Polar ice is melting and changing Earth’s rotation. It’s messing with time itself
One day in the next couple of years, everyone in the world will lose a second of their time. Exactly
when that will happen is being influenced by humans, according to a new study, as melting polar ice
alters the Earth’s rotation and changes time itself.
The hours and minutes that dictate our days are determined by Earth’s rotation. But that rotation is
not constant; it can change ever so slightly, depending on what’s happening on Earth’s surface and in
its molten core.
These nearly imperceptible changes occasionally mean the world’s clocks need to be adjusted by
a “leap second,” which may sound tiny but can have a big impact on computing systems.
Plenty of seconds have been added over the years. But after a long trend of slowing, the Earth’s
rotation is now speeding up because of changes in its core. For the first time ever, a second will need
to be taken off.
“A negative leap second has never been added or tested, so the problems it could create are
without precedent,” Patrizia Tavella, a member of the Time Department at the International Bureau of
Weights and Measures in France, wrote in an article accompanying the study.
But exactly when this will happen is being influenced by global warming, according to the study
published Wednesday in the journal Nature. Melting polar ice is delaying the leap second by three
years, pushing it from 2026 to 2029, the report found.
“Part of figuring out what is going to happen in global timekeeping … is dependent on
understanding what is happening with the global warming effect,” said Duncan Agnew, professor of
geophysics at the University of California San Diego and the study’s author.
(https://edition.cnn.com/2024/03/27/climate/timekeeping-polar-ice-melt-earth-rotation/index.html)
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