Climate Change And Rising Seas Heighten Mumbai’s Urban Health Risks, Study Warns

A new study co-led by Princeton University and the University of Chicago has revealed that heavy monsoon rainfall is responsible for more than 8% of deaths in Maharashtra’s Mumbai—almost ten times the number reported in official statistics—highlighting a hidden public health crisis in the city.

The research, which analysed individual death records from 2006 to 2015 alongside high-resolution hourly rainfall data, shows that slum residents bear the brunt of the disaster, accounting for over 80% of rainfall-related deaths.

Alarmingly, nearly one in five deaths among children under five occurs during periods of heavy rainfall, and women are at disproportionately higher risk.

The study also warns that rising sea levels will exacerbate the crisis. Even a modest increase of 5 to 15 centimetres, projected by 2030, could push rainfall-related mortality up by 7% to 21%, placing Mumbai’s dense, low-lying population at even greater risk.

“Mumbai’s monsoon floods are not just a disruption—they are a lethal hazard, especially for the city’s most vulnerable residents,” said Tom Bearpark, co-first author and STEP Ph.D. student at Princeton University. Using a model that accounts for tide levels, the team was able to quantify how rising seas can amplify the deadly impact of heavy rainfall.

The findings point out deep inequalities in urban regions. Poorer areas, with inadequate drainage, sanitation, and access to healthcare, are disproportionately affected. The city’s history of catastrophic flooding, such as the 2005 deluge that claimed over 1,000 lives, illustrates the scale of the threat, notes the study.

Experts emphasise urgent interventions, including improvements in drainage, waste management, sanitation, and climate-adaptive infrastructure. “Climate change is intensifying rainfall and sea-level rise. Immediate action is critical to save lives and reduce inequality,” said Ashwin Rode, co-first author and Director of Scientific Research at the University of Chicago’s Energy Policy Institute.

The study, published in Nature and co-authored by Archana Patankar from Green Globe Consulting, Mumbai, India, signals that without immediate action, the combination of urban growth, extreme rainfall, and rising seas will continue to exact a heavy human toll.

“Investments in infrastructure, sanitation, and public health are not optional—they are essential to safeguarding cities in the face of climate change,” reminded the authors.