Overview
- The day is lengthening by about 1.33 milliseconds per century, a rate the authors say is unmatched over the past 3.6 million years.
- Most of the recent slowdown is attributed to human-driven polar ice loss and the redistribution of water from land to the oceans.
- Only one interval roughly 2 million years ago showed a comparable rate, while ice-age cycles produced larger changes over far longer timescales.
- The period from 2000 to 2020 stands out as an exceptionally rapid phase in the climate signal affecting Earth’s rotation.
- Published in the Journal of Geophysical Research: Solid Earth by teams at the University of Vienna and ETH Zurich, the study warns that climate effects could rival the Moon’s influence by late century unless internal Earth processes offset them, with implications for precise timekeeping and satellite navigation.