As the Earth spins more slowly on its axis, the days get longer. Just a little bit, just milliseconds. Yet the consequences could be felt around the world, with disruptions to digital systems, internet traffic, navigation services, aviation, and financial transactions.

These systems are linked to atomic clocks that tell time around the world. Clocks may need to be adjusted, which can cause disruptions, for example in payment transactions and communication between computer systems.

The results were described in a new scientific study published in the United States. Scientific journal Proceedings of the National Academy of Sciences of the United States of America.

thick soil

The first reason: The polar ice caps are melting faster than at any time since the beginning of this century, due to the planet’s warming. Meltwater tends to accumulate around the equator, making our planet increasingly “thick around the waist.” “We’re slowing down because of the thicker material,” says Erik Dierks, who, as a scientist at the National Meteorological Institute VSL, is the Netherlands’ “timekeeper.”

He draws a comparison with ice dancers: “If they keep their arms close to their bodies while spinning, they speed up. If they spread their arms out, they slow down. The mass of water around the equator acts in the same way as those arms spread out.”

Slower but also faster

The Earth’s rotation has never been stable, explains Dericks. The slowdown has actually been going on for centuries. This is due to the friction of the Earth with the atmosphere, and also because of the gravitational force exerted by the Moon on the Earth. “But something strange has happened in the last five years: the rotation has accelerated. Science has yet to figure out why. It may have something to do with the Earth’s core.”

This shouldn’t cause panic, says Dericks: “It’s a matter of fractions of a second. It doesn’t bother us nearly as much. You could even say that the slowdown (partially) cancels out the acceleration that happened in the last five years.”

So the spin delay isn’t even the most noticeable element. The study’s authors emphasize the role that humanity plays in the slowdown.

This is also what Helen Ecker, climate specialist at RTL Nieuws, finds striking about the research: “This shows once again how much humanity has an impact on the Earth’s climate. If you even manage to influence the Earth’s movements, you will see how much impact it has.” -Finding out the consequences of human greenhouse gas emissions “We are messing with the Earth’s basic system.”

Dierikx finds it “somewhat exaggerated” for the scientists behind the new research to emphasize potential disruption to internet traffic, financial transactions, satellite navigation and aviation.

second jump

“Such digital systems are already linked to atomic clocks that tell time around the world,” he explains. “If the Earth’s motion slows down, we sometimes have to add a leap second to the time. This has sometimes led to systems malfunctioning. Computers no longer communicate properly. This is because of security. Then you couldn’t pay, for example. It was a bit annoying sometimes, but it was never a big problem.”

Even the acceleration of the rotation has an advantage for the stability of these systems, Dericks believes: “With more acceleration, we might have to subtract a leap second instead of adding it. That would be the first time in history. And that would be very exciting, because we have no idea how the systems will respond to that.”