MORE than 20 million people – almost a quarter of Vietnam's population – could be wiped out by 2050 due to rising seas caused by climate change.
According to a recent research paper, much of Ho Chi Minh City, the nation’s economic centre, would disappear with them.
The new research shows that some 150 million people are now living on land that will be below the high-tide line by mid-century.
The paper was authored by Climate Central, a science organisation based in New Jersey and published in the journal, Nature Communications.
According to the New York Times, Scott A. Kulp, a researcher at Climate Central and one of the paper’s authors, said standard elevation measurements using satellites struggle to differentiate the true ground level from the tops of trees or buildings. So he and Dr Benjamin Strauss, Climate Central’s chief executive, used artificial intelligence to determine the error rate and correct it.
The projections don’t account for future population growth or land lost to coastal erosion.
As for Thailand, more than 10 per cent of citizens now live on land likely to be inundated by 2050, compared with just 1 per cent according to the earlier technique.
The rising seas also threaten to consume Shanghai and other cities around it in the next 30 years.
However, Dr Strauss said the recent findings do not necessarily mean the end of these cities, as 110 million people already live in places that are below the high-tide line.
"Cities must invest vastly greater sums in such defences and they must do it quickly.
"But even if that investment happens, defensive measures can go only so far," he said.
He cited the example of New Orleans, a city below sea level that was devastated in 2005 when its extensive levees and other protections failed during Hurricane Katrina.
The new projections also suggest that much of Mumbai, India’s financial capital and one of the largest cities in the world, is at risk of being wiped out.
According to Dina Ionesco of the International Organisation for Migration, countries should start preparing now for more citizens to relocate internally.
“We’ve been trying to ring the alarm bells. We know that it’s coming,” she said.
In other places, the migration caused by rising seas could trigger or exacerbate regional conflicts.
Basra, the second-largest city in Iraq, could be mostly underwater by 2050.
John Castellaw, a retired Marine Corps lieutenant-general who was chief-of-staff for US Central Command during the Iraq War, said further loss of land to rising waters threatens to drive further social and political instability in the region, which could reignite armed conflict and increase the likelihood of terrorism.
“This is far more than an environmental problem.
“It’s a humanitarian, security and possibly military problem too,” he said.