Revealed: The major global cities at risk of being 'completely submerged within 30 years'

KIVALINA, ALASKA - SEPTEMBER 15:  An aerial view shows Kivalina, which is at the very end of an eight-mile barrier reef located between a lagoon and the Chukchi Sea on September 10, 2019 in Kivalina, Alaska. The road being built as an escape route for the village's people in case the ocean waters threatened is seen almost complete. The village is 83 miles above the Arctic circle. Kivalina and a few other native coastal Alaskan villages face the warming of the Arctic, which has resulted in the loss of sea ice that buffers the island’s shorelines from storm surges and coastal erosion. The residents of Kivalina are hoping to stay on their ancestral lands where they can preserve their culture, rather than dispersing due to their island being swallowed by the rising waters of the ocean.  City Administrator Colleen Swan says that the way of life in the village will change with the changing climate and they will adapt. In days gone by, they could migrate with the changes. But now, she says, with the magnitude of problem climate change brings, they must hope that the rest of the world reverses the trend, which she sees as being man-made, and save their way of life. (Photo by Joe Raedle/Getty Images)
Rising sea levels threatening Kivalina, which is at the very end of an eight-mile barrier reef located between a lagoon and the Chukchi Sea in Alaska (Getty)

Entire cities are at risk of being submerged under rising sea levels over the next 30 years, putting hundred of millions of people at risk of losing their homes, according to a new study.

A new digital elevation model known as CoastalDEM indicates that as many as 630 million people around the world live on land that lies below projected annual flood levels for 2100.

The figures, published in the Nature Communications journal, also show that some 340 million people will be living on land that falls below the levels of average annual coastal land by 2050 - up from the previous NASA estimate of 250 million.

Shanghai Center is under construction,Shanghai, China - July 5, 2012
Major Asian cities like Shanghai could be left unliveable over the next three decades (Getty)
Areas shaded pink show the new data predicting areas lying below sea level in Bangladesh (Nature Communications)
Areas shaded pink show the new data predicting areas lying below sea level in Bangladesh (Nature Communications)

People at risk of annual floods live in major cities including Bangladesh, Jakarta and Thailand - with the threat of being entirely submerged making the areas at risk of being uninhabitable.

Other cities across Asian countries are vulnerable - such as Shanghai, Tianjin and Hong Kong - while the Vietnamese capital Hanoi and the entire southern tip of the country could be flooded, according to the projections.

Nineteen other countries, including Brazil and the UK - where London is predicted to be affected - could also see land being lost beneath the waves.

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Benjamin Strauss, co-author of the study and CEO of Climate Central, said: "The results indicate that, yes, a great deal more people are on vulnerable land than we thought.”

He added that the affected regions need to take immediate action to avoid the impending "economic and humanitarian catastrophe”.

The study adds: ”Recent work has suggested that, even in the US, sea-level rise this century may induce large-scale migration away from unprotected coastlines, redistributing population density across the country and putting great pressure on inland areas.”

Bangkok in Thailand. (AP Photo/Sakchai Lalit)
Bangkok in Thailand. (AP Photo/Sakchai Lalit)
Thailand's capital Bangkok has much more areas lying below sea levels (shaded pink) than previously thought (Nature Communications)
Thailand's capital Bangkok has much more areas lying below sea levels (shaded pink) than previously thought (Nature Communications)
An aerial view of Kampung Apung in Jakarta, Indonesia. Kampung Apung is like an island in the middle of the lake. The surface is full of puddles, except a 1 meter wide road with 50 meters length that heads to the residence area and splits the puddles. (Photo credit should read Afriadi Hikmal / Barcroft Media via Getty Images / Barcroft Media via Getty Images)
Jakarta in Indonesia is another major city at threat of rising sea levels, according to the study (Nature Communications)
Jakarta in Indonesia is another major city at threat of rising sea levels, according to the study (Nature Communications)

Climate Central researchers claim that previous predictions of sea levels rising by as much as three metres are too conservative.

The melting of Greenland’s ice sheets has resulted in over 275 gigatons being lost on average per year between 2006 and 2015, according to a UN report on climate change.

It is believed that rising sea levels contribute to warmer temperatures across the globe, resulting in a lack of food and running the risk of severe health crises.

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