http://www-test.fao.org//globalperspectives/resources/en/ How climate change may affect global food demand and supply in the long-term? © FAO: http://www.fao.org

1. Economic and Social Development Department
Food and Agriculture
Organization of the
United Nations
How climate change may affect
global food demand and
supply in the long-term?
Aikaterini Kavallari
Global Perspective Studies Team

2. Economic and Social Development Department
Challenges to ensure sustainable food security
in the future

3. Economic and Social Development Department
131
48
15
68
30
6
0
20
40
60
80
100
120
140
0
200
400
600
800
1,000
1,200
1,400
sub-Saharan Africa South Asia East Asia Near East & N.
Africa
Latin America Developed
countries
Incremental population growth 2005/07-2050, millions (left-axis)
Percent population growth 2005/07-2050 (right-axis)
Source: United Nations Population Division (2009).
An additional 2.5 billion persons—to 9.1 billion in 2050

4. Economic and Social Development Department
0
5
10
15
20
25
30
35
40
45
Developing
countries
sub-Saharan Africa South Asia East Asia Near East & N.
Africa
Latin America
Average per capita incomes relative to developed countries 2006, percent
Average per capita incomes relative to developed countries 2050, percent
GDP per capita gaps converge only modestly
Source: Development Prospects Group, The World Bank.

5. Economic and Social Development Department
Agricultural production growth slows down
Source: FAO.
24
77
60
57
317
170
0 50 100 150 200 250 300 350
Developed
countries
Developing
countries
World
Percent change over period
1961/63-2005/07 2005/07-2050

6. Economic and Social Development Department
Potential impacts of climate change on global
food demand and supply
- empirical results based on Agricultural Model Intercomparison
and Improvement Project (AgMIP) Phase 1-

7. Economic and Social Development Department
The climate modeling chain in AgMIP:
from biophysical to socioeconomic
General
circulation
models
(GCMS)
Global
gridded
crop
models
(GGCMs)
Global
economic
models
DTemp
DPrec
Dyield
(Biophysical)
DArea
DYield
DCons
DTrade
Climate Biophysical Economic
RCP’s
Farm
practices
CO2
Pop.
GDP
Source: Nelson et al., PNAS (2013).
Reference scenario: SSP2 (no climate change)
Climate scenario: RCP 8.5

8. Economic and Social Development Department
-25
-20
-15
-10
-5
0
5
Wheat Rice Coarse grains Oil seeds Sugar CR5
IPSL/LPJ HADGEM2/LPJ IPSL/DSSAT HADGEM2/DSSAT
Source: Nelson et al. (2014).
Note: CR5: average of the five crops
Climate change impacts, percent change in
exogenous yields relative to reference in 2050

9. Economic and Social Development Department
Percentchange
-60
-40
-20
0
20
40
60
n
Mean
SD
2891
-0.17
(0.131)
2891
-0.11
(0.166)
2891
0.11
(0.249)
2891
-0.02
(0.25)
2891
-0.01
(0.264)
2891
-0.03
(0.063)
2891
0.2
(0.242)
YEXO YTOT AREA PROD TRSH CONS PRICE
Climate induced changes to global yields, land use, production,
trade, consumption and prices relative to reference for CR5 in 2050
Source: Nelson et al. (2014).
Notes: YEXO: exogenous yields,; YTOT: final yields; AREA: crop area; PROD: domestic production; TRSH: net imports relative to production;
CONS: consumption; PRICE: average producer prices

10. Economic and Social Development Department
Conclusions

11. Economic and Social Development Department
Take away messages
• Climate impacts will negatively affect commodity prices, with
many of the increases ranging from 5-25%
• Food consumption is expected to drop implying that climate
change may well exacerbate food security concerns
• Globally consumption responds less than supply because food
demand is not so sensitive to price changes
• Still effects will be felt more in specific regions with already
stressed natural resources
• Variability in trade and crop area responses is due to the varying
assumptions about trade flexibility and ease of land conversion
in the models -> both of which imply different degrees of
adaptation to changes in agricultural markets

12. Economic and Social Development Department
Further reading
Special issue of Agricultural Economics (2014):
http://onlinelibrary.wiley.com/doi/10.1111/agec.2014.45.issue-1/issuetoc
• von Lampe, Willenbockel et al., “Why do global long-term scenarios for agriculture
differ? An overview of the AgMIP Global Economic Model Intercomparison”
• Robinson, van Meijl, Willenbockel et al., “Comparing supply-side specifications in
models of global agriculture and the food system”
• Valin, Sands, van der Mensbrugghe et al., “The future of food demand:
understanding differences in global economic models”
• Schmitz, van Meijl et al., “Land-use change trajectories up to 2050: insights from a
global agro-economic model comparison”
• Müller and Robertson, “Projecting future crop productivity for global economic
modeling”
• Nelson, van der Mensbrugghe et al., “Agriculture and climate change in global
scenarios: why don’t the models agree”
• Lotze-Campen, von Lampe, Kyle et al., “Impacts of increased bioenergy demand on
global food markets: an AgMIP economic model intercomparison”
Special issue
Proceedings of the National Academy of Sciences (PNAS) (2014):
http://www.pnas.org/content/111/9/3274.abstract
• Nelson, Valin et al., “Climate change effects on agriculture: Economic responses to
biophysical shocks”

13. Economic and Social Development Department
Annex

14. Economic and Social Development Department
Terminology
• SSPs: Shared Socioeconomic Pathways
• RCPs: Representative Concentration Pathways
• IPR: Intrinsic Productivity Rate
• AgMIP: Agricultural Model Intercomparison Project
(http://www.agmip.org/)
• LPJml: Lund-Potsdam-Jena managed Land Dynamic Global
Vegetation and Water Balance Model
• DSSAT: Decision Support System for Agricultural Technology
• HadGEM2: Hadley Centre Global Environment Model version 2
• IPSL: climate model of the Institute Pierre Simon Laplace

15. Economic and Social Development Department
Reference scenario details
• Based on the SSP2 narrative
• Assumes a middle of the road growth of the economy with
intermediate socioeconomic challenges to climate change
adaptation and mitigation
• Population and GDP growth path taken over from the SSP
database, based in IIASA and OECD projections respectively
https://secure.iiasa.ac.at/web-
apps/ene/SspDb/dsd?Action=htmlpage&page=about

16. Economic and Social Development Department
Climate scenario details
• Radiative forcing of over 8.5 watts per square meter by the end
of the century
• Excludes potentially positive effects of increasing CO2
concentration
• Crop models assume constant management practices (e.g.
sowing dates)
• Crop models did not include effects of increased ozone
concentration, increased weather variability and greater biotic
stress