By 2050, Vietnam’s temperature increases will range from a minimum of below one degree to a maximum of about two degrees. From now to 2040 or 2050, the combined impacts of these changes are likely to slow economic growth.

The year 2050 will also see one metre sea level rises, which will devastate 171,400 kilometres of asphalted and earth roads, according to the study made by University of Copenhagen and World Institute for Development Economics Research supported by Danida.

"An increase in rainfall and flooding will deteriorate roads and raise costs for maintaining roads. Investors in infrastructure and roads in Vietnam will have to be cautions before deciding to invest in these projects," said University of Copenhagen professor Finn Tarp.

Professor Yohannes Gebretsadik, from US’s Colorado State University, said Vietnam had 14 operational hydropower plants, with 4,577 megawatts of installed capacity providing 20,112 gigawatt hour of energy per year, occupying 30 per cent of Vietnam’s total energy potential. The percentage would be raised to 86 per cent after under-construction hydroelectricity plants came into operation.

"However, hydropower plants’ generating capacities will be affected by climate change with a maximum 14 per cent reduction by 2041-2050. It is because climate change will change water flows in river basins," Gebretsadik said.

He said the best solution for Vietnam to ensure operation of its hydropower plants was to build additional multipurpose reservoirs and increase storage systems, which would enable Vietnam’s water infrastructure to provide for dry season flow and significantly reduce flooding risks.

"However, few foreign investors currently want to invest in these projects now because they don’t see power investment in Vietnam as a good cake," he said.

The study said after 2050, temperature rises and associated impacts, especially higher sea level rise, are expected to become more profound.

Le Ngoc Bich, a senior climate change expert from a foreign organisation in Hanoi, said this study was another alarm for Vietnam’s government and policy-makers.

She said similar studies had been made and them seemingly ignored by the government. It was because they recommend the government give specific incentives to investors if it wanted to attract them into investing in environmentally-friendly technology.

"However, almost no incentives have been introduced. No big action has been taken by the government, though many foreign donors like my organisation are so keen to know," she said.