Overview
- A peer-reviewed study in the Journal of Geophysical Research: Solid Earth finds Earth’s day lengthened at about 1.33 milliseconds per century from 2000 to 2020.
- The team from the University of Vienna and ETH Zurich concludes this pace has no match in at least 3.6 million years, with only a near-comparable interval around 2 million years ago.
- Scientists attribute the modern slowdown primarily to human-driven melting of polar ice sheets and mountain glaciers, which increases Earth’s moment of inertia.
- Researchers reconstructed past sea levels from benthic foraminifera chemistry and used a physics-informed probabilistic diffusion model to infer historical changes in rotation.
- The study warns that continued warming could make climate effects on day length exceed lunar influences by late century, threatening precision systems such as GPS, space navigation and atomic clock synchronization.