If you've been paying attention at all the past decade, it's impossible not to be aware of sea-level rise and the dangers it poses to coastal cities. While other, less apparently impacts of climate change have led to an increase in the number of deniers and even conspiracy theorists, it's more difficult to argue that sea-level rise isn't happening, as several cities and even countries around the world face the prospect of going under well before the turn of the next centuries.
To be sure, while there's a healthy correlation between cities being located on the coast and their likelihood of being underwater within our lifetimes, many metropolitan areas on our planet are sinking, independent of their distance from any large body of water. Here are some of the ones you might want to visit most—better go soon, just to make sure you can walk instead of swim when you arrive!
Mexico City, Mexico
Case in point: Mexico City, which sits almost 250 miles from the nearest ocean, yet still manages to be one of the world's sinking cities. The explanation? According to EcoWatch, the cause of the city's three-feet-per-year rate of sinking is groundwater extraction, the empty caverns left by which allows the porous ground to compress further, resulting in a sinking longtime residents claim they can see when they look at familiar buildings.
Fun fact: Mexico City was built on a drained swamp, which almost certainly also has to do with its rate of sinking. Actually, that's not really very fun, at least not if you plan to live in or travel to Mexico City at any point in the future past about the next 50 years.
Like Mexico City (and, to be frank, most of the entries on this list), Shanghai is sinking in large part because of the groundwater extraction demands of its 20 million cities. Unlike Mexico City, however, Shanghai doesn't sit hundreds of miles from an ocean. As evidenced by its Chinese name 上海, which literally means "above the sea," the Shanghai metro area sits at the mouth of the Yangtze River as it opens into the Pacific Ocean.
This says nothing of the voluptuous Huangpu River that flows through the center of the city, dividing it into its east ("Pudong") and west ("Puxi") halves. These factors, when combined, make it likely that Shanghai will be among the first cities on this list to sink.
That is, if Miami doesn't beat it to the punch. Miami boasts both of the factors that are causing Mexico City and Shanghai to sink, plus the fact that it was built on a sandbar geologists now believe would've been temporary, even under the best of circumstances. As my chemistry professor at the University of Tampa once said, "Florida is basically just one giant beach!"
Due to the sandy composition of Miami's soil, the bedrock under the city is porous limestone, which will allow salt water to seep up into the city, no matter how strong or advanced a sea wall is built. Already, high tides have begun flooding low-lying areas of Miami Beach. The more severe effects of Miami's sinking state can't be far away.
In ancient times, Thai people were well attuned to the rhythms of nature in their low-lying country, building their houses on high stilts, and using boats to get around during the wet months. While you can still see this in practice in some of Thailand's more rural regions, and in historical cities like Ayutthaya, most people who live in Thailand (and especially, the capital Bangkok) live in a way that might seem more familiar to New Yorkers or Los Angelenos—take a look at MahaNakhon, the recently-completed tallest skyscraper in Thailand.
While Bangkok sits a good ways inland from the Gulf of Thailand, its Chao Phraya River's floods have gotten more intense as years have passed, and although it boasts canals designed to drain out unnecessary water, it's unlikely to withstand the demands of 10 million people sucking groundwater out from underneath it, at least not in the long run.
Speaking of canals, it's no news that Venice is sinking. This fact is part of why canals have become so ubiquitous in the old city—they're a feature that's as much about function as about charm. Unfortunately, because Venice actually sits in the sea (it has an exposure level more comparable to, say, the Maldives than Miami), it's perhaps at the highest risk of sinking, out of any city on this list.
While Venice's low population, relatively speaking, means that groundwater depletion isn't as severe as in other places, you also have to consider that Venice has been under street for centuries, while certain cities on this list have only had significant populations for decades, or even less than that.
New York City, USA
You probably know New York as the "City That Never Sleeps." Thus far, with the exception of Super Storm Sandy, it's also been a city that never sinks—that's about to change, unfortunately. Indeed, New York suffers from basically all the problems on this list, from a huge population depleting groundwater, to a location near the rising sea, to not one, but two large rivers that have a tendency to flood.
Add this to the fact that Manhattan is actually an island, and you have a recipe for a sinking city that's as disastrous as New York-style pizza is delicious. New York is one of the most expensive cities in the world, but you should probably splurge on a trip there sooner rather than later.