1. Climate Change Impacts on Agriculture
in Vietnam
Tingju Zhu1 and Mai Van Trinh2
1International Food Policy Research Institute, Washington, DC
2Institute for Agricultural Environment, Hanoi, Vietnam
June 10-12, 2010
Beijing, China
International Conference on Agricultural Risk and Food Security (ARFS)

2. 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

3. 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

4. Climate Change already under Way?
Changes of Precipitation, Temperature and Solar Radiation
during 1971-2007
104 106 108
10
12
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22 Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
Zone 8
104 106 108
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22 Zone 1
Zone 2
Zone 3
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104 106 108
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Zone 2
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
Zone 8
-350
-300
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-150
-100
-50
0
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-28
-24
-20
-16
-12
-8
-4
0
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28
mm
oC
Watt/m2
Rainfall average
temperature
radiation

5. Selection of Climate Scenarios:
Moisture Index for GCM Climate Projection in 2050
Drier Wetter

6. • 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

7. Climate Change Scenarios (II)
Mean Annual Temperature Changes by Agro-ecological Zone (oC)
Mean Annual Precipitation Changes by Agro-ecological Zone (%)

8. Climate Change Scenarios (III)
Mean Monthly Precipitation
0
50
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450
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Precipitation(mm)
NorthWest
0
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450
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Precipitation(mm)
NorthEast
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350
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Precipitation(mm)
RedRiver Delta
0
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550
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Precipitation(mm)
NorthCentral Coast
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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Precipitation(mm)
SouthCentral Coast
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550
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Precipiation(mm)
Central Highland
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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Precipitation(mm)
East South
0
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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Precipitation(mm)
Mekong Delta

9. Analytical Models

10. Climate Change Impacts (I)
% Basin Runoff Changes
-50
0
50
100
150
200
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
RedRiver Basin- 2030
IPSL
GISS
MONRE
-50
0
50
100
150
200
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
RedRiver Basin- 2050
IPSL
GISS
MONRE
-60
-40
-20
0
20
40
60
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Mekong DeltaInflowChanges - 2030
IPSL
GISS
HadCM3
-60
-40
-20
0
20
40
60
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Mekong DeltaInflowChanges - 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

11. 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

12. 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)

13. Crop Production in 2007
Rice is the single most
important crop!

14. 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

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

16. 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

17. 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
984
756 812
591
1616 1608
2567
1823
3581
127
2884
1451
3050
1249
349
79
290
355
299
254
165
269
334
0
1000
2000
3000
4000
5000
6000
NW NE RRD NCC SCC CHL SE MRD
LandArea(000ha)
OtherLand Use ForestLand Agricultural Production Land
Present Land Use in Vietnam

18. Climate Change Adaptation (II)
Ag. Research & Extension
Ag. Research & Extension: Additional yield growth by 13.5% by 2050
for all crops.
80
100
120
140
160
180
200
220
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
Rice
Maize
Cassava
Coffee
Sweetpotato
Soybean
Yield Index (Historical Yield Growth)

19. 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

20. 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

21. Pham Quang Ha and Tran Van
Institute for Agricultural Environment, Ministry of Agriculture and Rural
Development (MARD)
Le Hung Nam, To Trung Nghia, Le Hong Tuan, Truong Trong Luat, Vu Dinh Huu
Institute of Water Resources Planning, MARD
Do Duc Dung
Southern Institute of Water Resources planning, MARD
Bao Thanh, Luong Van Viet, Nguyen Thi Phuong, Bui Chi Nam
Sub-institute of Hydrometeorology of South Viet Nam, Ministry of Natural
Resources and Environment
21
Acknowledgements