NASA reported that global sea levels rose more than expected last year, putting hundreds of coastal cities at greater risk of flooding. The agency had predicted a 0.43 cm rise in 2024, but measurements showed the sea level climbed 0.59 cm. Agency scientists say that an unusually strong warming of the oceans, combined with melting land ice—especially glaciers—drove the higher-than-expected rise. “The rise we observed in 2024 was higher than we anticipated. One thing is clear: ocean levels continue to rise, and the rate of increase is accelerating,” said Josh Willis, a sea level researcher at NASA’s Jet Propulsion Laboratory in Southern California.
Since 1993, global sea level has risen 10.1 cm. If levels continue to climb at the current pace, hundreds of densely populated cities worldwide could end up underwater. In recent years, about two-thirds of that rise was caused by melting ice sheets and glaciers, while roughly one-third came from ocean warming. In 2024, those roles reversed, said Nadia Vinogradova-Shiffer, head of the physical oceanography programs and the Integrated Earth Observatory at NASA headquarters in Washington, D.C. “As 2024 became the warmest year on record, the Earth’s oceans expanded, reaching their highest levels in the last three decades,” she explained.
NASA uses a fleet of satellites to track sea level changes around the world. Over the past 30 years, the annual rate of sea level rise has more than doubled. And the situation is likely to worsen, the Daily Mail reports. Given the current pace, NASA researchers predict that global sea level could rise another 7 cm by 2040. That increase would put hundreds of coastal cities and towns at risk of inundation. In Europe, the greatest threats include much of the Netherlands and the city of Venice. In the United States, several areas along the southern and eastern coasts—such as Galveston, New Orleans, and Charleston—face higher risk. Other vulnerable cities include Bangkok in Thailand, Basra in Iraq, and Navi Mumbai in India.
“Sea level rise is a disaster that is currently creeping up on us slowly but relentlessly,” said Richard Allan, a professor of climatology at the University of Reading in the UK. “Low-lying coastal regions, including cities like Miami, Mumbai, Shanghai, and Tokyo, will be affected this century and for many centuries to come.” He added, “Large-scale adaptation to rising sea levels will likely be unavoidable, and only rapid achievement of net-zero carbon emissions can reduce the costs and scale of that adaptation.”
