19
96
19
97
19
98
19
99
20
00
year
%
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
rainfall variability
GDP growth
Ag GDP growth
Unmitigated rainfall and hydrological variability
Source: World Bank, 2006. A Country Water Resources Assistance Strategy
for Ethiopia
Growth in Yields
United States
China
Latin America
Sub-Saharan Africa
IPCC – yields in SSA will decline by 50% because of climate change
It is possible to more than double yields in SSA in spite of climate change.
SolutionsOlivia Molden
Water Management
Around 70% of the world’s under-nourished live in rural areas where non-agricultural livelihood options are limited.
Get water to poor people, use it better
Improve and Safeguard Water Access
Access to Technologies
But need to re-think water storage: role of groundwater and soil moisture.
And beyond: insurance, local trade, …
Cub
ic m
eter
s pe
r ca
pita
Water Storage Mitigates Climate Variability
4 43 7
46 128
7
140
6 248
6
325
5 472
9 615
0
01,0002,0003,0004,0005,0006,0007,000
Ke
nya
Eth
iopi
aS
out
hA
fric
aT
hai
lan
d
Lao
s
Ch
ina Bra
zil
Au
stra
liaN
ort
hA
me
rica
Source: World Bank data from
ICOLD
Water for a food-secure world
Physical Water Storage Continuum
Growing Enough Food
With Water Scarcity andClimate Change
David Molden
Irrigation potential
developed:
Egypt, Morocco,
Somalia, South Africa > 75%
Botswana, Sudan,
Zimbabwe, Madagascar, Mali, Malawi,
Uganda 50-75%
Rest < 50%
% Irrigated Land
INDIA: ~50
SSA: 5
Upgrade Water Management in Rainfed Landscapes
Even if large scale irrigated area doubles, the contribution to food production for SSA from irrigation would change from 5 to 11%.
Rainfed land has the highest potential for poverty reduction and water productivity gains.
Consider A Range of Agricultural Water Management Options
Fish, Livestock, Crops, Ecosystem Services
A range of options Water sources in Krishna basin
Krishna river basin
24 major reservoirs
6100 small reservoirs
High groundwater use
Water for a food-secure worldMap source: Survey Dept.
For Water Security
Storage is the best “No regret” option!
Water for a food-secure worldWater for a food-secure world
Doubling Yields water + more
• Access to technology, seeds, fertilizers?• Is there enough money
or credit to buy them?• Are markets available to sell?• Financially viable?• Water and land resources available?• Is it sustainable – financial, ecological?• Supportive policies?• “Mind mobilization” Matsepo Khumbane
FAO - SSA 245 Million 58% are rural poor
AWM Team - SSA 279 Million 65% are poor
AWM Team - India
220 Million 90% are poor
Who could benefit from Agricultural Water Management Solutions?
From Scoping Study for Agricultural Water Management Solutions Project
If this is so good, why doesn’t it happen?
It is happening….
Small Reservoirs
Multiple-use systems integrating domestic water, irrigation, fisheries, livestock,
industries – provide income, nutrition and health benefits, and improve water productivity
healthlabour saving,gender
resilient food and income….
..from livestock..from fish
..from enterprise
..from crops
Groundwater – offers opportunities for the rural poor.
Needs:1) Better information on availability1) Access to technologies2) promote sustainable use
IDE rope pump, Ethiopia
A groundwater revolution in SSA: Benefits with little cost?
Groundwater is under-utilized in Sub-Saharan Africa
Groundwater is under-utilized in Sub-Saharan AfricaCu
ltiva
ted
area
as
% o
f cel
l are
a
In Asia groundwater is often the only water available
In Asia groundwater is often the only water available
Water for a food-secure world
It is happening….
But not fast enough!
Why doesn’t it happen faster?
• Missed opportunities:– AWM falls between institutional cracks– Failure to focus on women
• Water focus is on drinking water, hydropower, large irrigation
• Its not just about technologies, but about markets, institutions, capacity
What will it take?• Continuous learning from a range of
knowledge and experience• A new and significantly increased capacity • Crafting solutions, paying attention to
context• Adapting technologies and institutions• Engaging public, policy makers & investors • You…..
Water for a food-secure world
Thank You !
“Anyone who can solve the problems of water will be worthy of two Nobel Prizes – one for peace and one for science”
John F Kennedy
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