Flooded Earth: How the global map and countries’ coastlines will change by 2100

Vast swathes of London, New York, Bangkok and other major cities will be underwater by 2100, according to terrifying sea level predictions based on the current trajectory of rising global temperatures.

As a result of rising water levels, the global map is set to change as we know it before the end of this century. Coastlines will be altered, and many cities will be rendered uninhabitable – displacing hundreds of millions.

With a recent United Nations report finding ‘no credible pathway’ to stopping global temperatures from rising above the 1.5 decrees Celsius (the ‘preferable’ target set by the Paris agreement), rising sea levels as a result of increasing global temperatures are considered inevitable by 2100.

As they meet in Egypt for Cop27, some world leaders are working to limit global temperatures from rising any further. Thanks to the rapid growth in clean energy technologies, the world has already started to curtail emissions. However, the current emissions pathway is still predicted to cause a global temperature rise of 2.7C to 3.1C by the end of the century.

A global temperature rise of 3C by 2100 would have a disastrous impact on millions around the globe, and nowhere would be immune to the effects. 

Heatwaves will last longer and become more common, causing droughts and global food shortages. Global migration will rise, as will the spread of disease. And, as polar ice melts, sea levels will rise. 

Scientists at Climate Central, a non-profit organisation, estimate as many as 275 million people currently live in areas that will be flooded in this scenario.

Low-lying London is predicted to be one of the worst affected major cities in the western world. A rise of even 2C could see central parts of the British capital along the River Thames flooded by 2100.

According to maps modelled by Climate Central, other parts of England will not be spared, either. A large portion of the Midlands will be submerged, while cities and towns along the Humber – including Hull – will also be flooded. Much of the coast on the South-East will also be at risk.  

Across the English Channel, Northern France, Belgium, Germany and then around half of the Netherlands will also be underwater by 2100. The situation is particularly bleak for the low-lying Holland region of The Netherlands, known for its flat landscape of canals, tulip fields and windmills.

Should the sea level rise in-line with current predictions, only the centre of Amsterdam, and The Hague further south, could become islands in an otherwise flooded landscape.

Some major cities in the United States also face disaster in the 3C scenario. Rising sea levels and floods resulting from more extreme tidal activity would see parts of New York City, including lower Manhattan, under water. Across the Hudson river, Jersey City and parts of Newark are also in the danger zone. 

Looking east, the southern coast of Long Island and its Barrier Islands will also see rising floodwaters.

Further down America’s east coast, several coastal communities are also at risk. In the South, New Orleans – like Amsterdam in Europe – is expected to become an island as the surrounding flood plains are submerged.

Some projections say Miami, on the southern coast of Florida, would simply cease to exist in 3C rises.

On the West Coast, southern Los Angeles including Long Beach and Seal Beach are predicted to flood in the 3C scenario. Further north, communities around San Francisco bay – including Oakland – are also predicted to suffer.  

With all that being said, it is the population of Asia that is expected to be most adversely affected by rising waters. 

When it comes to flooding, Shanghai in China is one of the world’s most vulnerable cities. Models suggest that 17.5 million people could be displaced by a global temperature rise of 3C, thanks to the former fishing village’s location on the Yellow Sea. The Yangtze river runs to the north, while the Huangpu river runs through the centre.

Cities such as Shanghai, which rely heavily on water-based infrastructure, are particularly vulnerable. The vast city is built on several islands, has two long coastlines, several shipping ports and miles of canals.

In recent years, China has been building vast flood prevention walls to protect Shangai. Some have blocked the ocean from view entirely to its residents.

Climate Central’s projections of sea level rises also show Thailand’s capital of Bangkok being all but wiped out by flood waters in the event the world hits 3C. While the sea level itself would not be enough to submerge the whole city, the whole of Bangkok would be at risk of severe flood waters.

Similarly, the southern point of Vietnam, reaching almost as far as Ho Chi Minh City, is also at great risk. The projections show the entire southern point underwater by 2100 at the current rate of warming. 

In June, devastating floods in Pakistan submerged a third of the country, causing eight million people to be displaced and billions of pounds worth of damage to the country.

It has taken months for the flood waters to recede, but millions remain homeless. Roads are destroyed and thousands of key buildings – including schools and hospitals – lie in ruin.

But while the flooding – caused by intense monsoon rains and unusual heat in the Karakoram Mountains leading to unprecedented glacial melt – was one of the world’s most severe climate disasters, it was but a glimpse of what is to come for millions more living in coastal areas – including in Britain, the United States and Europe.

Meanwhile, this month has seen COP27 hosted in Egypt. World leaders have flocked to Sharm El-Sheikh with many hoping new pledges can be made to limit rising global temperatures further, and limit sea level rises.

Island nations, such as Tuvalu and Vanuatu, have been warning the world for years that their very existence is threatened in the coming years thanks to rising global temperatures and sea levels.

Tuvalu, a group of nine islands and 12,000 people halfway between Australia and Hawaii, has long been a cause celebre for the risks of climate change and rising sea levels. Up to 40% of the capital district is underwater at high tide, and the entire country is forecast to be under water by the end of the century.

The Pacific island state of Vanuatu, meanwhile, said it will consider the COP27 climate talks ‘a failure’ if they conclude without a new fund for vulnerable countries to tackle ‘loss and damage’ fuelled by global warming.

For many, the small island nations may seem like a world away. But the threats faced by the likes of Tuvalu and Vanuatu will soon become a reality for millions more across the globe, unless global leaders agree to cut emissions further to get closer to the target of 1.5C.

While COP27 was being hosted, the world’s population hit an estimated 8 billion people, according to a United Nations projection, with much of the growth coming from developing nations in Africa.

Rapid population growth also means more people vying for scarce water resources and leaves more families facing hunger as climate change increasingly impacts crop production in many parts of the world.

‘There is also a greater pressure on the environment, increasing the challenges to food security that is also compounded by climate change,’ said Dr. Srinath Reddy, president of the Public Health Foundation of India.

‘Reducing inequality while focusing on adapting and mitigating climate change should be where our policy makers’ focus should be.’

Still, experts say the bigger threat to the environment is consumption, which is highest in developed countries not undergoing big population increases.

‘Global evidence shows that a small portion of the world’s people use most of the Earth’s resources and produce most of its greenhouse gas emissions,’ said Poonam Muttreja, executive director of the Population Foundation of India. ‘Over the past 25 years, the richest 10% of the global population has been responsible for more than half of all carbon emissions.’