The Impact of Rising Sea Levels in India

The Impact of Rising Sea Levels in India

This article relates to A Guardian and a Thief

Boomba, one of the protagonists of Megha Majumdar's A Guardian and a Thief, is living on the east coast of India with his family when their home becomes permanently flooded due to rising sea levels. Although the novel is set in the near future, this type of displacement is already occurring.

It's estimated that the oceans have risen by eight to nine inches (20 to 23 centimeters) since 1880, with the rate dramatically increasing in the past ten years. That may not sound like a huge amount, but small island nations such as Fiji and Tuvalu have already been impacted, and countries such as India, Bangladesh, China, and the Netherlands are at risk in the coming years. Nearly 900 million people in those nations are currently living in low-lying coastal areas and are considered in acute danger of displacement, according to a recent United Nations report.

Some effects of rising sea levels are obvious: As the water rises, coastal erosion and flooding occur, displacing the population. Beyond that, there's a ripple effect (pun unintended) of ecological disaster. In India, as seawater makes further incursions, the coast's mangrove swamps and estuaries are threatened, which in turn decreases biodiversity and depletes fish stocks, which then impacts the economy and people's livelihoods. Saline intrusion may ultimately affect the groundwater as well, making potable water scarcer. And infrastructure, too, may become damaged to the point of becoming unusable, impacting industry and tourism. The far-reaching effects of the havoc caused by rising sea levels in India are frighteningly but realistically described in A Guardian and a Thief. (On encountering flooded streets, some characters joke that "Kolkata was at last Venice.")

There are many factors that are influencing rising sea levels worldwide. Most people think of melting glaciers as the culprit, and indeed, they are thought to account for 25 to 30% of the rise in sea levels between 2020 and 2023. During that timeframe, the world's glaciers lost over 7,200 billion tons of ice. Even more impactful, however, is thermal expansion, which occurs when the molecules in water heat up. The particles become more active and vibrate more energetically, requiring more space, which means that the water itself expands. Some sources claim that over the past few decades, thermal expansion has been responsible for up to 40% of rising sea levels.

India has the additional disadvantage of being near the equator. Scientists believe that as the polar ice caps melt and the mass at the Earth's poles lessens, the gravitational shift will draw water toward the planet's center, increasing the risk of flooding in equatorial countries. On top of that, land in India is sinking, particularly in its largest cities, because the country is pumping out its underground aquifers for drinking water faster than they can be replenished.

In some areas, it is necessary to start planning for coastal flooding now, by moving habitations and critical infrastructure farther inland. Indonesia, for example, is building a new capital on higher ground and planning to relocate its government from the sinking city of Jakarta. Mumbai, India's financial capital and its most populous city, may become unlivable by 2050 due to prolonged flooding.

Some scientists believe it may be too late to keep some areas, like India's coast, from experiencing the devastating effects of rising sea levels. A portion of the massive Greenland ice sheet may be at its tipping point, which means it would continue to melt irreversibly regardless of whatever actions are taken to rein in global warming. Should the entire ice sheet melt—which would take centuries—global seas would raise as much as 23 feet. And, of course, there are many more glaciers melting. Antarctica's Hektoria Glacier retreated five miles in two months, which is ten times faster than the previous record. Scientists fear that if other glaciers crumble as quickly, sea levels will rise faster than anticipated.

Photo of people in India driving motorcycles through a flooded street by Dibakar Roy.

Filed under Nature and the Environment

This article relates to A Guardian and a Thief. It first ran in the November 19, 2025 issue of BookBrowse Recommends.