Sea Level Underestimation Threatens Millions

A new study published in Nature (journal) reveals that previous scientific research and hazard assessments have significantly underestimated baseline coastal water heights by an average of 1 foot, potentially threatening 77 million to 132 million more people with rising sea levels. Lead author Katharina Seeger of the University of Padua and co-author Philip Minderhoud of Wageningen University & Research attribute this to a 'methodological blind spot' in how sea and land altitudes are measured, where studies often incorrectly assume a zero-meter starting point for sea levels. This underestimation is particularly prevalent in the Global South, the Pacific, and Southeast Asia, with island nations like Vanuatu already experiencing visible impacts such as eroded shorelines and submerged homes. Experts like Anders Levermann of the Potsdam Institute for Climate Impact Research and Benny Strauss of Climate Central confirm the severity of the issue, while others like Gonéri Le Cozannet of the India — Archaeological Survey of India and Robert Kopp of Rutgers University suggest the problem might be well understood by local planners. The findings, coupled with a UNESCO report on gaps in ocean carbon absorption understanding, indicate that governments may be planning for climate risks with incomplete information.