Mekong hit by climate change
|Fish farms in the Mekong Delta province of An Giang. Climate change is likely to have a great impact on fish farming along the Mekong River as erratic rainfall will disrupt the flood pulse cycle of the river, predicts a new study. — VNA/VNS Photo Huy Hung
BANGKOK (VNS)— A new study on Climate Change Impact and Adaptation in the Lower Mekong Basin released on March 29 has revealed that the effects of climate change in the basin is worse than the global average.
Final results of the United States Agency for International Development (USAID)-funded study, that were released at a regional workshop in Bangkok, indicate that changes in climate will likely trigger decreases in yields and in the suitability of key commercial and staple crops of the region.
The basic staple crop of the region – the rain-fed rice – would see a significant decrease in yield in seven out of eight provinces across the region that had been identified by the study as "hot spots."
These included two provinces of Viet Nam in Gia Lai in the Central Highlands and Kien Giang in the Cuu Long (Mekong) Delta.
The study- that falls under USAID's Lower Mekong Initiative – downscaled the global climate models for this region that is not only highly vulnerable to the impact of climate change but also significantly dependent on its natural resources for livelihoods.
Apart from detailing climate projections and trends, the study examined how changes in temperature and rainfall would affect land suitability and species productivity for a range of livelihood sectors.
Speaking at the workshop, lead author of the study, Dr. Jeremy Carew-Reid of the International Centre for Environmental Management, said: "We've found that this region is going to experience climate extremes in temperature and rainfall beyond anything that we expected."
The study projected that the annual average temperature in some parts of the Lower Mekong Basin, including the eastern plains of Cambodia and Tay Nguyen (Central Highlands) of Viet Nam, would increase by 4 to 6 degrees Celsius by 2050.
This figure, which is two or three times higher than the so-called "critical threshold" of 2 degrees Celsius, makes a climate catastrophe a realistic possibility.
The region is projected to have drier dry seasons that start earlier and wetter wet season which start later. Changes will be greatest in the wet season and the areas that will experience greatest change include the Sekong, Sesan and Sre Pok catchment area of eastern Cambodia and the Cuu Long (Mekong) Delta of Viet Nam and Cambodia.
While hotter climate and higher rainfalls may trigger shifts in crop suitability around the region, some areas in higher altitudes, such as northern Thailand or northern Lao, would be better adapted and will be able to grow a number of industrial crops such as rubber, Robusta coffee and cassava.
"Meanwhile, Robusta coffee which is now widely grown in the Central Highlands of Viet Nam would see reduced suitability in the future," said Carew-Reid.
Climate change is projected to cause an overall reduction in fish stocks in this export-oriented region, as the erratic rainfall would disrupt the Flood Pulse cycle of the Mekong River which in turn would harm fish migration and fish production.
The study found out that the greatest impact would be expected in fish farming. The region is already coping with the extreme limits of the aquaculture system and any additional stress could cause a collapse, Carew-Reid warned.
Flash floods occurring in a higher frequency would cause a sudden drop in salinity and invite diseases into shrimp ponds in Viet Nam's Mekong Delta.
While the study's main objective was to understand the impact of climate change, other participants at the workshop called for a more integrated approach that would take into consideration the development influences that are already going on.
For example, the current threat to fisheries, as some suggested, has to do more with the 30,000 dams and structures that are now in place in the region, which block various waterways for fishes.
Representatives from the Vietnamese agriculture ministry at the workshop, while welcoming the study, took its results with caution, arguing that the input for the study's modelling should have been more comprehensive.
The Lower Mekong Basin, which covers parts or whole of four country Thailand, Laos, Cambodia and Viet Nam, is home to 65 million people, 70 per cent of whom are farmers and fishermen. — VNS