climate change and agriculture: impacts and costs of adaption

Climate Change and AgricultureImpacts and costs of adaptation

Gerald C. Nelson

Senior Research Fellow

Environment and Production Technology Division

5 October 2009

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

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

Outline

Climate Change Modeling Methodology

Impacts

• Yields, prices, production, trade

• Calorie consumption, child malnutrition

Adaptation Costs

• Need to reduce malnutrition

Conclusions and Policy Recommendations

MODELING METHODOLOGY FOR

CLIMATE CHANGE IMPACTS

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

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

CLIMATE DATA:

TODAY AND SCENARIOS FOR

TOMORROW

Temperatures have been rising…

Source: http://data.giss.nasa.gov/gistemp/graphs/

… and could increase much more

Source: Figure 10.4 in Meehl, et al. (2007)

Recent emissions

1990 1995 2000 2005 2010

CO

2 E

mis

sio

ns (

GtC

y-1)

5

6

7

8

9

10Actual emissions: CDIAC

Actual emissions: EIA

450ppm stabilisation


A1FI

A1B

A1T

A2

B1

B2

1850 1900 1950 2000 2050 2100C

O2 E

mis

sio

ns (

GtC

y-1)

0

5

10

15

20

25

30Actual emissions: CDIAC



A1FI

A1B

A1T

A2

B1

B2

2006

2005

2007

(Avgs.)

2008

Observed emissions are well above A2

simulated emissions

SRES (2000)

A2 aver.

growth rate for

2000-2010

2.13 %

Observed

2000-2007

3.5%

Raupach et al 2007, PNAS; Global Carbon Project 2009, update

A2

AVERAGE ANNUAL

PRECIPITATION CHANGE IN

CLIMATE SCENARIOS DIFFER

GREATLY

Watch Sub-Saharan Africa, the Amazon, and South Asia

Change in Precipitation (mm), 2000-2050

CSIRO, A2, AR4

Change in Precipitation (mm), 2000-2050

NCAR, A2, AR4

CLIMATE CHANGE YIELD

EFFECTS

Climate change reduces average yields

Crop/

management

system

Sub Saharan

Africa

East Asia and

Pacific

South Asia

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

AVERAGES CONCEAL GREAT

VARIATION

Irrigated rice

NCAR A2

CSIRO A2

Irrigated rice

Rainfed rice

NCAR A2

Rainfed rice

CSIRO A2

Rainfed maize

NCAR A2

Rainfed maize

CSIRO A2

FOOD SUPPLY, DEMAND AND

TRADE RESULTS

IMPACT2009

Biophysical effects from crop and hydrology models and

economic effects from global agriculture model

Climate Change Makes Food Price

Increases Greater

-

50

100

150

200

250

300

350

400

450

Rice Wheat Maize Soybeans

Do

llars

Per

Metr

ic T

on

2000 2050 No climate change 2050 CSIRO NoCF 2050 NCAR NoCF

Prices increase

without climate

change

Greater price

increases with

climate change

Rice Production

Wheat Production

Large production

increases in some

regions without

climate change

Climate change

eliminates those

gains

Maize Production

Cereal Trade Flows

… and therefore more

imports into

developing countries

Note that CSIRO results

in more exports from

developed countries

Note change in

direction for the

different scenarios

Climate Change Increases Childhood

Malnutrition

-

10

20

30

40

50

60

70

80

South Asia East Asia and Pacific

Europe and Central Asia

Latin America and

Caribbean

Middle East and North

Africa

Sub Saharan Africa

Millio

ns o

f C

hild

ren

2000 2050 No CC 2050 with CC

Without climate change, child

malnutrition falls except in

Sub Saharan AfricaWith climate change, child

malnutrition increases

everywhere

CLIMATE CHANGE ADAPTATION

COSTS

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

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

CONCLUSIONS AND

POLICY RECOMMENDATIONS

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

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

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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