9 cities that could be underwater by 2030

There’s a reason they’re called the Low Countries. Amsterdam and the cities of Rotterdam and the Hague sit low, flat and close to the North Sea. The Dutch are famed for their flood defences, and looking at these sea-level projections, it seems the country’s system of dikes, dams, barriers, levees and floodgates will become even more essential in the years to come.  

Iraq’s main port city of Basra lies on the Shatt al-Arab, an enormous and wide river that feeds into the Persian Gulf. Due to its intricate network of canals and streams, as well as neighbouring marshland, Basra and its surrounding areas are especially vulnerable to a rise in sea levels. And as if that wasn’t worrying enough, Basra already suffers significantly from waterborne diseases – so increased flooding carries even more significant threats. 

See those sharp, thick grey borders on the above map around the centre of New Orleans? That’s the city’s system of levees that protects it from the swarm of red building up from Lake Maurepas in the north and from Lake Salvador and Little Lake in the south. Without those defences, New Orleans would be severely threatened by rising sea levels, but even with them, the damage looks catastrophic. The Biloxi and Jean Lafitte wildlife preserves look particularly vulnerable – on the map both appear almost totally submerged.

In the very near future, Venice faces a twin threat: sea levels are rising and the city itself is sinking – by two millimetres every year. The Venetian capital has already been hit by servere flooding, and climate change is likely to increase the frequency of high tides that submerge it. Like New Orleans, Venice has a system of flood-defence systems in place, but as the crisis worsens, these will be more difficult (and expensive) to maintain.

Climate Central’s map shows that the areas most at risk in Ho Chi Minh City are its eastern districts – particularly the flat, heavily built-up marshland of Thủ Thiêm. But it also looks like the city will be increasingly threatened along the Mekong Delta. While the centre of Ho Chi Minh City itself is unlikely to find itself underwater by 2030, it will almost certainly be more vulnerable to flooding and tropical storms.

Much of west Bengal has thrived for centuries because of its fertile landscape, but as the map above shows, that has become great cause for concern in Kolkata and its surroundings. Like Ho Chi Minh City, the city could struggle during monsoon season as rainwater has less land to run off into. This map of the potential situation in 2100 is even more concerning.

A 2020 study found that Bangkok could be the city that’s worst hit by global warming in the short term. The Thai capital sits just 1.5 metres above sea level and, like Venice, it’s sinking (only much, much faster – by about two to three centimetres a year). But Bangkok is also built on very dense clay soil, which makes it even more prone to flooding. By 2030, most of the coastal Tha Kham and Samut Prakan areas could be underwater, as could its main airport, Suvarnabhumi International.

For centuries, Guyana’s capital Georgetown has relied on sea walls – or, more accurately, one gigantic, 280-mile long sea wall – for protection from storms. That’s because most of the coastline is between 0.5 and one metre below high tide. Some 90 percent of Guyana’s population lives on the coast, and as you can see, the country will need to substantially bolster its sea wall if Georgetown’s central areas are to avoid massive damage.

The city of Savannah, Georgia sits in a hurricane hotspot, but even without extreme weather events, the historic city could see land swallowed up by the sea on all sides. The Savannah River in the north and Ogeechee River in the south could both spill out into the nearby marshland, meaning that when hurricanes and flash floods do hit the city (and by 2050 the city is predicted to experience once-per-century historical flood levels every year), the effects may be even more severe.