A groundbreaking study published in One Earth has sounded the alarm for Bangladesh’s vulnerable coastline, revealing that destructive storm tides could occur 10 times more frequently due to climate change. Once considered a once-in-a-century event, these coastal surges could now hit the country every decade, especially under high emission scenarios.
A storm tide a deadly mix of storm surge and astronomical tide poses grave flood threats to low-lying coastal regions. Bangladesh’s densely populated mega-delta, home to over 8 million people has long suffered from this dual hazard with historical cyclones in the Bay of Bengal claiming over 140,000 lives in single events.
The study, co-authored by Sai Ravela from the Massachusetts Institute of Technology (MIT) emphasizes that stronger storms and rising sea levels rather than an increase in cyclone numbers, are the key drivers of this intensifying threat. “Our simulations show that even without more cyclones, the existing ones will have amplified flood impacts,” Ravela explained.
The research team used a unique approach to model tens of thousands of synthetic tropical cyclones under future climate scenarios ranging from “business as usual” to high-emissions projections. They tracked storm tide heights and frequencies for each, revealing how higher sea levels and warmer waters would escalate coastal flooding risks.
Even more troubling the study warns of a new pattern emerging by the end of this century tropical cyclones overlapping with the monsoon season. Currently, monsoon rains (June–September) and tropical cyclones (May–June and October–November) occur at different times. But warming oceans and delayed monsoon withdrawal could create a “shoulder season”, where storm and monsoon conditions co-exist.
Such overlap raises the danger of compound flooding when cyclonic storm tides collide with already saturated soils and swollen rivers, increasing the intensity and reach of floodwaters. This could severely strain infrastructure and emergency response systems.
Adding to the challenge Bangladesh lacks adequate storm tide risk assessments for future climate conditions. The researchers aim to bridge this gap by turning their projections into decision-making tools for local adaptation and infrastructure planning.
The message is clear: without aggressive climate action and investment in coastal resilience, Bangladesh could face a storm tide nightmare far more often—and with far greater consequences.