UN Warns Mumbai, Kolkata of Rising Sea Threat
A new United Nations report has warned that millions of people living in low-lying parts of Kolkata, Mumbai and Dhaka face an immediate risk of displacement as rising sea levels threaten permanent inundation. The report says sea-level rise is already damaging infrastructure, freshwater supplies and coastal ecosystems across the world.
Over 14 Million Face Displacement Risk in South Asia
The UN estimates that more than 14 million people across vulnerable areas of Kolkata, Mumbai and Dhaka are at immediate risk of losing their homes to permanent inundation.
Unlike wealthier coastal cities where the primary threat is to high-value infrastructure and property, the report identifies large-scale human displacement as the defining concern for South Asian cities.
Low-lying and densely populated areas are particularly exposed as higher seas combine with land subsidence, erosion and increasingly severe coastal flooding.
Global Sea Levels Continue to Rise
Global sea levels rose at an average rate of 4.7 millimetres per year between 2014 and 2023.
The annual increase reached 5.9 millimetres in 2024, driven largely by exceptional ocean warming, while global mean sea levels remained close to record highs during 2025.
Nearly 770 million people worldwide — around 10% of the global population — live in coastal areas less than five metres above the high-tide line.
Mumbai and Kolkata Face Infrastructure Risks
Rising seas threaten transport networks, buildings, power systems, sanitation infrastructure and groundwater supplies in major coastal cities.
Saltwater intrusion can also contaminate freshwater sources and agricultural soil, while repeated flooding increases health, livelihood and economic risks.
The UN has called for long-term adaptation planning, stronger scientific monitoring, predictable climate financing and more resilient infrastructure to protect communities increasingly exposed to sea-level rise.
