ADB warns coastal flood costs could soar to $199 billion annually by 2050
The Asian Development Bank projects that annual damages from coastal flooding may reach $172-199 billion by 2050 and $520-739 billion by 2100 if no adaptation measures are taken.
According to the Asian Development Bank’s 2026 climate report, annual coastal flood damages could climb to roughly $172-199 billion by 2050 and $520-739 billion by 2100 without adaptation. Today, flooding costs about $27 billion across 30 economies, with India, China and Indonesia facing the largest financial hits. In atoll nations, yearly losses may surpass half of GDP, and small-island states such as the Maldives, Kiribati, Tonga and the Federated States of Micronesia account for nine of the ten biggest welfare losses.
Trade values at risk total $40-45 billion annually, and the number of heritage sites exposed to flooding is expected to double by 2100. The report estimates that investing $9-19 billion per year in flood protection could keep damages at current levels, delivering benefits up to 20 times the cost. It highlights a youth-led mangrove and salt-tolerant bioshield project in Gujarat as a promising adaptation example.
Why it matters
Rising flood costs threaten economies, heritage and food security across Asia, demanding urgent investment in adaptation.
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