Biến đổi khí hậu ở Việt Nam

CLIMATE CHANGE
AND IMPACTS IN VIET NAM
CLIMATE CHANGE
AND IMPACTS IN VIET NAM
• Viet Nam is considered as one of the most vulnerable
countries due to CC and sea level rise.
• If sea level rise of 1 m, Viet Nam will loose about 12% of
land, 23% of population will be affected.
• Typhoons occur more frequently with higher intensity.
• Temperature increases and change in rainfall pattern will
affect agriculture and water resources.
1 m
2 m
3 m
4 m
5 m
WB 2007
Impacts of sea level rise
“Large percentage of
Vietnam’s population and
economic activities are
located in these two river
deltas. 14% of Vietnam
population would be
impacted by a 1m SLR. This
is the largest percentage of
impacted population among
all 84 countries. Vietnam
impacted population would
reach 35% with a 5m SLR.
The impact of SLR on

Vietnam’s GDP and urban
extent follow the impact on
its population”.
Inundation in Mekong River Delta
due to 1 m Sea Level Rise
Source: HMS
• Annual average temperature
increases about 0.10C per decade.
In some summer months,
temperature increases about 0.1-
0.3
o
C per decade.
Source: Vietnam National communication
21.0
21.5
22.0
22.5
23.0
1974 1979 1984 1989 1994 1999 2004
2
1
3
4
O
C
Yea
r
Variability (1), climatological average (2), moving average (time
step - 11 year) (3) and linear trend (4) of Temperature at A Luoi

station.
Annual temperature
Climate Change in Vietnam
Climate Change in Vietnam
• More heavy
rainfalls
causing severe
floods;
• Rainfall
decreases in
dry season
(Jul., Aug.) and
increases in
rainy season
(Sep. to Nov.).
1000
2000
3000
4000
5000
1974 1979 1984 1989 1994 1999 2004
2
1
3
4
m
m
Year
Variability (1), climatological average (2), moving average
(time step - 11 year) (3) and linear trend (4) of August-

December rainfall at A Luoi station.
Rainfall of Aug
Dec.
Typhoon trajectory moves southward
and typhoon season shifts to later
months of the year;
Climate Change in Vietnam
Climate Change in Vietnam
Cumulative tracks of tropical cyclones (1985–2005)
[Nicholls et al , 2007]
• High floods occur more frequently in the Central
and Southern Vietnam.
•
•
Drought happen every year in most regions of the
Drought happen every year in most regions of the
country.
country.
Climate Change in Vietnam
Climate Change in Vietnam
• ENSO has stronger effects
on weather regime and
climatic features in various
areas of Viet Nam;
• Sea level rises from 2.5-3
cm per decade in the last
century.
Climate Change Vietnam
Climate Change Vietnam
Vulnerability of delta dwelling populations

[Source: Nicholls et al., 2007]
Impacts on Coastal Zone
Impacts on Coastal Zone
Impacts of
Impacts of
Climate Change
Climate Change
Public
Health
Environ
ment
Tourism
Energy
Forestry
Agriculture
Water
Respurses
Climate
Change
Impact on Agriculture
Impact on Agriculture
• Shift of planting boundary: By 2070s,
tropical trees/ crops would be able to grow
at the altitude 100-550 meters higher and
move 100-200 km northwards compared to
present.
• Large areas in Mekong and Red River deltas
would be under salt water due to sea level
rise.
Yield of rice decrease

Yield of rice decrease
by 10% for every 1
by 10% for every 1
o
o
C
C
increase in growing
increase in growing
season minimum
season minimum
temperature
temperature
(IPCC AR4
WG2TS, 2007)
Source: Vietnam
National
communication
Impacts on Water Resources
Impacts on Water Resources
• Instability in rainfall would cause
more severe floods in rainy season
and droughts in dry season.
• Increase in frequency and intensity
of typhoons, storms would cause
high floods & inundation, flash
floods, landslide and erosion.
• Increasing water shortage and
growing water demand threaten
water supply, water use conflicts.

Source: Vietnam National communication
Impacts on Forestry
Impacts on Forestry
• Decrease of mangrove forest,
due to sea level rise.
• Forest with drought stand
varieties would increase due to
low soil moisture and high
evapotranspiration.
• Biodiversity degradation:
extinction of endangered
species;
• Increasing risk of forest fire;
• Increase and wide spread of
plant pests and diseases.
Source: Vietnam National communication
Impacts on Aquaculture & Fisheries
Impacts on Aquaculture & Fisheries
• Sea level rise would reduce fresh
water creatures in rivers &
estuaries, high temperature –
reduce high valuable sub-tropical
fishes;
• Habitat loss for young creatures
due to mangrove decrease;
• Reducing sea products
productivity and commercial
quality due to:
– Migration of fishes;
– Reduction of body weight.

Source: Vietnam National communication
Impacts on Coastal Zone
Impacts on Coastal Zone
• Large areas of the Mekong, Red River
deltas and Central coastal zone would
be inundated due to sea level rise.
• Coastal & estuarine wetlands would
be affected due to frequent floods,
severe drought & salinity (Ca Mau,
Ho Chi Minh City, Vung Tau and
Nam Dinh)
• Livelihood of coastal population will
be affected by more severe storms,
flood, drought and sea level rise.
Projections for a 1 m sea level rise: 15,000-
20,000 km
2
of Mekong River delta flooded,
affecting 3.5 to 5 million people, respectively
.
IPCC AR4, 2007
Impacts on Energy, Transportation
Impacts on Energy, Transportation
• Oil, gas platforms would be
affected by typhoons, storms;
• Seaports and roads designed
basing on historical sea level
would be affected.
• Less energy generation due to drought ;
• Unstable flow regimes may lead to conflict in water

regulation at hydropower stations.
• More energy consumption for due to high temperature and
humidity.
Source: Vietnam National communication
Impacts on Human Health
Negative Impact Positive
Impact
Very high confidence
Malaria: contraction and expansion,
changes in transmission season
High confidence
Increase in malnutrition
Increase in the number of people suffering
from deaths, disease and injuries from
extreme weather events
Increase in the frequency of cardio-respiratory
diseases from changes in air quality
Change in the range of infectious disease vector
Reduction of cold-related deaths
Medium confidence
Increase in the burden of diarrheal diseases