Most people picture climate change as something dramatic. A hurricane battering a coastline, a wildfire swallowing a California hillside, a news crew standing in chest-deep floodwater. But there is another version of the story, and it’s far more unsettling precisely because it unfolds in slow motion. Beneath the streets, under the foundations, and inside the aquifers of America’s biggest cities, something is quietly shifting.
While land subsidence is often considered solely a coastal hazard due to relative sea level rise, it also threatens inland urban areas, causing increased flood risks, structural damage, and transportation disruptions. The threat is not always loud. Sometimes it’s measured in millimeters, in insurance premiums, in hairline cracks in a bridge support that nobody notices until it’s too late. Let’s dive in.
1. Miami, Florida: The City That Is Running Out of Time
Miami is the city that climate scientists tend to bring up first, and honestly, for good reason. Parts of low-lying Florida, such as Miami, are already dealing with more frequent and impactful high tide flooding events, happening more often in many coastal communities even on generally quiet weather days, according to NOAA.
Miami showed the greatest share of exposure to flooding, with up to 122,000 people and up to 81,000 properties that could be at risk of flooding by 2050. That’s not a distant-future problem. That’s a single generation away, affecting real homes, real neighborhoods, real property values.
In Miami, the typical single-family homeowner with a standard HO-3 policy now pays annual premiums equal to 3.7% of the home’s market value, the highest ratio among the nation’s 100 largest metros. Think of it like paying a monthly fee just to live on borrowed ground. Miami’s net outflow widened to 67,418 in 2024 from 50,637 in 2023, the largest acceleration of any high-flood-risk county.
2. New Orleans, Louisiana: A City Below the Waterline
New Orleans is, without exaggeration, one of the most geologically vulnerable cities in the world. When swamps were drained, it led to subsidence, or sinking, of the land levels, and now the city rests six feet below sea level on average. Six feet below sea level. Let that sink in for a moment.
Buildings at risk in New Orleans average about a 39% chance of a flood about 2.2 feet deep over 30 years, and of 248 census tracts in New Orleans, 231 have more than half of buildings with significant risk from storm surge, high tide flooding, surface flooding, and riverine flooding.
In a typical year around 1990, people in New Orleans experienced about 7 days above 95.5 degrees Fahrenheit per year. By 2050, people in New Orleans are projected to experience an average of about 50 days per year over 95.5 degrees Fahrenheit. The heat crisis compounds everything else. It’s a city being squeezed from above and below simultaneously, and the window for meaningful intervention is narrowing fast.
3. Houston, Texas: America’s Fastest Sinking Major City
Here’s the thing about Houston: it is a city that already knows flooding. But the scale of what’s happening underground makes the flood problem dramatically worse. Among all metro areas, Houston, Dallas, and Fort Worth are the fastest sinking cities in the U.S., with large portions of land subsiding more than 5 millimeters per year, nearly 2 inches every decade.
Certain parts of Houston are seeing as much as 10 millimeters of subsidence per year, according to the study. Parts of the city have already sunk by several feet, the result of decades of people pumping out too much groundwater and too much fossil fuel. Houston already struggles with flooding from hurricanes and rainstorms made worse by climate change, while subsidence creates depressions for all that water to accumulate.
Nearly 1 in 3 homes face high flood risk in Harris County, and Houston also faces other climate risks, namely extreme heat, with 100% of homes in Harris County facing high heat risk. Harris County saw its net outflow widen to 31,165 in 2024 from 22,035 in 2023, the second biggest acceleration among high-flood-risk counties. People are voting with their feet.
4. New York City, New York: Slowly Sinking Into Its Own History
New York City carries immense historical weight, and apparently that weight is also literal. Major cities on the U.S. Atlantic coast are sinking, in some cases as much as 5 millimeters per year, with New York City and Long Island particularly hard hit, seeing areas of rapid subsidence alongside more slowly sinking ground, increasing the risk to roadways, runways, building foundations, rail lines, and pipelines.
New York City faces a unique challenge where land subsidence intersects with rising sea levels and increased storm activity. According to the New York City Panel on Climate Change, sea levels are projected to rise between 8 to 30 inches by the 2050s, and as much as 15 to 75 inches by the end of the century.
New York City’s LaGuardia Airport is sinking a fifth of an inch a year, according to researchers. That’s an airport. A piece of critical infrastructure that connects millions of people to the rest of the country. A study published in the Bulletin of the American Meteorological Society indicates that climate change is increasing the frequency of compound flooding events, where storm surge and heavy rainfall occur simultaneously, in New York City.
5. Phoenix, Arizona: A Furnace That Keeps Getting Hotter
Phoenix does not have a flooding problem in the traditional sense, nor is it sinking into the sea. Its climate risk is of a different, equally alarming nature. In 2024, the maximum temperature in Phoenix sat at or above 100 degrees for approximately 30% of the year, and Phoenix experienced 113 consecutive days of 100 degrees or hotter, the longest run ever recorded.
While 2024 was the hottest year on record for the state, those 645 heat-related deaths in Maricopa County in 2023 made up more than half of all heat-related deaths reported nationally, according to Centers for Disease Control data. Half the nation’s heat deaths, from a single county. That is a staggering concentration of suffering.
The global temperature has risen by approximately 2 degrees Fahrenheit since 1880, but in Phoenix you can add another 5 degrees to that due to the urban heat island effect, where temperatures in urban areas increase due to the heat retained by structures and ground coverings, lack of vegetation, and other impacts of urbanization. It’s a compounding trap. More concrete means more heat, which means the city bakes even faster than the rest of the planet.
6. Baltimore, Maryland: Infrastructure Crumbling From Below
Baltimore rarely dominates climate headlines, which is precisely why it belongs on this list. Baltimore is particularly hard hit among population centers on the East Coast, seeing areas of rapid subsidence alongside more slowly sinking or relatively stable ground, increasing the risk to roadways, runways, building foundations, rail lines, and pipelines, according to a study published in the Proceedings of the National Academies of Sciences.
Subsidence can undermine building foundations, damage roads, gas, and water lines, cause building collapse, and exacerbate coastal flooding, especially when paired with sea level rise caused by climate change. Baltimore sits on the Chesapeake Bay, where sea level rise is already outpacing the global average. When the ground is also dropping, these effects multiply in ways that city planners have historically been slow to model.
For the U.S. East Coast, sinking is driven by glacial isostatic adjustment, natural sediment compaction, and groundwater extraction. Glacial isostatic adjustment is the land still responding to the massive glaciers that covered it thousands of years ago. I know it sounds crazy, but the ground is still adjusting to events from the last ice age, and that ancient shift now collides with modern climate change in cities like Baltimore in very real and costly ways.
7. Norfolk and Virginia Beach, Virginia: The Fastest-Sinking Urban Stretch on the East Coast
If any region in America illustrates the double threat of sinking land combined with rising seas, it is the Hampton Roads area of Virginia. Major cities on the U.S. Atlantic coast are sinking, in some cases as much as 5 millimeters per year, a decline at the ocean’s edge that well outpaces global sea level rise, according to research from Virginia Tech and the U.S. Geological Survey.
In addition to sea level rise, many areas along the Southeast Atlantic coast are experiencing sinking land, called subsidence, which exacerbates the effects of rising seas. Norfolk is home to the largest U.S. naval base in the world, making this not just a local housing issue but a matter of national security infrastructure. Roads flood during high tides on calm, sunny days with alarming regularity.
Even when considering current coastal defense structures, further land area of between 1,006 and 1,389 square kilometers is threatened by relative sea level rise by 2050, and in the short term of one to three decades, only continued observed rises in sea level are sufficient to trigger cascading hazards, with a projected increase in the frequency and intensity of storm surges, saltwater intrusion, high-tide flooding, and coastal erosion. The cascading nature of these hazards is what makes Norfolk’s situation particularly precarious.
8. Chicago, Illinois: An Inland City Facing an Underestimated Threat
Most people would never think to list Chicago alongside Miami or New Orleans when discussing climate risk. Yet the data tells a different story. Research published in Nature Cities shows that 25 of the 28 largest U.S. urban areas are sinking, and Houston, Fort Worth, Dallas, New York, and Chicago are all sinking at a rate of over 2 mm per year.
Land subsidence is a slow-moving hazard with adverse environmental and socioeconomic consequences worldwide. While often considered solely a coastal hazard due to relative sea level rise, subsidence also threatens inland urban areas, causing increased flood risks, structural damage, and transportation disruptions. Chicago’s aging infrastructure, some of it dating back over a century, sits on ground that is gradually shifting and compressing beneath it.
Groundwater withdrawal was responsible for roughly 80% of total subsidence in the studied cities. As urban areas grow, and as climate change exacerbates droughts, especially in the American West, their people and industries demand more water. This dynamic is not limited to arid cities. Even cities near the Great Lakes are drawing down underground water reserves in ways that contribute to the slow, largely invisible problem of ground subsidence.
9. Washington, D.C.: A Capital Built on Unstable Ground
Washington, D.C. was literally built on a swamp. That is not a political metaphor. It is a geological fact. Hot spots for subsidence include Los Angeles, Las Vegas, San Francisco, and Washington, D.C., with researchers noting that cities with denser populations and buildings have faster rates of land subsidence and higher risk of damage.
When the team assessed how infrastructure risks increase when subsidence rates vary, they found that New York, Las Vegas, and Washington, D.C. also had high rates of variance. Differential subsidence, where different parts of a city sink at different speeds, is often more damaging than uniform sinking. Imagine one end of a building dropping faster than the other. That’s the kind of structural stress that quietly compromises bridges, tunnels, and metro systems.
Climate change is already exacerbating a variety of hazards including extreme heat, extreme precipitation, flooding, drought, and sea level rise in Washington, D.C. Critical infrastructure such as drainage and sewer systems, transportation systems, and power supply were not designed for the projected wider variability of future climate conditions. The city’s own 2024 climate projections make clear that what was engineered for yesterday’s climate is increasingly inadequate for today’s.
10. San Francisco, California: Bay Area Risks Are Broader Than Most Assume
San Francisco occupies a strange position in the climate conversation. It is a city widely associated with environmental awareness, yet it faces deeply serious and growing climate exposure that goes well beyond earthquake risk. Large cities surrounded by water, like Boston, New Orleans, and San Francisco, will be among the regions that could experience flooding in the near future due to land elevation changes combined with sea level rise of about 4 millimeters per year, the 2024 study found.
San Francisco is listed among the major hot spots for subsidence in the U.S. In coastal cities such as San Diego and New York, subsidence amplifies sea level rise and leaves communities more exposed to storm surge and tidal flooding. The same dynamic applies across the Bay Area, where large portions of land along the shoreline sit barely above the current high tide line.
By 2100, 70% of the coastal population will be exposed to shallow or emerging groundwater, a far more significant exposure than daily flooding, with the research projecting that this groundwater hazard will affect approximately $1 trillion in property value, creating new challenges for infrastructure such as roads, buildings, septic systems, and utilities. The groundwater hazard is perhaps the least visible and least discussed, yet it may be the most persistent of all. Rising groundwater doesn’t announce itself with a storm warning. It just quietly corrodes the foundations of everything built above it.
The Bigger Picture: A Nationwide Pattern Nobody Can Ignore
Taken individually, each city’s story might feel like a local problem. Taken together, they reveal something deeply systemic. At least 20% of the urban area is sinking in all studied cities, mainly due to groundwater extraction, affecting approximately 34 million people, with more than 29,000 buildings located in high and very high damage risk areas.
In 2024, there were 27 individual weather and climate disasters with at least $1 billion in damages each. These disasters caused at least 568 direct or indirect fatalities, and the cost was approximately $182.7 billion. These figures represent only what we can already measure. The slow-burn risks, the sinking ground, the rising groundwater, the accumulating heat, are not yet fully priced into those numbers.
As one researcher put it, land subsidence is not just a coastal problem or something happening far away. It is occurring in many of America’s cities and affecting millions of people. More than 34 million urban residents live on sinking ground, and over 29,000 buildings are in high-risk zones. Subsidence often occurs slowly, millimeters per year, but its effects accumulate and can silently undermine infrastructure like roads, bridges, and homes.
What makes this so quietly alarming is that the risks discussed in this article are not hypothetical. They are already unfolding, already measurable, already shaping where people choose to live and how much they pay to stay. The cities most affected are not equally prepared, not equally resourced, and not equally warned. That gap, between what the science shows and what the public understands, may be the most important problem of all. What do you think needs to change first? Share your thoughts in the comments.
