29 August 2026
Land is being inundated, homes are
flooding, livelihoods are being lost, driving significant
hardships on people in search of a more secure
future.
It is not just the environment that is being
affected, rising sea levels also have a significant impact
on human rights, economic development, health, culture, the
future of many countries and basic human
dignity.
Everyone and pretty much everywhere are
affected across developed and developing nations. The
ability to act and adapt today will prove decisive for
whether rising seas become a manageable challenge or a
generational crisis.
What is sea-level
rise?
Simply put, sea levels are getting higher due
to the effects of human-induced climate
change.
Between 2014 and 2023, the global sea level
rose 4.7mm a year. In 2024, it jumped a record
5.9mm.
Even under the most optimistic scenario, oceans
will likely rise up to 0.55 metres by 2100; under the worst,
over a metre. A small, but high-impact, chance exists under
high emission scenarios, of nearly 2 metres by the end of
the century.
What’s causing it?
- Melting
glaciers and ice sheets. - Thermal expansion; warming
oceans literally take up more space. - About 91 per
cent of the planet’s excess heat is being absorbed by the
ocean, so as the climate warms due to increased harmful gas
emissions, future rises will be locked in.
The
human impact
Around 770 million people, roughly 1 in
10 humans, live less than five metres above the high tide
line.
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That is uncomfortably close and its proximity is
already being felt.
- Freshwater wells and farmland
are turning salty. - Flooding is damaging hospitals,
schools and sanitation systems. - Increased exposure
to waterborne disease threatens drinking water supplies and
contributes to growing psychological
stress. - Fisheries and tourism, the backbone of many
coastal economies, are being disrupted. - Some
projections suggest up to 1.2 billion
people could be displaced globally by 2050, as
people look not just for safer ground but also somewhere
they can build a new livelihood. - New evidence
suggests sea-level risks may be significantly underestimated
in some regions, meaning tens of millions more people could
be vulnerable than previously thought.
Beyond
the physical: cultural heritage, ancestral land and
traditional ways of life are being lost, with real
psychological toll
The price tag
- Coastal
infrastructure damage already exceeds $1.8
trillion. - Without adaptation, annual global
losses could hit $1.4
trillion. - Small Island Developing States
lost $153 billion to climate hazards
between 1970–2020. - US home insurance premiums
jumped by 33 per cent between 2020–2023 in disaster-risk
areas - Ports that handle more than 80 per
cent of global trade are increasingly exposed to
flooding and rising seas, creating risks for global supply
chains.
Where is most at risk?
Many of
the countries facing the most immediate risks contribute
least to the emissions driving sea-level rise and often have
the fewest resources to respond.
- Small
Islands: Some Pacific nations face relative
sea-level rise of more than twice the global average and
remain particularly vulnerable to increasingly frequent
flooding events. - Low-lying delta
cities: Dhaka, Mumbai and Kolkata, where over 14
million people risk losing their homes, livelihoods and
lives. - Coastal megacities: Miami,
New York and Guangzhou face losses of trillions of dollars
if infrastructure is damaged.
Can it be
stopped?
Not entirely, some rise is already locked
in.
But how much more happens depends on the
extent to which the harmful emissions can be cut
now.
One flashpoint: Antarctica’s Thwaites
Glacier, covering around 190,000 sq km. Its
collapse alone could trigger a sudden, irreversible
sea-level jump of over half a metre a
genuine and possible tipping-point from which there is no
going back.
Adapting to the inevitable
Moving
away from climate-changing fossil fuels is the world’s
most important priority to slow down global warming and thus
the rise of seas, but adaptation measures are also needed
now.
- Early warning systems so that people can be
protected before disaster strikes. - Sea walls,
mangroves, dune restoration and the managed retreat of
people from threatened areas. - Better data; many
regions still lack basic monitoring of sea
conditions. - Clarity in relation to legal aspects,
including on statehood and maritime zones, in the event that
land is submerged.
Developing countries need an
estimated $310-365 billion a year for
adaptation, but global adaptation finance was only about
$26 billion in 2023
The bottom
line
Rising seas can feel like an unstoppable force,
but how much damage is done, and to whom, still depends on
the choices that people, communities and governments make
today.
Ultimately, boosting adaptation finance,
ensuring that statehood is not affected by rising seas, and
giving sea-level rise the standing and urgency of a
permanent global priority is what is needed to protect
people’s homes, histories, livelihoods and
identities.
