Mumbai could be swallowed by the sea. BMC begins a fresh risk check

Mumbai, a city perilously close to permanent submersion due to rising sea levels, has prompted the Brihanmumbai Municipal Corporation (BMC) to initiate a new assessment of its vulnerability. This is the second such review in five years, reflecting the urgency of the situation. The assessment is expected to be unveiled next year, focusing on a 149-km coastline and identifying areas at risk due to shifting land use and climate patterns.

The UN's latest report highlights a concerning trend – global sea levels have risen by a record 5.9 mm in 2024, with a projected minimum 0.5-meter increase by 2100 even with aggressive emissions cuts. In a worst-case scenario, with unstable West Antarctic ice sheets, the rise could reach as high as two meters.

A senior official revealed that the new study is crucial given the significant changes along Mumbai’s coastline over the past five years. These include the construction of the Coastal Road along the western seafront, reclamation of over 100 hectares of the Arabian Sea, and urban development on salt pan lands. The city's overall land-use pattern has also evolved, necessitating a fresh risk evaluation.

Unlike the UN assessment, which addresses sea-level rise globally, the BMC study will concentrate on Mumbai, examining local factors contributing to coastal vulnerability, projecting future sea-level rise, and pinpointing populations at risk near the shoreline. The BMC's first Mumbai Climate Action Plan (MCAP), released in 2022, had warned of coastal flooding, pollution increase, loss of green cover, and rising urban heat. It projected that 80% of Mumbai could be submerged by 2050.

Scientific evidence points to global warming and rising sea surface temperatures as key contributors to sea-level rise. The MCAP noted a slight, steady increase in SST in the Arabian Sea over the past two decades. However, scientists like Raghu Murtugudde and Roxy Mathew Koll emphasize that Mumbai's unique geography, rapid development, and land-use changes exacerbate the city's vulnerability.

They stress the importance of protecting mangroves and coastal wetlands to enhance Mumbai's resilience to sea-level rise while providing habitats for biodiversity and marine life.