Climate Change Impacts on Agriculture in Vietnam

Tingju Zhu1 and Mai Van Trinh2

1International Food Policy Research Institute, Washington, DC2Institute for Agricultural Environment, Hanoi, Vietnam

June 10-12, 2010

Beijing, China

International Conference on Agricultural Risk and Food Security (ARFS)

Background

2

• Area - 332 K km2 with 3300

Km coastline

• Population - 85.8 millions

(2009)

• Rapid economic growth

• Agriculture accounts for

~20% GDP, 65%

employment, 30% exports

• Hydro-climatic disasters

cause serious damages

Potential Climate Change Impacts

3

• Vietnam is among a few countries that will be worst

affected by climate change – tropical location, long

coastal line, mega deltas

• Climate change channelizes its impacts on agriculture

through changes in precipitation, temperature,

atmospheric CO2 concentration, and sea level rise

(inundation and salinity intrusion)

• Hydrological impacts of climate change affects water

availability and irrigation

• Adverse impacts of climate change can affect economic

growth and the status of poverty and malnutrition

Climate Change already under Way?Changes of Precipitation, Temperature and Solar Radiation

during 1971-2007

104 106 108

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Zone 2

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Zone 2

Zone 3

Zone 4

Zone 5

Zone 6

Zone 7

Zone 8

-350

-300

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-28

-24

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-16

-12

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28mm

oCWatt/m2

Rainfall average temperature

radiation

Selection of Climate Scenarios:Moisture Index for GCM Climate Projection in 2050

Drier Wetter

• Dry Scenario: IPSL-CM4

• Wet Scenario: GISS-ER

• MONRE Scenario

Baseline: 1971-2000

Two Future Period:

2030 (2016-2045)

2050 (2036-2065)

Climate Change Scenarios (I)

Average Country Climate Moisture Index

All climate change scenarios are from IPCC AR4’s GCM projections for

SRES A2 emission scenario

MONRE scenario is the Vietnamese government official climate change

scenario for A2

Sea level rise scenario: 17 cm by 2030, 30 cm by 2050

Climate Change Scenarios (II)

Mean Annual Temperature Changes by Agro-ecological Zone (oC)

Mean Annual Precipitation Changes by Agro-ecological Zone (%)

Climate Change Scenarios (III)Mean Monthly Precipitation

0

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Pre

cip

itat

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(mm

)

North West

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

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North East

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

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cip

itat

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(mm

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Red River Delta

050

100150200250300350400450500550

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Pre

cip

itat

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(mm

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North Central Coast

050

100150200250300350400450500550600650

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

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cip

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(mm

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South Central Coast

050

100150200250300350400450500550

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Pre

cip

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(mm

)

Central Highland

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(mm

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East South

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Mekong Delta

Analytical Models

Climate Change Impacts (I)% Basin Runoff Changes

-50

0

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100

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Red River Basin - 2030

IPSL

GISS

MONRE

-50

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Red River Basin - 2050

IPSL

GISS

MONRE

-60

-40

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Mekong Delta Inflow Changes - 2030

IPSL

GISS

HadCM3

-60

-40

-20

0

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Mekong Delta Inflow Changes - 2050

IPSL

GISS

HadCM3

Red River Basin: Decreased rainy season flow under IPSL,

increased dry season flow under GISS and MONRE

Mekong Delta: Major flow reduction under IPSL

Climate Change Impacts (II)Sea Level Rise (17 cm by 2030, 30 cm by 2050)

Threshold Values for Judging

Rice Area Loss

Inundation:

water depth > 0.5 m

Salinity Intrusion:

Salinity Concentration > 4 g/l

Climate Change Impacts (III)Sea Level Rise by 30 cm

Mekong River Delta: by 2050, flood inundation area (depth > 0.5 m)

increases by 276 thousand ha; salinity intrusion area (salinity > 4 g/l)

increase by 420 thousand ha. About 13% rice production area is lost by

2050.

Inundation Area (000 ha) Salinity Affected Area (000 ha)

Crop Production in 2007

Rice is the single most important crop!

Climate Change Impacts (IV)Rice Yield Changes (%)

• Major rice yield reduction are predicted for IPSL and GISS scenarios

with carbon fertilization

• Without carbon fertilization, all agro-ecological zones have yield

reduction under all scenarios except South East

With CO2 Fertilization Without CO2 Fertilization

Climate Change Impacts (V)Crop Production Changes (%)

Climate Change Impacts (VI)Crop Production Changes – cont.

• Without CO2 fertilization, productions decline for all crops across

all the three climate change scenarios

• With CO2 fertilization, MONRE scenario has production increase

for all crops, while production of IPSL and GISS decline

• Positive effects of CO2 fertilization may overplay adverse effects

from temperature and water changes, thus not necessarily 2030

production changes being lower than 2050

• Without CO2 fertilization, rice production losses range from 2.1 to

6.4 million ton per year in 2030, and 3.4 to 6.7 million ton in 2050

• Sea level rise along can cause about 2.7 million ton rice

production loss in 2050, in the Mekong Delta

Climate Change Adaptation (I)Irrigation Expansion

Irrigation Expansion: Total irrigation expansion of ~690 thousand ha

by 2050, including 355 ha for rice, ~180 ha for maize, distributed

across agro-ecological zones.

502

984756 812

591

1616 1608

25671823

3581

127

2884

1451

3050

1249

349

79

290

355

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254

165

269334

0

1000

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6000

NW NE RRD NCC SCC CHL SE MRD

La

nd

Are

a (

00

0 h

a)

Other Land Use Forest Land Agricultural Production Land

Present Land Use in Vietnam

Climate Change Adaptation (II)Ag. Research & Extension

Ag. Research & Extension: Additional yield growth by 13.5% by 2050

for all crops.

80

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Rice

Maize

Cassava

Coffee

Sweet potato

Soybean

Yield Index (Historical Yield Growth)

Other Adaptation Options (III)Shifting Planting Dates

Shifting Planting Dates: On average, yield increases by 0.47

ton/ha in the Red River Delta.

Winter-spring Rice Planting Area

in Red River Delta

Conclusions

• Vietnam is among the few countries that will be

worst affected by climate change

• The most productive deltas face serious

challenges

• Impacts on agricultural and water sectors can

be serious, affecting economic growth and the

status of poverty and malnutrition

• Appropriate adaptation measures can be

effective in reducing impacts, but expensive and

irreversible actions should be avoided

Pham Quang Ha and Tran VanInstitute for Agricultural Environment, Ministry of Agriculture and Rural

Development (MARD)

Le Hung Nam, To Trung Nghia, Le Hong Tuan, Truong Trong Luat, Vu Dinh HuuInstitute of Water Resources Planning, MARD

Do Duc DungSouthern Institute of Water Resources planning, MARD

Bao Thanh, Luong Van Viet, Nguyen Thi Phuong, Bui Chi NamSub-institute of Hydrometeorology of South Viet Nam, Ministry of Natural

Resources and Environment

21

Acknowledgements