DHAKA, October 21, 2026 — Annual coastal flood damage across Asia and the Pacific could surge from around $27 billion today to as much as $739 billion by 2100 without adequate climate adaptation, according to a new report by the Asian Development Bank (ADB).
The Asia-Pacific Climate Report 2026: Coastal Risks on the Rise—Actions for a Resilient Future estimates annual losses across 30 coastal economies could reach $172–199 billion by 2050 and $520–739 billion by 2100.
However, annual investment of $9–19 billion in coastal protection could keep damage near current levels and avert an estimated $178–360 billion in losses each year, the report says.
The report warns that rising sea levels and intensifying climate hazards threaten coastlines that generate around $7 trillion in annual economic output. More than 400 million people in ADB’s developing member economies with coastlines live within 10 kilometers of the sea.
Major coastal cities, including Bangkok, Jakarta, Kolkata and Mumbai, face escalating flood risks. Under a high-emissions scenario, floods that historically occurred once every 100 years could become annual events by the end of the century. Small atoll nations could face particularly severe impacts, with annual flood damage potentially reaching 30–60% of GDP.
The report calls for stronger coastal planning, improved governance and greater investment from public, private and international sources. Although international adaptation finance for coastal economies rose to an average of $11.4 billion annually in 2022 and 2023, ADB warns that a substantial funding gap remains.
