Adaptation to climate change in the countries of - Mekong River ...

3.4 Viet Nam
Existing knowledge of national climate change
Investigations to date indicate that Viet Nam is amongst the countries with the potential to be
the most severely impacted by climate change (Dasgupta et al., 2007); with the Mekong and
Red River delta regions most at risk, predominantly as a result of increased inundation (Carew-
Reid, 2007). Viet Nam’s Initial Communication to the United Nations Framework Convention
on Climate Change (MONRE, 2003) provides predictions regarding potential climate change
impacts in Viet Nam. Further work has commenced to improve the scenarios and climate
change predictions (Nguyen and Hoang, 2007).
The average temperature is estimated to increase by 2.5°C in 2070. Temperature increases
are predicted to be more significant in the highlands region, while coastal temperatures are
predicted to increase by 1.5°C. Annual average maximum and minimum temperatures are also
expected to increase; similarly the number of days with a temperature higher than 25°C will
increase. Possible effects of such increases will include a large area of the country suffering
from drought, reduction in agricultural productivity, and an increase in the incidence of
epidemic diseases.
In the northern and southern regions, seasonal rainfall is predicted to decrease in July and
August and increase in September, October and November. In the central region, rainfall is
predicted to increase by approximately 19% in the rainy season by 2070; while rainfall in the
dry season will decrease and drought conditions are predicted to become more frequent.
Over the past 30 years, sea level in Viet Nam has increased 5 cm. Sea level is expected to
rise by another 9 cm in 2010, 33 cm in 2050, 45 cm in 2070 and 1 m in 2100 (MONRE, 2003).
In the past, typhoons affected northern Viet Nam predominantly in August, in October in
the central region, and in November in the south. Climate change could lead to more typhoons
occurring in the northwest Pacific Ocean which could affect Viet Nam. An increase in sea
surface temperature is also expected to cause higher wind velocities during typhoons and
increase the duration of such events. The typhoon intensity will be stronger, especially during
El Ninõ years.
Simulations of temperature, rainfall and sea level changes in various regions are shown in
Table 3.1 below. According to this scenario, in the year 2070, the surface average temperature
will increase in the range of 1.5°C to 2.5°C and variation in precipitation will be from -5% to
10%.
With a sea level rise (SLR) of 1.0 metre, which is predicted to occur by 2100, approximately
10% of the population could be directly affected and economic losses equivalent to 10% of the
GDP experienced. The sea level rise in combination with increased rainfall in the rainy season
could have serious impacts on low lying lands in the coastal zone. Approximately 40,000 km 2
of coastal delta area could be inundated, including 90% of the Mekong Delta. This region is the
most densely populated in the country, with over 18 million inhabitants, or 22% of the national
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