Mumbai, Chennai to lose 10% and 7% of their land to rising sea levels in just 15 years, says study

A recent study by the Center for Study of Science, Technology and Policy (CSTEP) has sounded alarm bells about the escalating threat of sea level rise to India's coastal cities. The data is stark: Mumbai has experienced the most significant rise in sea levels among 15 major coastal cities in recent decades, a worrying trend that is set to worsen.

Mumbai saw a rise of 4.44 cm between 1987 and 2021. Following Mumbai, Haldia recorded a rise of 2.726 cm, Visakhapatnam 2.381 cm, Kochi 2.213 cm, Paradip 0.717 cm, and Chennai 0.679 cm.

To make matters worse, the study forecasts that sea levels will continue to rise until the end of the century, with Mumbai expected to face the highest increase. By 2100, projections indicate that sea levels will rise by 76.2 cm in Mumbai, 75.5 cm in Panaji, 75.3 cm in Udupi, 75.2 cm in Mangalore, 75.1 cm in Kozhikode, 74.9 cm in Kochi, 74.7 cm in Thiruvananthapuram, and 74.7 cm in Kanyakumari, even under a medium-emission scenario.


The study also explores potential inundation areas in these cities under the Intergovernmental Panel on Climate Change’s (IPCC’s) medium- and high-emission Shared Socio-economic Pathway (SSP) scenarios for 2040, 2060, 2080, and 2100. These scenarios consider how socio-economic factors such as population, education, and urbanisation might affect greenhouse gas emissions, impacting climate change.

The report categorises the cities into Tier-I (Chennai and Mumbai), Tier-II (Thiruvananthapuram, Kochi, Mangaluru, Visakhapatnam, Kozhikode, and Haldia), and towns (Kanyakumari, Panaji, Puri, Udupi, Paradip, Thoothukudi, and Yanam).

By 2040, more than 10% of the land in Mumbai, Yanam, and Thoothukudi, 5%-10% in Panaji and Chennai, and 1%-5% in Kochi, Mangalore, Visakhapatnam, Haldia, Udupi, Paradip, and Puri are predicted to be submerged due to rising sea levels. The percentage is expected to increase by 2100, with higher risks in Mangalore, Haldia, Paradip, Thoothukudi, and Yanam compared to Mumbai and Chennai under a high-emission scenario.


Dr. Anushiya J, a Research Scientist at CSTEP and the lead author of the report, emphasised the far-reaching implications of rising sea levels. "Climate change brought on by fossil-fuel burning and greenhouse gas emissions has led to a steady increase in global temperatures. As a result, sea surface temperatures and glacier melting have increased, eventually rising sea levels and posing a major threat to coastal cities worldwide, including Indian coastal cities," she stated.

She highlighted that many Indian coastal cities are major economic hubs with natural ports, cultural centres, biodiversity hotspots, and religious monuments. The continuing sea level rise necessitates immediate action to frame suitable adaptation and risk mitigation strategies.

The report underscores the urgent need for comprehensive policies to address the challenges posed by rising sea levels. The sectors most vulnerable include water, agriculture, forest and biodiversity, and health. The beaches, backwaters, and mangrove forests, which are crucial for biodiversity and tourism, are particularly at risk.