Aligning Sea-Level and Elevation Data Reveals Greater Global Exposure to Sea-Level Rise

Nature, 4 March 2026

A review of 385 coastal hazard studies published between 2009 and 2025 found that more than 99% of them inadequately integrate sea levels with land elevation data, often underrepresenting coastal risk. About 90% of studies relied on “zero elevation geoid models” rather than measured sea-level data, which led to systematic errors. Researchers found that measured coastal sea level is about 0.25 meters higher on average than commonly used in risk estimates, with some errors however exceeding 1 meter in parts of the Global South, particularly in the Indo-Pacific. When coastal elevation is correctly aligned with measured sea level, global land area falling below 1 meter of relative sea-level rise increases by 31-37%, placing 77-132 million people residing in these areas at risk. This indicates that many existing coastal hazard assessments may underestimate exposure, with major implications for coastal populations.

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