The ocean is rising faster now than at any other time on record. The effects are already being felt, and the threats continue to grow.
Lands are flooded, homes suffer waterlogging, and livelihoods are lost, causing serious hardship and forcing many people to seek a safer future.
But the environment is not the only thing affected. Rising sea levels also have significant repercussions for human rights , economic development, health, culture, the future of numerous countries, and human dignity itself.
The problem affects virtually everyone, everywhere, in both developed and developing countries. The ability to act and adapt today will be crucial in determining whether rising sea levels become a manageable challenge or a crisis that will define entire generations.
What is sea level rise?
Simply put, sea levels are rising as a result of climate change caused by human activities.
Between 2014 and 2023, the global average sea level rose by 4,7 millimeters per year . In 2024, the increase reached a record 5,9 millimeters.
Even in the most optimistic scenario, ocean levels are likely to rise by up to 0,55 meters by 2100 ; in the worst-case scenario, the rise would exceed one meter. Under high-emissions scenarios, there is also a small but consequential possibility that the rise could approach two meters by the end of the century.
What is causing this increase?
- The melting of glaciers and ice sheets.
- Thermal expansion: when the oceans heat up, the water literally occupies more space.
- Around the 91% of the planet's excess heat is absorbed by the oceansTherefore, as long as the climate continues to warm due to increased emissions of harmful gases, some future sea level rise will be inevitable.
The impact on people
Around 770 million people, approximately one in ten worldwide, live less than five meters above the high tide line.
It is a worrying proximity and its consequences are already being felt.
- Freshwater wells and agricultural lands are becoming salinized.
- Floods damage hospitals, schools, and sanitation systems.
- Increased exposure to waterborne diseases threatens sources of drinking water and contributes to growing psychological stress.
- Fishing and tourism, pillars of many coastal economies, are suffering disruptions.
- Some projections indicate that Up to 1200 billion people could be displaced worldwide by 2050, in search not only of safer places, but also of places where they can rebuild their livelihoods.
- New evidence suggests that sea level-related risks may be significantly underestimated in some regions, meaning that tens of millions more people could be vulnerable.
The consequences extend far beyond physical damage. Cultural heritage, ancestral lands, and traditional ways of life are also disappearing , with significant psychological effects on the affected communities.
The economic cost
- Damage to coastal infrastructure already exceeds 1,8 trillions of dollars.
- Without adaptation measures, annual global losses could reach 1,4 trillions of dollars.
- Small Island Developing States lost 153.000 million due to climate threats between 1970 and 2020.
- Home insurance premiums in the United States increased by 33% between 2020 and 2023 in disaster-prone areas.
- The ports, through which it passes over 80% of world tradeThey are increasingly exposed to flooding and rising sea levels, creating risks for global supply chains.
Where are the greatest risks?
Many of the countries facing the most immediate risks are precisely those that have contributed the least to the emissions driving sea level rise and, often, those with the fewest resources to respond.
- Small island states: Some Pacific nations are experiencing a relative sea level rise more than twice the global average and remain especially vulnerable to increasingly frequent flooding.
- Cities located in low-altitude deltas: in Dhaka, Mumbai and Kolkata, more than 14 million people They risk losing their homes, their livelihoods, and even their lives.
- Coastal megacities: Miami, New York, and Guangzhou could face losses of billions of dollars if their infrastructure is damaged.
Can it be stopped?
Not entirely. Some of the increase is already inevitable.
However, how much higher sea levels will rise will depend on how much harmful emissions can be reduced now.
One of the main critical points is the Thwaites Glacier in Antarctica , which covers approximately 190.000 square kilometers. Its collapse alone could cause a sudden and irreversible rise in sea level of more than half a meter, a true and potential tipping point with no turning back.
Adapting to the inevitable
Abandoning climate-altering fossil fuels is the most important priority for curbing global warming and, consequently, sea-level rise. But adaptation measures are also needed now.
- Early warning systems that allow people to be protected before a disaster occurs.
- Dikes, restoration of mangroves and dunes, as well as the planned relocation of people from threatened areas.
- Better data is needed, as many regions still lack basic systems for monitoring sea conditions.
- Greater clarity on legal issues, including those related to statehood and maritime zones in the event that certain territories become submerged.
Developing countries need between $310.000 billion and $365.000 billion annually for adaptation , but global funding for this purpose was only $26.000 billion in 2023.
Ultimately
Rising sea levels may seem like an unstoppable force, but the extent of the damage and who will suffer the worst consequences still depends on the decisions made today by individuals, communities, and governments.
Ultimately, increasing funding for adaptation, ensuring that statehood is not affected by rising sea levels, and giving this phenomenon the importance and urgency of a permanent global priority will be critical to protecting the homes, histories, livelihoods, and identities of millions of people.