Melting polar ice driven by human-caused climate change is redistributing mass across the planet and slowing Earth’s rotation, lengthening our days by a fraction of a second each century according to a study published in the Journal of Geophysical Research: Solid Earth. This shift, which adds 1.33 milliseconds to a century, poses distinct calibration challenges for satellite navigation systems and deep-space spacecraft operations.
How Melting Polar Ice Slows Earth’s Rotation
Massive amounts of ice melting at Earth’s North and South Poles release water that flows closer to the equator. According to the study, moving this water away from Earth’s axis creates a dragging effect that slows the planet’s spin.
“We see the same principle in figure skating,” said study author Benedikt Soja, a professor at the Swiss Federal Institute of Technology in Zurich, Switzerland, in an interview with CBC Kids News. “If skaters want to spin fast, they tuck their arms close to their body, toward their own axis of rotation. If they want to slow down, they reach their arms out.”
Earth normally takes 24 hours to complete one full rotation. The research team calculated that human-led climate change lengthens the day by 1.33 milliseconds per century. Soja noted that this marks the most rapid climate-driven increase in day length observed in the past 3.6 million years.
Comparing Climate Change and Lunar Tidal Effects
Natural lunar tidal effects represent the biggest factor slowing down Earth’s rotation, operating at a rate of 2.4 milliseconds per century. However, the study projects that by the end of this century, climate-driven ice melt will surpass the moon’s influence to become the biggest factor in slowing Earth’s spin.
Did You Know?
While wildfire and extreme weather present immediate hazards, scientists monitor day-length changes because even millisecond variations impact high-precision infrastructure.
Technology Risks for Satellites and Spacecraft
While a millisecond equals one-thousandth of a second, these minute changes carry significant implications for modern technology. Soja explained that satellite navigation networks and deep-space missions depend on precise clock calibration.
Without accounting for these adjustments, consumer GPS applications on mobile devices would accumulate navigation errors. Furthermore, spacecraft executing planetary landings require exact timing; a millisecond discrepancy could cause a vessel to land hundreds of meters farther than intended.
David Holland, a professor of math and environmental science at New York University who completed his PhD on Arctic sea ice at McGill University in Montreal, Quebec, expressed surprise at the findings. “It’s just mind-boggling to me that we started burning fossil fuels roughly 150 years ago and we’re now having effects like these on the Earth,” Holland told CBC Kids News.
Frequently Asked Questions
How much is climate change lengthening our days?
According to the study in the Journal of Geophysical Research: Solid Earth, climate change lengthens Earth’s days by 1.33 milliseconds per century.
Why does melting polar ice slow down the Earth?
As polar ice melts, water redistributes toward the equator and away from Earth’s axis, creating a physical drag that slows down the planet’s rotation rate.
Will climate change surpass the moon’s effect on Earth’s rotation?
Yes. Researchers project that by the end of this century, climate change will exceed the deceleration rate caused by lunar tidal effects, which currently operates at 2.4 milliseconds per century.
Does this day-length change affect GPS technology?
Yes. Unaccounted changes in Earth’s rotation introduce calibration errors into satellite navigation systems and deep-space spacecraft landings, according to study author Benedikt Soja.
Join the Conversation: Share your thoughts on this study in the comments below, or subscribe to our newsletter for weekly updates on environmental research and space technology.