A LARGE swath of Pacific Island nations are slowly being eaten away until residents will be forced to evacuate and the islands eventually sink into the sea — and it’s coming sooner than we think.

This modern-day Atlantis is thanks to sea levels across small island nations that have seen a dramatic rise over the past few decades, a rate of up to 3-4 times larger than the global average. Tuvalu, in the western Pacific Ocean, will reportedly be uninhabitable by 2050, while its island neighbour Kiribati, is expected to be fully submerged by 2100.

The Maldives, which has the lowest elevation in the world and a population of 427,000, may also have sunk by the end of the century.

It has led experts — including Professor Tim Flannery, climate change expert and Professor at La Trobe University — to believe we are “on a trajectory that will see those nations compromised”.

Five reef islands in the Solomon Islands have already been lost forever while a further six have been completely eroded. Last year, the island of Nuatambu had already lost half of its habitable area.

Professor Flannery told news.com.au The Maldives, Kiribati, Marshall Islands, Tokelau and Tuvalu were most at risk.

“It’s very much on their minds, they’re trying to work out how to deal with it,” Mr Flannery told news.com.au.

Scientists are convinced more and more of these tiny islands at risk of sinking into the sea in the next 30 years and Pacific Island leaders have gathered to urge its neighbours, including Australia, to take action to save their dwindling nations.

“There only remains a few years before we exceed carbon dioxide levels that will make temperature rise to levels that will see many parts of the Pacific disappear,” the president of Nauru, Baron Waqa, said during a meeting with Pope Francis at climate talks in Germany this month.

“The president is right, it’s very concerning times, particularly if you live in a small island nation,” Mr Flannery said.

Mr Flannery said the threat of sinking islands was real and a “widespread phenomenon” affecting low lying islands and beaches — and it seems the locals agree.

“There is overwhelming evidence that if we do not wake up now and act, we will hasten the calamities that await us and threaten our future survival and existence,” read an article in Fiji’s Sun Online.

“Those, who live in coastal settlements in Fiji, threatened by the encroaching sea, know. Those, whose plantations have been destroyed by sea water, know. Those, who have been relocated from their ancestral site because it is no longer safe to live there, know. Those, whose homes have been destroyed, know.

“In a nutshell, we need to adapt to the rapidly changing conditions. Otherwise, we and our posterity face a grim future.”

Rising sea levels are considered an “existential threat” to the inhabitants of these islands and combined with melting glaciers, some anxious nations are already planning their escape.

In 2014, Kiribati, an island republic in the Central Pacific, purchased land 2000 kilometres away in Fiji, as rising tides continue to besiege the tiny nation.

“I carry a huge burden and responsibility,” Enele Sopoaga, the prime minister of Tuvalu, 965 kilometres north of Fiji, told a climate summit in 2015.

“It keeps me awake at night. Will we survive? Or will we disappear under the sea?”

It comes as New Zealand ponders becoming the first nation in the world to create a new visa category for Pacific Islanders based on island displacement.

For many island nations like Kiribati, it comes as a welcome proposal. Coastal erosion and freshwater contamination have already altered the lives of Kiribati’s 110,000 citizens and the future for the island looks grim.

“It’s hard to say how this will unfold but many of those nations are already making agreements to deal with the problem as it develops,” Mr Flannery said.

“Things are happening, we hope it doesn’t unravel so quickly that it will cause a big crisis but people are aware of it and they are adapting.

Mr Flannery explained that not only are the islands at threat of disappearing into the ocean, but residents were threatened with loss of freshwater and agriculture before the cataclysmic event.

“As sea water rises it starts to penetrate the freshwater on the land, that’s the most immediate threat for a lot of the islands,” Mr Flannery said.

“Beach and coastal erosion and flooding is another threat. With these two factors it’s entirely possible within the next 30 years some islands could be rendered uninhabitable.”

While Professor Flannery said it was impossible to predict the future with 100 per cent accuracy, he said it was likely we would see evacuations of various Pacific Islands over the next three decades.

“After all there’s already been a few very small islands that people have left and climate impact has been one of the factors. It’s probable that it will happen again.

While Australia has committed a $300 million climate change package for the Pacific, experts say it’s not enough, and are demanding a moratorium on coal mines to stop the threat of carbon emissions.

Meanwhile, though Australia says it is on track to meet its Paris Agreement commitment to reduce emissions, it hasn’t reassured Pacific leaders who pointed out approximately two-thirds of the coal made in Australia will be sent predominantly to India.

“We should be doing more to help those nations,” Mr Flannery said, citing the end of coal mining would be the “easiest fix”.

Though it’s not all doom and gloom. National Geographic reports some island have flourished in the past decade, with some even growing in size.

“Some islands grew by as much as 5.6 hectares in a single decade, and Tuvalu’s main atoll, Funafuti — 33 islands distributed around the rim of a large lagoon — has gained 32 hectares of land during the past 115 years,” it read.

“The islands are going to fight back as the environment changes, and adjust themselves to new equilibriums. But there may come a point when they can no longer do that, and we don’t know when that point will be reached. The biggest fear island people have is not knowing what will happen beyond that point.”

— Professor Tim Flannery spoke to news.com.au on behalf of An Inconvenient Sequel, Al Gore’s award-winning, impassioned, stirring and proudly memorable follow-up to 2006’s An Inconvenient Truth.

— An Inconvenient Sequel is out on DVD and Blu-ray this week.