Ho Chi Minh City is constantly flooded, while Bangkok continues to sink below sea level.

It sounds like a science fiction movie set in Southeast Asia. But it’s what experts predict will happen within the next two to three decades in the major Vietnamese and Thai metropolises if current trends hold.

A recent study referred to by some as a “doomsday report” suggests that rising sea levels could flood three times more land than previously predicted.

If the study proves accurate, Southeast Asia is particularly vulnerable, with parts of Ho Chi Minh City and Bangkok to slip underwater by 2050. Meanwhile, millions of people in Vietnam’s Mekong Delta, the country’s fertile rice farming region, could be forced to flee coastal areas.

The report, prepared by a United Nations Intergovernmental Panel on Climate Change (IPCC) with contributions from over 130 scientists around the world, was issued in September last year.

Rising sea levels in Southeast Asia have been driven by man-made greenhouse gas emissions, climate change, warming waters, heavy rainfall, and accelerated melting of ice in the Arctic and Antarctica. The West Antarctic ice sheet, in particular, is collapsing sooner and faster than predicted.

The IPCC report corrects previous satellite elevation data and asserts that coastlines are much more exposed to rising sea levels than was previously believed. It says that past sea-level-rise scenarios had underestimated land loss and population displacement by about one-third.

Vulnerability to climate change in Southeast Asia accounting for exposure to climate hazards, sensitivity and adaptive capacity. 0 = lowest vulnerability, 1 = highest vulnerability. Source: ResearchGate

Nonetheless, while acknowledging that the IPCC report was done by serious researchers, some scientists maintain that it presents a “worst-case scenario” that must be checked and hedged against their own data.

Those who will or are already suffering the most from climate change-affected rising waters are likely to be poor farmers and fishermen who live along or close to their coastlines in Southeast Asia.

A recent paper published by Climate Central, a non-profit organization, made waves in Vietnam when it forecasted that most of the Mekong Delta would be under water by 2050, Financial Times reported.

To the average reader, the most amazing thing about all of this is likely to be the origin of rising sea levels in the faraway Arctic and Antarctica regions. Ocean currents have to carry the rising seas more than 6,000 miles to reach Bangkok and Ho Chi Minh City.

As the National Geographic explains it, “the unexpectedly rapid collapse of ice-rich permafrost, or permanently frozen subsoil, in the Arctic, “could pump billions of additional tons of methane and carbon dioxide into the atmosphere every year—a threat that has yet to be fully accounted for in climate models.”

In sum, this sounds like a slow-moving, but accelerating catastrophe of which many around the world are still barely aware. The leaders of a number of nations are obviously well aware of the situation. In 2015, 195 nations signed an agreement known as the Paris Accord, which set goals for limiting global warming and greenhouse-gas emissions.

But during two weeks of negotiations recently in Madrid, Spain, delegates from nearly 200 nations meeting at a climate summit failed to strengthen targets to cut emissions that trap heat in the atmosphere.

Financing to help poorer countries transition to less-polluting technology proved to be one of the most contentious issues that caused the summit’s failure, according to a The Wall Street Journal report. An impending US exit from the pact “exacerbated challenges to cut record-high planet warming gases,” the report said.

Ho Chi Minh City, which is located in the Saigon Delta close to the Mekong Delta, already faces annual flooding due to a combination of storms, heavy rainfall, and upstream discharges from reservoirs.

Floods in Vietnams Mekong Delta in a file photo. Photo: IMF/Twitter

Still frequently referred to by residents by its pre-communist era name of Saigon, Ho Chi Minh City is one of most rapidly growing cities in Southeast Asia, with a population of about nine million.

The city, the most densely populated in Vietnam, is reported to generate 21% of the country’s gross domestic product (GDP).

According to the online Vietnamese newspaper VnExpress, Ho Chi Minh City plans to spend US$354 million on anti-flood projects this year. These will cover the city’s downtown area and part of its suburbs.

City officials are also discussing the possibility of constructing a Thames Barrier-type river barrage to contain future major flooding.

In Ca Mau, in the Mekong Delta, state media recently reported that authorities had evacuated and were building new housing for 5,000 people affected by rising waters.

When it comes to both Vietnam and Thailand, people appear to be aware that more water is coming and likely sooner than was earlier expected.

But several sources in Bangkok and Ho Chi Minh City told this reporter recently that the threat from the sea wasn’t getting the high-level attention that it deserves from Thai and Vietnamese government leaders.

Bangkok, a city of 8.2 million people, was built on marshy land and buildings there have sunk as much as 20 millimeters in recent years, according to scientists.

In an interview with Nik Martin, a broadcast journalist for Deutsche Welle, a leading Thai scientist recently said that adding the figures together means the sinking rate will be about three centimeters, or 30 millimeters, per year.

Workers build the first phase of a concrete embankment to prevent flooding and improve the canal-side areas around Klong Prem Prachakorn in Don Muang district of Bangkok. Photo: AFP Forum

“It’s fast,” said Anond Sanitwong, director of the Thai Geo-Informatics and Space Technology Development Agency (GISTDA), was quoted saying in the report.

According to Anond, while the practice has officially been banned, more than 50% of the sinking has been caused by the tapping of groundwater by industry, the report said.

Citing scientists, Martin reported that the Thai government “has been ignoring the fact that Bangkok is sinking for years.”

The Thai capital is not alone in this regard. Indonesia’s President Joko Widodo announced this past summer that his country will move its capital from Jakarta, which has been sinking into the sea, to Kalimatan on Borneo.

The worst affected neighborhoods in Jakarta have been sinking at a rate of 10 to 20 centimeters a year, one of the fastest rates in the world.

On January 3, The Wall Street Journal cited a World Bank report saying that some 40% of Jakarta has sunk below sea level, largely because residents rely on pumping underground water for daily use, causing the land above it to subside.

As a result, floodwater doesn’t drain into the sea as it would normally. The World Bank report noted that Jakarta’s poor are productive members of the city’s economy but are also “the most vulnerable to flood-related risks.”

That’s been seen in recent floods that hit Jakarta this month that have killed at least 60 and displaced over 170,000 in temporary shelters.

A man walks amid heavy flooding in Jakarta, January 2, 2020. Photo: AFP/Donal Husni/NurPhoto

In the Philippines, the same sinking phenomenon is affecting offshore islands as well as the coastline near the capital city of Manila.

The Agence France Presse reported several months ago that some coastal towns in the Philippines face disaster as the ground underneath them sinks. One cause has been unregulated wells being dug for factories and farms, the report said.

The steady sinking of some towns and coastal villages like Sitio Pariahan, located some 10 miles north of Manila, has caused brackish water to flow in. According to the Philippines Star Online, “rising waters caused by global warming could make this village unlivable.”

Meanwhile, along the banks of the 2,700-mile-long Mekong River, which flows through six countries namely China, Myanmar, Laos, Thailand, Cambodia, and Vietnam, the climate change stakes are especially high.

More than 60 million people depend on Southeast Asia’s longest river and its tributaries for food and transportation.

But according to scientists, the Mekong’s lower region banks are increasingly threatened by rising sea levels, salt intrusions as well as a loss of sediment held back by upstream dams in China and Laos.

Dan Southerland is the former executive editor at Radio Free Asia