- Agriculture accounts for over 80% of global freshwater usage, mainly for food production. Meeting future global food and energy demands in a sustainable manner poses challenges due to increasing water constraints. - Closing yield gaps through irrigation expansion could help boost food production, but over 40% of current irrigation is unsustainable due to exceeding local water availability. Agricultural intensification must be pursued carefully to avoid environmental degradation. - Transitioning to more efficient irrigation practices, suitable crops, and agricultural production systems could allow for sustainable increases in food supply while reducing overall water usage. However, ensuring local and global food and water security remains complex with growing population and dietary changes.

1. Food-Energy-Water
nexus: Implications for
developing countries
Paolo D’Odorico,
Department of Environmental Science, Policy,
and Management
University of California, Berkeley

2. Water Use
Food Production
Domestic
Drinking
600-1800
1
(data from Falkenmark & Rockstrom, 2005)
Most of the water we use is for agriculture
Water Footprint
Agriculture
Domestic
Industrial
85.8%
9.6%
(data from Chapagain and Hoekstra, 2004)
(Units: m3/person/yr)
…mainly for food production

3. Water Use in Agriculture
19% of agricultural land is irrigated and produces 40% of the food
IrrigatedRainfed
Uses “green” water Both “blue & green” water
“Green Water”: Root-zone soil moisture
“Blue Water”: Water from Rivers, Lakes, Aquifers

4. Land Oceans
ET=73
P=120
E=509
P=462
(1 unit=1012 m3/y)
GR=1
SR=46
Advection=47
Data Source: Chow et al., (1988)
Global Water Cycle
In 2010: ≈12 ×1012 m3/y (Carr, D’Odorico et al., 2013)
10% of precipitation over land is used for agriculture
16% of terrestrial evapotranspiration is from agroecosystems
Water Used in Agriculture
How much water is used by agriculture?
87%
4%
4%
5%
Global Blue Water Uses
67%
3%
30%
Water Consumption in Agriculture
(Blue + Green)
87%
4%
4%
5%
Global Blue Water Uses
Irrigation Domestic
Industrial Energy
67%
3%
30%
Water Consumption in Agriculture
(Blue + Green)
Food and Fiber Crops
Biofuels
Livestock (feed + rangeland)

5. Irrigated Areas in Year 2000
(After Rosa et al., ERL, 2018, Based on
Irrigation maps by Portmann et al., 2010)
Unsustainable if Irrigation Water Consumption > Local Availability=Runoff-Environmental Flows
40% of irrigation is unsustainable loss of environmental flows & environmental stocks

6. Irrigation in Africa
Irrigation Water
Consumption
(km3
/y)
Unsustainable
Irrigation
(km3
/y)
%
Unsustaina
ble
World 847.0 336.0 40%
Africa 75.0 31.0 41%
Egypt 40.2 17.4 43%
Sudan 9.6 2.9 31%
South Africa 6.8 2.7 40%
Morocco 6.0 3.8 63%
Algeria 2.3 1.2 51%
Libya 1.7 1.5 86%
Tunisia 1.5 0.6 41%
Madagascar 1.4 0.0 2%
Mali 1.1 0.1 12%
(After Rosa et al., ERL, 2018,
Based on Irrigation maps by Portmann et al., 2010
Assuming no deficit Irrigation in irrigated areas)

7. Increase in Global Water Demand
(Davis & D’Odorico, ERL 2015)
Population Growth Increase in Meat Consumption Biofuels: 2-6% of Water Use
0
50
100
150
2006 2008 2010 2012
X106m3
Bioethanol Biodiesel
(data source: FAO-OECD, 2013)
“Meat” requires 4-8 times more
water per calorie than “vegetables”.
≈ 20% increase in per
capita water footprint
between 2009-2050
(Davis et al., GEC, 2016)

8. What about Water for Energy?
• Biofuel Production (1.8 x 1011 m3y-1)(Rulli et al., 2016)
• Extraction of fossil fuels (1.8 x 1010 m3y-1)(IEA, 2016)
• Non-fuel based renewable energy
Irrigation: ≈1.2 ×1012 m3/y (Siebert et al., 2010)
Both blue and green water
Only blue water

9. Water for Energy
(IEA, 2016;
D’Odorico et al., Rev. of
Geophys., 2018)
0 0.2 0.4 0.6 0.8 1 1.2 1.4
Global Irrigation
Energy Production
Blue Water Consumption (x 10 12 m3 y-1)
(IEA, 2016; D’Odorico et al., Rev. of Geophys., 2018)
Biofuels
Fossil Fuels
Power
Generation
BLUE WATER
CONSUMPTION FOR ENERGY
PRODUCTION

10. 10
Global Bioethanol and Biodiesel Consumption
Bioethanol
Water (million m3)
Water Used (106 m3)
Biodiesel
In 2000: 2-6% water use in agriculture (Rulli et al., Sci. Rep. 2016)

11. How many people can the Planet support, in case the presently
cultivated land were used for both food and energy production?
% of Fuels used for
transport from
Biofuels
Population Size
(billions)
10% 6.7
20% (*) 4.4
100% (*) 2.5
Applying the EU consumption rates per
capita to the entire world
(Rulli et al., Scientific Reports, 2016)
Assumptions:
1) No expansion of agriculture
2) Using current crop Yields
3) Only energy for the transport sector
4) Applying EU per capita consumption to
the entire world
Land for Food, Energy or both?

12. Water Footprint of Fossil Fuels
Fossil Fuel
Extraction
Fossil Fuel
Replacement
Natural Gas
Crude Oil
Coal
80 x 1012
70 x 1012
60 x 1012
50 x 1012
40 x 1012
30 x 1012
20 x 1012
10 x 1012
(m3y-1)
(m3y-1)
2 x 1010
1 x 1010
The Water-Energy Nexus of Fossil Fuels
• Biofuels: Use of present time water & land – Renewable
• Fossil Fuels: Produced with resources from the past – Not Renewable
We are virtually “burning” water from the past
More water than the water cycle could sustain(D’Odorico et al., Earth’s Future, 2017)

13. Not enough water and land to rely only on fuels from plant biomass
Reliance on:
• Non-fuel based energy (solar, wind,…)
• Fossil fuels: 20% increase by 2040 (US EIA, 2016; Exxon Mob Corp. 2016)
- Unconventional fossil fuels : 25-40% increase by 2040
1) Oil sands/Tar Sands/Heavy Oil
2) Shale Oil
3) Shale Gas

14. Areas where shale oil/gas extraction could compete with agriculture for water
Are we running out of Freshwater Resources for Food and Energy?
31–44% of shale deposits are in water stressed
areas; (Rosa et al, Earth’s Future, 2018)

15. How can we meet the increasing demand for water for food?
Agricultural
Intensification
(Godfray, Science, 2010; Foley
et al., Nature, 2011)
Close the Yield Gap
(irrigation, fertilizers,…)
Transition to Commercial
Agriculture
- Loss of livelihoods?
Agricultural
Extensification
Expand the
cultivated area
Land Use Change
Deforestation
Biodiversity losses
Ecologists Advocate for
Intensification
…because it avoids habitat
destruction
… however, in some regions
there is no sufficient water to
sustainably close the yield gap

16. … but, is there enough water to do it sustainably?
by closing the yield gap we can feed 4 Billion people
(Davis et al., Earth’s Future, 2014)
Yield Gaps (Mueller et al., 2012)Billionsofpeople

17. If we account for water availability and environmental flows
(Rosa et al., ERL, 2008)
The Water Sustainability of Yield Gap Closure through Irrigation ExpansionIt is possible to sustainably
- expand irrigation to 26% of currently rainfed areas
- feed an additional 2.8 billion people
Eliminating unsustainable irrigation:
- In this case the world could feed “only” additional 1.8 billion people

18. In Africa: Great potential for sustainable
expansion irrigation to rainfed areas 
Increase in food production
Water
Current Irrigation
Water Consumption
(km3
/y)
Current
Unsustaina
ble (%)
Max Net
Sustainable
Increase (%)
World 847.0 40% 9%
Africa 75.0 41% 101%
Egypt 40.2 43% -43%
Sudan 9.6 31% 99%
South Africa 6.8 40% 64%
Morocco 6.0 63% 94%
Algeria 2.3 51% 237%
Libya 1.7 86% -32%
Tunisia 1.5 41% 0%
Madagascar 1.4 2% 61%
Mali 1.1 12% 214%
Food
Total
Production
(1012
kcal y-1
)
Rainfed
Production
(1012
kcal y-1
)
Net
Sustainable
Increase (%)
World 8981 6104 25%
Africa 466 379 100%
Egypt 69 0 -54%
Sudan 17 15 76%
South Africa 43 40 56%
Morocco 15 13 107%
Algeria 7 7 71%
Libya 1 1 0%
Tunisia 4 4 125%
Madagascar 7 3 186%

19. Potential Self-sufficiency
Self-sufficient Barely self-sufficient Trade dependent
2000 In 2030 at gap closure
Even in the best gap closure/intensification scenario, locally, areas of food scarcity persist…
particularly in Africa.
Davis et al., Earth’s Future, 2014

20. The Global Food Trade Network
1986
2010
(D’Odorico, et al., Earth’s Future, 2014)Net Importers
Net Exporters
Globally, 24% of the food we eat reaches us through international trade

21. Virtual Water Trade
In some regions of the world the
water resources are not sufficient
to feed the local population.
Do they import water or food?
Source: www.waterfootprint.org
The notion of “Virtual Water”
By Trading water we virtually
trade food (Allan, 1998)
Global virtual water flows: 2.4-3.2 × 10 12 m3/y
Physical water flows (inter-basin transfers): 0.5 × 10 12 m3/y
Local Supply>Demand
Local Supply<Demand
TotalFlux(1012m3y-1)
Plants
Luxury
Animal
Others
1980 1990 2000 2010
2.8 ×1012 m3/yr
(Carr, et al., PLOS1, 2013)
1986
2011

22. Number of trade connections in space and time
Carr, D’Odorico, Laio, Ridolfi, PLoS-One, 2013
Africa Remains less integrated in the global food market
Number of trade
partnerships

23. Globalization of Water through
International Land Acquisitions
Rulli, Saviori and D’Odorico, PNAS, 2013
Davis et al., Nature Geoscience, 2015
Dell’Angelo et al., World Development, 2017
- >67 million ha
Area (millions ha)
Do land acquisitions induce agricultural intensification or
expansion?
• Agricultural Intensification in previously cultivated land 
Dispossession of local communities  Loss of Rural Livelihoods
 Local Food Insecurity?
• Agricultural Expansion  Deforestation of “virgin land”? 
Environmental Impacs
Based on Data from the Land Matrix, 2018
Questions:
-How much more food can be produced?
-What’s the role of water?
0
10
20
30
40
50
60
70
80
Africa Asia &
Oceania
South
America
Total
Area(×106ha)
Not Under Production
Under Production

24. Total for Africa (Millions):
52-89: with Existing Technology
123-212: at Gap Closure (140% increase)
223 Million Malnourished People in
Sub-Saharan Africa (FAO, 2013)
(Rulli and D’Odorico , Environm. Res. Lett., 2014)
72% foreign
3% under production

25. The hidden goals of land investments:
- motivated by Water Needs
- invoked as an approach to yield gap closure
Rulli, Saviori and D’Odorico, PNAS, 2013
Yield gaps are still “big” in the developing world
Large-scale land acquisitions transition from
subsistence to large-scale commercial farming
0
50
100
150
200
250
300
350
400
Africa Asia &
Oceania
South
America
Total
WaterAppropriation(×109m3)
Blue Water
Green Water

26. How can we meet the increasing demand for water for food?
Agricultural
Intensification
(Godfray, Science, 2010; Foley
et al., Nature, 2011)
Close the Yield Gap
(irrigation, fertilizers,…)
Transition to Commercial
Agriculture
- Loss of livelihoods?
Agricultural
Extensification
Expand the
cultivated area
Land Use Change
Deforestation
Biodiversity losses
Sustainable
Intensification
Improve
Efficiency
Adopt More
Suitable Crops
Increase production
without requiring
more land, more
water, more
investments

27. - Sustainable irrigation expansion on rainfed areas (yield gap closure)
- Use water more efficiently - “more crop per drop”
Soil water conservation (reduce soil evaporation)
Crops with better water-use efficiency. Plant the right crop in the right place
- Feed 825 million people more
- Reduce water use by 12%
(Davis et al., Nature Geoscience, 2017)
Sustainable Intensification

28. Conclusions
• Water remains a major constraint on food production
• Some countries are in conditions of chronic water deficit
• Trade and international investments  Globalization of Water, Land, and Food
• Agricultural intensification often requires water and investments in technology
- To what extent can it be done sustainably?
- Change in system of production from small-scale to large scale farming…
• Sustainable intensification
Acknowledgements: Maria Cristina Rulli, Luca Ridolfi, Francesco Laio, Kyle Davis, Joel Carr,
Lorenzo Rosa, Samir Suweis, Davide Chiarelli, Stefano Casirati, Stefano Vandoni, David
Seekell, Jampel Dell’Angelo

29. Extra Slides (no need to translate)

30. Trade
Intensification
Green Revolution
Industrial Revolution
Food Crises: “running
out of water?”
Erisman et al., Nature Geoscience, 2012.
Green Revolution

31. Meat Consumption vs. GDP per Capita (2013) Meat Consumption vs. GDP per Capita (1961-2013)
GDP per Capita GDP per Capita
MeatConsumptionperCapita(kg/yr)
MeatConsumptionperCapita(kg/yr)
Bennett’s Law
Increase in per capita meat consumption
“Meat” requires 4-8 times more
water per calorie than “vegetables”.
≈ 20% increase in per
capita water footprint
between 2009-2050
(Davis et al., GEC, 2016)
Kenya
Tanzania
Egypt
Ethiopia
Nigeria
0
20
40
60
80
100
120
1000 10000 100000
Meatconsumptionpercapita(kg/year)
Real GDP per capita at chained PPPs in US$
Gabon
Meat Consumption vs. GDP per Capita (2013)
In Africa