Published

4 months ago

December 2, 2025

Alice Rush

Coastal flooding could bring $500bn of annual damages to the Asia-Pacific by the year 2100, if countries do not adapt to rising sea levels.

This is according to new research, published in the journal Scientific Reports, which assesses how coastal flooding is impacting the Asia-Pacific region – and models how the damages could worsen as sea level rises over the 21st century.

The paper finds that coastal flooding is already driving $26.8bn of damage every year across 29 countries in Asia and the Pacific, equivalent to 0.1% of the region’s GDP.

It projects that, under current policies, annual coastal flood damages in the region could rise to $518bn by 2100 – but this could drop to $338bn if warming is capped at 1.5C.

Small island states face the greatest risks from coastal flooding and will continue to bear the brunt of the damage as the planet continues to warm, according to the research.

For example, it finds that Tuvalu will face annual coastal flood damage equivalent to 38% of its GDP by the end of the century.

Meanwhile, small island states such as Kiribati, the Maldives, Micronesia and Tuvalu will permanently lose around 10% of their total land area.

The study’s lead author says the research shows how “rising seas” create “existential” and “economic” risks for low-lying islands in the Asia-Pacific.

He tells Carbon Brief that the paper highlights a “sharp inequality”, as developing nations with little historical responsibility for sea level rise face the brunt of its impacts.

Coastal damage

More than one billion people – about 15% of the world’s population – currently live within 10km of a coast.

Asia is home to some of the largest cities in the world, many of which are located near the sea, such as Mumbai, Tokyo, and Shanghai. The continent is home to 60% of the world’s coastal population.

However, there are hazards to living near the water.

Coastal flooding is caused by a combination of gradually rising sea levels and “episodic extreme sea levels”, such as high tides and storm surges, the study explains.

To assess these two factors, the study combines components including an ocean model and tide-height data.

The authors model flooding in all coastal Pacific and Asian countries that are listed as “developing member countries” by the Asian Development Bank. These 29 countries include Bangladesh, the Philippines and Tuvalu.

They calculate the economic damage caused by flooding, by combining their flood model with data on land use and “asset values” across the residential, commercial, industrial, infrastructure and agricultural sectors.

The authors assume when land floods permanently, the “assets” are completely lost. For areas that only flood periodically, the authors use a model linking flood depth to a percentage of land damaged to calculate the economic consequences.

They find that coastal flooding currently drives $27bn of damage every year in the Asia-Pacific.

China and Indonesia bear the greatest damage, each losing more than $6bn every year. The study authors say this is because both countries have “extensive coastlines, large populations in flood-prone areas and critical economic infrastructure concentrated near the coast”.

However, the study finds that small islands face the greatest economic damage as a percentage of their GDP.

The percentage of its annual GDP currently lost to coastal flooding in 29 Asia-Pacific countries. Small islands are shown in red. Data: Monioudi et al, (2025). Chart by Carbon Brief.

The study shows that the five most-severely affected countries are small island states. Vanuatu tops the ranking, losing 1.5% of its GDP to flooding every year. It is followed by Papua New Guinea and Micronesia.

Dr Michalis Vousdoukas is a researcher in coastal geography at the University of the Aegean in Greece and lead author of the study.

He tells Carbon Brief that even these damage estimates are “conservative” as they do not consider indirect economic losses, such as disruption to business, the loss of critical infrastructure, such as airports, or social impacts, such as migration.

Vousdoukas tells Carbon Brief that the study “highlights a sharp inequality between responsibility and impact”, explaining that the “countries that contributed the least to global emissions, particularly atoll nations, face the highest relative damages”.

Island nations in the Asia-Pacific region made of atolls – ring-shaped coral reefs or islands – include Kiribati, the Marshall Islands and Tuvalu.

Exposure

The authors also calculate population exposure to flooding, by overlaying their flood model with world population data.

Vousdoukas explains that “a person is considered exposed if they live in an area that appears as flooded in our model”.

The paper finds that six million people across the Asia-Pacific are currently at risk of coastal flooding each year, accounting for 0.2% of the region’s total population. The paper says:

“Although this may appear to be a small percentage, it still represents millions of individuals and families whose lives and livelihoods are under constant threat.”

Ranjan Panda is the convenor of the Combat Climate Change Network in India. Panda, who was not involved in the study, tells Carbon Brief that sea level rise is already forcing “millions of people to migrate out in distressed conditions to cities and other countries”.

China and Bangladesh rank the highest, with 2.2 million and 1.5 million people, respectively, exposed to coastal flooding each year.

However, small islands have the greatest percentage of their population exposed to flooding. Vanuatu again tops the table, with 2% of its population facing coastal flooding every year, according to the study. It is followed by Micronesia and the Maldives.

Bangladesh is the highest ranking non-island country, due to its “densely populated and flood-prone delta region”, the study finds.

Rising seas

As the climate warms, coastal flooding is worsening.

Average global sea levels have risen by more than 20cm since 1900, driven mainly by the thermal expansion of the ocean and the melting of glaciers and ice sheets.

Global warming is also “supercharging” hurricanes and typhoons, causing storm surges – the temporary rise in sea level that happens during a storm – to become more intense.

The study uses projections from the IPCC’s sixth assessment report to model sea level rise over the 21st century. These include thermal expansion and meltwater from glaciers and ice sheets, but exclude “low-likelihood, high-impact” events, such as ice-sheet collapse.

The authors assess five future scenarios:

SSP1-1.9: A very-low emissions reductions pathway that “aligns with” the Paris Agreement’s 1.5C limit
SSP1-2.6: A “low” emissions pathway achieving net-zero emissions after 2050
SSP2-4.5: A “moderate” emissions scenario, often described as the trajectory under current climate policies.
SSP3-7.0: A “high” emissions pathway
SSP5-8.5: A very-high emissions pathway of “high fossil fuel reliance” throughout the 21st century

They find that, even under the lowest 1.5C warming scenario, countries in the Asia-Pacific will face damages of $338bn due to coastal flooding every year by the end of the century. This accounts for 1.3% of the region’s present-day GDP. (The authors assume no adaptation measures, changes in land use or inflation over the century.)

Under the current policy scenario, annual damage from coastal flooding rises to $518bn by the end of the century.

The chart below shows coastal flood damage as a percentage of annual GDP by the end of the century under the five scenarios for each country. Each horizontal bar shows the damage for one country, with the lowest warming SSP1-1.9 scenario on the left (grey) and highest warming SSP5-8.5 scenario (black) on the right.

Coastal flood damage as a percentage of annual GDP by the year 2100 under the five emissions scenarios, for 29 countries in the Asia Pacific. Data: Monioudi et al, (2025). Chart by Carbon Brief.

The study finds that, by the end of the century, the Pacific island of Tuvalu will face the worst economic consequences from coastal flooding. Even under the 1.5C warming scenario, its annual economic losses due to coastal flooding will reach 38% of its GDP.

The authors also assess the amount of land that will be permanently lost to the sea.

They find that small island states – such as Kiribati, the Maldives, Micronesia and Tuvalu – will experience the highest percentage of their land permanently submerged, each losing around 10% of their total land area.

Two million people currently live in areas of the Asia-Pacific that will be permanently flooded by the end of the century under the 1.5C warming scenario, according to the research.

Finance gap

Countries can reduce the impacts of coastal flooding through adaptation. This can include building flood defenses, making infrastructure more resilient to flooding, or arranging “managed retreat” to move people away from vulnerable areas as the seas encroach.

The study authors model the cost of building defences – such as sea walls, levees, embankments and sand dunes – high enough that the economic damage from coastal flooding over the 21st century does not worsen beyond 2020 levels.

The research highlights that the cost of investing in these defences is substantially lower than the potential economic damages of sea level rise.

The authors estimate that, under a 1.5C warming scenario, building flood defenses to limit flood damage to 2020 levels would cost $9bn in total. However, building these defences would avoid $157bn in damages due to coastal flooding, they find.

Dr Rafael Almar is a researcher at the Laboratory of Space Geophysical and Oceanographic Studies in France and was not involved in the study. He says the study has “significant implications for development banks and financial institutions” as it could help them prioritise investments in “clearly identified hotspots”.

However, he emphasises that building flood defences “is not the only solution”. For example, he argues that “relocation and renaturalisation” – the process of moving people away from the coast and allowing the area to return to its natural state – can make an area “more resilient”.

Panda also warns that physical flood defenses “could actually be triggering further local environmental crises that accelerate the losses and damages faced by people due to sea level rise and flooding impacts”.

Sea walls have been shown to damage wildlife – for example, blocking animals such as turtles from reaching parts of the beach – according to an article in Climate Home News. The piece adds that physical defenses are “inflexible” and “mainly benefit the rich and encourage risky building near the coast”.

Sourcing money for developing countries to adapt to the impacts of climate change is an ongoing talking point at international climate negotiations.

A group of developed nations, including much of Europe, the US and Japan, is obliged under the Paris Agreement to provide international “climate finance” to developing countries. This money can be used for both mitigation – reducing emissions to limit warming – and adaptation.

In 2023, developed nations provided $26bn in international adaptation finance to developing nations, according to a recent UN report. This is roughly the amount that Asia-Pacific countries currently lose every year due to coastal flooding alone.

The post Asia-Pacific faces ‘$500bn-a-year’ hit from rising seas if current policies continue appeared first on Carbon Brief.

Asia-Pacific faces ‘$500bn-a-year’ hit from rising seas if current policies continue

Climate Change

Wondering How to Talk About Climate Change? Take a Lesson from Bad Bunny

Published

20 hours ago

March 21, 2026

Alice Rush

Discussing climate change can make a difference. Focusing on the impacts in everyday life is a good place to start, experts say.

By David Sun

When Bad Bunny climbed onto broken power lines during his Super Bowl halftime show, millions of viewers saw a spectacle. Climate communicators saw a lesson in how to talk about climate change.

Wondering How to Talk About Climate Change? Take a Lesson from Bad Bunny

Climate Change

Greenpeace response to escalating attacks on gas fields in Middle East

Published

1 day ago

March 20, 2026

Alice Rush

Sydney, Thursday 19 March 2026 — In response to escalating attacks on gas fields in the Middle East, including Israeli strikes on Iran’s giant South Pars gas field and Iranian retaliations on gas fields in Qatar and Saudi Arabia, the following lines can be attributed to Solaye Snider, Campaigner at Greenpeace Australia Pacific:

“The targeting of gas fields across the Middle East is a perilous escalation that reinforces just how vulnerable our fossil-fuelled world really is.

“Oil and gas have long been used as tools of power and coercion by authoritarian regimes. They cause climate chaos and environmental pollution and they drive conflict and war. The energy security of every nation still hooked on gas, including Australia, is under direct threat.

“For countries that are reliant on gas imports, like Sri Lanka, Pakistan and South Korea, this crisis is just getting started. It can take months to restart a gas export facility once it is shut down, meaning the shockwaves of these strikes will be felt for a long time to come.

“It is a gross and tragic injustice that while civilians are killed and lose their homes to this escalating violence, and families struggle with a tightening cost-of-living, gas giants like Woodside and Santos have seen their share prices surge on the prospect of windfall war profits.

“We must break this cycle. Transitioning to local renewable energy is the way to protect Australian households from the inherent volatility of fossil fuels like gas.”

-ENDS-

Images available for download via the Greenpeace Media Library

Media contact: Lucy Keller on 0491 135 308 or lkeller@greenpeace.org

Greenpeace response to escalating attacks on gas fields in Middle East

Climate Change

DeBriefed 20 March 2026: Energy crisis deepens | Brazil’s new climate plan | New Zealand climate case

Published

1 day ago

March 20, 2026

Alice Rush

Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.

This week

Iran war fallout continues

WORK FROM HOME: The International Energy Agency has advised its member countries to take 10 steps in response to the ongoing energy crisis fuelled by the Iran war, including reducing highway speeds and encouraging people to work from home, said the Guardian. It came after retaliatory attacks between Israel and Iran continued to destroy energy infrastructure in the Middle East, causing energy prices to soar further, said Reuters.

SUPPLY DISRUPTED: The IEA also said it is prepared to make more of its member nations’ 1.4bn-barrel oil reserves available to help ease the impacts of what it called the “biggest supply disruption in the history of the oil market”, reported Bloomberg. The outlet noted that Asian countries have been hit hardest by the shortages, caused by a “near-halt” of shipping through the Strait of Hormuz.

EU SUMMIT: The energy crisis dominated talks at an EU leaders summit on Thursday, said Politico. Arriving at the summit, Spain’s prime minister Pedro Sánchez attacked other European leaders for using the energy crisis as an excuse to “gut climate policies”, according to the EU Observer. The Financial Times said that some European leaders have asked the European Commission to overhaul its flagship emissions trading system (ETS) by summer in response to the energy crisis.

COAL BOOST: In response to the conflict, utility companies in Asia are “boosting coal-fired power generation to cut costs and safeguard energy supply”, said Reuters. UN climate change executive secretary Simon Stiell told Reuters: “If there was ever a moment to accelerate that energy transition, breaking dependencies which have shackled economies, this is the time.”

Around the world

WINDFARM WINDFALL: The Trump administration in the US is considering a nearly $1bn settlement with TotalEnergies to cancel the French energy company’s two planned windfarms off the US east coast and have it instead invest in fossil-gas infrastructure in Texas, according to documents seen by the New York Times.
BUSINESS CLASH: Following “clashes” with the agribusiness sector, Brazil launched its new climate plan, which calls for a 49-58% reduction in greenhouse gas emissions from 2022 levels by 2025 and includes “specific guidelines for different sectors”, reported Folha de Sao Paolo.
SALES SLUMP: Sales of liquified petroleum gas from India’s state-run oil companies have fallen by 17% this month due to cuts in deliveries to commercial and industrial consumers “amid the widespread logistical bottlenecks triggered by the Iran war”, said the Economic Times.
CUBAN ENERGY CRISIS: The US imposed an “effective oil blockade” on Cuba, leaving the country facing its “worst energy crisis in decades”, reported the Washington Post. Meanwhile, Chinese exports of solar panels to the island have “skyrocketed” since 2023, it added.
RECORD HIGHS: An “unprecedented” heatwave in the western and south-western US is “shattering dozens of temperature records” and could lead to drought in California in the coming months, reported the Los Angeles Times.
VULNERABILITY CONCERNS: Landslides that killed more than 100 people in southern Ethiopia have “renewed concerns about Ethiopia’s vulnerability to climate-related disasters”, said the Addis Standard.

1%

The percentage of England’s land surface that could be devoted to renewables by 2050, according to the long-awaited “land-use framework” released by the UK government this week and covered by Carbon Brief.

Latest climate research

Approaching international climate action by shifting the burden of mitigation onto higher-income countries could avoid 13.5 million premature deaths from air pollution in middle- and lower-income countries by 2050 | The Lancet Global Health
Beavers can turn the ecosystems surrounding streams into “persistent” sinks of carbon that can sequester an order of magnitude more than non-beaver-modified ecosystems can store | Communications Earth & Environment
Mobile-phone data from seven diverse countries during the summer heatwaves of 2022-23 showed a “widespread tendency to withdraw into homes” and an increase in out-of-home activities that can offer cooling, such as indoor retail | Environmental Research: Climate

(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)

Captured

Nearly_750_studies_have_found_that_climate_change_has_made_extreme_events_more_severe_or_likely

Carbon Brief this week published a significant update to its map of how climate change is affecting extreme weather events around the world. The map now includes 232 new extreme weather events from studies published in 2024 and 2025. Of these events, 196 were made more severe or more likely to occur by human-driven climate change, 12 were made less severe or less likely to occur and 10 had no discernible human influence. (The remaining 14 studies were inconclusive.)

Spotlight

New Zealand breaks new ground on climate litigation

This week, Carbon Brief speaks to experts about a first-of-its-kind climate lawsuit in New Zealand.

Earlier this week, representatives from two environmentally focused legal advocacy groups challenged the New Zealand government’s climate-action plan in court.

The plaintiffs argued that the measures laid out in the plan are insufficient to achieve the country’s legal obligation to hold global warming to 1.5C above pre-industrial temperatures.

The case could be “influential” in shaping lawsuits and rulings around the world, one legal expert not involved in the case told Carbon Brief.

Reductions vs removals

The new case contends that there are several issues regarding the New Zealand government’s response to climate change.

One of the key arguments the plaintiffs make is that New Zealand’s second emissions reduction plan, which covers the period from 2026-30, is overreliant on the use of tree-planting to achieve its targets.

When the plan was released in December 2024, it was “immediately clear that it was a pretty lacklustre plan”, Eliza Prestidge Oldfield, senior legal researcher at the Environmental Law Initiative, one of the groups behind the legal case, told Carbon Brief.

The plan called for large-scale planting of pine tree plantations, which are not native to New Zealand and have a high risk of burning. Because of this, there are concerns about how permanent any carbon removal provided by these plantations actually can be, experts told Carbon Brief.

Catherine Higham, senior policy fellow at the Grantham Research Institute on Climate Change and the Environment who was not involved in the case, said:

“The lawyers are arguing that there are real challenges with equating the emissions that you may be able to remove from the atmosphere through afforestation with actual emissions reductions, which are much more certain.”

‘Global dialogue’

While other climate lawsuits elsewhere in the world have also focused on the inadequacy of a government’s plan to meet its stated emissions-reduction targets, this is the first such case that addresses the role of removals head-on.

Lucy Maxwell, co-director of the Climate Litigation Network, told Carbon Brief that the lawsuit “builds on a decade of climate litigation” in national, regional and international courts.

Maxwell, who was not involved in the New Zealand case, added that there is a “real global dialogue” between, not just plaintiffs, but national courts as well. She said:

“[National courts] look to common issues that have been decided in other countries. They’re not binding on that court if it’s at the national level, but they are influential.”

Given that many other countries have legal frameworks requiring their governments to create plans outlining the pathway to their long-term climate targets, Prestidge Oldfield told Carbon Brief that other jurisdictions “should be interested in these questions around the level of certainty”.

Higham noted that, even if the case is successful, addressing the plan’s shortfalls will face its own set of challenges. She told Carbon Brief:

“A lot of these decisions are political and they can be politically contentious…Those [measures] have to be put into action through legislation and that is then subject to the usual political process. So that’s where the challenge comes in.”

While she could not speculate on the outcome of the case, Prestidge Oldfield said it was “very heartening” to see that both the judge and the opposing counsel “appreciated how much of a concern climate change is globally”.

She added:

“It’s not a given that the judge would even be interested in climate change.”

Watch, read, listen

COMMON APPROACH: The Heated podcast analysed fossil-fuel advertisements and highlighted the most common deception tactics they employed.

THREAT ASSESSMENT: Mongabay mapped the potential threat that oil extraction poses to Venezuela’s ecosystems, including the Amazon rainforest and its coral reefs.

SALT LAKES? GREAT!: High Country News interviewed journalist Dr Caroline Tracey about her new book on saline lakes – such as Utah’s Great Salt Lake – the threats that face them and what they can teach us.

Coming up

23 March-2 April: Third meeting of the preparatory commission for the High Seas Treaty, New York
24-27 March: 64th session of the Intergovernmental Panel on Climate Change, Bangkok
26-29 March: 14th ministerial conference of the World Trade Organization, Yaoundé, Cameroon

Pick of the jobs

International Centre of Research for the Environment and Development (CIRAD), IPCC chapter scientist | Salary: €3,200-3,750 per month. Location: Nogent-sur-Marne, France
Avaaz, chief of staff | Salary: Dependent on location. Location: Remote, with preferred time zones
Green Party, social media officer | Salary: £31,592-£32,192. Location: Remote or Westminster, UK

DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org.

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