The fastest sea level rise on Earth is happening in the western tropical Pacific, where rates have reached nearly three times the global average over the past two decades. But the answer depends on whether you’re asking about ocean water alone or the combined effect of rising seas and sinking land. When land subsidence enters the picture, parts of the U.S. Gulf Coast, Southeast Asia, and major river deltas jump to the top of the list.
Globally, sea levels are rising at about 3.3 millimeters per year on average, but that rate has been accelerating. It was roughly 2.1 mm per year in 1993 and had doubled to 4.5 mm per year by 2024. Total rise from 1993 to 2023 was 11.1 centimeters, or about 4.4 inches. That’s the baseline. In many regions, the local number is far higher.
The Western Tropical Pacific
The region with the highest pure ocean-driven rise is the western tropical Pacific, including island nations like the Marshall Islands, Tuvalu, and parts of the Philippines. Since the early 1990s, sea levels there have climbed at rates nearly three times the global average. The primary driver is a steady intensification of the trade winds blowing across the Pacific. These winds essentially push surface water westward, piling it up on that side of the ocean basin. The trend shifted abruptly in the early 1990s, and multiple atmospheric models confirm that strengthening trade winds account for both the speed and geographic pattern of the rise.
For low-lying Pacific island nations, even modest additional rise threatens freshwater supplies, coastal infrastructure, and long-term habitability. These communities are among the most vulnerable on Earth despite contributing almost nothing to the emissions driving the change.
The U.S. Gulf Coast
From south Texas to south Florida, the Gulf Coast is experiencing what researchers have called “presumably unprecedented change.” Coastal wetlands that grew steadily for thousands of years are now rapidly drowning. Southern Louisiana, home to some of the largest wetlands in the country, has reversed from a period of significant land growth over the past several thousand years to widespread shoreline retreat. The Florida Everglades face a similar fate.
The main culprit is the combination of accelerating sea level rise and severe land subsidence. Much of the Gulf Coast sits on soft sediment that naturally compacts over time, and decades of groundwater and oil extraction have made the sinking worse. When the land drops while the ocean rises, the effective rate of sea level rise can exceed 9 mm per year in the worst spots. NOAA models project that portions of the Gulf Coast will be inundated by roughly 30 centimeters (about one foot) of additional rise by around 2040.
The U.S. East Coast
The Atlantic seaboard from the Carolinas to New England is another hotspot, and ocean currents play a significant role. The Gulf Stream, which runs north along the coast, helps regulate water levels. There are signs of weakening near Florida, and any slowdown in the current allows water to slosh back toward the coastline, raising local sea levels beyond what warming and ice melt alone would cause. Farther north, the picture is more complicated: some sections of the current appear steady or even stronger. The takeaway is that Gulf Stream changes don’t affect the coast uniformly, but they do add an unpredictable variable on top of the global trend.
Cities like Miami, New York, and Norfolk, Virginia sit in this zone of compounding risk, where even moderate global rise translates into outsized local flooding.
Why Rise Varies So Much by Location
Three main forces cause sea level rise to differ dramatically from place to place: land movement, ocean current shifts, and the gravitational effects of melting ice sheets.
Land subsidence is the most straightforward. When ground near the coast sinks, it has the same practical effect as the ocean rising faster. River deltas are especially prone to this because they’re built on loose sediment. The Ganges-Brahmaputra delta (home to Dhaka), the Mekong delta, and the Mississippi delta all face this problem, often worsened by human activities like pumping groundwater or extracting natural gas.
Ocean current changes redistribute water in ways that create winners and losers. Warmer temperatures and freshwater flowing in from melting ice sheets alter the speed and position of major currents. When currents shift even slightly, they can raise or lower sea levels along nearby coastlines by several millimeters per year.
The gravitational fingerprint of melting ice is the least intuitive factor. A massive ice sheet like Greenland’s exerts a gravitational pull on the surrounding ocean, drawing water toward it. As that ice melts and the mass shrinks, the gravitational pull weakens, and nearby ocean water actually moves away. The result is that regions far from the melting ice experience more rise, not less. NASA-funded research has confirmed these “sea level fingerprints” in the tropics. Sea level rise in California and Florida caused specifically by Antarctic ice loss is up to 52 percent greater than the global average effect of that same melting. Greenland’s melt, by contrast, disproportionately raises water in the Southern Hemisphere and tropics.
Cities With the Most at Stake
The risk isn’t just about millimeters per year. It’s about what’s in the water’s path. Miami, Guangzhou, and New York top the list for sheer economic exposure, with assets at risk from coastal flooding estimated between $2 and $3.5 trillion through 2070. But the human toll is concentrated elsewhere: Kolkata, Mumbai, and Dhaka each have between 11 and 14 million people vulnerable to coastal inundation. These South Asian megacities sit on low-lying deltas and floodplains where subsidence, population density, and limited infrastructure combine to multiply the danger.
Jakarta has already committed to moving Indonesia’s capital inland, in large part because the city is sinking so fast that parts of it drop by as much as 25 centimeters per year. Shanghai, Ho Chi Minh City, Lagos, and Bangkok round out the list of cities where rising seas and sinking land pose existential planning challenges in the coming decades.
What Global Projections Show for 2050
By 2050, global sea levels are projected to rise between 15 and 29 centimeters (roughly 6 to 11 inches) above a 1995-2014 baseline, depending on emissions. Even under the most optimistic scenario, the median projection is 18 centimeters. Under the highest-emissions pathway, it reaches 23 centimeters at the median, with an upper range of 40 centimeters if ice sheet instability plays out faster than expected.
These are global averages. In the hotspots described above, local rise will be significantly higher. A region experiencing twice the global rate today can expect that multiplier to persist or worsen, meaning some coastlines could see 30 to 60 centimeters of effective rise by mid-century. For communities already dealing with regular tidal flooding, that difference is the margin between manageable nuisance and permanent loss of land.