Earth’s Rotation Is Slowing Faster Than In 3.6 Million Years

BreakingInnovationScienceEarth’s Rotation Is Slowing Faster Than In 3.6 Million YearsByJamie Carter,Senior Contributor.Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky.Follow AuthorJun 07, 2026, 02:00am EDTToplineEarth’s rotation is gradually slowing as climate change melts glaciers and polar ice sheets, redistributing water across the planet and subtly lengthening the day. According to new research from the University of Vienna and ETH Zürich, the current increase in day length — 1.33 milliseconds per century — is unprecedented over at least the past 3.6 million years. It’s a new measure of how profoundly human-driven warming is affecting the Earth system, even as only 48% of Americans believe climate change is the result of human activity.Earth is illuminated against the blackness of space in this photo taken by an Artemis II crew member through an Orion spacecraft window on April 2, 2026.NASAKey FactsEarth’s day is currently lengthening at a rate of about 1.33 milliseconds per century due largely to climate-driven sea-level rise. Even though the changes are minuscule, they can cause problems in satellite navigation, space missions and global timekeeping systems, which require accurate information on Earth's rotation.Melting ice sheets and glaciers move mass from the poles toward the oceans, slowing the planet’s rotation.Researchers reconstructed changes in day length over the past 3.6 million years using fossil remains of benthic foraminifera — single-celled marine microorganisms on the seafloor — and advanced machine-learning techniques.The study, published in the Journal of Geophysical Research: Solid Earth, found that no period in the past 3.6 million years experienced a climate-driven increase in day length as rapid as that observed between 2000 and 2020.The moon remains the dominant long-term influence on Earth’s rotation rate, over time slowing Earth’s spin and ma...