Gerald Nelson, Senior Research Fellow (IFPRI) 5th October 2009, International Food Policy Research Institute (IFPRI), Washington D.C.

1. Climate Change and Agriculture
Impacts and costs of adaptation
Gerald C. Nelson
Senior Research Fellow
Environment and Production Technology Division
5 October 2009

2. Acknowledgements
 The IFPRI authors
• Gerald C. Nelson, Mark W. Rosegrant, Jawoo Koo, Richard
Robertson, Timothy Sulser, Tingju Zhu, Claudia Ringler,
Siwa Msangi, Amanda Palazzo, Miroslav Batka, Marilia
Magalhaes, Rowena Valmonte-Santos, Mandy Ewing, and
David Lee
 Thanks also to
• Ken Strzepek and Adam Schlosser of MIT for downscaled
climate scenarios
• Urvashi Narain, Sergio Margulis, Bob Schneider, and other
members of the EACC global study report of the World Bank
• ADB staff and reviewers for valuable comments and insights
on the ADB report
Page 2

3. Preview of Results
 Unchecked climate change will result in a 20 percent
increase in malnourished children by 2050
 Agricultural productivity expenditures of over $7 Billion
per year are needed to compensate
Page 3

4. Outline
 Climate Change Modeling Methodology
 Impacts
• Yields, prices, production, trade
• Calorie consumption, child malnutrition
 Adaptation Costs
• Need to reduce malnutrition
 Conclusions and Policy Recommendations
Page 4

5. MODELING METHODOLOGY FOR
CLIMATE CHANGE IMPACTS

6. Location-specific Biological and
Socioeconomic Modeling is Critical
 Climate change brings location-specific changes
• in precipitation, temperature and variability to
• local agronomic and market conditions
 Modeling challenge – To reconcile
• limited resolution of macro-level economic models with
• crop model detail
 Result
• More realistic modeling of climate change effects
(biological and economic) on global/regional agriculture
Page 6

7. Global Change Model Components
 Two GCM climate scenarios to show variability
• NCAR (wetter) and CSIRO (drier)
 DSSAT crop model
• to estimate biological effects
 ISPAM data
• to show where to estimate effects
 IMPACT2009
• To integrate biological effects from crop and hydrology
results with detailed economic model

8. CLIMATE DATA:
TODAY AND SCENARIOS FOR
TOMORROW
Page 8

9. Temperatures have been rising…
Source: http://data.giss.nasa.gov/gistemp/graphs/ Page 9

10. … and could increase much more
Source: Figure 10.4 in Meehl, et al. (2007)

11. 5
Recent emissions
Observed emissions are well above A2
0
1850 simulated emissions 2100
1900 1950 2000 2050
10
Actual emissions: CDIAC
Actual emissions: EIA SRES (2000)
9
CO2 Emissions (GtC y-1)
450ppm stabilisation 2008 A2 aver.
2007
650ppm stabilisation
2006
growth rate for
A1FI (Avgs.) 2000-2010
2005
8 A1B
A1T 2.13 %
A2
7 B1 Observed
B2 2000-2007
A2 3.5%
6
5
1990 1995 2000 2005 2010
Page 11
Raupach et al 2007, PNAS; Global Carbon Project 2009, update

12. AVERAGE ANNUAL
PRECIPITATION CHANGE IN
CLIMATE SCENARIOS DIFFER
GREATLY
Watch Sub-Saharan Africa, the Amazon, and South Asia

13. Change in Precipitation (mm), 2000-2050
CSIRO, A2, AR4

14. Change in Precipitation (mm), 2000-2050
NCAR, A2, AR4

15. CLIMATE CHANGE YIELD
EFFECTS

16. Climate change reduces average yields
Crop/ Sub Saharan East Asia and South Asia
management Africa Pacific
system
Irrigated rice
NCAR -14.1 -19.8 -15.5
CSIRO -11.4 -13.0 -17.5
Rainfed maize
NCAR -4.6 1.5 -7.8
CSIRO -2.4 -3.9 -2.9
Rainfed wheat
NCAR -21.9 -14.8 -44.4
CSIRO -19.3 -16.1 -43.7
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17. AVERAGES CONCEAL GREAT
VARIATION
Page 17

18. Irrigated rice
NCAR A2

19. Irrigated rice
CSIRO A2

20. Rainfed rice
NCAR A2

21. Rainfed rice
CSIRO A2

22. Rainfed maize
NCAR A2

23. Rainfed maize
CSIRO A2

24. FOOD SUPPLY, DEMAND AND
TRADE RESULTS
IMPACT2009
Biophysical effects from crop and hydrology models and
economic effects from global agriculture model

25. Climate Change Makes Food Price
Increases Greater
Greater price
2000 2050 No climate change 2050 CSIRO NoCF 2050 NCAR NoCF
increases with
450 Prices increasechange
climate
400 without climate
Dollars Per Metric Ton
350 change
300
250
200
150
100
50
-
Rice Wheat Maize Soybeans
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26. Rice Production
Page 26

27. Wheat Production
Climate change
Large production
eliminates those
increases in some
regions withoutgains
climate change
Page 27

28. Maize Production
Page 28

29. Cereal Trade Flows
Note that CSIRO results
in more exports from
developed countries
… and therefore more
imports into
developing countries
Note change in
direction for the
different scenarios
Page 29

30. Climate Change Increases Childhood
Malnutrition
80
2000 2050 No CC 2050 with CC
70 Without climate change, child
60 malnutrition falls except in
With climate change, child
Millions of Children
Sub Saharan Africa
50 malnutrition increases
everywhere
40
30
20
10
-
South Asia East Asia and Europe and Latin America Middle East Sub Saharan
Pacific Central Asia and and North Africa
Caribbean Africa
Page 30

31. CLIMATE CHANGE ADAPTATION
COSTS

32. Our Definition of Agricultural Adaptation
 Agricultural investments that reduce child malnutrition
with climate change to the level with no climate
change
 What types of investments are considered?
• Agricultural research
• Irrigation expansion and efficiency improvements
• Rural roads
Page 32

33. Adaptation Costs are over $7 billion
 Required additional annual expenditure
• Wetter NCAR scenario = US$7.1 billion
• Drier CSIRO scenario = US$7.3 billion
 Regional level
• Sub-Saharan Africa - $3 billion (40% of the total), mainly
for rural roads
• South Asia - US$1.5 billion, research and irrigation
efficiency
• Latin America and Caribbean - US$1.2 billion per year,
research
• East Asia and the Pacific - $1 billion per year, research
and irrigation efficiency
Page 33

34. CONCLUSIONS AND
POLICY RECOMMENDATIONS

35. Conclusions
 Climate change will have negative impacts
• Lower yields
• Higher prices
• More malnourished children
• Changes in trade flows reduce the negative effects
 Agriculture is critical for
• Poverty reduction
• Economic development and
• Food security
 Large additional expenditures should start now to
reduce the adverse impacts of climate change
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36. Policy and Program Recommendations
 Design and implement good overall development
policies and programs
 Recognize that enhanced food security and climate-
change adaptation go hand in hand
 At least $7 billion per year in additional productivity
investments are needed just for climate change
adaptation in developing countries
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37. Think and Act Globally and Locally
 Global public goods are needed
• Improve global data collection, dissemination, and analysis
• Make agricultural adaptation a key agenda point within the
international climate negotiation process
• Complete the Doha Round
• Expand international agricultural research
 National public goods are needed
• Reinvigorate national research and extension programs
• Build supporting national infrastructure – roads, etc.
• Provide supportive policy environment
 Local public goods are needed
• Support community-based adaptation strategies
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