10 Cities That Could Be Lost to Climate Change – And What Their Disappearance Would Mean
Tides are already climbing pavements in Miami. Saltwater is seeping into fields near Alexandria. Jakarta is moving its capital because the old one is sinking. What used to be far-off climate warnings are now reshaping real cities in real time.
Climate change is driving sea levels higher, pushing storm surges further inland and amplifying flooding in low-lying coastal areas. At the same time, many of the world’s biggest cities are sinking under their own weight, or because of groundwater extraction. Together, these forces raise a stark question: which cities could become effectively unliveable or be largely “lost” this century?
This article looks at ten major cities on the front line. It explains why they are vulnerable, what “loss” would actually mean in practice, and how governments, businesses and communities are trying to buy time. It also explores what is at stake for global finance, trade, heritage and human security if some of the world’s most iconic urban centres are forced to retreat from the sea.
Key Points
Global sea level has already risen about 8–9 inches since 1880 and the rate is accelerating, increasing the risk of chronic flooding in coastal cities.
By mid-century, hundreds of millions of people in low-lying urban areas could live below high-tide lines without major new flood defences.
Cities facing a mix of sea-level rise, land subsidence and extreme weather include Jakarta, Miami, Bangkok, Shanghai, Mumbai, Dhaka, Lagos, Alexandria, London and Saint-Louis in Senegal.
“Lost” does not always mean completely underwater; it often means repeated displacement, uninsurable neighbourhoods, failing infrastructure and partial abandonment.
The economic stakes are huge, with trillions of dollars in coastal assets and critical infrastructure exposed to flooding and erosion.
Adaptation decisions taken in the 2020s and 2030s—seawalls, managed retreat, zoning, and emissions cuts—will determine whether these cities shrink, transform or slowly drown.
Background
For much of the last 10,000 years, sea level was relatively stable. That stability allowed ports, deltas and estuaries to become natural sites for human settlement. Today, those same locations sit on the front line of a rapidly changing climate.
Global sea level has risen primarily because oceans expand as they warm and because ice sheets and glaciers are melting. The average rise of 8–9 inches since 1880 might sound modest, but it stacks on top of tides and storm surges. Even small increases can turn “once in a century” floods into regular events.
At the same time, human activity is causing land to sink. In cities like Jakarta, Bangkok and Shanghai, heavy buildings compress soft soils while groundwater extraction creates further subsidence. When subsidence and rising seas combine, relative sea level can rise several times faster than the global average.
Urbanisation has magnified the risk. More than half of humanity now lives in cities, many of them coastal. A growing share of global GDP, trade, data cables, airports and energy hubs is concentrated within a few metres of the current high-tide line. Studies suggest that by 2050, around 800 million people could live in cities where sea levels may rise by more than half a metre, unless emissions fall sharply and adaptation accelerates.
Analysis
Ten Cities on the Climate Front Line
The following ten cities illustrate different ways climate change could “erase” urban space—not always through dramatic submersion, but through gradual damage, salinisation, retreat and socio-economic collapse.
Jakarta, Indonesia – A megacity already on the move
Around 40% of Jakarta is already below sea level, and parts of the city are sinking by 3–10 centimetres a year due to groundwater pumping and soft soils. At the same time, coastal waters are rising and storm surges are becoming more damaging. The government has begun building a vast seawall system along the north coast of Java and is creating a new capital, Nusantara, in Borneo to relieve pressure on Jakarta. In the worst case, large areas of North Jakarta could be permanently flooded or walled off behind dikes by mid-century, with poorer communities forced to move inland.
Miami, United States – A wealthy city on porous rock
Miami is built on porous limestone, which means water can seep up from below even if seawalls are built. Projections of 5–6 feet of sea-level rise by 2100 would physically displace hundreds of thousands of residents and render large areas uninhabitable without massive investment. Rising seas are already eroding beaches, flooding roads during “sunny day” high tides and threatening billions of dollars in property and infrastructure. In a high-emissions world, some low-lying districts may be surrendered to the water, while developers and wealthier residents shift to higher ground—a pattern already described as “climate gentrification.”
Bangkok, Thailand – The sinking capital of a river delta
Bangkok sits on a low-lying delta where rivers meet the sea. Rapid urbanisation and groundwater use have caused widespread subsidence, while climate change is raising both sea levels and the intensity of rainfall. The World Bank has warned that up to 40% of Bangkok could be inundated by 2030 in severe scenarios. Recent research confirms that the metropolitan area faces compounding river and coastal floods this century. Without stronger planning and flood defences, large parts of the city could spend more time underwater than above it.
Shanghai, China – A coastal giant testing adaptation at scale
Shanghai, one of the world’s largest ports and manufacturing hubs, has experienced land subsidence and sits close to the Yangtze River estuary. It already faces frequent typhoons and heavy rainfall, with projections of above-average increases in flooding by 2050. Flood-risk assessments show large numbers of buildings and industrial areas exposed under plausible future sea-level scenarios. Shanghai is investing heavily in “sponge city” designs, seawalls and drainage, but the long-term question is whether engineering alone can keep ahead of a rising and more volatile sea.
Mumbai, India – A financial hub ringed by water
Mumbai, home to more than 20 million people, spreads across a series of islands and reclaimed land. It is already highly flood-prone, as seen during past monsoon disasters that caused major loss of life and economic damage. Studies highlight Mumbai and Kolkata among the Indian cities at highest flood risk this century, especially under high-emission pathways. Rising seas will amplify storm surges and high tides, and low-income communities in informal settlements are likely to be hit first. If adaptation lags, key business districts, slums and transport corridors may become uninsurable or periodically unusable.
Dhaka, Bangladesh – A megacity absorbing climate migrants
Dhaka is not directly on the coast, but it sits in a low-lying river system that drains a large part of the Himalaya-to-sea watershed. Bangladesh as a whole is only a few metres above sea level and is highly exposed to cyclones, storm surges and river floods. Rising seas and more intense storms are expected to submerge chunks of coastal land and displace millions of people, many of whom move to Dhaka as a last resort. That inflow is already straining infrastructure and housing. Without resilient drainage, embankments and planning, Dhaka risks becoming a crowded, flood-damaged city where climate-distressed migrants struggle to survive.
Lagos, Nigeria – Africa’s coastal powerhouse on a vanishing shore
Lagos is a fast-growing megacity on the Gulf of Guinea. Rising seas, stronger storms and coastal erosion are erasing beaches and swallowing coastal communities. Recent reports suggest more than 80% of Lagos’ coastline is already eroded, with villages losing homes, farmland and even graveyards to the sea. Lagos authorities now describe climate change and rising seas as the city’s biggest long-term threat, forcing the development of adaptation and resilience plans. Yet unregulated construction and major coastal infrastructure projects also push water towards vulnerable settlements. In a worst-case scenario, informal communities are repeatedly wiped out while wealthy enclaves protect themselves behind expensive barriers.
Alexandria, Egypt – An ancient port under pressure
Alexandria, on Egypt’s Mediterranean coast, lies on a low, sandy strip that is subsiding while the sea advances. Rising water, coastal erosion and saltwater intrusion threaten historic districts, fishing communities and vital infrastructure in the Nile Delta. Localised flooding episodes are already routine, and climate projections suggest severe inundation risks by 2100 if seas keep rising and defences lag. Relocation programmes have begun for some residents, but emotional ties and economic dependence on the sea make retreat difficult.
London, United Kingdom – Protected, but for how long?
London sits inland along the Thames, but its estuary is tidal and exposed to storm surges from the North Sea. The Thames Barrier has protected the city from catastrophic flooding since the 1980s, yet it was built for a different climate. NASA assessments have placed London and the east coast of England among the world’s most vulnerable areas for sea-level rise, with millions potentially affected if defences fail or are overtopped. UK climate risk assessments suggest the country will almost certainly have to adapt to more than one metre of sea-level rise in the long term, even if that full rise arrives after 2100. That would require new barriers, higher river walls and, in some scenarios, strategic retreat from parts of the estuary.
Saint-Louis, Senegal – A UNESCO site on the brink
Saint-Louis, sometimes called the “Venice of Africa,” is built on a narrow island and low-lying sandspit on Senegal’s Atlantic coast. Rising seas, river flooding and erosion are undermining homes, heritage buildings and critical defences. In recent years, ocean storms have destroyed hundreds of houses and forced thousands of residents to move to inland resettlement sites. Experts warn that much of the city could be underwater by the end of the century, even as local authorities and international partners fund protective works. For Saint-Louis, the debate is not abstract: the city is already living the slow-motion loss that others fear. Le Monde.fr
Political and Geopolitical Dimensions
Decisions about which districts to protect, which to abandon and who pays for what are deeply political. National governments must weigh the costs of megaprojects—such as Jakarta’s proposed giant seawall or new capital—against social spending, debt constraints and other priorities. Regional rivalries can surface when upstream dams, coastal defences or land-use choices shift flood risks downstream.
Internationally, there is growing debate over “loss and damage”—the idea that countries most responsible for emissions should contribute to the costs of climate-driven destruction in vulnerable states. Cities like Dhaka, Lagos and Saint-Louis sit at the heart of that conversation. As some coastal populations are forced to move, questions about cross-border migration, security and responsibility will become harder to avoid.
Economic and Market Impact
Coastal cities are economic engines. Ports handle a large share of global trade; financial districts cluster near waterfronts; tourism depends on beaches and historic waterfronts. When these areas flood more often, insurance premiums rise, mortgages become harder to obtain and capital quietly shifts to safer ground.
Studies suggest that, by 2100, up to trillions of dollars in coastal assets could be at risk from sea-level rise and coastal flooding under moderate emissions scenarios. Cities are already facing multi-billion-dollar bills for seawalls, raised roads, drainage upgrades and relocated infrastructure. Those that cannot finance large-scale adaptation may see investors demand higher returns, or simply move elsewhere.
Social and Cultural Fallout
The social impacts of losing parts of a city to climate change go far beyond property values. Informal settlements on marginal land are often hit first and hardest. Residents may be displaced multiple times, each move eroding social networks, livelihoods and mental health.
Culture and heritage are also at stake. Historic waterfronts in Alexandria, Saint-Louis and other port cities carry centuries of memory, from colonial architecture to religious sites. When these areas are damaged or abandoned, communities lose not only homes but also the places that anchor identity and shared history.
Inequality can deepen as wealthier residents secure protection or move to safer neighbourhoods, while poorer households remain in the most exposed zones. This pattern risks fuelling resentment and political instability.
Technological and Security Implications
Urban planners and engineers are racing to design flood-resilient infrastructure: movable barriers, “sponge city” parks that absorb rainfall, raised buildings and early warning systems. Some cities are experimenting with floating architecture or nature-based solutions like mangrove restoration and reef rebuilding to soften wave energy.
At the same time, security concerns are rising. Sea-level rise threatens coastal military bases, energy terminals and data cables. Cyber–physical infrastructure—such as electricity substations and telecommunication hubs—may be clustered in low-lying zones built for a cooler, calmer climate. As flood risk grows, so does the chance of compounding failures: a storm that knocks out power, overwhelms hospitals and disrupts financial markets in quick succession.
Why This Matters
The people most affected by climate-driven city loss are often those with the fewest resources. Low-income residents in informal settlements, migrants, small-scale fishers and workers in tourism or port services may see their homes and jobs disappear together.
In the short term, the main impacts are rising insurance costs, more frequent flood evacuations, salt-damaged crops near cities and regular disruption of transport and utilities. Over the long term, entire neighbourhoods may be decommissioned, ports relocated, and government services re-sited on higher ground.
These changes tie into wider global trends. As sea-level rise intersects with food insecurity, conflict and economic stress, climate-driven migration is likely to increase. Some people will relocate within their own countries; others will cross borders. The way governments handle today’s at-risk cities will shape future debates over migration, security and global justice.
Key moments to watch include:
National adaptation plans and funding commitments in major coastal countries.
Decisions on international “loss and damage” finance and climate funds.
Major infrastructure choices: new barriers, ports, airports and industrial zones.
Emissions trajectories that influence long-term sea-level rise over centuries, not just decades.
Real-World Impact
Consider a low-income family in a coastal informal settlement outside Lagos. Each rainy season, floodwaters now reach higher into their home. The parents lose days of work cleaning, roads become impassable and children miss school. Savings that might have gone into education or a small business instead buy replacement furniture and repairs. Eventually, after one storm too many, the family moves inland to a crowded resettlement site, far from the sea that once sustained their livelihoods.
In Miami, a small café owner near the waterfront watches “king tide” floods creep closer each year. At first, the floods are a nuisance—some sandbags, shortened hours, higher insurance. Over time, premiums spike and coverage shrinks. Lenders become nervous about offering long-term loans in the area. The business survives, but only by relocating to a less scenic, higher-elevation neighbourhood, losing tourist footfall in the process.
In Dhaka, a climate migrant from a coastal village arrives after their fields are ruined by saltwater and storms. They find work in a garment factory and rent a room in a flood-prone slum. When heavy monsoon rains combine with blocked drains and high river levels, the streets fill with polluted water. Illness spreads faster, medical costs rise, and the thin line between coping and crisis grows ever narrower.
In Saint-Louis, an elderly resident in a fishing district sees relatives relocated inland after their homes collapse into the sea. The new housing is safer from waves but far from traditional fishing grounds. Younger family members look for work in construction or services, while older ones feel cut off from the maritime culture they grew up in. The city continues to exist, but the version of it that shaped their identity has already been partly lost.
Conclusion
Whether cities are “lost” to climate change is not just a question of maps and tide lines. It is about when places stop functioning as safe, liveable homes and start becoming zones of constant repair, retreat and inequality.
The ten cities highlighted here show different paths. Some are building walls and re-engineering landscapes. Others are experimenting with new capitals, managed retreat and nature-based defences. All face the same core tension: how to protect lives and livelihoods in the near term while cutting emissions enough to limit even more severe sea-level rise for future generations.
The fork in the road is already visible. One path leads to reactive crises, piecemeal evacuations and cultural loss as neighbourhoods drown bit by bit. The other leads to planned adaptation, fairer sharing of costs and a serious effort to reduce greenhouse gas emissions. The signals to watch are clear: where governments invest, how insurance and finance respond, and whether global climate commitments translate into real cuts in emissions. The fate of these cities—and many others—will show how seriously the world takes the rising tide.
