Environment

Sea level rise has nearly doubled since 1960, study finds

07:37

By: Dakir Madiha

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Global sea levels have risen at an average rate of roughly 2 millimeters per year since 1960, but the pace has accelerated sharply in recent decades, according to a new study published in Science Advances. Researchers found that the annual rate of sea level rise almost doubled between 2005 and 2023 compared with the long-term historical average.

The study examined ocean data collected between 1960 and 2023 and calculated an average increase of 2.06 millimeters per year across the full period. Between 2005 and 2023, however, the rate climbed to 3.94 millimeters annually. Scientists said the findings help resolve a long-standing discrepancy between observed sea level rise and the combined impact of known contributing factors.

Researchers described the work as a major step toward closing the “sea level budget gap,” a problem that had challenged climate scientists for years. John Abraham of the University of St. Thomas said advances in measurement tools and analytical methods allowed scientists to align observed ocean changes with physical causes more accurately than before.

The study identified thermal expansion of warming oceans as the largest driver of sea level rise, accounting for 43% of the increase since 1960. Mountain glaciers contributed 27%, while melting from the Greenland ice sheet represented 15%. The Antarctic ice sheet accounted for 12%, and changes in land water storage made up the remaining 3%.

Ocean warming also emerged as the leading cause behind the acceleration itself. Scientists found that rising ocean temperatures explained 41% of the faster rate of sea level increase in recent decades. Reduced land water storage contributed another 21% of the acceleration.

The findings arrive as concern grows over the vulnerability of coastal regions worldwide. A separate study published earlier this year in Nature found that more than 90% of coastal assessments conducted between 2009 and 2025 underestimated present sea levels, in some cases by as much as 150 centimeters in Southeast Asia.

Researchers said the new analysis strengthens the scientific basis for long-term coastal planning and flood protection policies. The study warns that rising seas will continue to threaten vulnerable coastal communities for decades, even if greenhouse gas emissions decline in the future.