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Melting polar ice driven by climate change is affecting Earth’s rotation, according to new research.
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We may have to adjust the timing by “skipping” a second in 2029.
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A human-driven change in the Earth’s rotation has never been seen before, and it could disrupt the calculation.
The climate crisis has gone so far that it is changing the shape and spin of our planet, and changing our experience of time itself, according to a new study published in the journal Nature on Wednesday.
“Enough ice has melted to move the sea level enough that we can see that the Earth’s rotation rate is affected,” Duncan Agnew, a geophysicist at the Scripps Institution of Oceanography and author of the study, told Nature.
Don’t worry – this change in the Earth’s rotation won’t be catastrophic. However, it means we will have to adjust our timekeeping, which can be problematic for much of the computing we rely on.
Melting ice could delay the second negative negative jump
People track time in seconds, minutes, and hours, and it is the rotation of the Earth on its axis and the position of the sun in the sky – what is known as the solar time scale.
But the solar timescale is not very precise because the planet’s spin has never been constant – it changes based on how fluids move above and below the crust.
So people invented a more accurate way of time with atomic clocks and the atomic time scale.
But, every 1.5 years or so, on average, these two time scales are aligned due to the Earth’s inconsistent rotation rate. When that happens, we experience what is called a second leap: a second is added to the atomic time scale to realign it with the solar time scale.
We’ve been adding leap seconds this way since 1972, but we haven’t needed one since 2016.
That’s because the Earth has spun faster and faster over the past eight years for reasons that scientists are still trying to understand.
As a result, scientists predicted that for the first time ever we would need it negative jump into second place by 2026. Meaning we needed subtract seconds from the atomic time scale, instead of adding one.
But this new research suggests that climate change is slowing the acceleration of Earth’s rotation and will delay that second negative jump until 2029.
It might not seem like much to lose a single second of time. But the addition and subtraction of leap seconds creates major problems for computing, so much so that the International Bureau of Weights and Measures has voted to do away with them by 2035.
Computers, financial exchanges, GPS and spaceflight rely on extremely precise timekeeping, so leap seconds can cause “serious malfunctions in critical digital infrastructure,” the Bureau wrote in its resolution. He added that a second negative jump that may soon be necessary “has not been predicted or tested”.
“We don’t know how to deal with one missing second. That’s why time metrologists are concerned,” Felicitas Arias, former director of the Time Department at the International Bureau of Weights and Measures, told Nature.
Although Agnew’s study suggests that we have more time before this worrisome unknown, it is worth noting that predicting the Earth’s spin is very difficult, and the new study is not necessarily a definitive prediction.
“There’s a lot of uncertainty about this,” Judah Levine, a physicist at the National Institute of Standards and Technology, told The Washington Post. “A few years ago, there was a prediction in the opposite direction.”
How the melting ice slows the rotation of the Earth
There are three main mechanisms that control the Earth’s spin:
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One is tidal friction, or the interaction between moving ocean water and the ocean floor, which slows the Earth’s rotation.
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The second is changes in the ice caps that covered Northern Canada and Scandinavia during the last Ice Age, which made the Earth more spherical, speeding up its rotation rate, according to Agnew.
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And finally, magma flows inside the Earth’s spinning, liquid core change irregularly, causing it to rotate faster or slower and changing the rotation of the entire planet in the process.
But now, a fourth impact has come to the attention of scientists: climate change.
As average global temperatures rise, polar ice is melting at an unprecedented rate, dumping water into the oceans. As that meltwater moves from the Arctic toward the equator — a process that’s raising sea levels and causing devastating coastal flooding — our planet grows slightly wider around the center, slowing its rotation.
Picture of a really clean skater spinning with her arms above her head. Now imagine that she lowers her arms to extend them out to her sides, making her walk more slowly. Earth’s extended equator has a similar effect on its spin.
“To me, it’s amazing that humans caused the change in the Earth’s rotation,” Agnew told CNN.
You may have managed to escape the mega clouds of wildfires, historic floods, and debilitating heat waves so far. But this new study shows that the climate crisis is affecting even the most intimate aspects of our daily lives. No one escapes time.
Read the original article on Business Insider
