The climate crisis is making each day slightly longer, a new analysis reveals, due to the melting of polar ice.
Scientists say this is a clear sign of how human activities are changing the planet, rivalling natural processes that have been happening for billions of years.
While the change in day length is measured in milliseconds, it can still disrupt internet traffic, financial transactions, and GPS navigation, all of which depend on precise timekeeping.
The Earth's day has been getting longer over time because of the moon's gravitational pull on our oceans and land. However, human-caused global warming is speeding this up. Melting ice from Greenland and Antarctica is adding more water to the oceans, especially near the equator. This extra water makes the Earth bulge slightly, slowing its rotation and lengthening the day.
Research has also shown that this shift in water is moving Earth's axis, and emissions are shrinking the stratosphere.
“We can see our impact on the entire Earth system, not just locally, like the rise in temperature, but in how the planet moves in space and rotates,” said Professor Benedikt Soja of ETH Zurich in Switzerland. “We've made these changes in just 100 or 200 years, while natural processes took billions of years.”
Human timekeeping relies on very precise atomic clocks, but the exact length of a day varies due to factors like tides and climate impacts. These variations need to be accounted for to keep systems like the internet and GPS running smoothly.
The study, published in the Proceedings of the National Academy of Sciences, used observations and computer models to study how melting ice affects day length. Between 1900 and 2000, the day lengthened by 0.3 to 1.0 milliseconds per century. Since 2000, as ice melting has sped up, the rate of change has increased to 1.3 milliseconds per century.
Comments