Context:

A recent study reveals that melting glaciers are expected to contribute nearly 2 cm to global sea level rise this century. Over the past 25 years, glaciers have been losing 273 billion tonnes of ice annually, significantly increasing sea levels.

Key highlights made:

The study highlights two key factors driving this rise:

1.   Melting Glaciers/Ice Sheets – Since 2000, glaciers have lost 2%-39% of their ice, making a significant contribution to sea level rise.

2.   Thermal Expansion of Seawater – Rising global temperatures cause seawater to warm and expand, contributing to one-third to half of the global sea level rise.

Global and Regional Trends:

Since 1880, the global sea level has risen by 21 cm. However, the rate of increase has accelerated from 0.18 cm/year in 1993 to 0.42 cm/year today, marking an unprecedented rise.

Not all regions experience the same impact. For example, the southwestern Indian Ocean is witnessing a rise of 2.5 mm/year, surpassing the global average.

Impact on Coastal Cities:

Among Indian cities, Mumbai has recorded the highest sea level rise, increasing by 4.44 cm between 1987 and 2021, making it highly vulnerable. Other cities, including Haldia, Visakhapatnam, and Kochi, have also seen rising sea levels, posing threats to coastal infrastructure and communities.

Concerns and Consequences:

An increase in sea levels presents severe risks to human populations and ecosystems, with key consequences including:

·         Coastal Flooding – Higher sea levels intensify flooding and coastal erosion, leading to land loss and displacement of communities living along coastlines.

• Case Study – Between 1990 and 2016, the West Bengal coast lost nearly 99 sq km of land, a significant loss attributed to rising sea levels.

·         Global Vulnerability – A 2024 study indicates that 29% of the global population resides within 50 kilometers of the coast, with 15% living within just 10 km. These populations face heightened risks from rising sea levels.

·         Intensified Storm Surges – Higher sea levels contribute to stronger storm surges, pushing seawater further inland during tropical storms. This threatens coastal ecosystems like mangroves, coral reefs, and salt marshes, which play a vital role in biodiversity conservation and freshwater protection.

·         Freshwater Contamination – As seawater intrudes inland, it contaminates freshwater supplies, reducing access to clean water and disrupting daily life for affected populations.

Conclusion:

The ongoing rise in sea levels, primarily driven by melting glaciers and thermal expansion, poses an escalating risk, especially for coastal cities and vulnerable populations. Urgent climate action is necessary to reduce emissions and mitigate further damage.